Study design and procedures in the incontinence post robot-assisted radical prostatectomy: anatomical and functional causes (IPA) - a prospective observational clinical trial.

Objective: To describe the study design and procedures of the incontinence post robot- assisted radical prostatectomy, anatomical and functional causes (IPA) trial. This trial aims to identify and study patient and procedure specific factors leading to urinary incontinence post robot-assisted laparoscopic radical prostatectomy (RALP).

Material and methods: The IPA study is a prospective, multicentre, open non-randomised surgical trial, including patients prior to RALP and registered on-line (ISRCTN67297115). IPA is administered from the Department of Urology at Sahlgrenska University Hospital, Gothenburg, Sweden. Patients undergo an anatomical and functional evaluation using magnetic resonance imaging (MRI), urodynamics including cystometry, pressure-flow and urethral pressure profile, and dynamic transrectal ultrasound prior to and 3 months after RALP. The incontinence data are gathered using patient reported outcome measure questionnaires. The primary endpoint is incontinence at 3 months after RALP, defined as need of any pad. The secondary endpoints are incontinence 12 months post RALP defined as need of any pad, and 3- and 12-months post RALP, defined as use of more than a safety pad.

Results: Until October 2023, 207 patients have been included of the stipulated 1,000, with an increasing rate of accrual. Out of these patients,187 have had a pre- and post-operative MRI and 177 have undergone pre- and post-operative urodynamics.

Conclusions: The design of the IPA study, together with promising accrual and coming multicentre inclusion, will hopefully result in the identification, and deeper understanding, of the various risk-factors for post-RALP incontinence. This could improve information and decision making regarding adequate treatment for patients with prostate cancer.