Male Urogenital Function After Confirmed Nerve-Sparing Total Mesorectal Excision with Dissection in Front of Denonvilliers’ Fascia

This prospective study addresses the rate of male genital dysfunction following total mesorectal excision (TME) for rectal carcinoma using the anterior extramesorectal plane and its correlation with early urinary function, pelvic autonomic nerve preservation (PANP), and intraoperative neurostimulation (INS). A consecutive series of 44 men operated on by the same surgical team was analyzed. After excluding 18 patients considered to be impotent preoperatively, urogenital function was evaluated in 26 patients on the basis of the International Prostatic Symptom Score and International Index of Erectile Function. PANP was assessed with INS of parasympathetic nerves. PANP was complete in 21 patients (80.8%). Deterioration of urinary function was observed in six patients (23.1%) at early follow-up. Postoperative erectile dysfunction assessed in seven patients (26.9%) was associated with micturition disturbances in four (57%). Despite dissection in front of Denonvilliers´ fascia, the incidence of erectile dysfunction was low in patients with nonanterior tumors (1/10). INS results had higher sensitivity for predicting urinary dysfunction than for predicting erectile dysfunction (67% vs. 43%). Values for specificity and accuracy were 95% and 90%, and 89% and 77%, respectively. The correlation between the findings on INS and urinary function was good (κ = 0.66) at a fair (κ = 0.36) correlation for erectile function. Nerve-sparing TME using the anterior extramesorectal plane results in a justifiable rate of postoperative impotence in patients with nonanterior tumors. Patients with negative results on INS or early urinary dysfunction are at greater risk of erectile dysfunction.