Intraoperative frozen section monitoring during nerve-sparing radical prostatectomy: evaluation of partial secondary resection of neurovascular bundles and its effect on oncologic and functional outcome

Purpose: Intraoperative frozen sections (IFS) of the prostate have demonstrated to be effective in reducing positive surgical margins (PSM) and biochemical recurrence (BCR). The aim of this study was to assess partial secondary resection of neurovascular bundles (NVB) and report for the first time corresponding functional results. Methods: A total of 500 consecutive patients were included in this prospective series. All patients underwent open nerve-sparing radical prostatectomy. Intraoperatively, both posterolateral aspects of the prostate were sent for IFS. In case of PSM, additional tissue was partly resected from the prostatic bed along the NVB. BCR was the oncologic endpoint (PSA ≥ 0.2 ng/ml). The impact of IFS on PSM and BCR-free survival, and the effect of secondary partial resection of NVB on continence and erectile function (EF) recovery were analyzed by Kaplan–Meier analyses. Results: Twenty-nine patients were excluded because of neoadjuvant treatment/lymph node positive disease. PSM were detected in 137/471 patients (29.1 %). After secondary resection, 127/137 patients (92.7 %) converted to definitive negative surgical margins (NSM). Out of 137 patients, ten (7.3 %) showed persistent PSM. False-negative rate was 3.3 % (11/334). Out of 471 patients, two (0.4 %) showed PSM outside the IFS area. Overall, final PSM rate was 4.9 % (23/471). Five-year BCR-free survival did not differ significantly in patients with primarily and converted NSM. Continence and EF recovery after 12 months were 95.8 versus 94.3 %, and 65.7 versus 56.1 %, respectively (all p > 0.05). Conclusion: IFS are highly effective in reducing PSM and avoiding compromised oncologic outcome. Partial secondary resection of the NVB ensures ns status and consequently preserves continence and EF.