Stress urinary incontinence (SUI) following holmium laser enucleation of the prostate (HoLEP) remains one of the most vexing side effects for both surgeons and patients. Although temporary in most cases, it often diminishes—albeit briefly—the quality-of-life benefits otherwise offered by this highly effective procedure. In efforts to minimize postoperative SUI, the endoscopic appearance of the membranous urethral mucosa (MUM) at the end of HoLEP has been widely—though perhaps uncritically—adopted as a surrogate marker for external urethral sphincter (EUS) preservation. Our study, driven by the lack of robust clinical validation for this assumption, set out to challenge the reliability of this visual marker.
In a prospective analysis involving 40 patients and AI-based video segmentation of surgical footage, we examined the interobserver consistency of MUM grading and its correlation with postoperative continence outcomes. Despite a structured evaluation involving experienced surgeons and residents, we found only weak inter-rater agreement (κ = 0.26 overall), underscoring the highly subjective nature of MUM appearance grading. More importantly, there was no significant correlation between the endoscopic MUM grade and actual SUI rates at either 1 or 3 months postoperatively.
It is important to emphasize that our findings do not discount the potential importance of MUM preservation, nor do we in any way advocate for disregard or injury to this structure. On the contrary, surgical techniques that minimize trauma to the membranous urethra and the surrounding sphincter complex remain a prudent goal in HoLEP. Our study merely underscores that the visual endoscopic appearance of the MUM is not a reliable or reproducible surrogate for functional EUS integrity, nor a valid predictor of postoperative continence.
We suggest that visual assessment of the MUM at the end of HoLEP—though appealing in its simplicity—is neither reproducible nor clinically reliable as a predictor of SUI. While these results may be counterintuitive to those who have long relied on MUM appearance as an intraoperative checkpoint, they call for a re-evaluation of long-standing assumptions in endoscopic enucleation. It is increasingly clear that postoperative continence is influenced by a multifactorial interplay, including radial forces exerted by the resectoscope, pre-existing detrusor dysfunction, prostate volume, and individual anatomical variation—factors not captured by mucosal imaging alone.
The implications of this study are twofold: first, it challenges the over-reliance on a subjective visual marker that lacks interobserver reliability; second, it highlights the need for objective, reproducible, and functionally relevant intraoperative tools—possibly electrophysiological or biomechanical—to more accurately predict and prevent postoperative incontinence.
- Department of Urology, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel.
- Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel.