Hypothesis / aims of study
Urinary retention and incomplete bladder emptying after transurethral resection of the prostate (TURP) and laser failures are caused by persistent urethral obstruction and/or detrusor underactivity (DU). The aim of this study is to compare urodynamic findings and surgical outcomes of TURP and KTP laser prostate ablation (KTPLAP) in catheter-dependent men who were advised that they were no longer surgical candidates by their prior urologists, but subsequently underwent surgery at our institution.
Study design, materials and methods
This is a retrospective observational study of catheter-dependent men due to urinary retention thought to be unsuitable for surgery after failing TURP or KTPLAP. A database was searched for catheter-dependent men who underwent urodynamics after failed TURP or KTPLAP. Exclusion criteria were neurogenic bladder and temporary catheterization. All patients underwent routine assessment including cystoscopy and videourodynamics (VUDS) and were divided into 3 groups based on the bladder outlet obstruction index (BOOI) and bladder contractility index (BCI): 1) DU, 2) bladder outlet obstruction (BOO), and 3) detrusor acontractility (DA). See table 2 for definitions. The primary outcome measures were the Patient Global Impression of Improvement (PGII) and catheter independence. Secondary outcomes were uroflow (Q) and postvoid residual urine (PVR). Mann-Whitney and Pearson chi-squared tests were utilized.
100 catheter-dependent men were identified and 30 excluded due to complicating comorbidities (i.e., cancer), urethral stricture identified as the primary cause of obstruction, or insufficient records (i.e., VUDS). 24 declined surgery and 46 elected surgery of whom 70% had pure DU, 30% had pure BOO, and 13% had both. Mean follow-up time was 74 months, and median, 43 months (range 3 mo - 25 yr). At follow up, 38/46 (83%) of patients had a successful outcome based on the PGII and 89% were rendered catheter-free (see table 2). There was no difference in any preoperative characteristics between men who underwent surgery and those who declined. Pre-op, the DU group had a larger bladder capacity (as expected), lower Qmax on UDS, and greater PVR. In both BOO and DU patients (with or without BOO), surgery produced similarly good results in flow although the DU group had a greater improvement in PVR. One of three DA patients were rendered catheter-free.
Interpretation of results
Conventional thinking is that that men with DU are unsuitable candidates for TURP and KTPLAP because the underactive bladder is unable to contract forcefully or long enough to achieve a good outcome . Yet in this series, catheter-dependent men after failed TURP or KTPLAP, thought to be poor surgical candidates, had a high success rate after prostate surgery despite nearly 3/4 having DU. All BOO patients and 91% of DU patients were rendered catheter free and, from a subjective standpoint (PGII), 93% and 79% had a successful outcome. These data suggest that if the bladder can contract, albeit weakly, KTPLAP & TURP are effective in improving symptoms in the vast majority of patients. This is not the case, though, in patients with an acontractile detrusor; only one in three had a successful outcome. These data also suggest that conventional mathematical methods of defining bladder outlet obstruction are inaccurate in patients with detrusor underactivity .