Objective: We sought to determine the long-term efficacy, safety, and urodynamic effects of the Mersilene mesh suburethral sling in treating complicated forms of genuine stress incontinence.
Study design: Two hundred women diagnosed with genuine stress incontinence, complicated by recurrence, intrinsic sphincter deficiency, or chronically increased intraabdominal pressure underwent a suburethral mesh sling procedure (Mersilene; Ethicon Inc, Somerville, NJ). They were monitored with yearly clinical examinations plus short- and long-term postoperative urodynamic evaluations; statistical analysis was carried out by use of the Friedman 2-way analysis by rank, Fischer-Freeman-Halton exact testing, analysis of variance for repeated measures, Wilcoxon, exact Mann-Whitney U test, and Bonferroni paired t test. Of 176 patients who were 5 months or more postop, 127 (72%) had preoperative and short-term postoperative urodynamic evaluations (range 5 to 23 months, mean 12.6 months). Fifty-two of 117 women who were more than 19 months postop (44%) completed preoperative and long-term postoperative urodynamic evaluations at a mean of 63 months (range 20 to 107). One hundred thirty-six of 176 patients (77%) who were more than 4 months postop had a short- and/or long- term postoperative urodynamic evaluation (range 5 to 107 months, mean 30 months).
Results: Objective cure rate by stress test was 93% (126 of 136 patients) at a mean of 30 months follow-up. The long-term objective cure rate was 94% (49 of 52). Subjectively, the short- and long-term cure rates were 95.3% and 90.4%, respectively. The cotton swab angle deflection decreased by a mean of 54 degrees at 1 year and 50 degrees at 5 years. Of the 10 failures, the mean preoperative cotton swab straining angle was 19.6 degrees, with 6 being < 30 degrees. Nineteen patients had a negative preoperative cotton swab angle test result (mean straining angle 15 degrees before operation, -6 degrees after operation) and a long-term cure rate of 67%. The objective cure rate in patients with positive cotton swab angle results monitored long term (mean 62 months) was 100% (41 of 41). The postvoid residual increased by a mean of 25 mL short term and 10 mL long term. Thirty-eight patients (19%) had a total of 43 complications. Seven patients (3.5%) had long-term retention. De novo detrusor instability occurred in 12 patients (8.8%), although it was cured in 6 (4.4%). Eight patients (4%) had vaginal or inguinal sling erosion and were healed after revision. Delayed healing at the vaginal sling site responded completely to estrogen cream in two (1%) patients. Five women had treatable vaginal stenosis, 5 had a local inguinal collection/infection unrelated to the mesh, and 3 required a 2-unit transfusion of packed red blood cells. One patient each had an entrapped nerve released, a cystotomy repaired, or experienced thigh numbness or groin pain.
Conclusions: The suburethral Mersilene mesh sling has a very high long-term objective and subjective cure rate in the treatment of complicated forms of genuine stress incontinence. Frequent complications do occur but are remediable. The 33% failure rate among patients with a preoperative negative cotton swab angle test result and the very low cotton swab straining angle among the 7% who had sling failures further confirms the widely held belief that sling urethropexy in the absence of hypermobility lacks efficacy.