Post-pelvic surgery erectile dysfunction is of much interest to those performing sigmoid colon and rectal cancer surgery and their patients. Erectile dysfunction has been recognized to develop from damage to pelvic parasympathetic nerve, which are especially vulnerable during anterior rectal dissection. There may be also a contribution of psychological factors from the presence of stoma and fear of recurrent cancer. Recently, several studies reported that erectile dysfunction after rectal excision for rectal cancer was completely reversed or satisfactorily improved using oral erectile dysfunction drugs. Udenafil is a new phosphodiesterase type 5 (PDE 5) inhibitor for erectile dysfunction. Prior studies have also demonstrated a selectivity profile for udenafil that is similar to Sildenafil (viagra®) and tadalafil (Cialis®). But unlike tadalafil (Cialis®), it does not significantly inhibit the PDE11 isozyme and not produce significant myalgia. back pain, or leg pain.
This prospective, randomized study was designed to evaluate the efficacy of Udenafil treatment in treatment of erectile dysfunction after radical resection for sigmoid colon and rectal cancer. In order to conduct this study, enrolled patients will be randomly attributed to Udenafil group or placebo group.