Intraoperative electrical stimulation of cavernosal nerves with monitoringof intracorporeal pressure in patients undergoing nerve sparing radical prostatectomy

Objective To explore the utility of intraoperative cavernosal nerve stimula tion in facilitating atraumatic nerve dissection during radical prostatecto my, and thus help predict postoperative erectile function. Patients and methods Fourteen patients (aged 51-72 years) underwent nerve-s paring radical retropubic prostatectomy (NSRRP); 10 were potent before surg ery (group 1), and four had erectile dysfunction (group 2). A multi-acquisi tion system (MacLab/8e) with a Macintosh computer was used for real-time di splay and recording of intracavernosal pressure (ICP) during surgery. Nerve s were stimulated with a bipolar probe (monophasic rectangular pulses, 10 m A, 20 Hz, 0.22 s) before and after removal of the gland. The follow-up cons isted of interviews with patients and their partners' 12-18 months after tr eatment. Results The mean (SEM) basal ICP of 8.0 (2.0) cmH(2)O remained unchanged du ring nerve dissection. The mean increase in ICP during electrical stimulati on was > 50 cmH(2)O in seven potent patients (group 1) and was sustained as long as the nerve was stimulated. Postoperatively, these seven patients re ported erections sufficient for sexual intercourse. :However, the three rem aining patients in group 1 had pressure rises of <30 cmH(2)O, of whom two r eported partial erections and one reported total impotence postoperatively. The recovery time for erectile function was 6-12 months after surgery. Two patients from group 2 had transient increases in ICP to <40 cmH(2)O; one h ad an increase to 20 cmH(2)O and one had no response at all. All four patie nts remained totally impotent postoperatively. There were no complications. Conclusions Intraoperative electrical stimulation of the cavernosal nerves with ICP monitoring before and after NSRRP is a safe and reliable method fo r documenting nerve continuity and its functional status. Patients who have normal preoperative erectile function and show an adequate rise in ICP upo n electrical nerve stimulation during NSRRP will almost certainly be potent after surgery. This tool may be used to facilitate atraumatic nerve, disse ction during NSRRP.