Prediction of urinary retention after surgery for rectal cancer using voiding efficiency in the 24 h following Foley catheter removal.

ABSTRACT

PURPOSE: Postoperative urinary retention is a common adverse effect after rectal surgery. Current methods for assessing postoperative urinary retention (residual urine volume) are inaccurate and unable to predict long-term retention. Voiding efficiency is an effective indicator of postoperative urinary retention in urological and gynaecological fields, but not in colorectal surgery. We aimed to determine whether voiding efficiency in the initial 24 h after urinary catheter removal was more effective in predicting the incidence of postoperative urinary retention than residual urine volume. METHODS: In this retrospective, observational study using prospectively collected data from patients who visited the colorectal department of a single institution, 549 patients who underwent rectal cancer surgery between April 2012 and May 2016 were initially enrolled, of which 46 were excluded and 503 finally included. RESULTS: The incidence of postoperative urinary retention was 18.5% (93/503). Multivariable logistic regression analyses revealed that the association of postoperative urinary retention with voiding efficiency < 50% was stronger than that with residual urine volume > 100 mL (odds ratio, 38.30 (residual urine volume) and 138.0 (voiding efficiency)). Voiding efficiency was significantly lower in patients with long-term than in those with short-term postoperative urinary retention (adjusted p value = 0.02), whereas residual urine volume was not different between the two groups. Multivariable logistic regression analysis for long-term postoperative urinary retention showed the strongest association with voiding efficiency < 20% (odds ratio, 25.70). CONCLUSIONS: Voiding efficiency is a more effective predictor of postoperative urinary retention than residual urine volume in rectal cancer patients.