Waterjet ablation therapy vs. urethral-sparing robot-assisted simple prostatectomy for large prostate volumes (>80 mL): results of a retrospective multicentric series according to the standardized BPH6 achievement

BACKGROUND: The introduction of minimally invasive techniques for BPH treatment aimed to balance de-obstruction with maintenance of ejaculatory function. The aim of this multicentric series was to compare outcomes of waterjet ablation therapy (WAT) versus urethral-sparing robot assisted simple prostatectomy (us-RASP) for large prostate volumes (PV>80 mL) according to BPH-6 metric. METHODS: Four institutional BPH datasets were matched and queried for "PV>80 mL" (N.=86), "WAT" (Group A; N.=42) and "us-RASP" (Group B; N.=44). Baseline, perioperative and functional data according to BPH6 composite endpoint were compared between groups. Differences between continuous variables were assessed with t-test or Mann-Whitney U-test depending on their normal or not normal distribution, while Chi-square Test was used for categorical data. A two-sided P<0.05 was considered significant. RESULTS: Patients treated with WAT showed lower preoperative PSA median values (3.5 vs. 7.07 ng/mL) (P<0.05). Regarding perioperative outcomes, patients treated with us-RASP revealed increased median operative time (110 vs. 70 mins), prolonged bladder irrigation time (24 vs. 37.2 hours), longer median hospital stay (5 vs. 4 days), respectively (all P<0.05). At a median follow-up of 43.7 months (IQR 33.8-49.7), the BPH6 achievement rate was comparable between groups (54.7% vs. 56.8%; P=0.964). In the WAT series 1-year ejaculatory dysfunction rate was 19.1% while in the us-RASP cohort was 13.6%, respectively (P=0.21). Retrospective design and the lack of a propensity-score matching represent main limitations of this study. CONCLUSIONS: Compared to us-RASP, WAT showed comparable symptom relief and ejaculatory function preservation for prostate gland >80 mL with benefit in terms of main perioperative outcomes at mid-term follow-up.