Predictors of nerve stimulator success in patients with overactive bladder

Abstract

Purpose: To identify factors associated with successful sacral nerve stimulator (SNS) trial after SNS implantation for the treatment of medication refractory overactive bladder (OAB). Methods: Patients undergoing treatment for OAB at Lahey Hospital and Medical Center between 2004 and 2016 were identified. Patients undergoing SNS placement were identified; SNS success was defined as permanent implantation of the SNS. Demographic, clinical and treatment data were extracted from patient charts; uni- and multivariate analyses were conducted to identify factors associated with SNS treatment success. Results: A total of 128 patients were included. On univariate analysis, male sex, prior diagnosis of benign prostatic hyperplasia, and lower volume at first urge on urodynamics (UDS) were associated with unsuccessful SNS trial. On multivariate analysis, male sex (odds ratio [OR], 0.145; 95% confidence interval [CI], 0.036-0.530) and lower volume at first urge on UDS (OR, 0.982; 95% CI, 0.967-0.995) were associated with unsuccessful SNS trial. A threshold value of 100 mL at first urge during preoperative UDS had a specificity of 0.86 in predicting SNS success in men. Conclusions: SNS is frequently successful at relieving OAB symptoms. Male patients and those with lower volumes at first urge on UDS, particularly below 100 mL, are more likely to have an unsuccessful SNS trial. Patients in these groups should be counseled on the lower likelihood of SNS success.