Safety and Efficacy of Bipolar Versus Monopolar Transurethral Resection of the Prostate in Patients with Large Prostates or Severe Lower Urinary Tract Symptoms: Post Hoc Analysis of a European Multicenter Randomized Controlled Trial

PURPOSE: We compare bipolar vs monopolar transurethral prostate resection safety/secondary outcomes including efficacy in patients with large prostate volume or severe lower urinary tract symptoms. MATERIALS AND METHODS: From July 2006 to June 2009 candidates for transurethral prostate resection were recruited at 4 centers, randomized 1:1 into monopolar/bipolar transurethral prostate resection arms and followed up to 36 months. Post hoc data analysis from patients with large prostate volume or severe lower urinary tract symptoms is presented. Patients with large prostate volume or severe lower urinary tract symptoms were defined as those with transrectal ultrasound based prostate volume greater than 80 ml or International Prostate Symptom Score greater than 19. Safety was estimated using sodium/hemoglobin changes immediately after surgery, complications during the early postoperative period (up to 6 weeks), and short-term (up to 12 months) and midterm (up to 36 months) followup. Secondary outcomes included, among others, efficacy quantified by changes in maximum urine flow rate, post-void residual urine volume and International Prostate Symptom Score compared with baseline. RESULTS: A total of 279 patients were randomized. Post hoc analysis of data from patients with a large prostate volume or severe lower urinary tract symptoms was based on analysis A-in 62 of 279 participants (22.3%) (monopolar transurethral prostate resection 32, bipolar transurethral prostate resection 30) or analysis B-in 126 of 279 participants (45.2%) (monopolar transurethral prostate resection 57, bipolar transurethral prostate resection 69). Mean (SD) prostate volume was 108.0 (25.9) ml for monopolar transurethral prostate resection and 108.9 (23.4) ml for bipolar transurethral prostate resection (p=0.756). Mean International Prostate Symptom Score was 25.0 (4.2) for monopolar transurethral prostate resection and 25.3 (3.7) for bipolar transurethral prostate resection (p=0.402). Neither safety nor any secondary outcome differed significantly between the arms throughout followup. The only exception was the decrease in sodium (analysis A), which was significantly greater after monopolar transurethral prostate resection (-4.2 vs -0.7 mmol/l, p=0.023) and did not translate into a significant difference in transurethral resection syndrome rates (monopolar transurethral prostate resection 1 of 32 vs bipolar transurethral prostate resection 0 of 30, p=1.000). CONCLUSIONS: Bipolar and monopolar transurethral prostate resection show similar safety/efficacy in these patient subpopulations.