Objective: The purpose of this study was to use magnetic resonance imaging to observe the changes of the position of the levator ani muscle relative to the bladder neck after Burch colposuspension.
Study design: Women with urodynamic stress incontinence underwent Burch colposuspension. Magnetic resonance imaging was performed 1 week before surgery and 1 year after the operation. The levator ani muscle and the bladder neck were imaged in the parasagittal and sagittal planes, respectively; and their position was measured in relation to the pubococcygeal line. The reproducibility of these measures was investigated. Changes that occurred to levator ani muscle anatomy after the operation were correlated to surgical success. Surgical outcome was assessed objectively at 1 year with urodynamic testing.
Results: Of the 73 women who were studied, only 28 women were included in the study because the medial edge of the levator ani was visible clearly on a parasagittal magnetic resonance image. At the 1-year follow-up, the objective cure rate was 86%. Measures of bladder neck and levator ani position in relation to the pubococcygeal line were found to be reproducible. Burch colposuspension produces a significant elevation of the levator ani, with a reduced distance between the bladder neck and the levator ani muscle. Surgical success was associated significantly with a shorter distance between bladder neck and levator ani muscle.
Conclusion: The anatomy of the levator ani muscle is changed by colposuspension. The apposition of the levator ani muscle to the bladder neck may play a role in the restoration of continence.