Planned nerve preservation to reduce positive surgical margins during robot-assisted laparoscopic radical prostatectomy

Purpose: The main objective of radical prostatectomy (RP) is optimal oncologic resection with preservation of sexual function (SF). During our initial experience with robot-assisted laparoscopic radical prostatectomy (RLRP), we noted a high rate of posterolateral location of positive surgical margins (PSM) with nerve preservation (NP). With its magnified view of the surgical field and improved instrument precision, one potential advantage of RLRP is the ability to tailor the degree of NP. We evaluated the effect of a protocol for side-specific NP based on preoperative variables on PSM rates and SF outcomes. Methods: Between June and November 2006, 150 consecutive RLRPs were performed using a surgical protocol to select side-specific NP techniques (interfascial [IF], partial extrafascial [pEF], and wide extrafascial resection [WEFR]) based on preoperative risk factors (clinical stage, biopsy Gleason score, percentage of positive cores and maximal core cancer percentage, and preoperative PSA). Pathologic and SF outcomes in these patients were compared with those of a control group of 245 consecutive RLRPs in whom non-selective IF dissection was performed. All data were prospectively collected. Results: Mean patient age, PSA, clinical stage, biopsy Gleason score and positive core involvement, pathologic Gleason score, and stage were comparable among the two groups. The overall PSM rate (12.6% v 20.4%; P = 0.04) and posterolateral location of PSMs (37% v 70%; P = 0.04) were significantly lower in the study group. At 12 months, potency was reported in 80%, 67%, and 11% of men undergoing bilateral IFNP, partial extrafascial nerve preservation (pEFNP), and WEFR, respectively (P = 0.27). Conclusions: Planning side-specific NP during RLRP, according to selected preoperative variables, can significantly reduce overall and posterolateral PSM rates. Furthermore, partial nerve sparing (pEFNP) also appears to confer favorable early SF outcomes.