INTRODUCTION AND OBJECTIVE:
Urinary continence (UC) recovery dramatically affects quality of life of patients after radical prostatectomy (RP). Membranous urethral length (MUL) has been the most studied anatomical variable associated with UC recovery. The aim of this study is to investigate whether Levator Ani thickness (LAT), assessed with multi-parametric magnetic resonance imaging (mpMRI), correlates with UC recovery in patients undergoing robot assisted radical prostatectomy (RARP).
The study included 209 patients treated with RARP at San Raffaele Hospital - Milan, Italy and Gasthuisberg Hospital - Leuven by expert surgeons with extensive robotic experience (>100 cases AND >30 cases/year) from 2017 to 2019. All patients had complete, clinical, mpMRI, pathological and post-operative data including pelvic floor muscle training (PFMT) protocols. Two urologists (after a training with an expert radiologist) examined the images, independently. They were blinded to clinical and pathological findings as well as to postoperative continence status. On mpMRI, LAT, bladder neck (BN) shape, membranous urethral length (MUL) and apex overlapping (AO) were measured. UC recovery was defined as use of 0 or 1 safety pad at follow-up. Multivariable models were used to assess the association between the aforementioned variables, and UC recovery.
Overall, 173 (82.8%) patients, were continent after a median follow-up of 23 months (IQR: 17-28). Of these, 98 (46.9%) recovered within 3-months after surgery, 42 (20.1%) from 3 to 6 months, and 33 (15.8%) from 6 months onwards. A significant higher rate of patients with LAT >10 mm (88.1 vs. 75.8%; p=0.03) experienced UC recovery, compared to those with LAT<10 mm. This difference was observed in the first 3 months after surgery. At multivariable analysis, LAT (OR: 1.18, 95%CI 1.02-1.37; p=0.02), pre-operative ICIQ score (OR 0,91, 95%CI 0.82-0,98, p=0.03) and PFMT (OR: 1.98, 95%CI 1.01-3.93; p=0.04) independently predict higher UC recovery within 3 months, after accounting for age, BMI, preoperative PSA, D’Amico risk group, MUL, BN shape and AO.
This study demonstrates that LAT is an independent predictor of early UC recovery and patients with a LAT greater than 1cm seem to present a higher urinary continence rate at 3 months after RARP compared to those with LAT < 1cm. The inclusion of LAT in future predictive models could improve this accuracy and could be used in the pre-operative counselling to better inform patients about the probability of urinary continence recovery.