Pudendal nerve function in women with symptomatic utero-vaginal prolapse

Pelvic floor function has been studied in 27 women with symptomatic utero-vaginal prolapse and 15 age-matched control subjects. There was no evidence in the patients on physiological testing of significant denervation of the pelvic floor muscles, with no significant difference in the maximum resting and squeeze anal pressures, the pudendal nerve terminal motor latency or external anal sphincter fibre density on single fibre electromyography between the groups. However, those patients with a small rectocele (less than 2 cm) had a significantly higher fibre density than the group with a large rectocele (p = 0.03) and the control group (p less than 0.001). Six of eight patients with a small rectocele had increased fibre density compared with 3/19 with a large rectocele (p = 0.006) and 2/15 control subjects (p = 0.006). This was independent of age, obstetric factors and the presence of internal rectal prolapse. These findings suggest that patients with symptomatic utero-vaginal prolapse and small rectoceles have pelvic nerve damage, and development of a large rectocele may provide some protection against perineal descent and pudendal neuropathy, although the number of patients in the small rectocele group was small and confirmation from further similar studies is required.