Postoperative urinary retention after surgery for benign anorectal disease: potential risk factors and strategy for prevention.

PURPOSE: This study was undertaken to determine the incidence of and risk factors for urinary retention after surgery for benign anorectal disease.
METHODS: We reviewed 2,011 consecutive surgeries performed under spinal anesthesia for benign anorectal disease from January through June 2003 to identify potential risk factors for postoperative urinary retention. In addition, we prospectively investigated the preventive effect of perioperative fluid restriction and pain control by prophylactic analgesics on postoperative urinary retention.
RESULTS: The number of procedures and the urinary retention rates were as follows: hemorrhoidectomy, 1,243, 21.9%; fistulectomy, 349, 6.3%; incision/drainage, 177, 2.3%; and sliding skin graft/lateral subcutaneous internal sphincterotomy, 64, 17.2%. The overall urinary retention rate was 16.7%. With hemorrhoidectomy, female sex, presence of preoperative urinary symptoms, diabetes mellitus, need for postoperative analgesics, and more than three hemorrhoids resected were independent risk factors for urinary retention as assessed by multivariate analysis. With fistulectomy, female sex, diabetes mellitus, and intravenous fluids >1,000 ml were independent risk factors for urinary retention. Perioperative fluid restriction, including limiting the administration of intravenous fluids, significantly decreased the incidence of urinary retention (7.9 vs 16.7%, P<0.0001). Furthermore, prophylactic analgesic treatment significantly decreased the incidence of urinary retention (7.9 vs 25.6%, P=0.0005).
CONCLUSIONS: Urinary retention is a common complication after anorectal surgery. It is linked to several risk factors, including increased intravenous fluids and postoperative pain. Perioperative fluid restriction and adequate pain relief appear to be effective in preventing urinary retention in a significant number of patients after anorectal surgery.