Inter-observer variability in male pelvic-floor MRI measurements that might predict post-prostatectomy incontinence.

INTRODUCTION: Current studies are focusing on the relationship between anatomical variables in preoperative prostate MRI and the development of post-prostatectomy incontinence (PPI). Nevertheless, there is little evidence regarding the reliability of these measurements. The objective of this study was to analyze the concordance between urologists and radiologists for anatomical measurements that might be PPI predictors. MATERIAL AND METHODS: Pelvic floor measurements with 3T-MRI were performed by two radiologists and two urologists independently and blindly. Interobserver agreement was determined using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. RESULTS: The concordance was good-acceptable for most measurements, except for the levator ani and puborectalis muscle thickness (some ICC values < 0.20/p value > 0.05). The anatomical parameters with the highest degree of agreement were intravesical prostatic protrusion (IPP) and prostate volume (most of the ICC values > 0.60). The membranous urethral length (MUL) and the angle of the membranous urethra-prostate axis (aLUMP) presented ICC > 0.40. The obturator internus muscle thickness (OIT), urethral width and intraprostatic urethral length presented a fair-moderate degree of agreement (ICC > 0.20). Regarding the agreement between different specialists, the highest degree was obtained for the two radiologists and for urologist 1-radiologist 2 (moderate median agreement), while urologist 2 with each of the radiologists had a regular median agreement. CONCLUSIONS: MUL, IPP, prostate volume, aLUMP, OIT, urethral width and prostatic length show acceptable inter-observer concordance and they would be reliable as possible predictors of PPI. Levator ani and puborectalis muscle thickness show bad agreement. Interobserver agreement might not be greatly influenced by previous professional experience.

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

AIMS: There is scarce evidence of anatomical risk factors that might affect long-term post-prostatectomy incontinence (PPI) in patients undergoing robot-assisted laparoscopic prostatectomy (RALP). This systematic review aims to identify anatomical measurements in preoperative magnetic resonance imaging (MRI) that might be associated with increased risk of urinary incontinence (UI) 1 year after RALP. METHODS: A comprehensive search on Pubmed and Scopus databases up to November 2020 was performed. Eight articles met the inclusion criteria and were finally selected. RESULTS: The selected studies included 1146 patients. Seven articles focused on membranous urethral length (MUL); all of them related MUL to long-term PPI in univariate analysis and five of them in multivariate analysis. Four studies presented MUL difference to measure the magnitude of the effect. Average MUL (mm) was 15.9 (SD, 2.6), 16.1 (95% confidence interval [CI]: 13.9-18.9), 12.1 (95% CI 9.7-14.9) and 14.5 in continent patients and 13.9 (SD, 2.9), 10 (95% CI: 8.7-12.1), 10.3 (95% CI: 8.7-12.4) and 9.3 in incontinent patients, with statistically significant differences in all cases. Five studies presented the odds ratio as a result; although there was substantial heterogeneity in the methods used to obtain it, there was consistency in finding an inverse association between MUL and PPI. Other measurements including prostatic-urethral angle, membranous urethral thickness, intraprostatic urethral length and intravesical prostatic protrusion have been reported in few studies, and no association with long-term PPI was found. Levator ani muscle thickness was related to long-term PPI in one article. CONCLUSION: Greater MUL on preoperative MRI is associated with lower risk of UI 1 year after RALP.