Predictive value of resistive index, detrusor wall thickness and ultrasound estimated bladder weight regarding the outcome after transurethral prostatectomy for patients with lower urinary tract symptoms suggestive of benign prostatic obstruction.

OBJECTIVES

To evaluate the value of three parameters from preoperative ultrasonography in predicting the outcome of transurethral prostatectomy in patients with lower urinary tract symptoms suggestive of benign prostatic obstruction.

METHODS

A total of 239 patients with lower urinary tract symptoms suggestive of benign prostatic obstruction entering our department for surgical therapy were prospectively recruited. All of them underwent both ultrasound and urodynamics before receiving standard transurethral prostatectomy by the same team of surgeons. For 202 patients, 6-month follow-up data were available after the surgery, including the International Prostate Symptom Score, the Quality of Life score and the maximum flow rate. Preoperative data stratified by different degree of recovery were compared and the influence of ultrasound parameters on the surgical outcome was analyzed by using logistic regression and receiver-operator characteristic curve analyses.

RESULTS

Baseline transitional zone index, intravesical prostatic protrusion, resistive index, detrusor wall thickness and ultrasonic estimation of bladder weight were significantly different between patients with an effective outcome and those with an ineffective outcome (P < 0.05). Resistive index, detrusor wall thickness and ultrasonic estimation of bladder weight were selected as independent factors correlated with the efficacy of transurethral prostatectomy by logistic regression (P < 0.05). All three factors had adequate area under receiver-operator characteristic curve with resistive index having the largest area (0.816, 95% CI 0.759-0.874). The combined positive predictive value in effective surgical outcome of resistive index, detrusor wall thickness and ultrasonic estimation was 96.3%.

CONCLUSIONS

Resistive index, detrusor wall thickness and ultrasonic estimation adequately predict the outcome of transurethral prostatectomy. Measuring these parameters by preoperative ultrasound might aid in determining the need for surgical intervention.