Correlation between detrusor thickness, intravesical prostatic protrusion and maximum urinary flow in the monitoring of benign prostatic hyperplasia

Abstract

Detrusor thickness (DT) and intravesical prostatic protrusion (IPP) are closely related to bladder outlet obstruction. The aim of our study was to look for correlation between DT, IPP and maximum urinary flow (Qmax). It is a prospective, observational study including men over fifty managed for benign prostatic hyperplasia. Low urinary tract symptoms were assessed with the International Prostatic Symptom Score (IPSS). Pelvic ultrasound was performed for all patients measuring prostatic volume, bladder volume, post- void residual, DT and IPP. Uroflowmetry was performed for all patients, Qmax was noted. Qmax equal or less than 15ml/s was considered pathologic. Sixty patients were included for our study. Strong negative correlation was noted between DT, IPP and Qmax (r=-0.59, r=-0.61 respectively). Patients with pathologic Qmax had higher DT and IPP than those with normal Qmax, the difference was significant (P<0.01). Threshold values predicting pathologic Qmax were 3mm for DT and 7mm for IPP. ROC analysis reveals for DT an AUC of 0.84 (95% CI 0.76-0.92) and for IPP an AUC of 0.88 (95% CI 0.80-0.97). Detrusor thickness and intravesical prostatic protrusion have strong negative correlation with Qmax. These parameters could be an alternative to Qmax measurement if uroflowmetry is unavailable. Grade B.