The Predictors of Acute Urinary Retention in Patients with Benign Prostatic Hyperplasia

Kim, Je Hee; Kim, Hyeong Gon; Park, Won Hee

Abstract

PURPOSE: Acute urinary retention is one of the most severe complications in patients with benign prostatic hyperplasia (BPH). We investigated the efficacy of age, International Prostatic Symptom Score (I-PSS), quality of life (QOL) score and various parameters obtained by transrectal ultrasonography (TRUS) as predictors of acute urinary retention.
MATERIALS AND METHODS
Of 153 patients with BPH, who underwent transurethral resection of the prostate, 72 were treated due to acute urinary retention (retention group) and 81 due to lower urinary tract symptoms (symptomatic group). TRUS was used to calculate the total prostate (TP) and transitional zone (TZ) volumes, the transitional zone index (TZ index=TZ volume/TP volume) and the elongation ratio (ER=the ratio of the maximal anteroposterior to transverse diameter of the prostate). To compare the usefulness of various parameters between the retention and symptomatic groups, the area under the receiver-operating characteristic (ROC) curve was calculated for each parameter.
RESULTS
There were significant differences in the TP and TZ volumes, the TZ index and the elongation ratio between both groups, but no significant differences in age, I-PSS or QOL score. In the retention group, the most effective cutoff values were 40cc, 20cc, 0.55 and 0.75 for the TP volume, the TZ volume, the TZ index and the elongation ratio, respectively. The area under the ROC curves were 0.894, 0871, 0843 and 0771 for the TZ index, the elongation ratio, the TZ volume and the TP volume, respectively.
CONCLUSIONS
The TP and TZ volumes, the TZ index, and the elongation ratio are useful predictors of acute urinary retention in patients with BPH. The TZ index is the most useful predictor, and may be a useful parameter in selecting the treatment for BPH.