Ideal Timing of Prostate Operation in Chronic Urinary Retention due to Benign Prostatic Hyperplasia by Serial Urodynamic Study: A Prospective Longitudinal Study

Abstract

Introduction: Chronic Urinary Retention (CUR) due to prostatomegaly causes impaired detrusor function, secondary to obstruction-related changes in the bladder wall. Urodynamic study is the “gold standard” to determine detrusor function in CUR patients. Traditional management of all CUR patients due to Benign Prostatic Hyperplasia (BPH) is temporary catheter drainage of the urinary bladder, so that detrusor impairment may be corrected. There is no consensus regarding the ideal timing of prostate operation in Bladder Outlet Obstruction (BOO) patients presenting with CUR due to BPH. Aim: To assess the ideal timing of Transurethral Resection of the Prostate (TURP) in chronic urinary retention patients due to BPH. Materials and Methods: This was a prospective, longitudinal study of 57 eligible patients with non neurogenic lower urinary tract symptoms, who presented with chronic urinary retention due to benign prostatic hyperplasia and attended the Department of Urology, Institute of Post-Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital (IPGME&R SSKM) hospital, Kolkata, West Bengal, India from August 2019 to July 2022. Four serial Urodynamic Studies (UDS) were performed after initial catheterisation in sterile urine culture on the day 5, day 14, day 30, and at 6th week. As per UDS findings, patients were classified into Preserved Detrusor function group (n=18), at peak flow rate (Qmax) {Detrusor Pressure (Pdet) at peak flow rate} >30 cm H2 O and Impaired Detrusor function group (n=39), Pdet at Qmax ≤30 cm H2 O. Descriptive statistics were performed as means, standard deviations and ranges using Microsoft Excel software. For categorical variables percentages were used. The Student’s paired-test and Chi-square test were used for statistical analysis. The p-value <0.05 was considered statistically significant. Results: In the present study, mean age of preserved detrusor function group was 56.17 years and impaired detrusor function group was 67.08 years. In preserved detrusor function group (n=18), 83.3% patients had upper urinary tract changes and in impaired detrusor function group (n=39) only 15.4% patients had upper tract changes (p-value <0.05). On the urodynamic study done 6 th week after initial catheterisation, in impaired detrusor function group, n=36 (92.30%) patients had Pdet at Qmax>30 cm H2 O and only n=3 (7.7%) patients had Pdet at Qmax≤ 30 cm H2 O (p-value<0.001). Conclusion: Urodynamic study is the gold standard to determine detrusor function in chronic urinary retention patients. It is ideal to wait till six weeks or beyond, for TURP in chronic urinary retention patients due to BPH after initial catheterisation.