The aims of the study were to determine the extent of male sexual dysfunction after surgical treatment of rectal cancer and to examine the outcome of postoperative treatment with sildenafil.

A prospective study was performed in patients who underwent attempted curative total mesorectal excision (TME) for low rectal cancers. Sexual function scores were determined by questionnaire preoperatively and at 3 and 12 months postoperatively. Outcomes were examined in patients who were sexually active preoperatively.

From 2000 to 2007, 207 patients underwent TME at our institution, of whom 49 (24%) were sexually active preoperatively. Erectile dysfunction and ejaculatory problems were present in 80% and 82%, respectively of the 49 patients at 3 months postoperatively, and in 76% and 67%, respectively at 12 months. Lateral lymph node dissection was a strong risk factor for postoperative sexual dysfunction. The impotency rate was 37% and 47% of patients were unable to ejaculate. Sildenafil was administered to 16 patients who requested the drug during follow-up, and sexual dysfunction was improved in 11 of these patients (69%).

Sexual dysfunction occurs frequently after rectal cancer treatment and is mainly caused by surgical damage in lateral lymph node dissection. Sildenafil may be effective for the treatment of sexual dysfunction.