Aquablation therapy in large prostates (80–150 cc) for lower urinary tract symptoms due to benign prostatic hyperplasia: WATER II 3‐year trial results

Abstract Objective The objective of this study is to determine if Aquablation therapy can maintain its effectiveness in treating men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) with large‐volume (80–150 cc) prostates at 3 years. Subjects and Methods One hundred one men with moderate‐to‐severe BPH symptoms and prostate volumes between 80 and 150 cc were enrolled in a prospective, nonrandomized, multicenter, international clinical trial in late 2017. Baseline, procedural, and follow‐up parameters were recorded at baseline and scheduled postoperative visits. IPSS, Qmax, and treatment failure are reported at 3 years. Results The mean prostate volume was 107 cc (range 80–150). Mean IPSS improved from 23.2 at baseline to 6.5 at 3 years (16.3‐point improvement, p < 0.0001). Mean IPSS quality of life improved from 4.6 at baseline to 1.1 at 3 years (improvement of 3.4 points, p < 0.0001). Maximum urinary flow increased from 8.7 to 18.5 cc/s. At 3 year follow‐up, 6% of treated patients needed BPH medication and an additional 3% required surgical retreatment for LUTS. Conclusions Three‐year follow‐up demonstrates a sustained symptom reduction response along with low irreversible complications to Aquablation in men with LUTS due to BPH and prostates of 80–150 cc. Current treatment options available for men with prostates of this size have similar efficacy outcomes but are burdened with high rates of irreversible complications. There are now numerous clinical studies with Aquablation used in various prostates sizes, and it should be offered as an option to men with LUTS due to BPH.

and larger (80-150 cc) prostates. 2,3 Postmarket studies have confirmed these findings. 4,5 Studies have shown persistent improvements in symptoms related to BPH, uroflow measures, and quality of life (QOL). Surgical revision rates have been found to be approximately 1% per year. 3,4,6 Compared with TURP, the Aquablation procedure has a lower rate of postoperative ejaculatory dysfunction for small (30-80 cc) and large (80-150 cc) prostate glands. 1,7 Alternative surgical management options for men with larger prostates are limited. Simple open prostatectomy carries increased surgical risks and transurethral resective procedures for large prostates can be very long along with increased risk of bleeding, transfusions, and retreatment. Moreover, while holmium laser enucleation of the prostate (HoLEP) is globally accepted as a gold standard endoscopic treatment for large-volume prostates, its skillset and practice remain limited to few urologists. 8,9 By leverage imaging, software, and robotics, Aquablation has standardized the procedure regardless of prostate size that results in a short learning curve and reproducible, consistent operating times. 10 Herein, we report 3-year outcomes in men with larger (80-150 cc) prostates who underwent the Aquablation procedure as part of a prospective multicenter clinical trial.  The Aquablation procedure was performed using the AQUABEAM System (PROCEPT BioRobotics, Redwood City, California, USA). 14 Briefly, after induction of general or spinal anesthesia, a 24F singleuse handpiece was inserted into the prostatic urethra and secured into place using a bed-mounted arm. Using real-time transrectal ultrasound guidance, the surgeon defined the target anatomic resection contour on a computer console. Contours were selected to avoid damage to the bladder neck, ejaculatory ducts, and urinary sphincter. Furthermore, apical treatment was also planned ipsilaterally to ensure no injury to the verumontanum and its underlying ejaculatory ducts (butterfly cuts). Tissue was then treated utilizing an automated, roboticexecuted, high-velocity waterjet with up to 2.4-cm treatment depth.
For larger prostates, the Aquablation procedure typically required two treatment passes of the AQUABEAM probe for larger tissue removal.
Post-Aquablation, the bladder was irrigated using a 24-27 resectoscope sheath along with a Toomey syringe. Thereafter, hemostasis was delivered via low-pressure tamponade with a standard three-way 24 French hematuria Foley catheter inflated to 40-80 cc of saline either at the bladder neck (98 cases) or within the prostatic fossa (three cases), followed by continuous bladder irrigation as previously described, followed by use of the continuous traction device. 15 The continuous traction device was designed for the specific purpose to hold catheter traction. Catheter traction was held for an average of 18 h in this study. Unlike contemporary Aquablation treatment series, 16 it is noteworthy that no cases utilized electrocautery for hemostasis.

| Data monitoring
All study data were collected using an electronic data capture system. Study data were 100% source-verified by study monitors.

| Statistical analysis
Changes in continuous measures were assessed using t tests and/or repeated measures analysis of variance. Exact binomial methods were used to calculate confidence intervals for proportions. All statistical analysis was performed using R, 17 and a p value of <0.05 was considered clinically significant.

| RESULTS
In the original study, 101 men were enrolled at 16 sites (24 surgeons) between September and December 2017. Consent for study extension at all 16 sites was obtained in 86 subjects (85%).
Baseline patient characteristics (n = 101) are summarized in  After Year 2, no subject underwent a surgical procedure for urethral stricture, bladder neck contracture, or urinary incontinence. The number of urologic events was small with no remarkable difference compared to previous results ( Table 2).