Pelvic magnetic resonance imaging parameters predict urinary incontinence after robot‐assisted radical prostatectomy

Abstract

Objective: Urinary incontinence (UI) is a major prostate cancer (PCa) treatment-related morbidity. It has been reported that post-prostatectomy UI is related to the width of the pelvic floor muscles (PFM) and the length of the urethra. However, the details of these anatomical parameters are unknown. The aim of this study was to investigate whether preoperative pelvic parameters or anatomical parameters of the urethra, as measured by magnetic resonance imaging (MRI), are correlated with UI. Methods: Between 2010 and 2017, 571 patients with localized PCa underwent robot-assisted radical prostatectomy (RARP) at Okayama University Hospital. Patients treated by a single experienced surgeon were included in the study. Preoperative prostate volume, obturator internal muscle, anal sphincter muscle, levator ani muscle (LAM), urethra wall thickness (UWT), and membranous urethral length (MUL) were measured by MRI. Patients were divided into two groups depending on leakage status 1 year after RARP using Expanded Prostate Index Composite Item 1.Results: Seventy patients were included in this retrospective study. Based on leakage status, 37 and 33 patients were allocated to the no-leakage and leakage groups, respectively. There were significant differences between the two groups in age (P = 0.03), MUL (P < 0.001), UWT (P = 0.03), and LAM (P = 0.001). Multivariate logistic regression analyses revealed that MUL and LAM predicted UI 1 year after RARP.Conclusions: Pelvic parameters measured by MRI before RARP may be useful in the prediction of UI. In particular, MUL and LAM can predict postoperative UI by strict definition. K E Y W O R D Scomputer-assisted surgery, incontinence, magnetic resonance imaging (MRI), prostate cancer, prostatectomy ;11:122-126. tum. The seminal vesicles and vas deferens were identified and the vas deferens were skeletonized, cauterized, and divided. The seminal vesicles were dissected free. Denonvilliers' fascia was incised in the midline and the rectum was dropped posteriorly off the prostate. Then, Retzius' space was dissected. | Statistical analysisTo determine the significance of differences in potential UI risk factors between the no-leakage and leakage groups, Fisher's exact test was used for categorical variables and the Mann-Whitney U-test was used for continuous variables. Predictors of UI 1 year after RARP were analyzed using logistic regression analysis, including age, BMI, PSA, diabetes mellitus, ASM, OIM, LAM, UWT, and MUL. Statistical significance was set at two-tailed P < 0.05 for all analyses. All statistical analyses were performed using JMP 13.2 software (SAS Institute, Cary, NC) and EZR version 1.36

The Effectiveness of Cystography-Measured Bladder Neck Elevation at Predicting the Return of Continence After Robot-Assisted Radical Prostatectomy

“…As they have been reported, many static cystographic findings could estimate the postoperative urinary continence. In addition to that, some researchers the similar results were reported using preoperative magnetic resonance imaging [10,11]. However, we believed that dynamic evaluation of cystography is needed.…”

Anatomical predictors of long‐term urinary incontinence after robot‐assisted laparoscopic prostatectomy: A systematic review

“…Average MUL in continent patients was 15.9 (±2.6) mm in the article by Song et al, 13 16.1 (95% confidence interval [CI]: 13.9–18.9) in the study by Regis et al, 12 14.5 in the article by Schmid et al, 15 and 12.1 (95% CI: 9.7–14.9) in the article of Sadahira 14 . Conversely, average MUL in incontinent patients was lower, 13.9 (±2.9) mm in Song, 13 10 (95% CI: 8.7–12.1) in Regis, 12 9.3 in Schmidt, 15 and 10.3 (95% CI: 8.7–12.4) in Sadahira 14 …”

Correlation between lumbar skeletal muscle size and urinary incontinence after radical prostatectomy

“…Of the preoperative patient characteristics, several meta‐analyses revealed that older age, obesity, and the presence of comorbidities and lower urinary tract symptoms influence postoperative UIN 2‐4 . Of the pelvic MRI parameters, a short membranous urethral length, urethral wall thickness, levator ani muscle, large prostate volume, and intravesical prostatic protrusion were identified as predictive of postoperative UIN 4,6,7,9,10 . However, these studies were limited by biases in interobserver measurements or MRI acquisition conditions.…”

“…Risk factors for UIN after RP in patients with PCa have been reported by several studies 2‐10 . Among them, patient age and obesity are common factors influencing UIN 2‐4 .…”

“…Pelvic magnetic resonance imaging (MRI) findings and the surgical technique, including nerve sparing, have also been associated with UIN. However, no risk factors for UIN after RP have been defined so far 4‐10 . The number of elderly patients diagnosed with PCa is increasing, and urinary QoL after RP is becoming a very serious issue in cancer care; better overall health care will enable longer survival.…”