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.