Presentation Authors: Andrew Schneider, Madison, WI, Matthew Grimes, Iowa City, IA, Sijian Wang, Piscataway, NJ, Wade Bushman*, Madison, WI
Introduction: Men choose surgical treatment of BPH/LUTS for a variety of indications including bothersome symptoms, failure of medical treatment, urinary retention, and complications related to incomplete bladder emptying. We performed a retrospective cluster analysis of objective patient characteristics including urodynamic variables and prostate volume of patients treated surgically for BPH/LUTS to identify meaningful subgroups within this cohort.
Methods: We identified 94 men who underwent either TURP or open simple prostatectomy (OSP) for BPH/LUTS for whom preoperative urodynamic data were available. Prostate volume, calculated from CT using the ellipsoid formula, was available for 49 patients. Comprehensive clinical and urodynamic data was abstracted from the medical record. Hierarchical cluster analysis was performed on 11 variables: age, HTN, DM, BMI, prostate volume, volume at first uninhibited detrusor contraction, number of uninhibited contractions during filling, Bladder Outlet Obstruction Index (BOOI) calculated from the formula BOOI= PdetQmax - 2Qmax), Bladder Contractility index (BCI) calculated from the formula BCI = PdetQmax + 5Qmax, and Bladder power calculated from the formula Power= (PdetQmax) (Qmax).
Results: Cluster analysis identified two meaningful subgroups in the patient cohort. Significant differences between the two groups included Prostate Volume (106 vs 55; p-value=0.014), BOOI (mean 75 vs 50; p-value=0.002), BCI (mean 127 vs 83; p-value < .0001) and Power (601 vs 233; p-value < .0001).
Conclusions: This analysis reveals two meaningful subgroups in patients undergoing surgery for BPH/LUTS. One group is distinguished by larger prostate volume, greater outlet resistance and greater bladder contractility and power. The other is distinguished by smaller prostate volume, lesser outlet resistance and weaker bladder contractility and power. This suggests that outlet obstruction due to prostatic enlargement and impaired detrusor function both drive the need for surgical treatment of BPH/LUTS.
Source of Funding: VA Merit Award: I01 BX003454-01 .