Intravesical Prostatic Protrusion Is a Risk Factor for Bladder Stone in Patients With Benign Prostatic Hyperplasia

Objective To assess the risk factor that influences bladder stone formation in patients with benign prostatic hyperplasia (BPH). Materials and Methods We reviewed the data of 271 consecutive patients with BPH who underwent transurethral resection of the prostate between January 2008 and December 2012. Patients were classified into 2 groups based on the presence of a bladder stone: Group 1 had a bladder stone and group 2 did not. Univariate analysis was performed to determine the association between the presence of bladder stone and the patients' age, body mass index, International Prostate Symptom Score, total prostate volume (TPV), transitional zone volume, intravesical prostatic protrusion (IPP), uroflow parameters, and urodynamic parameters. Results The overall rate of bladder stone in patients with BPH was 9.9%. The patients' body mass index, International Prostate Symptom Score, and urodynamic parameters did not significantly differ between the 2 groups. The patients' age, TPV, transitional zone volume, and IPP were all significantly higher and the Qmax was significantly lower in group 1 than that in group 2. Multivariate analysis revealed that age (hazard ratio [HR] = 1.089; P = .020), IPP (HR = 1.145; P