[Preoperative MRI parameters for prediction of early urinary continence after laparoscopic radical prostatectomy]

To explore the correlation of early urinary continence (UC) after laparoscopic radical prostatectomy (LRP) with relevant preoperative MRI parameters of the urinary tract structure and provide some theoretical evidence for screening the high-risk population with postoperative urinary incontinence.

This study included 49 PCa patients aged 50－78 years treated by LRP in Beijing Tongren Hospital from January 2015 to February 2021, and all followed up for 12 months. We collected the complete baseline data on the patients, the clinical data possibly related to early postoperative UC, the MRI anatomical parameters associated with UC, and the data on the recovery of early postoperative UC. We recorded the number of urinary pads used, submitted the data obtained to SPSS 23.0 statistical analysis, and identified the possible relevant factors by univariate correlation analysis, followed by R4 0.3 or SPSS 23.0 multivariate logistic regression analysis of the included factors and the results of UC.

MRI images manifested that the prostate anteroposterior diameter averaged (4.0 ± 1.11) cm, the transverse diameter (4.6 ± 0.83) cm, the cephalocaudal diameter 2.4－6.4 cm, the membranous urethral length (MUL) (13.16 ± 3.52) mm, and the thickness of the urethral rhabdosphincter (URS) 1.08－4.37 mm. Multivariate analysis showed that age was significantly correlated with the recovery of UC at 1 month after LRP (P＝ 0.035, OR = 0.16), and so was the URS thickness at 3 months (P＝ 0.011, OR = 0.02), 9 months (P＝ 0.014, OR = 0.039) and 12 months (P＝ 0.014, OR = 0.039). Urinary incontinence with the URS thickness ≤1.6 mm at 12 months after operation was found of a high severity (P＝ 0.010, OR ［95% CI］ = 0.858－6.240). The MUL was positively correlated with the recovery of UC at 9 months (P＝ 0.024, OR = 0.508) and 12 months (P＝ 0.024, OR = 0.508) postoperatively. Correlation analysis revealed that the prostate volume, prostate diameter and other factors included in this study were not significantly correlated to postoperative UC.

The thickness of the URS is positively correlated with the recovery of early UC, the thinner the URS, the severer the UC, and so is MUL. Age is an independent risk factor for the recovery of UC at 1 month after LRP. These findings need to be further verified by more prospective studies with long-term follow-ups.