Saline-assisted Fascial Exposure Microultrasound-guided Nerve Preservation During Robotic Prostatectomy: Interim Analysis of a Randomized Controlled Trial
In brief
Ultrasound-guided hydrodissection doubles 6-week erectile recovery after prostatectomy
In a randomized trial of 107 men, the SAFE technique raised erectile function at 6 weeks from 21% to 37% compared with standard robotic prostatectomy, though the 6-month recovery rate (52% vs 43%) did not meet the prespecified efficacy threshold. Safety and cancer control were unchanged, but longer follow-up is needed to confirm lasting benefit.
- Journal
- European urology oncology (Q1)
- Published
- 8 August 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Adriana M Pedraza, Monali Fatterpekar, Himanshu Joshi, Manish Choudhary, Coskun Kacagan, Asher Mandel, et al.
- PMID
- 42570880
- DOI
- 10.1016/j.euo.2026.07.015
Why clinicians should know about it
- Picked for Urology (paper of the day, 11 August 2026): SAFE technique RCT interim analysis for nerve preservation
Abstract
BACKGROUND: Erectile dysfunction remains a major morbidity after radical prostatectomy. The SAFE technique uses real-time, micro-ultrasound-guided low-pressure hydrodissection to enable atraumatic nerve sparing. OBJECTIVE: We compared functional and oncologic outcomes of SAFE versus standard robotic-assisted radical prostatectomy (RARP). DESIGN, SETTING, AND PARTICIPANTS: In this randomized trial, patients were assigned 1:1 to micro-ultrasound-guided SAFE-RARP or standard RARP. Surgeons were unblinded; patients and outcome assessors were blinded. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was erectile function recovery at 6 mo (SHIM ≥17), with secondary functional and oncologic outcomes. The primary endpoint was assessed at the prespecified interim analysis using a one-sided pooled z-test within a group-sequential O'Brien-Fleming α-spending framework (interim efficacy boundary, one-sided p < 0.002). RESULTS AND LIMITATIONS: A total of 107 patients were analyzed (SAFE, n = 54; control, n = 53). At 6 mo, erectile function recovery was higher with SAFE than with standard RARP (52% vs 43%; absolute difference 8.5%, 95% CI -10% to 27%; one-sided p = 0.22), without crossing the prespecified interim efficacy boundary. At 6 weeks, early recovery rates were higher with SAFE (37% vs 21%; one-sided p = 0.032), with a smaller difference at 3 mo. Linear mixed-effects modeling showed earlier improvement in SHIM with SAFE, with convergence by 6 mo. Continence, oncologic outcomes, and complication rates were similar between groups. Limitations include the prespecified interim nature of the analysis, the relatively small sample size, and the need for longer follow-up to determine the durability and clinical significance of functional differences. CONCLUSIONS: In this prespecified interim analysis, the primary endpoint of 6-mo recovery was not met. Exploratory analyses suggested earlier postoperative recovery with SAFE, without evidence of compromised safety or oncologic outcomes; these findings are hypothesis-generating.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.