Relationship between surgically induced neuropathy and outcome of pelvic organ prolapse surgery.

The aim of the study was to determine whether surgically induced perineal neuropathy relates to the outcome of surgery for the correction of pelvic organ prolapse. Perineal nerve terminal motor latencies (PeNTML) were obtained in 31 women prior to and following transvaginal surgery for the correction of pelvic organ prolapse consisting of bilateral sacrospinous ligament vault suspension and bilateral paravaginal cystocele repair. Mean follow-up was 32 months (range 12-60). Surgical outcome was defined as optimal (asymptomatic, with the apex of the vagina above the levator plate with no tissue protruding beyond the hymen in the upright position with maximum Valsalva), or suboptimal (apical descent of > 50%, or any vaginal wall protrusion beyond the hymen in the upright position with maximum Valsalva). Surgically induced neuropathy was defined as an increase of 0.6 ms or more in the averaged right and left PeNTML measurements following the surgery. All women had preoperative symptomatic prolapse and the mean preoperative PeNTML was prolonged compared to established normals. Using strict definitions, 11 women had optimal outcome and 20 had suboptimal outcome. The outcome groups were similar with respect to age, weight, parity, degree of preoperative prolapse and preoperative perineal neuropathy. Eleven women had surgically induced perineal neuropathy. This was associated with suboptimal outcome compared to optimal outcome (P = 0.03). The relative risk of suboptimal outcome with surgically induced neuropathy was 1.82 (95% CI 1.13-2.93). It was concluded that a relationship exists between the outcome of organ prolapse surgery and surgically induced perineal neuropathy as measured by PeNTML. Such neuropathy may play a role in failed pelvic reconstructive surgery.