Objectives: We evaluated a noninvasive method to predict bladder outlet obstruction (BOO) and bladder function in patients with benign prostatic enlargement (BPE) based on intravesical prostatic protrusion (IPP) using transabdominal ultrasound.
Methods: The records of 206 first-visit patients with BPE were reviewed. We divided patients into two groups based on the degree of IPP: the significant IPP group (greater than 10 mm) and the no significant IPP group (10 mm or less). We analyzed clinical data and urodynamic findings of the two groups to define the clinical significance of IPP.
Results: In the clinical data, increased prostate volume, serum prostate specific antigen, postvoiding residual urine volume (PVR), incidence of acute urine residual (AUR), and bladder trabeculation appeared more often in the significant IPP group (P <0.05). Positive correlation was found between IPP and prostate volume as well as PVR (Spearman's rho = 0.401 and 0.342, respectively). In the urodynamic findings, significantly lower peak flow rate (Qmax) and higher incidence of detrusor overactivity and low bladder compliance both existed in the significant IPP group (P <0.0l). In addition, maximum detrusor pressure (Pdet.max) and BOO index (BOOI) were significantly higher in the significant IPP group (P <0.05). The correlation coefficient (Spearman's rho) between IPP and Qmax, Pdet.max, and BOOI was -0.284, 0.252, and 0.456, respectively.
Conclusions: Intravesical prostatic protrusion is a useful predictor for evaluating BOO and detrusor function. BOO and impaired detrusor function in significant IPP patients are more severe. The significant IPP patients, especially those presenting with AUR, may benefit from early surgical intervention.