[Relationship between recovery of urinary continence after laparoscopic radical prostatectomy and preoperative/postoperative membranous urethral length].

OBJECTIVE: To evaluate the relationship between recovery of urinary continence after laparoscopic radical prostatectomy (LRP) and preoperative/postoperative membranous urethral length (MUL) on magnetic resonance imaging. METHODS: We retrospectively analyzed 69 patients with pathologic confirmed prostate carcinoma who underwent laparoscopic radical prostatectomy. Preoperative MUL was defined as the distance from the apex of prostate to the level of the urethra at penile bulb on the coronal image. Postoperative MUL was defined as the distance from the bladder neck to the level of the urethra at the penile bulb on the coronal image. MUL-retained rate was defined as the percentage of postoperative MUL to preoperative MUL. All patients received extraperitoneal LRP. Patients reported freedom from using safety pad (0 pad/d) were defined as urinary continence. Multivariate Logistic regression analyses were used to identify independent predictors of early continence recovery after LRP. Kaplan-Meier analyses and log-rank test were used to compare time to continence recovery between the groups. RESULTS: For all the 69 patients, the average age was (71.4±8.6) years. The prostate specific antigen before biopsy was (23.40±30.31) µg/L, and the mean preoperative prostatic volume by magnetic resonance imaging was (39.48±22.73) mL. The mean preoperative MUL was (13.0±3.3) mm, the mean postoperative MUL was (12.3±3.4) mm, and the mean MUL-retained rate was 93.9%±6.2%. The continence rate for all the patients after LRP was 57.9% and 97.1% in three months and one year, respectively. The patients achieving early continence recovery had significant smaller prostatic volume (P=0.028), longer preoperative MUL and postoperative MUL (P < 0.001). Multivariate Logistic regression analyses revealed postoperative MUL (P < 0.001) were predictors of continence recovery after LRP. Kaplan-Meier analyses and Log-rank test revealed that preoperative MUL (≥14 mm vs. < 14 mm, P < 0.001) and postoperative MUL (≥13 mm vs. < 13 mm, P < 0.001), MUL-retained rate (< 94% vs. ≥94%, P < 0.001) were all significantly associated with continence recovery. CONCLUSION: Post-operative MUL was independently predictors of early continence recovery after LRP. Preoperative MUL, postoperative MUL and MUL retained rate were significantly associated with recovery of urinary continence.