Intraoperative electrophysiological confirmation of neurovascular bundle preservation during radical prostatectomy: long-term assessment of urinary and sexual function

OBJECTIVE: We investigated the longitudinal recovery of urinary and sexual function after radical retropubic prostatectomy (RP) using an intraoperative electrophysiological test to confirm the functional preservation of the neurovascular bundle (NVB). METHODS: A total of 70 patients who underwent RP for localized prostate cancer were prospectively enrolled in our survey. During RP, electrophysiological testing was performed to confirm the NVB preservation. The NVB was electrostimulated and the responses were observed by monitoring the intracavernous or intraurethral pressure changes. All patients were classified into three groups according to the degree of nerve-sparing [a bilateral nerve-sparing group (BNS), a unilateral nerve-sparing group (UNS) and a non-nerve-sparing group (NNS)] based on the macroanatomical as well as the electrophysiological assessment. Both urinary and sexual function were measured before and 3, 6, 12 and 24 months after RP by a self-administered questionnaire. RESULTS: The concordance rate of nerve-sparing or non-nerve-sparing between the electrophysiological and macroanatomical assessment was 80%. According to the electrophysiological data, the BNS maintained significantly better urinary function at 3 months after RP than the NNS and UNS. After 6 months, each group had almost recovered continence. When considering sexual function, the BNS showed better sexual function scores than the NNS throughout the post-operative periods and the UNS at 2 years. According to the macroanatomical assessment, however, these differences were significant. CONCLUSIONS: Nerve-sparing RP as confirmed by intraoperative electrophysiological test may contribute significantly to the early recovery of continence and greater rate of sexual function after RP.