Description/Background
Urinary outlet obstruction is difficulty in the passage of urine from the bladder to the urethra caused by compression or resistance on the bladder outflow channel at any location from the bladder neck to the urethral meatus. In males, this can be caused by benign prostatic hyperplasia (BPH). BPH is a common age-related noncancerous condition in men that is characterized by an increase of epithelial and stromal cells in the periurethral area of the prostate. This increase in cells causes an enlargement of the prostate gland. This pathologic change is important because of the proximal anatomical relationship between the prostate and the bladder neck. The condition generally involves lower urinary tract symptoms (LUTS), which mayinclude increased urinary frequency, urgency, incontinence, or straining; nocturia; decreased and intermittent force of the stream; hematuria; and the sensation of incomplete bladder emptying. Given the substantive symptomatic impact of urinary outlet obstruction, symptomatic appraisal of interference with activities of daily living is a crucial aspect of evaluation. In an effort to quantify the severity of symptomatic BPH, a urodynamic investigation (e.g., urine flow rate assessment) may be performed.

Treatment for BPH includes watchful waiting (e.g., active surveillance), medical management with pharmacotherapy (e.g., alpha-blockers, 5-alpha-reductase inhibitors), minimally invasive treatments (e.g., transurethral needle ablation [TUNA], transurethral microwave thermotherapy [TUMT]), and surgery (e.g., TURP, laser treatments). If there is minimal bother (i.e., interference with activities of daily living) and no evidence of prostate enlargement, watchful waiting may be used. Medical management may be indicated for individuals with uncomplicated BPH or moderate to severe symptoms, and individuals who are waiting for surgery, unwilling to undergo surgery, or are poor surgical candidates. Individuals with BPH who have complications such as acute urinary retention, recurrent urinary tract infections, hematuria, bladder stones, or renal insufficiency/failure due to BPH may be treated surgically. Untreated BPH may worsen over time and increase the risk of stones, infection, or kidney failure. The choice of treatment for urinary outlet obstruction due to BPH should be based on the individual's presentation and anatomy, the surgeon's level of training and experience, and a discussion of the potential benefit and risks for complications.

The primary goal of treatment is to alleviate bothersome symptoms (i.e., symptoms that interfere with activities of daily living) that result from prostatic enlargement. More recently, treatment has been focused on altering disease progression and preventing complications associated with BPH. Standard surgical treatments such as transurethral resection of the prostate (TURP), transurethral incision of the prostate (TUIP) (in which an incision is made where the prostate meets the bladder), and open prostatectomy may be accompanied by undesirable complications such as blood loss, need for transfusion, salt imbalances from fluid absorption, and side effects such as incontinence and retrograde ejaculation. Newer surgical techniques that use lasers, as well as minimally invasive techniques that use various sources of energy such as heat, microwaves, radiofrequency, and ultrasound, have been developed.

SURGICAL TREATMENTS
STANDARD SURGICAL TREATMENTS
Transurethral resection of the prostate (TURP) is the standard treatment for BPH against which all treatments are measured. TURP involves removing the core of the prostate through the urethra using instruments and electrodissection. An electrified wire loop removes pieces of prostatic tissue and coagulated blood. TURP is performed under general or spinal anesthesia and requires a hospital stay. Other standard surgical options include TUIP and open prostatectomy.

THERMAL TREATMENT
Transurethral electrovaporization of the prostate (TUVP) vaporizes the enlarged prostate tissue, destroying it by coagulation and allowing it to slough away over several weeks. TUVP steams the tissue away using high heat, and dries out the tissue using lower heat. Advantages of TUVP have shown earlier post-treatment catheter removal and less bleeding-related complications when compared to TURP. Evidence in available published peer-reviewed literature demonstrates the safety and effectiveness of TUVP for the treatment of BPH (Poulakis 2004).

LASER TREATMENTS
These procedures involve a laser fiber that is passed into the prostatic channel under telescopic guidance. The laser is then used, through vaporization or ablation techniques, to destroy the obstructing portions of the prostate with heat. With laser vaporization, high instantaneo us heat is created to vaporize or steam away prostate tissue. Lower laser energy is applied with laser ablation, which heats the tissue enough to dry it out and allows it to shrink and slough away with time. Various types of lasertreatments include:

• Visual laser ablation of the prostate (VLAP)
  VLAP delivers a laser energy that is focused, without direct contact with the prostate, on the enlarged prostatic tissue, and causes thermal injury or coagulation necrosis of the tissue. The primary mechanism of tissue destruction is coagulation rather than vaporization, and the coagulated tissue sloughs away over several weeks following VLAP. VLAP requires a post-treatment catheterization from several days to several weeks. Interstitial laser coagulation (ILC) uses a fiber-optic laser probe that is inserted through a cystoscope into the prostate at fixed points. Laser energy is applied to coagulate each area of obstructing prostate tissue, producing coagulation necrosis. In contrast to other laser procedures, where coagulation necrosis occurs at the urethral surface, in interstitial laser coagulation, delivery of laser energy directly into the tissues produces coagulation necrosis inside the enlarged prostatic tissue. The treated tissue is absorbed over a period of several weeks.
• Transurethral ultrasound-guided laser-induced prostatectomy (TULIP)
  TULIP was one of the first laser treatments used for BPH. A laser probe is housed between two ultrasound transducers that are used for real-time scanning to position the laser while it is being used. Coagulation necrosis of the prostate tissue produces shrinking over several weeks following TULIP. TULIP has been replaced by other laser techniques that have fewer side effects, shorter post-treatment catheterization times, and fewer urinary symptoms.
• Holmium laser
  Holmium laser treatments of the prostate are treatments that use a holmium laser fiber and a specially adapted resectoscope to ablate, resect, or enucleate enlarged prostatic tissue. Relief of obstruction is immediate. Holmium lasers are among the most common laser technologies used to treat prostate disease. With the holmium laser, there is the ability to coagulate tissue simultaneously with tissue incision, ablation, resection or enucleation. This reduces intraoperative blood loss as well as post-operative bleeding. The American Urological Association (AUA 2010) states that holmium laser treatments are appropriate and effective treatment alternatives to TURP and open prostatectomy in individuals with moderate to severe LUTS due to BPH, and/or who are significantly bothered by these symptoms (i.e., interfere with activities of daily living). Additionally, according to AUA, these treatments have been associated with shorter post-treatment catheterization time and shorter length of hospital stay.
  • Holmium laser ablation of the prostate (HoLAP)
    This technology delivers laser energy at a wavelength of infrared range which is primarily absorbed by water. HoLAP is intended to be comparable to TURP, in that the prostatic lobes may be vaporized down to a surgical capsule resulting in a TURP-like effect. HoLAP does not yield tissue for histologic analysis. A controlled trial reported that although HoLAP took longer to perform than TURP, LUTS due to BPH and physiological measures improved to a similar degree after HoLAP and TURP (Mottet 1999).
  • Holmium laser resection of the prostate (HoLRP)
    This technology utilizes a specially adapted resectoscope to resect prostate tissue into pieces small enough to be removed with bladder irrigation and grasping forceps or a modified resectoscope loop. Improvements in LUTS due to BPH obtained by using HoLRP are comparable to TURP (Gilling 1999, Ruzat 2008).
  • Holmium laser enucleation of the prostate (HoLEP)
    HoLEP is typically used for larger glands that previously would have been treated with an open prostatectomy. Here, an entire prostatic lobe can be separated from connective tissue and deposited in the bladder. The tissue is then extracted from the bladder. HoLEP has been evaluated in clinical trials and compared favorably with TURP in meta-analyses and system reviews (Kuntz 2002, Elzayat 2007, Naspro 2009, Burke 2010).
• Photoselective vaporization (PVP)
  PVP uses a potasium-titanyl-phosphate (KTP) laser to vaporize prostate tissue. KTP laser wavelengths penetrate only 1 to 2 mm, and the vaporization process may help avoid the perioperative side effects such as tissue sloughing. Additional reported potential advantages of PVP include virtually bloodless tissue ablation, shorter length of hospital stay, and shorter post-treatment catheterization times. As compared with TURP, surgical treatment of high-risk populations such as individuals taking anticoagulants, may be possible with PVP (Burke 2010, Ruszat 2008). PVP is an appropriate and effective treatment alternative to TURP and open prostatectomy in men who have moderate to severe LUTS due to BPH and/or who are significantly bothered by the symptoms(i.e., interfere with activities of daily living).

MINIMALLY INVASIVE TREATMENTS
Although TURP is the most commonly used treatment option for BPH, minimally invasive treatments have been developed that use various sources of energy, such as heat, radiofrequency, ultrasound, and microwaves. Minimally invasive treatments available include the following:

• Water-induced thermotherapy (WIT)
  During this minimally invasive treatment, heated water is circulated through a proprietary closed-loop catheter system to produce coagulative necrosis and secondary ablation of obstructing prostatic tissue. Thermal insulation of the catheter shaft along the penile, bulbous, and membranous urethra, as well as in the sphincter region, prevents unwanted incidental damage of tissue along the urinary tract. According to the Urologic Clinics of North America, along with a review of the available published peer-reviewed literature and clinical guidelines, there is insufficient evidence to support the use of WIT for the treatment of urinary outlet obstruction due to BPH.
• Balloon dilation of the prostate
  This minimally invasive treatment utilizes a flexible balloon catheter, which is placed in the urethra at the level of the prostate above the external sphincter. The balloon is then inflated for a short time to distend the prostatic urethra. Currently, the AUA does not recommend the use of balloon dilation of the prostate. Furthermore, the safety and/or efficacy of this service cannot be established by review of the available publishedpeer-reviewed literature.
• Transurethral ethanol ablation (chemoablation) of the prostate (TEAP)
  This minimally invasive treatment involves injecting absolute ethanol transurethrally into the prostate tissue. The injected ethanol causes cells of the prostate to burst, killing the cells. The prostate shrinks as the necrosed cells are absorbed. Currently, the AUA does not recommend the use of transurethral ethanol ablation of the prostate. Furthermore, the safety and/or efficacy of this service cannot be established by review of the available published peer-reviewed literature.
• High-intensity focused ultrasound (HIFU)
  This minimally invasive treatment uses targeted high-intensity ultrasound to create coagulation necrosis in the prostate tissue. In contrast to other treatments, the HIFU device is inserted rectally and does not contact the prostate or urethra. Post-treatment catheterization time ranges from a few days to over a week. The safety and/or efficacy of this service cannot be established by review of the available published peer-reviewed literature. Randomized controlled trials comparing HIFU to standard treatments for BPH have not been published. Furthermore, at this time, the AUA considers HIFU as investigational, with additional long-term studies being warranted.
• Transurethral needle ablation (TUNA) of the prostate (also called transurethral radiofrequency needle ablation [RFNA])
  This minimally invasive treatment delivers selective thermal energy to the prostate using two 18-gauge needles at the end of a TUNA catheter. A lens inside the catheter is used to guide the placement of the catheter into the urethra, where the needles are advanced to cause heat-induced coagulation necrosis in the prostate parenchyma. The prostate shrinks as the necrosed cells are absorbed. AUA recommends the use of TUNA as an appropriate and effective treatment alternative for bothersome (i.e., interfere with activities of daily living), moderate, or severe LUTS due to BPH. TUNA has been compared favorably with TURP in clinical trials and meta-analysis (Bouza 2006, Boyle 2004, Hill 2004). Although the improvement of LUTS due to BPH does not reach the same level as TURP; fewer adverse events (e.g., incontinence, retrograde ejaculation) are demonstrated.
• Transurethral microwave thermotherapy (TUMT)
  This minimally invasive treatment begins by introducing a coolant into the urethra through a transurethral probe, which cools the urethra, followed by a microwave emission that heats and ultimately ablates prostatic tissue. AUA recommends the use of TUMT as an appropriate and effective treatment alternative for bothersome (i.e., interfere with activities of daily living), moderate, or severe LUTS due to BPH (Hoffman 2007).
• Prostatic Urethral Lift (UroLift^®)
  The UroLift^® system is a minimally invasive implant developed to treat LUTS related to urinary outflow obstruction secondary to BPH in men 50 years of age or older. In this procedure, permanent implants (made from common implantable materials: nitinol, stainless steel, and polyethylene terepthalate) are delivered trans-prostatically to retract the enlarged lateral lobes of the prostate. This procedure dilates the prostatic urethra in individuals leading to improvement in LUTS symptoms without the need for surgical resection or the application of thermal energy to the prostate. Current evidence for this intervention includes 1 randomized sham-controlled trial (n = 206) published by Roehrborn et al. (2013) which found that at 12-month follow-up, both objective and subjective outcomes were significantly improved in individuals undergoing the UroLift procedure with no adverse impact to sexual function reported among any of the participants. An RCT directly comparing UroLift to TURP is scheduled for completion in December 2015.

Regulatory Status
The use of devices in the minimally invasive treatment of urinary outlet obstruction due to benign prostatic hyperplasia (BPH) should be in accordance with all of the FDA-approved labeling requirements and/or criteria.

Policy
The surgical and minimally invasive treatment of urinary outlet obstruction due to benign prostatic hyperplasia (BPH) is considered MEDICALLY NECESSARY and, therefore, covered when all of the following criteria are met:

• One of the following surgical or minimally invasive treatments is used:
  • Transurethral resection of the prostate (TURP)
  • Holmium laser ablation of the prostate (HoLAP)
  • Holmium laser enucleation of the prostate (HoLEP)
  • Holmium laser resection of the prostate (HoLRP)
  • Photoselective vaporization (PVP)
  • Transurethral electrovaporization of the prostate (TUVP)
  • Transurethral needle ablation (TUNA), also known as transurethral radiofrequency needle ablation (RFNA) (including TUNA using water vapor, Rezum system(also known as convective radiofrequency transurethral water vapor therapy))
  • Transurethral microwave thermotherapy (TUMT)
  • Interstitial laser coagulation of the prostate (ILCP)
  • Contact laser ablation of the prostate (CLAP)
  • Transurethral ultrasound-guided laser induced prostatectomy (TULIP)
  • Visually-guided laser ablation of the prostate (VLAP, also called non-contact laser ablation of the prostate)
  • Transurethral incision of the prostate (TUIP)
  • Ultrasonic aspiration
  • Aquablation
• The individual has a diagnosis of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) (e.g., increased urinary frequency, urgency, incontinence, or straining; nocturia; decreased and intermittent force of the stream; hematuria; and the sensation of incomplete bladder emptying) that interfere with activities of daily living.
• The individual has failed a trial of satisfactory voiding with medication (alpha blocker and/or alpha-reductase inhibitor) or intolerance to medication (alpha blocker and/or 5-alpha-reductase inhibitor).
• In addition to the above criteria, if the individual has a diagnosis or history of prostate cancer and meets either of the following criteria:
  • The individual is not a candidate for surgical resection of the prostate but will be treated by radiation therapy and has symptoms that are so severe that immediate relief is required.
  • The individual is clinically in remission as evidenced by a PSA ≤ 1.0 ng/mL.

UroLift for the treatment of urinary outlet obstruction due to BPH is considered MEDICALLY NECESSARY and, therefore covered if the following criteria are met:

• The individual has a diagnosis of LUTS secondary to BPH (e.g., increased urinary frequency, urgency, incontinence, or straining; nocturia; decreased and intermittent force of the stream; hematuria; and the sensation of incomplete bladder emptying) that interfere with activities of daily living.
• "The individual's symptoms are caused by enlargement of either lateral or medial prostate lobes.”
• The individual has mild to moderate symptoms that are refractory to medication or the individual does not wish to take daily medication.
• The individual is a poor candidate for other surgical interventions for BPH, or the individual opts to undergo a minimally invasive procedure.
• The individual's prostate gland volume is ≤ 80ml.

UroLume, an endourethral prosthesis (urethral stent) is medically necessary to relieve prostatic obstruction secondary to BPH in men at least 60 years of age, or men under 60 years of age who are poor surgical candidates, and whose prostates are at least 2.5 cm in length. (Note: UroLume is NOT intended for temporary use).

UroLume is also considered medically necessary for the treatment of recurrent bulbar urethral stenosis/strictures when previous therapeutic approaches such as dilation, urethrotomy or urethroplasty have failed (i.e., treatment was ineffective or there is recurrent stricture requiring additional treatment).

The use of the above procedures to treat conditions other than those described above is considered NOT MEDICALLY NECESSARY and, therefore, not covered because the available published peer-reviewed literature does not support their use in the diagnosis or treatment of other conditions.

The following procedures are investigational and/or unproven and therefore are considered NOT MEDICALLY NECESSARY and, therefore, not covered because their safety and/or effectiveness in the treatment of urinary outlet obstruction due to BPH has not been established by review of the available published peer-reviewed literature, this list may not be all inclusive:

• Balloon dilation of the prostate
• Transurethral ethanol ablation of the prostate (TEAP)
• High-intensity focused ultrasound (HIFU)
• Water-induced thermotherapy (also known as hot-water balloon thermoablation and thermourethral hot-water therapy)

Policy Guidelines 
Serum prostate-specific antigen (PSA) level and prostate size should not be used as the sole basis of treatment recommendations.

Benefit Application
BlueCard^®/National Account Issues 
Subject to the terms and conditions of the applicable benefit contract, surgical and minimally invasive treatments for urinary outlet obstruction due to BPH are covered under the medical benefits of the Company’s products when medical necessity criteria listed in the medical policy are met. 

Rationale 
This policy is based primarily on the practice guideline of management of benign prostatic hyperplasia (BPH) from the American Urological Association. While a number of treatment modalities have been shown to be effective for BPH, it is not yet evident which of these techniques will prove to be superior or which will approach the effectiveness of transurethral resection of the prostate (TURP) in treating BPH. 

Temporary stents are designed primarily for short-term use in the treatment of symptomatic BPH, for a duration of 6 months to 3 years (van Dijk and de la Rosette, 2003). Temporary stents are made of non-absorbable material, which prevents epithelial ingrowth and therefore allows easy removal. However, this may lead to unintended migration. Some temporary stents are biodegradable, so that they break down into small fragments, which are excreted through the urethra over time. Although no explantation of biodegradable stents is required, the excreted fragments may cause urethral obstruction. 

According to the guidelines by the American Urological Association (AUA, 2003), "because prostatic stents are associated with significant complications, such as encrustation, infection and chronic pain, their placement should be considered only in high-risk patients, especially those with urinary retention." AUA guidelines explain: "Clinical trials of temporary prostatic stents are ongoing, and some long-term efficacy and safety studies have been published. It is unclear whether prostatic stents have applications in men with symptomatic BPH who have not developed urinary retention and whose medical conditions permit other forms of treatment." 

One temporary prostatic urethral stent currently in development is the Spanner, which is designed for temporary use (30 days or less) in men with bladder outlet obstruction to reduce elevated post-void residual and improve voiding symptoms. The stent design is very similar to the proximal 4 to 6 cm portion of a Foley catheter. It includes a proximal balloon to prevent distal displacement, a urine port situated cephalad to the balloon, and a reinforced stent of various lengths to span most of the prostatic urethra. There is also a distal anchor mechanism attached by sutures, and a retrieval suture which extends to the meatus and deflates the proximal balloon when pulled. 

Corica et al. (2004) reported that the Spanner significantly improved voiding function and quality of life among patients with prostatic urethral obstruction (n = 30). However, in a review on recent developments in the management of symptomatic BPH, Ogiste and colleagues (2003) stated that the role of stents as an intermediary in cases of treatment failure, or as definitive therapy for BPH and its associated problems are still unclear, when compared with newer, minimally invasive options. Current literature on stents is relatively sparse. However, recent studies showed that permanent and temporary prostatic urethral stenting are effective in relieving obstruction and urinary retention. Nevertheless larger controlled clinical studies are needed to demonstrate the real value of this intervention. 

Azuyma and Chancellor (2004) commented that although the results of the use of bioabsorbable spiral stents are encouraging, "there are still too many failures." The authors state that controlled studies are needed to compare bioabsorbable stents with other forms of therapy. 

The California Technology Assessment Forum (2002) concluded that water-induced thermotherapy for BPH does not meet CTAF's technology assessment criteria. The assessment concluded that "[E]xisting studies have not yet demonstrated that WIT results in better health outcomes as much as or more than the established alternative of TURP, TUNA, or microwave thermotherapy." Furthermore, in a review on minimally invasive therapies for BPH, Naspro et al. (2005) noted that "currently, transurethral microwave thermotherapy seems to offer the soundest basis for management of the condition, providing the longest term follow up and the largest numbers of studies completed to date. Among surgical alternatives, holmium laser enucleation has gained ground as an encouraging new approach, being similar to standard transurethral resection of the prostate, but reducing perioperative morbidity with the same long-term results. More randomized comparisons correctly conducted need to be undertaken before an accurate general picture is available for the urologist."

Transurethral electrovaporization of the prostate (TUVP) is another alternative, minimally invasive procedures to treat BPH. This procedure combines electrosurgical vaporization and desiccation to remove obstructive hyperplastic prostatic tissue with minimal morbidity. It entails a special electrosurgical modification involving a grooved roller electrode with a large surface area and multiple edges of contact; thus allowing high current density to be delivered to an extensive area of tissue to be vaporized. The device fits standard resectoscopic equipment, and its use requires no special skills other than those needed for conventional TURP. 

Fowler et al. (2005) compared the clinical and cost-effectiveness of TUVP with TURP. Men requiring surgery for lower urinary tract symptoms deemed to be due to BPH were recruited from 4 centers in southeast England. Main outcome measures were the International Prostate Symptom Score (IPSS) and the IPSS quality of life (QOL) question. Secondary outcome measures included urinary flow rate, post-void urinary volume, prostate volume and pressure-flow urodynamics. TURP and TUVP were both effective in producing a clinically important reduction in IPSS and positive change in the IPSS QOL question. The success rate for relief of symptoms was 85% for TURP and 74% for TUVP. Neither the success of the treatment nor the change in aggregated IPSS was significantly different between the groups. The improvement was sustained to 24 months after treatment with no significant difference between the groups. The effectiveness of both treatments was also equivalent when assessed through improvement in objective measures of urinary tract function, reduction in prostate size and the change in health questions of SF-36. The absolute incidence of adverse events was similar between the 2 groups. The incidence of severe or prolonged bleeding was less with TUVP, as evidenced by the need for blood transfusion and the drop in hemoglobin level 24 hours post-operatively. This study did not show any significant difference in inpatient stay or use of outpatient resources between the groups. The authors concluded that TURP and TUVP are equivalently effective in improving the symptoms of benign prostatic enlargement over at least 2 years. TUVP is associated with less morbidity due to hemorrhage than TURP. This finding is in agreement with that of the National Institute for Health and Clinical Excellence (2003), which stated that there is adequate support for the use of TUVP, and that of Nohuglu et al. (2005) who found that TUVP is as effective as TURP with similar morbidity. The advantages of TUVP are that the urethral catheter is withdrawn earlier, hospitalization is shorter, and bleeding is less. 

Thomas et al. (2006) noted that botulinum neurotoxin (BoNT) application recently has been extended to prostate disorders. While BoNT has shown promising preliminary results for male lower urinary tract symptoms, and translational research suggests novel mechanism of action of BoNT in the prostate, it is important to remember that the application of BoNT in the prostate is not approved by the regulatory agencies and caution should be applied until larger randomized clinical trials are completed. This is in agreement with the observations of Azzouzi et al. (2006) as well as Chuang and Chancellor (2006). 

Kuo and Liu (2009) evaluated the effectiveness of BoNT-A in patients with large BPH with an unsatisfactory response to combined alpha-blocker and 5-alpha-reductase inhibitor therapy. A total of 60 patients with total prostate volume (TPV) of greater than 60 ml with unsatisfactory response to combination medical therapy were randomly assigned to receive add-on intra-prostatic BoNT-A injection (n = 30) or continued medical therapy (control group). Patients in the treatment group received 200 to 600 U of Botox injected into the prostate. Outcome parameters including IPSS, quality of life index (QOL-I), TPV, maximum flow rate (Qmax) and post-void residual (PVR) volume were compared between treatment and control groups at baseline, 6 months and 12 months. Significant decreases in IPSS, QOL-I and TPV, and increase in Qmax were observed at 6 months and remained stable at 12 months in the treatment group. Improvements in IPSS and QOL-I were also observed at 6 months and a decrease in TPV at 12 months was noted in the control group. However, no significant changes in any parameters except for QOL-I at 6 and 12 months were noted between the treatment and control groups. Acute urinary retention developed in 3 patients receiving BoNT-A treatment. Three BoNT-A and 2 medical treatment patients converted to trans-urethral surgery at the end of study. The authors concluded that the findings of this study showed that add-on prostatic BoNT-A medical treatment can reduce prostate volume and improve lower urinary tract symptom score and QOL-I within 6 months in the treatment of large BPH. However, the therapeutic effect at 12 months was similar to combination medical treatment. 

Oeconomou and Madersbacher (2010) summarized the mechanisms through which BoNT-A could inhibit the progression of BPH and eliminate the lower urinary tract symptoms (LUTS) according to the findings of animal studies. Furthermore, these researchers reviewed clinical studies to report the safety and effectiveness of intra-prostatic BoNT-A injection according to various injection protocols. The experimental studies reported induced relaxation of the prostate, atrophy, and reduction in its size through inhibition of the trophic effect of the autonomic system on the prostate gland. Also, a possible mechanism of reduction in LUTS might take place through inhibition of sensory afferents from the prostate to the spinal cord. Clinical studies reported symptomatic relief and improvement in the measured parameters during the follow-up period, whereas local or systematic side-effects are rare. The authors concluded that it should be recognized that, at present, this therapy is still experimental. Although the results of the clinical studies are encouraging, the level of evidence is low. Large-scale, clinical, placebo-controlled, randomized studies, including long-term surveillance to document the evidence of this therapy are needed. 

In a phase II prospective study, Richter et al. (2009) recorded the effectiveness and complications of holmium laser enucleation of the prostate (HoLEP) in the first post-operative year. Eighty-six of 343 consecutive patients with benign prostatic obstruction (IPSS greater than 10] were treated with the VersaPulse 100-W laser (Lumenis), 2.0 J/50 Hz or 3.2 J/25 Hz. Pre-operative and post-operative prostate-specific antigen (PSA), Qmax, IPSS, prostate gland volume, and PVR volume were prospectively measured. The median follow-up time was 8 months (3 to 21). Median patient age was 71 (50 to 83) years, and mean operating time was 77.5 (9 to 135) mins. There was only 1 case of significant bleeding. In 14 of 86 cases (16 %), HoLEP was combined with TURP. Short-term voiding complaints were expressed by 26.7% of the questioned patients. The length of hospital stay was in most cases less than 48 hrs. IPSS, Qmax, PSA, PVR volume, gland volumes, and QOL improved significantly after 3 months, and all parameters remained unchanged after 12 months. The re-operation rate within 12 months was 6.8 %. The authors concluded that the advantage of HoLEP over TURP is the very low bleeding rate and thus a shorter hospital stay and possible out-patient therapy. In particular, patients with prostate gland volume less than 50 mls profit from HoLEP. Post-operative voiding complaints are comparable to those with TURP. Moreover, the authors stated that long-term results are needed to confirm the low re-operation rate. 

Erol et al. (2009) prospectively evaluated vaporization efficiency of the high-power, 980-nm diode laser for bladder outlet obstruction due to BPH. A total of 47 consecutive patients were included in the study. Inclusion criteria were maximal flow rate 12 ml per second or less with voided volume 150 ml or greater, IPSS of 12 or greater, and QOL score 3 or greater. Patients with a history of neurogenic voiding dysfunction, chronic prostatitis, or prostate or bladder cancer were excluded from analysis. Pre-operative maximal flow rate, post-void residual urine, IPSS, QOL, International Index of Erectile Function-5, PSA, and prostate volume were compared with values at 3 and 6 months. Complications were assessed. Month 3 assessment revealed that the mean (+/- standard deviation [SD]) IPSS decreased significantly from 21.93 +/- 4.88 to 10.31 +/- 3.79 (p = 0.0001). The mean maximal flow rate increased significantly from 8.87 +/- 2.18 to 17.51 +/- 4.09 ml per second (p = 0.0001). Quality of life score changed considerably compared to baseline. All of these values showed slight improvement at month 6. There was no deterioration in erectile function according to the International Index of Erectile Function-5 short form. Post-void residual urine decreased significantly; reductions in prostate volume and PSA were also significant. The most common post-operative complications were retrograde ejaculation (13 of 41 patients or 31.7 %) and irritative symptoms (11 of 47 or 23.4 %), which subsided in the maximal flow rate at 2 weeks. Re-catheterization was necessary in 2 patients due to urinary retention after catheter removal; 2 patients had temporary combined urge and stress incontinence for 2 weeks. Late bleeding in 1 patient 4 weeks post-operatively resulted in catheterization and irrigation. The authors concluded that the high-power diode laser provided significant improvements in IPSS and the maximal flow rate with low morbidity. Thus, these results of prostate vaporization with the high-power diode laser, representing what is to the authors' knowledge the first clinical study in the literature, are encouraging. The authors stated that further randomized clinical trials are needed to ascertain the role of high-power diode laser as an alternative to TURP or other laser techniques for BPH. 

Van Cleynenbreugel et al. (2009) presented recent clinical and urodynamic data on trans-urethral photo-selective vaporization of the prostate, and reported on the recent introduction of the 120-W GreenLight laser (GLL) high-performance system. These researchers noted that recent studies confirm improved urodynamic findings following GLL treatment. Moreover, it can be used safely in high-risk patients (e.g., those on anti-coagulant medication and patients with cardiopulmonary diseases), and has been proposed as an alternative to prostate enucleation for larger glands. The introduction of the 120-W high-performance system GLL does, however, place distinct demands on training and operative schemes. The authors concluded that the clinical results of GreenLight prostate vaporization are equivalent to those following TURP, with reduced operative risks, even for the high-risk patient. These clinical benefits have been confirmed by improved urodynamic parameters. Moreover, they noted that the potential advantages of the new 120-W high-performance system GLL have yet to be validated in larger randomized trials. 

Ruszat et al. (2008) evaluated the intermediate-term clinical effectiveness and the rate of complications in 80-W photo-selective vaporization of the prostate (PVP) with the potassium-titanyl-phosphate laser (GreenLight, Minnetonka, MN) compared with TURP in a prospective non-randomized 2-center study. A total of 396 patients (PVP = 269, TURP = 127) with lower urinary tract symptoms secondary to BPH were included in the study. There was a significant difference in mean age (72 years for PVP versus 68 for TURP, p = 0.001). Patients were therefore stratified in age categories (less than 70, 70 to 80, greater than 80 years) and compared for peri-operative variables, functional outcome and complications, with a follow-up of up to 24 months. The mean prostate size was greater (overall, 62 versus 48 mls, p < 0.001) and mean operative duration longer (overall 72 versus 53 mins; p = 0.001) for PVP in all age categories. The rate of intra-operative bleeding (3% versus 11 %), blood transfusions (0% versus 5.5 %) and capsule perforations (0.4% versus 6.3 %), and early post-operative clot retention (0.4% versus 3.9 %) was significantly lower for PVP. Hospitalization time was significantly shorter in the PVP group for patients aged less than 70 years (3.0 versus 4.7 days) and 70 to 80 years (4.0 versus 5.0 days; p = 0.001). The improvement of peak urinary flow rate was higher after TURP for any age category. The IPSS and PVR volume during the follow-up showed no significant difference. After 12 months, the overall prostate size reduction was 63% (-30 mls) after TURP and 44% (-27 mls) after PVP. The rate of repeat TURP/PVP was higher in the PVP group (6.7% versus 3.9 %, not significant) within the follow-up of up to 2 years. The incidence of urethral and bladder neck strictures was comparable. The authors concluded that PVP was more favorable in terms of peri-operative safety. Although patients assigned for PVP were older and had larger prostates, PVP resulted in a similar functional outcome. They stated that further follow-up is needed to draw final conclusions about the long-term effectiveness of PVP.

Naspro and colleagues (2009) noted that HoLEP and 532-nm laser vaporization of the prostate (with potassium titanyl phosphate [KTP] or lithium borate [LBO]) are promising alternatives to TURP and open prostatectomy (OP). These investigators evaluated the safety, effectiveness, and durability by analyzing the most recent evidence of both techniques, aiming to identify advantages, pitfalls, and unresolved issues. A Medline search of recently published data (2006 to 2008) regarding both techniques over the last 2 years (January 2006 to September 2008) was performed using evidence obtained from randomized trials (level of evidence: 1b), well-designed controlled studies without randomization (level of evidence: 2a), individual cohort studies (level of evidence: 2b), individual case control studies (level of evidence: 3), and case series (level of evidence: 4). In the last 2 years, several case-control and cohort studies have demonstrated reproducibility, safety, and effectiveness of HoLEP and 80-W KTP laser vaporization. Four randomized controlled trials (RCTs) were available for HoLEP, 2 compared with TURP and 2 compared with OP, with follow-up greater than 24 months. Results confirmed general effectiveness and durability of HoLEP, as compared with both standard techniques. Only 2 RCTs were available comparing KTP laser vaporization with TURP with short-term follow-up, and only 1 RCT was available comparing KTP laser vaporization with OP. The results confirmed the overall low peri-operative morbidity of KTP laser vaporization, although effectiveness was comparable to TURP in the short-term, despite a higher re-operation rate. The authors concluded that although they are at different points of maturation, KTP or LBO laser vaporization and HoLEP are promising alternatives to both TURP and OP; KTP laser vaporization needs further evaluation to define the re-operation rate. Increasing the number of quality prospective RCTs with adequate follow-up is mandatory to tailor each technique to the right patient. 

Chung and Te (2009) stated that traditionally, the gold standard for treatment of BPH has been the electrocautery-based TURP. However, the number of laser techniques being performed is rapidly increasing. Potential advantages of laser therapy over traditional TURP include decreased morbidity and shorter hospital stay. There are several techniques for laser prostatectomy that continue to evolve. The main competing techniques are currently the HoLEP and the 80-W 532-nm laser prostatectomy. The HoLEP, using the Holmium:YAG laser, has been shown to have clinical results similar to TURP and is suitable for patients on anti-coagulation as well as those with large prostates. Disadvantages of this technique are the high learning curve and requirement of a morcellator. When used to treat BPH, studies have demonstrated that, like the HoLEP, the 80-W KTP laser is safe and effective in patients with large prostates and in those taking oral anti-coagulation. Several studies have compared these 2 techniques to TURP. Frequently reported advantages of the HoLEP over the 80-W laser prostatectomy are the availability after the procedure of a pathology specimen and ability to remove a higher percentage of prostate tissue during resection. However, the trans-urethral laser enucleation of the prostate addresses these concerns and has shown to have durable outcomes at 2-year follow-up. Two new laser systems and techniques, the thulium laser and the 980-nm laser, have emerged recently. However, clinical data from these procedures are in their infancy and large long-term studies are needed to ascertain their clinical effectiveness.

Lourenco and colleagues (2008) ascertained the clinical effectiveness and cost utility of procedures alternative to TURP for BPH unresponsive to expectant, non-surgical treatments. Electronic searches of 13 databases to identify relevant RCTs were carried out. Two reviewers independently assessed study quality and extracted data. The International Prostate Symptom Score/American Urological Association (IPSS/AUA) symptom score was the primary outcome; others included QOL, peak urine flow rate and adverse effects. Cost-effectiveness was assessed using a Markov model reflecting likely care pathways. A total of 156 reports describing 88 RCTs were included. Most had fewer than 100 participants (range of 12 to 234). It was found that TURP provided consistent, high-level, long-term symptomatic improvement. Minimally invasive procedures resulted in less marked improvement. Ablative procedures gave improvements equivalent to TURP. Furthermore, HoLEP resulted in greater improvement in flow rate. Holmium laser enucleation of the prostate is unique amongst the newer technologies in offering an advantage in urodynamic outcomes over TURP, although long-term follow-up data are lacking. Severe blood loss was more common following TURP. Rates of incontinence were similar across all interventions other than TUNA and laser coagulation, for which lower rates were reported. Acute retention and re-operation were commoner with newer technologies, especially minimally invasive interventions. The economic model suggested that minimally invasive procedures were unlikely to be cost-effective compared with TURP. Transurethral vaporization of the prostate was both less costly and less effective than TURP; whereas HoLEP was estimated to be more cost-effective than a single TURP but less effective than a strategy involving repeat TURP, if necessary. The base-case analysis suggested an 80% chance that TUVP, followed by HoLEP if required, would be cost-effective at a threshold of 20,000 pounds per quality-adjusted life-year. At a 50,000 pounds threshold, TUVP, followed by TURP as required, would be cost-effective, although considerable uncertainty surrounds this finding. The main limitations are the quantity and quality of the data available, in the context of multiple comparisons. The authors concluded that in the absence of strong evidence in favor of newer methods, the standard — TURP — remains both clinically effective and cost-effective. There is a need for further research to establish: (1) how many years of medical treatment are necessary to offset the cost of treatment with a minimally invasive or ablative intervention, (2) more cost-effective alternatives to TURP; and (3) strategies to improve outcomes after TURP. 

Hashim and Abrams (2010) noted that benign prostatic enlargement (BPE) leading to benign prostatic obstruction (BPO) affects an increasing number of men as they grow older. They can affect QOL and cause LUTS including urinary retention. The currently available pharmacotherapies are alpha-blockers and 5-alpha reductase inhibitors, which may be effective but can have adverse effects and long-term compliance problems. Thus, it is important to find new medical treatments for LUTS/BPO and this review aimed to identify the potential future drugs undergoing clinical trials in this field. Articles were identified by means of a computerized Google, PubMed and Cochrane Library search over the last 10 years (using the following keywords: benign prostate hyperplasia, enlargement and obstruction) and a search of the PharmaProjects database. The exact etiology of BPH and its consequences, BPE and BPO, are not known; however, aging and functioning testes have been implicated. Several classes of drugs are currently undergoing clinical trials such as phosphodiesterase-5 (PDE5) inhibitors and lutenizing hormone-releasing hormone antagonists. Others include phytoestrogens, progestogens, NX1207 and PRX302. Some of these work by affecting testosterone level and, therefore, on the static component of BPO, while it is not known how the rest work. The authors stated that until the exact etiology of BPH/BPE/BPO is known, it is unlikely the cure for this disorder will be found. 

Wang (2010) examined the use of PDE5 inhibitors for BPH/LUTS treatment and highlighted the clinical significance. Pre-clinical and clinical studies have provided promising evidence that PDE5 inhibitors may be an effective and well-tolerated treatment option for BPH/LUTS. Combination therapy using PDE5 inhibitors and alpha1-adrenergic blockers resulted in greater improvements in BPH/LUTS than did either drug alone. There has been increasing interest in the use of PDE5 inhibitors to treat BPH/LUTS. Combination of PDE5 inhibitors and alpha1-adrenergic blockers may have an additive beneficial effect on BPH/LUTS compared with monotherapy. Mechanisms of action of nitric oxide/cyclic guanosine monophosphate/PDE5 pathway in the treatment of BPH/LUTS deserve further investigations. The author concluded that larger-scale, well-designed clinical trials are needed to ascertain the safety, effectiveness and cost-effectiveness of PDE5 inhibitors in the treatment of LUTS secondary to BPH. 

Andersson et al. (2011) reviewed the published literature describing the pathophysiology of male LUTS, with an emphasis on mechanisms that may be modulated or improved by PDE5 inhibition. Literature (through March 2010) was obtained via Medline searches and from the individual reviewers files. Articles were selected for review based on describing in-vitro, pre-clinical, or clinical studies of pathological processes contributing to LUTS, or possible effects of PDE5 inhibition in the lower urinary tract. Major mechanisms contributing to LUTS include: reduced nitric oxide/cyclic guanosine monophosphate signaling; increased RhoA kinase pathway activity; autonomic over-activity; increased bladder afferent activity; and pelvic ischemia. Tadalafil and other PDE5 inhibitors have demonstrated beneficial effects on smooth muscle relaxation, smooth muscle and endothelial cell proliferation, nerve activity, and tissue perfusion that may impact LUTS in men. The authors concluded that the pathophysiology of male LUTS is complex and not completely understood. LUTS may occur independently of BPH or secondary to BPH but in both cases involve obstructive or irritative mechanisms with substantial pathophysiological overlap. While the precise mechanism remains unclear, inhibition of PDE5 seems to have an effect on several pathways that may impact LUTS. 

While surgical resection and ablation using many different forms of energy remain the reference standard for BPH treatment, many patients seek a less invasive approach that will improve symptoms but not risk the complications associated with tissue removal. The UroLift system (NeoTract Inc., Pleasanton, CA) permanent implant is such a modality; it is delivered under cystoscopic visualization. The implant "holds open" the lateral prostatic lobes creating a passage through the obstructed prostatic urethra. Voiding and symptoms are significantly improved without the morbidity or possible complications following prostate resection. The entire procedure can be readily performed using local anesthesia (Barkin et al., 2012). 

On Sept. 13, 2013, the FDA approved the marketing of the UroLift, the first permanent implant to relieve low or blocked urine flow in men aged 50 and older with BPH. Minor adverse events reported included pain or burning during urination, blood in the urine, frequent or urgent need to urinate, incomplete emptying of the bladder, and decreased urine flow. 

Chin et al. (2012) evaluated the effectiveness of the prostatic urethral lift in relieving LUTS secondary to BPH. A total of 64 men, aged greater than or equal to 55 years, with moderate-to-severe symptomatic BPH were treated and followed-up at 6 Australian institutions. The treatment consisted of transurethral delivery of small implants to secure the prostatic lobes in an open condition, thereby reducing obstruction of the urethral lumen. The effectiveness, including International Prostate Symptom Score, quality of life, benign prostatic hyperplasia Impact Index, and peak urethral flow rate were assessed at 2 weeks and 3, 6, 12 and 24 months. The effect of this treatment on erectile and ejaculatory function was assessed using the Sexual Health Inventory for Men and Male Sexual Health Questionnaire for Ejaculatory Dysfunction. The prostatic urethral lift improved LUTS symptoms rapidly and durably. The International Prostate Symptom Score was reduced 42% at 2 weeks, 49% at 6 months, and 42% at 2 years in evaluable patients. The peak flow rate improved by greater than or equal to 30% (2.4 ml/s) at all intervals compared with baseline. No compromise in sexual function was observed after this treatment. The authors concluded that the findings of the present study demonstrated that LUTS and flow improvements without compromising sexual function. Moreover, they stated that although this was an early study with a small cohort, this therapy showed promise as a new option for patients with LUTS. 

Roehrborn et al. (2013) reported the first multi-center randomized blinded trial of the prostatic urethral lift for the treatment of LUTS secondary to BPH. Men at least 50 years old with AUASI (American Urological Association Symptom Index) 13 or greater, a maximum flow rate 12 ml/s or less and a prostate 30 to 80 cc were randomized 2:1 between prostatic urethral lift and sham. In the prostatic urethral lift group, small permanent implants are placed within the prostate to retract encroaching lobes and open the prostatic urethra. Sham entailed rigid cystoscopy with sounds mimicking the prostatic urethral lift. The primary end-point was comparison of AUASI reduction at 3 months. The prostatic urethral lift arm subjects were followed to 1 year and assessed for LUTS, peak urinary flow rate, quality of life and sexual function. A total of 206 men were randomized (prostatic urethral lift 140 versus sham 66). The prostatic urethral lift and sham AUASI was reduced by 11.1 ± 7.67 and 5.9 ± 7.66, respectively (p = 0.003), thus meeting the primary end-point. Prostatic urethral lift subjects experienced AUASI reduction from 22.1 baseline to 18.0, 11.0 and 11.1 at 2 weeks, 3 months and 12 months, respectively, p < 0.001. Peak urinary flow rate increased 4.4 ml/s at 3 months and was sustained at 4.0 ml/s at 12 months, p < 0.001. Adverse events were typically mild and transient. There was no occurrence of de-novo ejaculatory or erectile dysfunction. The authors concluded that the prostatic urethral lift, inserted with the patient under local anesthesia, provided rapid and sustained improvement in symptoms and flow, while preserving sexual function. 

McNicholas et al. (2013) described the surgical technique and results of a novel minimally invasive implant procedure that offers symptom relief and improved voiding flow in an international series of patients. A total of 102 men with symptomatic BPH were consecutively treated at 7 centers across 5 countries. Patients were evaluated up to a median follow-up of 1 year post-procedure. Average age, prostate size, and IPSS were 68 years, 48 cm(3), and 23, respectively. The prostatic urethral lift mechanically opens the prostatic urethra with UroLift implants that were placed transurethrally under cystoscopic visualization, thereby separating the encroaching prostatic lobes. Patients were evaluated pre- and post-operatively by the IPSS, QOL scale, Benign Prostatic Hyperplasia Impact Index, maximum flow rate (Qmax), and adverse event reports including sexual function. All procedures were completed successfully with a mean of 4.5 implants without serious adverse effects. Patients experienced symptom relief by 2 weeks that was sustained to 12 months. Mean IPSS, QOL, and Qmax improved 36 %, 39 %, and 38% by 2 weeks, and 52 %, 53 %, and 51% at 12 months (p < 0.001), respectively. Adverse events were mild and transient. There were no reports of loss of antegrade ejaculation. A total of 6.5% of patients progressed to TURP without complication. The authors concluded that prostatic urethral lift has promise for BPH. It is minimally invasive, can be done under local anesthesia, does not appear to cause retrograde ejaculation, and improves symptoms and voiding flow. 

McVary et al. (2014) analyzed data obtained from a randomized controlled blinded study of the prostatic urethral lift (PUL) to evaluate the sexual side effects of this novel treatment. Men greater than or equal to 50 years with prostates 30 to 80 cc, IPSS greater than 12, and Qmax less than or equal to 12 ml/s were randomized 2:1 between PUL and sham. Sexual activity was not an inclusion criterion. In PUL, permanent trans-prostatic implants were placed to retract encroaching lateral lobes and open the prostatic fossa. Sham entailed rigid cystoscopy with sounds to mimic PUL and a blinding screen. Blinded groups were compared at 3 months and active-arm then followed to 12 months for LUTS with IPSS and for sexual function with sexual health inventory for men (SHIM) and Male Sexual Health Questionnaire for Ejaculatory Dysfunction (MSHQ-EjD). Subjects were censored from primary sexual function analysis if they had baseline SHIM less than 5 at enrollment. Secondary stratified analysis by ED severity was conducted. There was no evidence of degradation in erectile or ejaculatory function after PUL. SHIM and MSHQ-EjD scores were not different from control at 3 months but were modestly improved and statistically different from baseline at 1 year. Ejaculatory bother score was most improved with a 40% improvement over baseline. Twelve-month SHIM was significantly improved from baseline for men entering the study with severe ED (p = 0.016). IPSS and Qmax were significantly superior to both control at 3 months and baseline at 1 year. There was no instance of de-novo sustained anejaculation or ED over the course of the study. The authors concluded that the PUL improved LUTS and urinary flow while preserving erectile and ejaculatory function. 

Guidance from the National Institute for Health and Clinical Excellence (NICE, 2014) states: "Current evidence on the efficacy and safety of insertion of prostatic urethral lift implants to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia is adequate to support the use of this procedure provided that normal arrangements are in place for clinical governance, consent and audit." 

Russo et al. (2014) stated that BPH is a very common condition in men over 50 years, often resulting in LUTS. Medical therapy aims at improving QOL and preventing complications. The range of drugs available to treat LUTS is rapidly expanding. Silodosin is a relatively new alpha 1-adrenoreceptor antagonist that is selective for alpha 1A-adrenergic receptor. While causing smooth muscle relaxation in the lower urinary tract, it minimizes blood pressure-related adverse effects. Tadalafil, a PDEs type 5 inhibitor, is a drug recently approved for the treatment of BPH/LUTS that challenges the standard therapy with alpha 1-blockers, especially in men with concomitant ED. Mirabegron is the first beta 3-adrenoceptor agonist approved for the treatment of symptoms of overactive bladder. Benign prostatic hyperplasia-related detrusor overactivity (DO) may be successfully targeted by mirabegron. Gonadotropin-releasing hormone antagonists, intra-prostatic injections with NX-1207 and vitamin D3 receptor analogs exerted beneficial effects on LUTS but need further evaluation in clinical studies. The authors concluded that choosing the right treatment should be guided by patients' symptoms, co-morbidities and potential side effects of available drugs. Silodosin is a valid option for elderly and for people taking anti-hypertensive drugs. They stated that BPH patients affected by ED can target both conditions with continuous tadalafil therapy. The encouraging data on mirabegron use in BPH-DO have to be further assessed in larger prospective RCTs. 

Faber et al. (2015) evaluated the safety and effectiveness of a novel robotic tissue ablation system (PROCEPT Aquablation™ System), in performing prostate ablation in a survival canine model. This novel technology uses a high-velocity saline stream that aims to selectively ablate prostatic glandular tissue while sparing collagenous structures such as blood vessels and capsule. Once the ablation is complete, a laser beam is captured by a low-pressure water jet to produce surface hemostasis. The extent and depth of ablation is pre-determined by endoscopic and transrectal ultrasonography guidance. The procedure was performed in 8 non-castrated male beagles aged 6 years or older (Acute 2, Chronic 6) through a previously created perineal urethrostomy. Aquablation time ranged from 40 to 84 seconds (mean of 60.5 sec). There was no active bleeding in any of the dogs during or after Aquablation. Water jet-guided laser coagulation was used for purposes of monitoring its safety and effectiveness; 5 of the 6 dogs reached the pre-determined 6-week mark. Complications included 2 dogs with infection successfully treated with antibiotics, a false passage created during catheter placement, and 2 bladder neck perforations (from mechanical insertion), 1 leading to euthanasia. Histologic evaluation at 6 weeks revealed a normal cellular architecture and full re-epithelialization of the treatment cavity. The authors reported the initial survival data in the animal model of a novel robotic device developed for managing symptomatic BPH. They stated that Aquablation produced ablation of adenomatous elements while preserving collagenous structures and is a promising technology for surgical management of symptomatic BPH. 

Nair and colleagues (2015) stated that LUTS are common and are often caused by BPH. Traditional surgical methods of open enucleation and TURP have been effective in alleviating these symptoms however, these are operator-dependent and often come with significant side effects. These investigators discussed upcoming new surgical techniques in management of BPH. A systematic search of SCOPUS, MEDLINE, EMBASE and Cochrane databases was carried out using relevant key words. Intra-prostatic injections with a variety of agents have been explored as these can be readily performed under local anesthesia. Alcohol injections into the prostate have been abandoned due to potential side effects; but there has been ongoing development of 2 alternative agents, NX-1207 and PRX-302. Both have shown good safety profiles and early effectiveness in phase II studies. Thermal treatment with the Rezūm device performed as an out-patient procedure has shown both safety and effectiveness in phase I and II studies. Aquablation showed promise in phase II studies with few side effects and is a relatively automated procedure, albeit requiring general anesthesia. Prostate artery embolization has been reported in a number of studies, but clinical outcomes have been unpredictable. Histotripsy has had a number of complications in animal models and despite technical improvement has not yet progressed beyond feasibility studies in humans. The authors concluded that some of the new techniques and technologies available for BPH have been shown to be relatively safe and effective and await validation with phase III clinical trials. 

Aoun et al. (2015) noted that BPH represents a spectrum of related LUTS. The cost of currently recommended medications and the discontinuation rate due to side effects are significant drawbacks limiting their long-term use in clinical practice. Interventional procedures, considered as the definitive treatment for BPH, carry a significant risk of treatment-related complications in frail patients. These issues have contributed to the emergence of new approaches as alternative options to standard therapies. These investigators reviewed the recent literature regarding the experimental treatments under investigation and presented the currently available experimental devices and techniques used under local anesthesia for the treatment of LUTS/BPH in the vast majority of cases. They discussed devices for delivery of thermal treatment (microwaves, radiofrequency, high-intensity focused ultrasound, and the Rezūm system), mechanical devices (prostatic stent and urethral lift), fractionation of prostatic tissue (histotripsy and aquablation), PAE, and intra-prostatic drugs; and analyzed evidence for the safety, tolerability, and efficacy of these "minimally invasive procedures." 

Khokhlova et al. (2015) stated that in high intensity focused ultrasound (HIFU) therapy, an ultrasound beam is focused within the body to locally affect the targeted site without damaging intervening tissues. The most common HIFU regime is thermal ablation. Recently there has been increasing interest in generating purely mechanical lesions in tissue (histotripsy). These investigators provided an overview of several studies on the development of histotripsy methods toward clinical applications. They presented 2 histotripsy approaches and examples of their applications. In one approach, sequences of high-amplitude, short (microsecond-long), focused ultrasound pulses periodically produce dense, energetic bubble clouds that mechanically disintegrate tissue. In an alternative approach, longer (millisecond-long) pulses with shock fronts generate boiling bubbles and the interaction of shock fronts with the resulting vapor cavity causes tissue disintegration. Recent pre-clinical studies on histotripsy were reviewed for treating BPH, liver and kidney tumors, kidney stone fragmentation, enhancing anti-tumor immune response, and tissue de-cellularization for regenerative medicine applications. Potential clinical advantages of the histotripsy methods were discussed. Histotripsy methods can be used to mechanically ablate a wide variety of tissues, while selectivity sparing structures such as large vessels. Both ultrasound and magnetic resonance imaging (MRI) can be used for targeting and monitoring the treatment in real time. The authors concluded that although the 2 approaches utilize different mechanisms for tissue disintegration, both have many of the same advantages and offer a promising alternative method of non-invasive surgery. 

The Rezum System (Transurethral Water Vapor Therapy) 
TUNA using water vapor (i.e., the Rezūm^® System) delivers sterile water vapor (steam) transurethrally directly into hyperplastic tissue. Heat is released as the vapor condenses, causing cell death. The major difference between TUNA and Rezūm is how the RF energy is delivered to the prostate. In both cases energy is transferred via a transurethral needle injection. With the former, RF energy is directly delivered to the prostate tissue in a conductive manner. This causes necrosis of the tissue. However, in the Rezūm system the RF energy is used to heat sterile water to vapor and steam which when injected convectively treats the prostate tissue. This latter mechanism is intended to be safer for the patient and yield improved results. 

Dixon et al. (2015) evaluated the acute ablative characteristics of transurethral convective water vapor (steam) using the Rezūm^® system in men with BPH through histologic and radiographic studies. A total of 7 patients were treated with transurethral intra-prostatic injections of sterile steam under endoscopic visualization followed by previously scheduled adenectomies. The extirpated adenomas were grossly examined followed by whole mount sectioning and staining with triphenyl-tetrazolium chloride (TTC) to evaluate thermal ablation. Histology was performed after hematoxylin and eosin staining on 1 prostate. After review of results from the first patient cohort, an additional 15 patients with clinical BPH were treated followed by gadolinium-enhanced magnetic resonance imaging (MRI) at 1 week. In the first patient cohort, gross examination of TTC-stained tissue showed thermal ablation in the transition zone. In addition, there was a distinct interface between viable and necrotic prostatic parenchyma. Histopathologic examination revealed TTC staining-outlined necrotic versus viable tissue. Gadolinium-enhanced MRIs in the cohort of 15 patients demonstrated lesion defects in all patients at 1 week post-procedure. Coalesced lesions were noted with a mean (± standard deviation) lesion volume of 9.6 ± 8.5 cm³. The largest lesion volume was 35.1 cm³. Ablation using vapor was rapid and remained confined to the transition zone, consistent with the thermodynamic principles of convective thermal energy transfer. The authors concluded that thermal ablation was observed in all specimens. The resulting coalescing ablative lesions, as seen on MRI, were confined to the transition zone. They stated that these studies confirmed the ablative capabilities of vapor, validated the thermodynamic principles of convective heating, and allowed for further clinical studies. 

McVary et al. (2016) reported on the results of a multicenter, randomized, controlled study using transurethral prostate convective water vapor thermal energy to treat lower urinary tract symptoms associated with benign prostatic hyperplasia. Men 50 years old or older with an International Prostate Symptom Score of 13 or greater, maximum flow rate of 15 ml per second or less and prostate size 30 to 80 cc were randomized 2:1 between thermal therapy with the Rezūm^® System and control. Thermal water vapor was injected into the transition zone and median lobe as needed. The control procedure was rigid cystoscopy with simulated active treatment sounds. The primary end point compared International Prostate Symptom Score reduction at 3 months. Treatment subjects were followed for 12 months. There were 197 men randomized (active 136, control 61). Thermal therapy and control International Prostate Symptom Score was reduced by 11.2 ± 7.6 and 4.3 ± 6.9 respectively (p < 0.0001). Treatment subject baseline International Prostate Symptom Score of 22 decreased at 2 weeks (18.6, p = 0.0006) and by 50% or greater at 3, 6 and 12 months, p < 0.0001. The peak flow rate increased by 6.2 ml per second at 3 months and was sustained throughout 12 months (p < 0.0001). No de novo erectile dysfunction was reported. Adverse events were mild to moderate and resolved quickly. The investigators concluded that convective water vapor thermal therapy provides rapid and durable improvements in benign prostatic hyperplasia symptoms and preserves erectile and ejaculatory function. Treatment can be delivered in an office or hospital setting using oral pain medication and is applicable to all prostate zones including the median lobe. 

McVary and colleagues (2019) reported 4-year outcomes of the RCT of water vapor thermal therapy for the treatment of moderate-to-severe lower urinary tract symptoms due to BPH. A total 188 subjects; 135 men greater than or equal to 50 years of age, IPSS greater than or equal to 13, Qmax less than or equal to 15 ml/s and prostate volume of 30 to 80 cc treated with the Rezūm System thermal therapy were followed for 4 years; subset of 53 men who re-qualified for cross-over from control to active treatment were followed for 3 years. Lower urinary tract symptoms were significantly improved within 3 months or less following thermal therapy and remained consistently durable (IPSS 47%, QOL 43%, Qmax 50%, Benign Prostatic Hyperplasia Impact Index 52%) throughout 4 years (p < 0.0001); outcomes were similarly sustained in cross-over subjects at 3 years. Surgical re-treatment rate was 4.4% over 4 years. No disturbances in sexual function were reported. The authors concluded that minimally invasive thermal therapy provided effective symptom relief and improved QOL that remained durable for over 4 years. It is applicable to all prostate zones with procedures performed under local anesthesia in an office setting. These researchers stated that the procedure has a minimal physician learning curve and early intervention with this thermal therapy rather than use of pharmaceutical agents or invasive surgery may be an ideal option for men with moderate-to-severe LUTS at risk for BPH progression. 

Guidelines from the AAUA (Foster et al., 2019) stated that "Water vapor thermal therapy may be offered to patients with LUTS attributed to BPH provided prostate volume < 80 g; however, patients should be counseled regarding efficacy and retreatment rates." The guidelines stated that "Water vapor thermal therapy may be offered to eligible patients who desire preservation of erectile and ejaculatory function." These were "conditional recommendations" based upon evidence about which the panel has a low level of certainty (evidence level Grade C [RCTs with serious deficiencies of procedure or generalizability or extremely small sample sizes or observational studies that are inconsistent, have small sample sizes, or have other problems that potentially confound interpretation of data]). 

Transurethral Thulium Laser Ablation 
Zhu and colleagues (2015) evaluated the safety and effectiveness of thulium laser versus standard TURP for treating patients with BPO. These investigators performed a systematic search of the electronic databases, including Medline, Embase, Web of Science, and the Cochrane Library, up to Feb. 1, 2014. The pooled estimates of demographic and clinical baseline characteristics, peri-operative variables, complications, and post-operative effectiveness including IPSS, QOL, Qmax, and PVR were calculated. A total of 7 trials assessing thulium laser versus standard TURP were considered suitable for meta-analysis including 4 RCTs and 3 non-RCTs. Compared with TURP, although thulium laser prostatectomy (TmLRP) needed a longer operative time [weighted mean difference (WMD) 8.18 min; 95% CI: 1.60 to 14.75; p = 0.01], patients having TmLRP might benefit from significantly less serum sodium decreased (-3.73 mmol/L; 95% CI: -4.41 to -3.05; p < 0.001), shorter time of catheterization (WMD -1.29 days; 95% CI: -1.95 to -0.63; p < 0.001), shorter length of hospital stay (WMD -1.83 days; 95% CI: -3.10 to -0.57; p = 0.005), and less transfusion (odds ratio [OR] 0.09; 95% CI: 0.02 to 0.41; p = 0.002). During the 1, 3, and, 12 months of post-operative follow-up, the procedures did not demonstrate a significant difference in IPSS, QOL, Qmax, and PVR. The authors concluded that TmLRP had a similar efficacy to standard TURP in terms of IPSS, QOL, Qmax, and PVR, and offered several advantages over TURP in terms of blood transfusion, serum sodium decreased, catheterization time, and hospital stay, while TURP was superior in terms of operation duration. Moreover, they stated that well-designed multi-centric/international RCTs with long-term follow-up are still needed. 

Zhang et al. (2016) stated that all available surgical treatments for BPH have their individual advantages or disadvantages. However, the lack of head-to-head studies comparing different surgeries makes it unavailable to conduct direct analysis. To compare the safety and effectiveness among different lasers and TURP for BPH, RCTs were searched in Medline, Embase, Cochrane library, WHO International Clinical Trial Registration Platform, and Clinical Trial.gov by May 2015; and the effectiveness-, perioperation- and complication-related outcomes were assessed by network meta-analysis. A total of 36 studies involving 3,831 patients were included. Holmium laser through resection and enucleation had the best efficacy in Qmax. Thulium laser through vapo-resection was superior in improving IPSS and holmium laser through enucleation was the best for PVR volume improvement. Diode laser through vaporization was the rapidest in removing post-operative indwelling catheter, while TURP was the longest; TURP required the longest hospitalization and thulium laser through vapo-resection was relatively shorter. The authors concluded that holmium and thulium lasers appeared to be relatively better in surgical safety and effectiveness, so that these 2 lasers might be preferred in selection of optimal laser surgery. However, they stated that more large-scale and high quality head-to-head RCTs are needed to validate the conclusions. 

Marra and associates (2016) noted that although ejaculatory dysfunction is common for patients undergoing BPH surgery, no clear evidence is present to counsel patients seeking to preserve ejaculatory function. These investigators evaluated ejaculatory dysfunction in relation to BPH surgery. They carried out a Web and manual search using Medline and Embase including RCTs reporting ejaculatory dysfunction after BPH surgery: 42 RCTs comprising a total of 3,857 patients were included. Only 1 study had ejaculatory dysfunction as a primary outcome, and just 10 evaluated ejaculatory dysfunction before and after surgery. The definition of ejaculatory dysfunction was not standardized. Similarly, just 7 studies used internationally validated questionnaires to address ejaculatory dysfunction. The reported rates of ejaculatory dysfunction after resectional electro-surgery, laser procedures, coagulation, ablation and implant techniques were assessed and compared. Transurethral resection of the prostate and recent laser procedures including holmium, thulium and GreenLight caused similar rates of ejaculatory dysfunction, occurring in almost 3 out of 4 to 5 men. Although providing less symptomatic benefit compared with TURP, transurethral incision of the prostate, TUNA and TUMT should be considered for men aiming to maintain normal ejaculation. UroLift is also a recent promising option for this category of patients. The authors concluded that the vast majority of studies reporting ejaculatory dysfunction after BPH surgery used poor methodology to investigate this complication. They stated that future studies able to address clear hypothesis and considering ejaculatory dysfunction anatomical and pathophysiological features are needed to develop ejaculation preserving techniques and to increase the evidence to counsel men aiming to preserve ejaculation. 

Li et al. (2016) noted that LUTS/ BPH is common in adult men and can impair erectile function (EF). It was believed surgical treatments for this illness can improve EF due to the relief of LUTS while they were also reported harmed EF as heating or injury effect. Current network meta-analysis aimed to elucidate this discrepancy; RCTs were identified. Direct comparisons were conducted by STATA and network meta-analysis was conducted by Generate Mixed Treatment Comparison. Random-effects models were used to calculate pooled SMD and 95% CIs and to incorporate variation between studies. A total of 18 RCTs with 2,433 subjects were analyzed; 9 approaches were studied: TURP, plasmakinetic resection of the prostate (PKRP), plasmakinetic enucleation of the prostate (PKEP), holmium laser enucleation of the prostate (HoLEP), holmium laser resection of the prostate (HoLRP), photoselective vaporization of the prostate (PVP), Thulium laser, open prostatectomy (OP), and laparoscopic simple prostatectomy (LSP). In direct comparisons, all surgical treatments did not decrease post-operative IIEF-5 score except PVP. Moreover, patients who underwent HoLEP, PKEP, Thulium laser, and TURP had their post-operative EF significantly increased. Network analysis including direct and indirect comparisons ranked LSP at the highest position on the variation of post-operative IIEF-5 score, followed by PKRP, HoLEP, TURP, Thulium laser, PKEP, PVP, HoLRP, and OP. In subgroup analysis, only PVP was found lower post-operative EF in the short-term and decreased baseline group, whereas TURP increased post-operative IIEF-5 score only for patients with normal baseline EF. However, HoLEP and PKEP showed pro-erectile effect even for patients with decreased baseline EF and short-term follow-up. The authors concluded that their novel data demonstrating surgical treatments for LUTS/BPH showed no negative impact on post-operative EF except PVP. Moreover, HoLEP and PKEP were found pro-erectile effect for all subgroups. New technologies, such as LSP, PKRP, and Thulium laser, were ranked at top positions in the network analysis, although they had no pro-erectile effect in direct comparison due to limited original studies or poor baseline EF. They stated that further studies and longer follow-up are needed to substantiate these findings. 

Feng et al. (2016) compared the safety and effectiveness of thulium laser enucleation of the prostate (ThuLEP) with PKEP. A total of 127 patients with BPH were randomized to either ThuLEP (n = 61) or PKEP (n = 66). All patients were assessed pre-operatively and followed-up at 3, 6, and 12 months post-operatively. Baseline characteristics of the patients, peri-operative data, post-operative outcomes, and complications were recorded. The decrease in hemoglobin level and the catheter time were statistically significantly lower in the ThuLEP group compared with the PKEP group (0.80 ± 0.49 versus 0.99 ± 0.52, p = 0.037, and 1.85 ± 0.94 versus 2.28 ± 1.34, p = 0.042). There were no statistical differences in complications between the 2 groups (p > 0.05). There was a significant improvement in 3, 6, and 12 months' parameters compared with pre-operative values (p < 0.001). Assessment at the 12-month follow-up showed no difference in urinary parameters between the 2 groups. The authors concluded that ThuLEP and PKEP are both safe and efficient procedures for the treatment of patients with BPH. Compared with PKEP, ThuLEP provided less risk of hemorrhage and shorter catheter time, although the differences may be of little clinical relevance. Moreover, they stated that further well-designed trials with extended follow-up and larger sample size are needed to draw final conclusions about the effectiveness of these 2 procedures. 

Rieken et al. (2016) stated that surgical techniques are an integral part of the urologist's armamentarium for the treatment of BPO. Currently, several techniques are available. These investigators analyzed the long-term outcomes of currently available techniques. Open prostatectomy shows a low long-term re-operation rate. Available evidence suggests that bi-polar TURP is an attractive alternative to mono-polar TURP as both techniques lead to a long-lasting and comparable efficacy. For patients with a larger prostate volume, bi-polar enucleation of the prostate appears as safe and effective alternative to open prostatectomy. Holmium laser enucleation of the prostate appears as a durable alternative to TURP and open prostatectomy with comparable long-term results. For photo-selective vaporization of the prostate, differently powered models are available. Currently, only long-term data with lower powered 80 W laser are available, reporting re-operation rates higher than those reported from other surgical techniques. The authors noted that on the thulium laser, currently only 1 study reported 5-year results and despite encouraging results further confirmation seems necessary. 

In a meta-analysis, Zhao et al. (2016) compared the safety and effectiveness of thulium laser resection of prostate (ThuRP) and PKRP for BPH. A systematic search of PubMed, Web of Science, and China National Knowledge Infrastructure was performed up to Oct. 1, 2015. Outcomes of interest assessing the 2 techniques included demographic and clinical characteristics, peri-operative variables, follow-up data, and complications. A total of 9 eligible trials evaluating ThuRP versus PKRP for BPH were identified, including 6 RCTs and 3 retrospective trials. ThuRP was associated with longer operation time (p < 0.001), shorter hospital stay (p < 0.001), irrigation (p = 0.02), and catheterization (p < 0.001) duration. Estimated blood loss (p = 0.005) and drop in hemoglobin level (p = 0.02) were significantly more in PKRP. Except QOL score (p = 0.04), which was better in ThuRP, the post-operative data, including IPSS (p = 0.44), Qmax (p = 0.33), PVR urine volume (p = 0.55), and the complications such as severe bleeding (p = 0.52), temporary urinary retention (p = 0.20), temporary urinary incontinence (p = 0.64), urinary tract infection (p = 0.83), and urethral stricture (p = 0.22), did not differ significantly. The authors concluded that their analysis showed that there was no significant difference in terms of effectiveness between ThuRP and PKRP. Although ThuRP was associated with longer operation time, it possessed more safe capacity with less blood loss, shorter hospital stay, irrigation, and catheterization duration. They stated that more worldwide RCTs with long-term follow-up are still needed to support their conclusion. 

Zhuo et al. (2017) noted that the 2-μm thulium laser resection of the prostate-tangerine technique (TmLRP-TT) has been introduced as a minimally invasive treatment for BPH. These researchers evaluated the safety and effectiveness of TmLRP-TT for the treatment of BPH patients with previously negative trans-rectal prostate biopsy. A prospective analysis of 51 patients with previously negative trans-rectal prostate biopsy who underwent surgical treatment using TmLRP-TT was performed from December 2011 to December 2013. Pre-operative status, surgical details, and peri-operative complications were recorded. The follow-up outcome was evaluated with subjective and objective tests at 1 and 6 months; TmLRP-TT was successfully completed in all patients. Mean prostate volume, operative duration, and catheterization time were 93.3 ± 37.9 ml, 69.5 ± 39.5 mins, and 6.5 ± 1.3 days, respectively. The mean IPSS, QOL score, Qmax, and PVR urine volume changed notably at 6-month follow-up (22.5 ± 6.9 versus 6.1 ± 3.2, 4.8 ± 1.3 versus 1.1 ± 0.9, 7.3 ± 4.5 versus 18.9 ± 7.1 ml s-1 , and 148.7 ± 168.7 versus 28.4 ± 17.9 ml). Two (3.9 %) patients required blood transfusion peri-operatively, while 3 (5.9 %) patients experienced transient hematuria post-operatively, and 2 (3.9 %) patients received 3 days re-catheterization due to clot retention. The authors concluded that TmLRP-TT is a safe and effective minimally invasive technique for patients with previously negative trans-rectal prostate biopsy during the 6-month follow-up. They stated that this promising technology may be a feasible surgical method for previously negative trans-rectal prostate biopsy in the future. 

Tests for Diagnostic Evaluation for BPH 
An UpToDate review on "Clinical manifestations and diagnostic evaluation of benign prostatic hyperplasia" (Cunningham and Kadmon, 2017) states that "Most patients with benign prostatic hyperplasia (BPH) do not require additional testing. However, other studies may be useful in selected cases. These include urinary cytology (if bladder cancer is a concern), genitourinary ultrasonography (for evaluation of renal dysfunction or urinary tract infection), post-void residual volume (if urinary retention is a concern and prior to initiation of an anticholinergic drug), and urethrocystoscopy (for urethral stricture, bladder calculi, and bladder cancer). Other studies, including maximal urinary flow rate, pressure-flow studies, and prostate ultrasonography, are seldom indicated."  

Seldom indicated studies — These studies, which are not usually necessary in patients with BPH, may occasionally be requested or performed by a urologist: 

Prostate ultrasonography — Despite the fact that BPH often differentially occurs in the central or transitional zone of the prostate, ultrasound measurements of central zone volume do not appear to correlate better with lower urinary tract symptoms (LUTS) than measurements of total prostate volume. Total prostate volume can be measured by ultrasonography to assess disease progression, and it may be useful in selected patients when considering medical treatment with a 5-alpha-reductase inhibitor (e.g., finasteride), which reduces the size of the prostate gland, or if planning surgery. When prostate volume was compared with enucleated prostate weight in men with BPH undergoing open prostatectomy, transrectal ultrasonography slightly underestimated volume by 4.4% (95% CI: 1.7 – 10.5), whereas transabdominal ultrasonography over-estimated volume by 55.7% (95% CI: 31.8 – 79.6). This information may be helpful in interpreting different types of ultrasound in order to determine which patients should have open prostatectomies. 

Maximal urinary flow rate — Maximal urinary flow rate is performed by having the patient void into a collecting device shaped like a cone which has a flow meter embedded into its bottom. The report contains the following information: volume voided, peak and mean flow rates, and a graph of flow in ml/sec as a function of time. To reduce the variability in flow rates, the voided volume should be more than 150 ml. A pre-void bladder volume of > 250 ml with a bladder scan can help to insure that the void volume is > 150 ml. Maximal urinary flow rates > 15 ml/sec are thought to exclude clinically important bladder outlet obstruction. Maximal flow rates < 15 ml/sec are compatible with obstruction from prostatic or urethral disease; however, this finding is not diagnostic since a low flow rate can also result from bladder decompensation. In one study that included 3,140 men who with no or minimal LUTS, 54% had a peak flow rate < 15 ml/sec. However, a peak flow rate < 10 ml/sec was associated with an increased likelihood of incident LUTS (HR 1.44, 95% CI: 1.09 – 1.91). 

Pressure-flow studies — Measurement of the pressure in the bladder during voiding provides the most accurate means for determining bladder outlet obstruction; however, this test requires either transvesical or transurethral insertion of a catheter into the bladder. In a study of 108 men with obstructive symptoms in whom urine flow rates were measured and pressure-flow studies done, only 3% of those with maximal flow rates below 12 ml/sec were misclassified. This test is usually reserved for men with urinary symptoms and maximal flow rates above 15 ml/sec and those for whom the clinical manifestations are atypical and there is reason to suspect an alternative diagnosis.

Prostatic Artery Embolization for the Treatment of Benign Prostatic Hypertrophy 
Teoh and colleagues (2017) systemically reviewed the current evidence on (PAE in treating men with BPH. These researchers performed a systemic literature search in PubMed, Embase and Web of Science on May 1, 2016 without time constraints. Outcomes of interest included the changes in the IPSS, QOL score, Qmax, PVR, IIEF score, PV and PSA level. A total of 987 records were identified through database searching. After removing duplicates, screening and reviewing full-length texts, a total of 5 records remained, with 2 RCTs and 3 non-RCTs. Transurethral resection of prostate resulted in better IPSS than PAE. Open prostatectomy had better IPSS, QOL score, Qmax and PVR, but worse IIEF score than PAE at 1 year. Unilateral PAE had higher rate of poor clinical outcome than bilateral PAE, but the difference became statistically insignificant after adjusting for age; IPSS, QOL score, Qmax, PVR, IIEF score, PV and PSA did not differ between the 2 groups. PAE with 100 μm PVA particles resulted in greater reduction in PSA level, but worse IIEF score than PAE with 200 μm PVA particles; IPSS, QOL score, Qmax, PVR, PV and poor clinical outcome did not differ between the 2 groups. The authors concluded that the evidence on different aspects of PAE was limited. They stated that further studies are needed to examine the role of PAE as compared to other forms of medical and surgical treatment.

Shim and associates (2017) attempted to overcome the limitations of previous systematic reviews to determine the overall safety and efficacy of PAE compared with standard therapy. Meta-analyses were done of randomized, controlled and single group trials. Meta-regression analysis of the moderator effect was performed with single group analysis. The outcomes measured were mean changes in IPSS, QOL, Qmax, PV, PVR and PSA. Adverse events (AEs) were compared as proportional differences between the embolization group and groups receiving other therapies in comparative studies. A total of 16 studies met selection criteria and were included in the meta-analysis; 3 studies were comparative and included a total of 297 subjects, including 149 in the experimental groups and 148 in the control groups. The other 13 studies were non-comparative and included a total of 750 experimental subjects. Pooled overall standardized mean differences (SMD) for embolization in IPSS, Qmax and PV were significantly impaired in the experimental versus control groups. Overall weighted MD (WMD) for all outcomes except PSA were significantly improved from baseline by embolization treatment in non-comparative studies. Sensitivity analysis of study duration showed that all outcome measurements did not differ before versus after 6 months. The authors concluded that although there is growing evidence of the safety and efficacy of PAE for BPH, this systematic review using meta-analysis and meta-regression showed that PAE should still be considered an experimental treatment modality.

MRI-Guided Laser Focal Ablation for the Treatment of Benign Prostatic Hypertrophy
Zhang et al. (2016) stated that all available surgical treatments for benign prostatic hyperplasia (BPH) have their individual advantages or disadvantages. However, the lack of head-to-head studies comparing different surgeries makes it unavailable to conduct direct analysis. To compare the safety and effectiveness among different lasers and transurethral resection of prostate (TURP) for BPH, randomized controlled trials (RCTs) were searched in Medline, Embase, Cochrane library, WHO International Clinical Trial Registration Platform, and ClinicalTrial.gov by May 2015; and the effectiveness-, peri-operation- and complication-related outcomes were assessed by network meta-analysis. A total of 36 studies involving 3,831 patients were included. Holmium laser through resection and enucleation had the best efficacy in maximum flow rate. Thulium laser through vapo-resection was superior in improving international prostate symptom score and holmium laser through enucleation was the best for post-voiding residual volume improvement. Diode laser through vaporization was the rapidest in removing post-operative indwelling catheter, while TURP was the longest. TURP required the longest hospitalization and thulium laser through vapo-resection was relatively shorter. Holmium and thulium lasers appeared to be relatively better in surgical safety and effectiveness, so that these 2 lasers might be preferred in selection of optimal laser surgery. The authors concluded that more large-scale and high quality head-to-head RCTs are needed to validate the conclusions. This review did not mention MRI-guided laser focal ablation as a therapeutic option for BPH.

Furthermore, an up-to-date review on "Transurethral procedures for treating benign prostatic hyperplasia" (Cunningham and Kadmon, 2017) does not mention MRI-guided laser focal ablation as a therapeutic option.

Aquablation 
In a phase-2 clinical trial, Gilling et al. (2017) sought to establish the safety and effectiveness of aquablation, a novel, image guided, robotic assisted, water jet tissue ablation technology, for the treatment of benign prostatic hyperplasia (BPH). These researchers performed a prospective, single-arm, multi-center trial at 3 centers in Australia and New Zealand with 1-year follow-up. Participants were men 50 to 80 years old with moderate-to-severe lower urinary tract symptoms (LUTS) as determined by urodynamics. All patients underwent aquablation under image guidance. Primary end-points included procedural and peri-operative safety. The main clinical end-point was the change from baseline in I-PSS (International Prostate Symptom Score). Other secondary end-points included uroflow measures, prostate volume (PV) on transrectal ultrasound (TRUS) and detrusor pressure. Detrusor pressure at maximum flow was only measured at 6 months. A total of 21 men underwent aquablation at a mean age of 69.7 years (range of 62 to 78); PV was 57.2 ml (range of 30 to 102). Procedural duration averaged 38 mins with a mean aquablation treatment time of 5 mins. All but 1 subject were catheterized for 1 day only and 19 of 21 were discharged home the day after the procedure. Detrusor pressure at maximum flow decreased from 65 cm H2O at baseline to 39 cm H2O at 6 months (p < 0.0027); PV decreased from 57 ml at baseline to 35 ml (p < 0.0001). Mean I-PSS score improved from 23.0 at baseline to 6.8 at 12 months (p < 0.0001) and maximum urinary flow increased from 8.7 to 18.3 ml per second (p < 0.0001). There were no important peri-operative adverse events (AEs) No urinary incontinence (UI) developed and sexual function was preserved post-operatively. The authors concluded that the findings of this phase-II trial provided early evidence to support the safety and effectiveness of aquablation for symptomatic BPH. The main limitations of this study were its small sample size (n = 21), short-term follow-up (1 year), and the lack of a concurrent control group; and the editorial comment noted that there are still many questions yet to be resolved regarding this technology and technique. 

Desai et al. (2018) reported procedure process improvements and confirmed the preserved safety and short-term effectiveness of a second-generation Aquablation device for the treatment of LUTS attributable to BPH in 47 consecutive patients at a single institution. Baseline, peri-operative and 3-month urinary function data were collected. The mean (range) patient age was 66 (50 to 79) years, and TRUS-measured PV was 48 (20 to 118) ml. A median lobe was present in 25 patients (53 %) and 8 patients had catheter-dependent urinary retention. The mean (range) total procedure time was 35 (13 to 128) mins and the tissue resection time was 4 (1 to 10) mins; 5 Clavien-Dindo grade I/II and 5 Clavien-Dindo grade 3 complications were recorded in 8 patients. The mean (range) hospital stay was 3.1 (1 to 8) days and the mean (range) duration of urethral catheterization was 1.9 (1 to 11) days. The mean I-PSS decreased from 24.4 at baseline to 5 at 3 months; IPSS quality-of-life (QOL) score decreased from 4.5 to 0.3 points; peak urinary flow rate increased from 7.1 to 16.5 ml/s and post-void residual (PVR) urine volume decreased from 119 to 43 ml (all p < 0.01). The authors concluded that this study confirmed procedure process improvements resulting from system enhancements, with preservation of safety and effectiveness during use of a second-generation device for the treatment of LUTS attributable to BPH in the largest single-institution study conducted to-date. These researchers stated that comparative studies against established transurethral techniques will probably determine the role of Aquablation in the surgical treatment of symptomatic BPH. 

The authors stated that limitations of this study included the following. Throughout the treatment of this cohort, several parameters and treatment settings were improved to derive the best workflow. Whether these improvements affected safety or decreased symptom‐reduction efficacy in the long-term was not known. The study did not have long‐term follow‐up (many patients were from outlying rural areas and such follow‐up was not feasible); however, the focus of the study was the confirmation of device system enhancements as well as feedback on usability from multiple surgeons. Nonetheless, short‐term safety and efficacy up to 3 months were consistent with the 3‐month results reported in previous studies. Finally, for cultural reasons, the study did not include questions about sexual function, an important topic. Although previous reports have suggested preserved sexual function after Aquablation, prospective trials are underway comparing sexual function results, as well as other safety and effectiveness measures, against TURP outcomes. 

Yafi et al. (2018) noted that between September and December 2017, a total of 82 men with moderate-to-severe LUTS due to BPH and PV of 80 to 150 cc underwent Aquablation in a prospective, multi-center clinical trial in the United States. Baseline patient and clinical demographics and standardized post-operative parameters were collected and tabulated in a central independently monitored database; AEs through 3 months were adjudicated by an independent clinical events committee. Mean pre-treatment PV was 108 ± 21.1 cc. Mean operative time was 38.2 ± 14.4 mins and mean Aquablation resection time was 7.7 ± 3.3 mins. Additional electrocautery for hemostasis was not needed in any patient following Aquablation. The average length of stay (LOS) following the procedure was 1.6 ± 1.0 days. Mean pre- and 3 months post-treatment I-PSS scores were 23.7 ± 6.4 and 7.1 ± 5.1, -16.6, p < 0.01. Mean pre- and 3 months post-treatment Qmax were 9.2 ± 3.3 ml/s and 19.5 ± 13 ml/s, + 10.8 ml/s, p < 0.01. Mean pre- and 3 months post-treatment PVRs were 120.6 ± 119.1 cc and 50.6 ± 61.6 cc, -72.0 cc, p < 0.01. The observed Clavien-Dindo grade 2 or higher event rate at 3 months was 34.1 %. The authors concluded that Aquablation was a safe and effective therapeutic option for men with large prostates (80 to 150 cc) suffering from LUTS/BPH. Moreover, they stated that longer-term data are needed to validate Aquablation as a durable treatment for LUTS/BPH. The major drawbacks of this study were its short-term follow-up (3 months), relatively small sample size (n = 82); and the lack of a control group.

In a prospective, multi-center, double-blind, randomized controlled trial (RCT), Gilling et al. (2018) compared the safety and efficacy of Aquablation and trans-urethral resection of the prostate (TURP) for the treatment of LUTs related to BPH. A total of 181 patients with moderate-to-severe LUTS related to BPH underwent TURP or Aquablation. The primary efficacy end-point was the reduction in I-PSS at 6 months. The primary safety end-point was the development of Clavien-Dindo persistent grade 1, or 2 or higher operative complications. Mean total operative time was similar for Aquablation and TURP (33 versus 36 mins, p = 0.2752) but resection time was lower for Aquablation (4 versus 27 mins, p < 0.0001). At 6-month, patients treated with Aquablation and TURP experienced large I-PSS improvements. The pre-specified study non-inferiority hypothesis was satisfied (p < 0.0001). Of the patients who underwent Aquablation and TURP, 26% and 42%, respectively, experienced a primary safety end-point, which met the study primary non-inferiority safety hypothesis and subsequently demonstrated superiority (p = 0.0149). Among sexually active men the rate of anejaculation was lower in those treated with Aquablation (10% versus 36%, p = 0.0003). The authors concluded that surgical prostate resection using Aquablation showed non-inferior symptom relief compared to TURP; but with a lower risk of sexual dysfunction; larger prostates (50 to 80 ml) demonstrated a more pronounced superior safety and efficacy benefit. These researchers stated that these findings suggested that Aquablation of the prostate may be a safe and effective approach for the treatment of LUTS associated with BPB; they stated that longer term follow-up would help evaluate the clinical value of Aquablation. 

Hwang et al. (2019) stated that new, minimally invasive surgeries have emerged as alternatives to TURP for the management of LUTS in men with BPH. Aquablation is a novel, minimally invasive, water-based therapy, combining image guidance and robotics for the removal of prostatic tissue. In a Cochrane review, these investigators examined the effects of Aquablation for the treatment of LUTS in men with BPH. They performed a comprehensive search using multiple databases (the Cochrane Library, Medline, Embase, Scopus, Web of Science, and LILACS), trials registries, other sources of grey literature, and conference proceedings published up to Feb. 11, 2019, with no restrictions on the language or status of publication. They included parallel-group RCTs and cluster-RCTs, as well as non-randomized observational prospective studies with concurrent comparison groups in which participants with BPH who underwent Aquablation. Two review authors independently assessed studies for inclusion at each stage, and undertook data extraction and "risk of bias" and GRADE assessments of the certainty of the evidence. They considered review outcomes measured up to and including 12 months after randomization as short-term and beyond 12 months as long-term. These researchers included 1 RCT with 184 subjects comparing Aquablation to TURP. The mean age and I-PSS were 65.9 years and 22.6, respectively. The mean PV was 53.2 ml. They only found short-term data for all outcomes based on a single randomized trial. Primary outcomes up to 12 months, Aquablation likely resulted in a similar improvement in urologic symptom scores to TURP (mean difference (MD) -0.06, 95% confidence interval (CI): -2.51 to 2.39; participants = 174; moderate-certainty evidence). They down-graded the evidence certainty by one level due to study limitations. Aquablation may also result in similar quality of life (QOL) when compared to TURP (MD 0.27, 95% CI: -0.24 to 0.78; participants = 174, low-certainty evidence). They down-graded the evidence certainty by two levels due to study limitations and imprecision. Aquablation may result in little to no difference in major AEs (risk ratio (RR) 0.84, 95% CI: 0.31 to 2.26; participants = 181, very low-certainty evidence); but they were very uncertain of this finding. This would correspond to 15 fewer major AEs per 1,000 participants (95% CI: 64 fewer to 116 more). They down-graded the evidence certainty by one level for study limitations and two levels for imprecision. Secondary outcomes up to 12 months, Aquablation may result in little to no difference in re-treatments (RR 1.68, 95% CI: 0.18 to 15.83; participants = 181, very low-certainty evidence); but they were very uncertain of this finding. This would correspond to 10 more re-treatments per 1,000 participants (95% CI: 13 fewer to 228 more). They down-graded the evidence certainty by one level due to study limitations and two levels for imprecision. Aquablation may result in little to no difference in erectile function as measured by International Index of Erectile Function questionnaire Erectile Function domain compared to TURP (MD 2.31, 95% CI: -0.63 to 5.25; participants = 64, very low-certainty evidence), and may cause slightly less ejaculatory dysfunction than TURP, as measured by Male Sexual Health Questionnaire for Ejaculatory Dysfunction (MD 2.57, 95% CI: 0.60 to 4.53; participants = 121, very low-certainty evidence). However, they were very uncertain of both findings. These researchers down-graded the evidence certainty by two levels due to study limitations and one level for imprecision for both outcomes. They did not find other prospective, comparative studies comparing Aquablation to TURP or other procedures such as laser ablation, enucleation, or other minimally invasive therapies. The authors concluded that based on short-term (up to 12 months) follow-up, the effect of Aquablation on urological symptoms was probably similar to that of TURP (moderate-certainty evidence). The effect on QOL may also be similar (low-certainty evidence). They were very uncertain whether patients undergoing Aquablation were at higher or lower risk for major AEs (very low-certainty evidence). They were very uncertain whether Aquablation may result in little to no difference in erectile function but offer a small improvement in preservation of ejaculatory function (both very low-certainty evidence). These conclusions were based on a single study of men with a PV up to 80 ml in size. These researchers stated that longer-term data and comparisons with other modalities appeared critical to a more thorough assessment of the role of Aquablation for the treatment of LUTS in men with BPH. 

Misrai et al. (2019) noted that Aquablation has emerged as a novel ablative therapy combining image guidance and robotics for targeted waterjet adenoma resection. These researchers described a standardized technique of aquablation in the treatment of benign prostatic obstruction (BPO), and reported the peri-operative and 1-year functional outcomes obtained by multiple surgeons with no previous experience of the technique. Between September 2017 and January 2018, patients referred to 3 different urological centers for BPO surgical management were prospectively enrolled to undergo an aquablation procedure, which was performed using the AquaBeam system (Procept BioRobotics, Redwood Shores, CA) that combines transrectal prostatic image guidance and robotics bespoke tissue resection with a high-pressure saline jet. The surgeon defined the area of treatment, and the resection is executed automatically. The primary end-point was the change in total I-PSS score at 6 and 12 months. Functional outcomes were assessed at 1, 3, 6, and 12 months with I-PSS, International Index of Erectile Function (I-IEF)-15, Sexual Health Inventory for Men, and Male Sexual Health questionnaires and uroflowmetry. A total of 30 patients were enrolled in the study. The median operative time and resection time were 30.5 (24 to 35) and 4 (3.1 to 4.9) mins, respectively. The median catheterization time was 43 (23 to 49) hours. The median hospitalization stay was 2 (2 to 4) days. The I-PSS score improved to 3 (1 to 6) at the 6 months, with a mean change of 15.6 points (95% CI: 13 to 18.2); I-PSS improvements persisted at month-12. The maximum urinary flow rate improved to 20.4 (17 to 26) ml/s at 12 months. The 6-month rates of Clavien-Dindo grade 2 and 3 events were 13.3%. There were no reports of incontinence or de-novo ED. Post-operative de-novo ejaculatory dysfunction was observed in 26.7% of patients. The authors concluded that this clinical registry confirmed that aquablation was feasible, safe, and effective, and provided immediate good functional results and similar outcomes to those of prior studies despite the lack of surgeons' previous experience with the technique. These researchers stated that aquablation is feasible, safe, and reproducible with promising outcomes for treating BPH. 

Gilling and associates (2019) compared 2-year safety and efficacy outcomes after Aquablation or TURP for the treatment of LUTS related to BPH. A total of 181 patients with BPH were randomly assigned (2:1 ratio) to either Aquablation or TURP. Patients and follow-up assessors were blinded to treatment. Assessments included the IPSS, MSHQ, IIEF and uroflow. The focus of analysis was 2-year outcomes. At 2 years, IPSS scores improved by 14.7 points in the Aquablation group and 14.9 points in TURP (p = 0.8304, 95% CI: - 2.1 to 2.6 points). Two-year improvements in Qmax were large in both groups at 11.2 and 8.6 cc/s for Aquablation and TURP, respectively (p = 0.1880, 95% CI: - 1.3 to 6.4). Sexual function as assessed by MSHQ was stable in the Aquablation group and decreased slightly in the TURP group. At 2 years, PSA was reduced significantly in both groups by 0.7 and 1.2 points, respectively; the reduction was similar across groups (p = 0.1816). Surgical re-treatment rates after 12 months for Aquablation were 1.7% and 0% for TURP. Over 2 years, surgical BPH re-treatment rates were 4.3% and 1.5% (p = 0.4219), respectively. The authors concluded that 2-year efficacy outcomes after TURP and Aquablation were similar, and the rate of surgical re-treatment was low and similar to TURP; Aquablation may be an alternative for men who strongly prefer maintenance of ejaculatory function. 

Bhojani and colleagues (2019) reported 12-month safety and effectiveness outcomes of the WATERII trial, a prospective, multi-center trial of the Aquablation procedure for the treatment of men with symptomatic BPH and large-volume prostates (i.e., between 80 and 150 cc). A total of 101 men with moderate-to-severe BPH symptoms and prostate volumes of 80 to 150 cc underwent a robotic-assisted Aquablation procedure. Functional and safety outcomes were assessed at 12 months post-operatively. Mean prostate volume was 107 cc (range of 80 to 150). Mean operative time was 37 mins and mean Aquablation resection time was 8 mins. The average length of hospital stay following the procedure was 1.6 days. Mean IPSS improved from 23.2 at baseline to 6.2 at 12 months (p < 0.0001). Mean IPSS QOL improved from 4.6 at baseline to 1.3 at 12-month follow-up (p < 0.0001). Significant improvements were observed in Qmax (12-month improvement of 12.5 cc/sec) and PVR (drop of 171 cc in those with PVR greater than 100 at baseline). Antegrade ejaculation was maintained in 81% of sexually active men. No patient underwent a repeat procedure for BPH symptoms. There was a 2% de-novo incontinence rate at 12 months, and 10 patients did require a transfusion post-operatively while 5 required take back fulgurations. At 12 months, PSA reduced from 7.1 ± 5.9 ng/ml at baseline to 4.4 ± 4.3 ng/ml. The authors concluded that the Aquablation procedure was safe and effective in treating men with large prostates (80 to 150 cc) after 1 year of follow-up, with an acceptable complication rate and without a significant increase in procedure or resection time compared to smaller sized glands. 

The authors stated that that despite its merits to examine the Aquablation procedure in men with BPH and with significantly larger prostates, the main limitation of the WATERII trial was that it was a single-arm study without a control group preventing direct comparisons with those techniques. Furthermore, standardized reporting of events categorized by Clavien-Dindo (CD) scores was limited in the literature. In addition, surgeon experience with Aquablation is still relatively limited and additional experience will probably improve outcomes. Finally, while the outcomes are promising, longer follow-up are needed to confirm these findings. 

Guidelines from the AAUA (Foster et al., 2019) stated that "Aquablation may be offered to patients with LUTS attributed to BPH provided prostate volume greater than 30/less than 80 g, however, patients should be informed that long-term evidence of efficacy and re-treatment rates, remains limited. (Conditional Recommendation; Evidence Level: Grade C)." These were "conditional recommendations" based upon evidence about which the panel has a low level of certainty (evidence level Grade C [RCTs with serious deficiencies of procedure or generalizability or extremely small sample sizes or observational studies that are inconsistent, have small sample sizes, or have other problems that potentially confound interpretation of data]).

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99. Madersbacher S, Susani M, Marberger M. Thermal ablation of BPH with transrectal high-intensity focused ultrasound. Prog Clin Biol Res. 1994;386:473-478.
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106. McNicholas TA, Woo HH, Chin PT, et al. Minimally invasive prostatic urethral lift: Surgical technique and multinational experience. Eur Urol. 2013;64(2):292-299.
107. McVary KT. Surgical treatment of benign prostatic hyperplasia (BPH). UpToDate [online serial]. Waltham, MA: UpToDate; reviewed May 2020; November 2020.
108. McVary KT, Gange SN, Gittelman MC, et al. Minimally invasive prostate convective water vapor energy ablation: A multicenter, randomized, controlled study for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia. J Urol. 2016;195(5):1529-1538.
109. McVary KT, Gange SN, Shore ND, et al; L.I.F.T. Study Investigators. Treatment of LUTS secondary to BPH while preserving sexual function: Randomized controlled study of prostatic urethral lift. J Sex Med. 2014;11(1):279-287.
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112. McVary KT, Rogers T, Roehrborn CG. Rezūm water vapor thermal therapy for lower urinary tract symptoms associated with benign prostatic hyperplasia: 4-year results from randomized controlled study. Urology. 2019;126:171-179.
113. McVary KT, Saini R. Lower urinary tract symptoms in men. UpToDate [online serial]. Waltham, MA: UpToDate; reviewed September 2018.
114. Medical Services Advisory Committee (MSAC). TransUrethral Needle Ablation (TUNA) for the treatment of benign prostatic hyperplasia. MSAC Application 1014. Canberra, ACT: MSAC; 2002.
115. Milroy E, Allen A. Long-term results of urolume urethral stent for recurrent urethral strictures. J Urol. 1996;155(3):904-908.
116. Misrai V, Rijo E, Zorn KC, et al. Waterjet ablation therapy for treating benign prostatic obstruction in patients with small- to medium-size glands: 12-month results of the first French Aquablation clinical registry. Eur Urol. 2019;76(5):667-675.
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122. Nair SM, Pimentel MA, Gilling PJ. Evolving and investigational therapies for benign prostatic hyperplasia. Can J Urol. 2015;22(5 Suppl 1):82-87.
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124. Naslund MJ. Transurethral needle ablation of the prostate. Urology. 1997;50(2):167-172.
125. Naspro R, Bachmann A, Gilling P, et al. A review of the recent evidence (2006-2008) for 532-nm photoselective laser vaporisation and holmium laser enucleation of the prostate. Eur Urol. 2009;55(6):1345-1357.
126. Naspro R, Salonia A, Colombo R, et al. Update of the minimally invasive therapies for benign prostatic hyperplasia. Curr Opin Urol. 2005;15(1):49-53.
127. National Institute for Clinical Excellence (NICE). KTP laser (60-80W) vaporisation of the prostate. Interventional Procedure Consultation Document. London, UK: NICE; June 2003. 
128. National Institute for Clinical Excellence (NICE). Transurethral electrovaporisation of the prostate. Interventional Procedure Consultation Document 14. London, UK: NICE; October 2003. 
129. National Institute for Clinical Excellence (NICE). Transurethral radiofrequency needle ablation of the prostate. Interventional Procedure Guidance 15. London, UK: NICE; October 2003. 
130. National Institute for Health and Clinical Excellence (NICE). Insertion of prostatic urethral lift implants to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia. Interventional Procedure Guidance 475. London, UK: NICE; January 2014.
131. National Institute for Health and Clinical Excellence (NICE). Laparoscopic prostatectomy for benign prostatic obstruction. Interventional Procedure Guidance 275. London, UK: NICE; November 2008.
132. National Institute for Health and Clinical Excellence (NICE). Potassium-titanyl-phosphate (KTP) laser vaporisation of the prostate for benign prostatic obstruction. Interventional Procedure Guidance 120. London, UK: NICE; May 2005.
133. National Institute for Health and Clinical Excellence (NICE). Transurethral electrovaporisation of the prostate, guidance. Interventional Procedure Guidance 14. London, UK: NICE; October 2003. Available at: http://www.nice.org.uk/page.aspx?o=ipg014guidance. Accessed January 26, 2007.
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135. Ogden CW, Reddy P, Johnson H, et al. Sham versus transurethral microwave thermotherapy in patients with symptoms of benign prostatic bladder outflow obstruction. Lancet. 1993;341(8836):14-17.
136. Ogiste JS, Cooper K, Kaplan SA. Are stents still a useful therapy for benign prostatic hyperplasia? Curr Opin Urol. 2003;13(1):51-57.
137. O'Leary MP, Roehrborn CG, Black L. Dutasteride significantly improves quality of life measures in patients with enlarged prostate. Prostate Cancer Prostatic Dis. 2008;11(2):129-133.
138. Ontario Ministry of Health and Long-Term Care, Medical Advisory Secretariat (MAS). Energy delivery systems for treatment of benign prostatic hyperplasia: Health Technology Policy Assessment. Toronto, ON: MAS; August 2006.
139. Paz-Valinas L, Atienza G. Holmium laser enucleation of benign prostatic hyperplasia [summary]. CT2009/01. Santiago de ComPostela, Spain: Galician Agency for Health Technology Assessment (AVALIA-T); March 2009.
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141. Petas A, Isotalo T, Talja M, et al. A randomised study to evaluate the efficacy of a biodegradable stent in the prevention of postoperative urinary retention after interstitial laser coagulation of the prostate. Scand J Urol Nephrol. 2000;34(4):262-266.
142. Petrovich Z, Ameye F, Baert L, et al. New trends in the treatment of benign prostatic hyperplasia and carcinoma of the prostate. Am J Clin Oncol. 1993;16(3):187-200.
143. Pisco J, Bilhim T, Pinheiro LC, et al. Prostate embolization as an alternative to open surgery in patients with large prostate and moderate to severe lower urinary tract symptoms. J Vasc Interv Radiol. 2016a;27(5):700-708.
144. Pisco J, Campos Pinheiro L, Bilhim T, et al. Prostatic arterial embolization for benign prostatic hyperplasia: Short- and intermediate-term results. Radiology. 2013;266(2):668-677.
145. Pizzoccaro M, Cantanzaro M, Stubinski R, et al. [The use of temporary stents in the treatment of urethral stenosis]. Arch Ital Urol Androl. 2002;74(3):111-112.
146. Plante MK, Bunnell ML, Trotter SJ, et al. Transurethral prostatic tissue ablation via a single needle delivery system: Initial experience with radio-frequency energy and ethanol. Prostate Cancer Prostatic Dis. 2002;5(3):183-188.
147. Presti JC Jr., et al. Urology. In: Current Medical Diagnosis & Treatment. 38th Ed. LM Tierney, Jr et al., eds. Stamford, CT. Appleton & Lange; 1999; Ch. 23:894-931.
148. Ramon J, Lynch TH, Eardley I, et al. Transurethral needle ablation of the prostate for the treatment of benign prostate hyperplasia: A collaborative multicentre study. Br J Urol. 1997;80(1):128-134.
149. Ramsey EW. Office treatment of benign prostatic hyperplasia. Urol Clin North Am. 1998;25(4):571-580.
150. Ray AF, Powell J, Speakman MJ, et al. Efficacy and safety of prostate artery embolization for benign prostatic hyperplasia: an observational study and propensity-matched comparison with transurethral resection of the prostate (the UK-ROPE study). BJU Int. 2018;122(2):270-282.
151. Reale G, Cimino S, Bruno G, et al. "Aquabeam® System" for benign prostatic hyperplasia and LUTS: Birth of a new era. A systematic review of functional and sexual outcome and adverse events of the technique. Int J Impot Res. 2019;31(1):1-8.
152. Richter M, Schwarz J, De Geeter P, Albers P. Holmium laser ablation of the prostate. An alternative to GreenLight photoselective vaporization of the prostate. Urologe A. 2009;48(3):291-295.
153. Rieken M, Bachmann A, Shariat SF. Long-term follow-up data more than 5 years after surgical management of benign prostate obstruction: Who stands the test of time? Curr Opin Urol. 2016;26(1):22-27.
154. Roehrborn CG, Gange SN, Gittelman MC, et al. Convective thermal therapy: Durable 2-year results of randomized controlled and prospective crossover studies for treatment of lower urinary tract symptoms due to benign prostatic hyperplasia. J Urol. 2017;197(6):1507-1516.
155. Roehrborn CG, Gange SN, Shore ND, et al. The prostatic urethral lift for the treatment of lower urinary tract symptoms associated with prostate enlargement due to benign prostatic hyperplasia: The L.I.f.T. Study. J Urol. 2013;190(6):2161-2167.
156. Rosario DJ, Woo H, Potts KL, et al. Safety and efficacy of transurethral needle ablation of the prostate for symptomatic outlet obstruction. Br J Urol. 1997;80(4):579-586.
157. Ruszat R, Wyler SF, Seitz M, et al. Comparison of potassium-titanyl-phosphate laser vaporization of the prostate and transurethral resection of the prostate: Update of a prospective non-randomized two-centre study. BJU Int. 2008;102(10):1432-1438; discussion 1438-1439.
158. Schulman CC, Vanden Bossche M. Hyperthermia and thermotherapy of benign prostatic hyperplasia: A critical review. Eur Urol. 1993;23 Suppl 1:53-59.
159. Sertcelik N, Sagnak L, Imamoglu A, et al. The use of self-expanding metallic urethral stents in the treatment of recurrent bulbar urethral strictures: Long-term results. BJU Int. 2000;86(6):686-689.
160. Shim SR, Kanhai KJ, Ko YM, Kim JH. Efficacy and safety of prostatic arterial embolization: Systematic review with meta-analysis and meta-regression. J Urol. 2017;197(2):465-479.
161. Shore ND, Dineen MK, Saslawsky MJ, et al. A temporary intraurethral prostatic stent relieves prostatic obstruction following transurethral microwave thermotherapy. J Urol. 2007;177(3):1040-1046.
162. Steele GS, Sleep DJ. Transurethral needle ablation of the prostate: A urodynamic based study with 2-year follow-up. J Urol. 1997;158(5):1834-1838.
163. Stein BS. Neodymium:yttrium-aluminum-garnet laser prostatectomy. Mayo Clin Proc. 1998;73(8):787-791.
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165. Talja M, Tammela T, Petas A, et al. Biodegradable self-reinforced polyglycolic acid spiral stent in prevention of postoperative urinary retention after visual laser ablation of the prostate-laser prostatectomy. J Urol. 1995;154(6):2089-2092.
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167. Tan AH, Gilling PJ. Lasers in the treatment of benign prostatic hyperplasia: An update. Curr Opin Urol. 2005;15(1):55-58.
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169. Teoh JY, Chiu PK, Yee CH, et al. Prostatic artery embolization in treating benign prostatic hyperplasia: A systematic review. Int Urol Nephrol. 2017;49(2):197-203.
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174. Van Cleynenbreugel B, Srirangam SJ, Van Poppel H. High-performance system GreenLight laser: Indications and outcomes. Curr Opin Urol. 2009;19(1):33-37.
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177. Virasoro R, DeLong JM, Mann RA, et al. A drug-coated balloon treatment for urethral stricture disease: Interim results from the ROBUST I study. Can Urol Assoc J. 2020;14(6):187-191.
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Coding Section 

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies and accredited national guidelines.

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