Objective assessment of bladder neck elevation and urethral compression at colposuspension

Abstract

Objectives 1. To assess whether magnetic resonance imaging and intra-operative measurements are useful in assessing bladder neck elevation and urethral compression at colposuspension; 2. to see if intra-operative measurements could be a substitute for magnetic resonance scan measurements. Design Prospective, observational study. Setting Urogynaecology Unit, NHS Trust hospital. Population Seventy-seven women undergoing colposuspension. Methods Bladder neck elevation was assessed using magnetic resonance imaging and measuring the amount of suture bow-stringing intra-operatively. Urethral compression was assessed using magnetic resonance imaging and by two intra-operative measurements: the distance between the medial sutures (with a ruler) and the distance between the urethra and the pubic bone (using paired Hegar dilators). Results The assessment of bladder neck elevation and compression against the pubic bone using magnetic resonance imaging was reliable (95% limits of agreement: −7.1mm to +7.1mm and −1.7mm to +3.8mm, correlation coefficient 0.92 and 0.87, respectively). The intra-operative assessment of urethral compression with a ruler was also reproducible at both paravaginal and pectineal sites (95% limits of agreement −2.6mm to +2mm and −2.1mm to +2.4mm, respectively; correlation coefficient 0.99 for both distances). Other intra-operative measurements of bladder neck elevation (suture bow-stringing) and urethral compression (Hegars) did not correlate with equivalent magnetic resonance scan measurements (kappa = −0.046, P = 0.31; kappa = 0.052, P = 0.41, respectively). Conclusions Measurements have been found that can reliably assess bladder neck elevation and urethral compression at colposuspension. These measurements should be suitable for investigating morbidity following colposuspension.