Evaluation of electrophysiological changes after radical prostatectomy and their relationship with erectile function recovery.

Erectile dysfunction (ED) is a common complication of radical prostatectomy (RP), mostly due to cavernous nerve (CN) injury. Despite improved surgical techniques and tools, ED rates are still high. Electrophysiological studies help to understand the functional effects of RP on CN and cavernous smooth muscles. The aim of this study is to evaluate the clinical reflection of changes on corpus cavernosum electromyography (CC-EMG) parameters caused by RP. A total of 44 patients were included in this prospective cohort study who underwent RP. The patients were divided into three groups based on nerve-sparing status: bilateral nerve-sparing (Group A) (n = 21), unilateral nerve-sparing (Group B) (n = 12), and non-nerve-sparing (Group C) (n = 11). All patients underwent CC-EMG one month before the operation and at the postoperative third month and were administered the International Index of Erectile Function (IIEF)-5 one month before the operation and at the postoperative third and 12th months. The postoperative third-month CC-EMG showed that the degree of cavernous smooth muscle relaxation in Group A was significantly higher than in Group B and Group C (p = 0.010 and p = 0.032, respectively). In the regression analysis, it was determined that patients with a postoperative IIEF-5 score of 12 or higher at the 12th month had a significantly greater degree of relaxation on the postoperative third-month CC-EMG (p = 0.034). In conclusion, a greater relaxation degree on postoperative third-month CC-EMG correlates with better long-term recovery of erectile function in patients who underwent RP.