# Emerging Minimally Invasive BPH Therapies

## Introduction

Minimally invasive surgical therapies (MISTs) for benign prostatic hyperplasia (BPH) have been developed to fill the treatment gap between medical management and traditional surgical procedures such as transurethral resection of the prostate (TURP) and laser enucleation. These procedures, often performed in office or ambulatory settings, aim to relieve urinary obstruction while preserving sexual function—particularly ejaculatory function—with reduced morbidity and faster recovery times. The American Urological Association (AUA) guidelines now recognize several MIST options for select patients experiencing moderate-to-severe lower urinary tract symptoms (LUTS).

## Prostatic Urethral Lift (UroLift/iTind)

### UroLift System

The UroLift system employs permanent implants composed of a nickel-titanium capsular tab and a stainless steel urethral end piece to mechanically compress the lateral prostatic lobes. This action opens the urethral lumen without removing tissue or causing thermal injury. The procedure is performed cystoscopically under local anesthesia or light sedation, with typically four to six implants placed. Ideal candidates have prostates sized between 30 and 80 grams with lateral lobe obstruction and no obstructing median lobe, although indications have expanded to include selected median lobe treatments.

Outcomes from the L.I.F.T. study with five-year follow-up demonstrate a sustained 36% improvement in the International Prostate Symptom Score (IPSS) and a 44% increase in maximum urinary flow rate (Qmax). The retreatment rate requiring surgical reintervention was 13.6% at five years. A key advantage of UroLift is its preservation of ejaculatory function, supported by Level 1 evidence showing no impact on antegrade ejaculation. However, its durability is inferior compared to TURP or holmium laser enucleation of the prostate (HoLEP), it is not suitable for very large prostates, and it has a higher retreatment rate.

### iTind (Temporary Implantable Nitinol Device)

The iTind device is a temporary nitinol implant placed in the prostatic urethra. Over five to seven days, it expands to create channels through ischemic pressure necrosis at the bladder neck and lateral lobes, after which it is removed. Placement and removal are performed cystoscopically in the clinic. Clinical outcomes show an IPSS improvement of 10 to 12 points and a Qmax increase of 4 to 5 mL/s at three years. Like UroLift, iTind preserves ejaculatory function and leaves no permanent implant behind. However, it is a newer technique with limited long-term data but growing evidence supporting its use.

## Convective Water Vapor Thermal Therapy (Rezum)

### Mechanism and Technique

Rezum therapy utilizes radiofrequency-generated water vapor at 103°C, which is injected into the prostatic transition zone via a handheld transurethral delivery device. The steam disperses through tissue interstices, condenses on cell membranes, and releases stored thermal energy—540 calories per gram of water—causing immediate cell death followed by tissue remodeling. Each injection treats approximately 1 to 2 cm of tissue, with typically three to eight injections depending on prostate anatomy. Unlike UroLift, Rezum can treat both lateral and median lobes. The procedure is performed in the clinic under local anesthesia with a prostate block or in an ambulatory setting.

### Patient Selection

Rezum is FDA-approved for prostates sized between 30 and 80 grams and is effective for median lobe obstruction. It is particularly suitable for men who prioritize preservation of sexual function.

### Outcomes

Data from the WAVE study with five-year follow-up show a 50% reduction in IPSS sustained at five years and an approximately 50% improvement in Qmax. Ejaculatory function is preserved in over 90% of patients, with no new onset erectile dysfunction and stable ejaculatory bother scores. The retreatment rate at five years is 4.4%.

### Recovery

Post-procedure, a catheter is typically required for a median duration of three to five days, although some patients may need it for up to two weeks. Patients often experience transient irritative LUTS such as dysuria, frequency, and urgency for two to four weeks during tissue remodeling. Full symptomatic benefit is usually realized by three months as necrotic tissue is resorbed.

<image>Illustration of the Rezum water vapor therapy mechanism showing: (1) transurethral device positioned in the prostatic urethra, (2) retractable needle deployed into the transition zone adenoma, (3) radiofrequency-generated steam being injected into tissue with thermal energy dispersal zone marked, and (4) cross-section of prostate showing tissue necrosis and subsequent cavity formation at 3 months post-treatment</image>

## Aquablation (AquaBeam Robotic System)

### Mechanism and Technique

Aquablation uses a high-velocity waterjet to ablate prostatic tissue, guided by real-time transrectal ultrasound (TRUS). The robotic system maps the treatment area on TRUS, allowing the surgeon to define resection boundaries. The automated resection minimizes operator variability. Tissue removal is heat-free, as no thermal energy is applied during ablation. The handpiece delivers a saline jet at a controlled depth and angle through a rigid cystoscope. Hemostasis is achieved separately after resection, using TURP-style electrocautery or balloon tamponade.

### Patient Selection

Aquablation is FDA-approved for prostates ranging from 30 to 150 grams, offering a broader size range than most MISTs. It is particularly advantageous for large prostates between 80 and 150 grams, providing results equivalent to TURP without prolonged resection times. The technique effectively treats median lobe pathology.

### Outcomes

The WATER trial, which included prostates sized 30 to 80 grams, demonstrated that Aquablation is non-inferior to TURP in IPSS improvement and Qmax at two years. The WATER II trial, focusing on prostates 80 to 150 grams, showed an IPSS improvement of 17 points and a Qmax increase of 12 mL/s at three years. Ejaculatory function preservation was significantly higher compared to TURP (75% versus 25%). The retreatment rate was 4.5% at three years in the WATER trial.

### Considerations

Aquablation requires general or spinal anesthesia and is not an office-based procedure. Achieving hemostasis remains a challenge, with cautery or balloon tamponade required post-resection; early experiences noted a slightly higher bleeding complication rate compared to TURP. The procedure requires coordination between a urologist and a TRUS operator. An advantage of Aquablation is that tissue is obtained for pathological examination, unlike vaporization-based or thermal techniques.

<image>Diagram of the Aquablation system showing the robotic arm with waterjet handpiece inserted through a cystoscope into the prostatic urethra, with a simultaneous transrectal ultrasound probe displaying the mapped treatment boundaries on the console screen, and the high-velocity saline jet ablating tissue along the pre-planned resection zone</image>

## Prostatic Artery Embolization (PAE)

Prostatic artery embolization is an interventional radiology procedure involving selective embolization of prostatic arteries using microspheres delivered via a microcatheter. This induces prostatic ischemia and subsequent volume reduction of 15 to 30% at 12 months. It is typically offered to men who are poor surgical candidates or decline surgery, with moderate-to-severe LUTS and prostates larger than 40 grams.

Outcomes include an IPSS improvement of 10 to 15 points and a Qmax increase of 5 to 8 mL/s, although efficacy is inferior to TURP in head-to-head trials. Complications can include post-embolization syndrome characterized by pain and fever, rare non-target embolization causing bladder or rectal ischemia, and access-site hematoma. The AUA lists PAE as an option but acknowledges its inferior efficacy compared to established surgical therapies. Most patients preserve ejaculatory function following PAE.

## Comparative Summary

When comparing these therapies, UroLift and Rezum are performed under local anesthesia or sedation, while Aquablation requires general or spinal anesthesia, and PAE is done under sedation. UroLift and Rezum are suitable for prostates between 30 and 80 grams, Aquablation covers a broader range of 30 to 150 grams, and PAE is typically used for prostates larger than 40 grams. Both Rezum and Aquablation can treat median lobe obstruction, whereas UroLift has limited median lobe indications, and PAE can address median lobe pathology.

Only Aquablation provides tissue specimens for pathological analysis. Ejaculatory function is preserved in over 95% of UroLift patients, over 90% with Rezum, approximately 75% with Aquablation, and over 90% with PAE. Catheter duration varies, with UroLift patients often requiring none to three days, Rezum patients three to seven days, Aquablation one to two days, and PAE zero to three days. Retreatment rates at five years approximate 14% for UroLift, 4% for Rezum, 5% for Aquablation, and 15 to 20% for PAE.

| Feature | UroLift | Rezum | Aquablation | PAE |
|---|---|---|---|---|
| Anesthesia | Local/sedation | Local/sedation | General/spinal | Sedation |
| Prostate Size (g) | 30-80 | 30-80 | 30-150 | >40 |
| Median Lobe | Limited | Yes | Yes | Yes |
| Ejaculation Preserved | >95% | >90% | ~75% | >90% |
| Tissue Specimen | No | No | Yes | No |
| Catheter Duration | 0-3 days | 3-7 days | 1-2 days | 0-3 days |
| 5-Year Retreatment | ~14% | ~4% | ~5% | 15-20% |

<image>Side-by-side anatomic cross-sections of the prostate showing the mechanism of action for four minimally invasive BPH therapies: UroLift (mechanical compression with implants), Rezum (steam-induced thermal necrosis zones), Aquablation (waterjet tissue resection cavity), and PAE (embolized prostatic arteries with ischemic tissue), each with before-and-after urethral lumen comparison</image>

## Key Clinical Pearls

Preservation of ejaculatory function is the primary reason patients and clinicians choose MISTs over TURP, so it is essential to counsel patients about the tradeoff between durability and sexual function preservation. Rezum stands out as the most versatile office-based MIST, capable of treating both lateral and median lobes while preserving sexual function and demonstrating favorable five-year durability. UroLift offers the strongest evidence for ejaculatory function preservation but has the highest retreatment rate among MISTs. Aquablation fills an important niche for large prostates between 80 and 150 grams, where TURP is less optimal and HoLEP may not be available. All MISTs have less robust long-term data compared to TURP, so patients must understand the potential need for retreatment. Ultimately, selection of a MIST should be individualized based on prostate size, anatomy—particularly median lobe presence—sexual function priorities, anesthesia tolerance, and available expertise.

## References

1. Roehrborn CG, Barkin J, Gange SN, et al. Five-year results of the prospective randomized controlled prostatic urethral L.I.F.T. study. *Can J Urol*. 2017;24(3):8802-8813.  
2. McVary KT, Rogers T, Roehrborn CG. Rezum 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.  
3. Gilling P, Barber N, Bidair M, et al. WATER: a double-blind, randomized, controlled trial of Aquablation vs transurethral resection of the prostate in benign prostatic hyperplasia. *J Urol*. 2018;199(5):1252-1261.  
4. Ray AF, Powell J, Woolfall K, et al. Efficacy and safety of prostate artery embolisation for benign prostatic hyperplasia: an observational study and propensity-matched comparison with transurethral resection of the prostate (UK-ROPE study). *BJU Int*. 2018;122(2):270-282.