The assessment of erectile dysfunction after radical prostatectomy using pudendal somatosensory evoked potential

Erectile dysfunction in patients who underwent radical prostatectomy was evaluated with pudendal somatosensory evoked potentials (PSEP) to measure and predict erectile dysfunction objectively. Fifty-seven patients who completed requirements were included in the study. Patients were divided into 2 groups (potency/non-potency). Erectile function recovery was defined as question 2 and 3 on the IIEF-5 questionnaire at 12 months after surgery. The two-channel PSEP test was performed at the day before RP and 3–6 months after RP. Twenty patients were assigned to the potency group and 37 to the non-potency group. Mean age was less in the potency group. Other clinical variables were similar in two groups. The non-potency group had prolonged lumbar and cortical latencies in postoperative PSEP, and the mean differences of latencies between pre- and postoperative PSEP in lumbar and cortical regions were also greater in the non-potency group. Logistic regression analysis showed that age, lumbar post-operative latency, cortical post-operative latency, and difference of latency in lumbar region were associated with non-potency; odds ratios were 1.292 (p = 0.018), 0.425 (p = 0.047), 1.637 (p < 0.001), and 3.272 (p = 0.010), respectively. This study suggests that PSEP is an effective means of evaluating erectile dysfunction in prostate cancer patients after surgery.