Prostate surgery for bladder outflow obstruction (BOO) is primarily aimed to improve lower urinary tract symptoms (LUTS) in males. 1 The aim of the surgery is to help patients with refractory urinary retention to get rid of indwelling urethral catheter or clean intermittent self-catheterisation (CISC). However, patients with associated detrusor underactivity are generally considered candidates for CISC after prostate surgery. Detrusor pressure-flow urodynamic studies are performed to diagnose detrusor underactivity before surgery. 2 Around 48% of men with urinary retention or LUTS are reported as having a degree of detrusor underactivity.3 Aging is also associated with reduced detrusor contractility. In many cases, detrusor underactivity co-exists with BOO. Most urologists consider prostate surgery unnecessary in such cases, rather deeming it harmful for the patient. Hence, surgery to improve LUTS in patients with underactive detrusor is a controversial subject. Therefore, we have investigated the outcome of BOO surgery in males with detrusor underactivity.

This is a retrospective cohort study of patients who underwent endoscopic surgery for bladder outflow obstruction as well as detrusor underactivity in a single institution at Bedford Hospital, UK from March 2020 to May 2022. The surgery for these patents included either bipolar transurethral resection of prostate (TURP) or holmium laser enucleation of prostate (HoLEP). Indications for surgery in these patients included either refractory urinary retention or LUTS with a large post-void residual volume (PVR) in bladder. Patients with chronic high pressure urinary retention were also included. All of these patients had undergone pressure-flow urodynamic studies.
Patients were searched by computerised record (VIPER and Mediviewer), urodynamic studies and cystoscopy record as well follow-up record after the surgery. BOO was defined by bladder outflow obstruction index (BOOI) while detrusor underactivity contractility was defined by bladder contractility index (BCI) <100.
Patient outcomes that were reported included: patients’ international prostate symptoms score (IPSS), quality of life (QoL) score and whether they had indwelling urethral catheter due to refractory urinary retention or high pressure chronic urinary retention. Pre-operative uroflowmetry including maximum flowrate (Qmax), PVR in bladder and whether the patients had urethral catheter or regular CISC for high or low pressure chronic urinary retention were also recorded.
Post operative outcome of surgery was recorded in terms of whether patients had successful trial without catheter (TWOC). In those who had successful TWOC, improvements in IPSS, QoL Score, Uroflowmetry Qmax, PVR were quantified and whether they needed CISC was recorded. If multiple values of Qmax and PVR in bladder were documented, the highest and lowest were recorded respectively.

A total of 26 patients were eligible from the database who had undergone surgery for BOO with detrusor underactivity. Of 26 patients, 14 patients had indwelling urethral catheter, six required clean intermittent self-catheterisation and the remaining six had significant LUT (IPSS > 25, QoL score 4 or more, all six patients in this group had PVR > 1.2 litres). Urodynamic studies showed BOOI of >40 in all the patients while BCI was < 100 in 22 patients (84.61%) The rest of the four patients (15.39%) had BCI just above 100.
After surgery, all patients had successful TWOC. Four (15.38%) patients out of the 26 patients needed CISC while 22 patients (84.62%) did not need any catheter after 3 months of surgery. 23 (92%) patients noted improvement of IPSS (IPSS <10 and QoL Score 1-2). All patients had significant improvement in uroflowmetry parameters, with 19 patients (76%) having a Qmax >10. Only 6 patients (23.07%) had PVR >400 ml.

Impaired detrusor function has historically been considered a poor prognostic factor for successful outcome of BOO surgery in males. Our data in this study suggests that there is significant improvement of LUTS and only a few patients required CISC. Therefore, outcome of prostate surgery appears successful even if there is detrusor underactivity.

Surgery in patients with bladder outflow obstruction with detrusor underactivity results in reasonably successful outcome. Prospective studies with larger number of patient cohorts would be very useful to help confirm findings of this study.

Gratzke C, Bachmann A, Descazeaud A, Drake MJ, Madersbacher S, Mamoulakis C, et al. EAU Guidelines on the Assessment of Non-neurogenic Male Lower Urinary Tract Symptoms including Benign Prostatic Obstruction. Eur Urol. 2015;67:1099–1109.
Gammie A, Kaper M, Dorrepaal C, Kos T, Abrams P. Signs and Symptoms of Detrusor Underactivity: An Analysis of Clinical Presentation and Urodynamic Tests From a Large Group of Patients Undergoing Pressure Flow Studies. Eur Urol. 2016;69:361–369.
Chapple CR, Osman NI, Birder L, Koeveringe GA van, Oelke M, Nitti VW, et al. The underactive bladder: a new clinical concept? Eur Urol. 2015;68:351–353.

Continence 7S1 (2023) 100917
DOI: 10.1016/j.cont.2023.100917