Male Urinary and Sexual Functions After Mesorectal Excision Alone or in Combination with Extended Lateral Pelvic Lymph Node Dissection for Rectal Cancer

Mesorectal excision reduced the incidence of genitourinary dysfunction compared with conventional surgery. In Japan, extended lateral pelvic lymph node dissection (ELD) is added to mesorectal excision when lateral pelvic node metastasis is suspected. The aim of this study was to evaluate male genitourinary function after mesorectal excision or mesorectal excision plus ELD for rectal cancer. According to the degree of pelvic-plexus preservation (PPP) and ELD, patients were grouped into PG1, mesorectal excision alone (bilateral PPP without ELD) (n = 27); PG2, bilateral PPP with ELD (n = 12); PG3, unilateral PPP with ELD (n = 26); and PG4, no PPP with ELD (n = 4). The assessment included measurements of the time interval to residual urine becoming < 50 mL, interviews assessing sexual function, and nocturnal penile tumescence measurements. Proportions of patients with residual urine becoming < 50 mL within 14 days after surgery were 96% in PG1, 73% in PG2, 23% in PG3, and 0% in PG4 (P < .001). Proportions of patients answering the ability to maintain sexual intercourse at 1 year were 95% in PG1, 56% in PG2, 45% in PG3, and 0% in PG4 (P < .001). Proportions of patients having nocturnal penile rigidity of > 65% at 1 year were 95% in PG1, 33% in PG2, 50% in PG3, and 0% in PG4 (P < .001). Patients undergoing mesorectal excision alone can expect excellent genitourinary function, but functional results after mesorectal excision plus ELD are far worse. Degrees of dysfunction depend on the extents of both autonomic nerve resection and ELD.