Hypothesis / aims of study
Urinary incontinence (UI) following radical prostatectomy (RP) requiring one or more pads a day is experienced by nearly half of all men at 6 months after RP compared to 1% at baseline(1). Post RP UI has a detrimental effect on quality of life (QoL) for up to 2 years after RP when compared to active monitoring. Aside from membranous urethral length measured on MRI, no strong predictive factors for post-RP UI have been identified (2).
The Robotic and Open Surgery for Prostate Cancer: A Prospective, Multi-centre, Comparative Study of Functional and Oncological Outcomes (ROSE) study was set up in 2017 to assess oncological and functional outcomes of men undergoing robot assisted RP compared to open RP. The primary outcomes are oncological (positive surgical margins, extracapsular extension etc), urinary and sexual functional outcomes using EPIC and IIEF questionnaires and QoL outcomes using the physical and mental functioning domains of the SF-36 V2 questionnaire. Secondary outcomes of the ROSE study include the identification of urodynamic , dynamic 3D pelvic floor US and anatomical features such as prostate volume and urethral length measured on MRI and 3D pelvic floor US, that may impact urinary function after RP. Previous studies have shown moderate to severe LUTS to be present in 37% - 50% of men undergoing RP(3). The urodynamics of men undergoing RP has not been prospectively evaluated to date.
This study aims to analyse the baseline lower urinary tract symptoms, urodynamic parameters and establish any correlations in this contemporary cohort of men with localised prostate cancer undergoing open and robot assisted RP.
Study design, materials and methods
Men over 18, clinically suitable for radical prostatectomy and cognitively able to give consent were prospectively recruited into this trial.
Baseline oncological demographics together with IPSS, EPIC, IIEF questionnaires were collected at baseline and 2 weeks, 6 weeks, 3 months, 6 months, 9 months and 12 months.
At baseline, men underwent urodynamic studies following ICS guidelines and functional 2D and 3D pelvic floor Ultrasound. Men did not undergo urodynamics if their surgery was planned in less than 4 weeks from the date of initial assessment.
Demographic and clinical characteristics of patients were compared using chi-square tests and Fisher’s test. Mean differences in scores between patient groups was compared using t tests or Wilcoxon rank sum tests depending on the distribution of the data.
Results
88 men were prospectively recruited, with mean age 63.6 (44.5-77.8) years to undergo clinical assessment, urodynamic testing and functional pelvic floor ultrasound prior to RP.
Of 74 patients with complete baseline data, 39(53%), 28(38%) & 7(9%) had mild (IPSS <8), moderate (IPSS 8-19) & severe (IPSS>20) LUTS. Urodynamic abnormalities were noted in 41/88(46%). Of 62 patients who completed the voiding phase, 18(29%) were obstructed (BOOI>40) and 9(15%) showed poor contractility (BCI<100).
Of 38(52.1%) patients who reported overactive bladder (OAB), 19(50%) had urodynamic filling abnormalities.
Of 15(19%) patients with DO on UDS, 12(80%) reported OAB. Of 17(18%) who were obstructed, 6(35%), 10(59%) and 1(14%) reported mild, moderate and severe LUTS. Patients with filling abnormalities had higher IPSS-storage scores (p = 0.01) and lower filling capacity (p = 0.02).
Interpretation of results
OAB, moderate & severe LUTS are all more common in patients undergoing radical prostatectomy. Approximately 50% of all men undergoing radical prostatectomy were found to have moderate or severe LUTS
29.5% of men undergoing radical prostatectomy were obstructed on baseline UDS. Less than 50% of all men reporting OAB have urodynamic filling abnormalities. In those with DO on UDS, 80% reported OAB symptoms at baseline
The 20% with asymptomatic detrusor overactivity may represent a group whose symptoms significantly deteriorate after radical prostatectomy.