Impact of Urethral Stump Length on Continence and Positive Surgical Margins in Robot-Assisted Laparoscopic Prostatectomy

IntroductionWe previously reported the benefit of meticulous apical dissection in reducing positive surgical margins (SM+) at the apex. Herein we assess whether a more aggressive urethral transection will reduce positive margins and whether reduced urethral length affects return to continence.Technical ConsiderationsAll data were collected prospectively. A positive surgical margin was defined by the presence of cancer cells with ink on them. Continence, defined as no pads, was assessed with validated Expanded Prostate Cancer Instrument Composite questionnaires. Evaluation of 200 consecutive cases (group 1) revealed that 75% of surgical margins occurred at the apex. Concomitantly we assessed visual cues for urethral length, which demonstrated that even patients with very short urethral stumps requiring perineal pressure during anastomosis had equivalent times to continence as those with long, accessible stumps. We altered the point of transection, distally, to include 3 to 6 mm more of striated external urethral sphincter. The SM+ rate and time to continence for the ensuing 200 cases (group 2) were tracked. The overall SM+ and apical SM+ rates were significantly reduced (SM+ 17.6% versus 7.5%, P = 0.003; and apical SM+ 13% versus 5.5%, P = 0.01). Kaplan-Meier times to continence curves were not significantly different.ConclusionsA more aggressive apical resection resulted in marked reduction in overall SM+ rates without measurable change in time to continence or overall continence.