In a series of 55 women who underwent overlapping sphincteroplasty for fecal incontinence secondary to obstetric trauma, researchers contacted 47 (86%) patients by postal questionnaire and telephone interview with a median time since surgery of 77 months (range 60–96 months) (116). The investigators observed less symptomatic improvement when compared with the results at 15 months postoperative evaluation. After excluding one patient because of Crohn disease, eight (17%) failed because they required additional surgery, such as colostomy, postanal repair, and artificial bowel sphincter. Among the remaining 38 patients, 27 (71%) reported improved bowel control, 5 (13%) were unimproved, and 6 (16%) were worse. No patient was fully continent to solid and liquid stool and ﬂatus. Only 23 (50%) patients had “good” outcomes defined as not requiring further continence surgery and fecal incontinence less than once per month.
In another study, investigators contacted 49 (69%) of 71 patients by telephone interview (117). All underwent overlapping sphincteroplasty with a median follow-up of 62.5 months (range 47–141 months). Only 6 (12%) patients were totally continent, and another 18 (37%) were continent to liquid and solid stool. More than half of the patients had incontinence to liquid or solid stool. The largest series with long-term follow-up involved contact of 130 (71%) of 191 patients using a postal or telephone questionnaire (118). The median time from surgery for respondents was 10 years (range 7–16 years). Of those who responded, 6% had no incontinence, 16% were incontinent of ﬂatus only, 19% had soiling only, and 57% were incontinent of solid stool. These outcomes were significantly worse than the previously reported 3-year assessment (119). Despite the fact that 61% had a poor outcome defined as having fecal incontinence or requiring additional surgery for incontinence, 62% still considered their bowel control to be better than before surgery, and 74% were satisfied with the results of their surgery. Although control may be improved when compared with preoperative status, continence outcomes do not seem to be maintained at long-term follow-up.
The cause of this deterioration in long-term outcomes is unknown. Possible explanations include weakening of the muscles with normal aging, repair breakdown, and underlying nerve damage from either obstetric injury or the repair itself. A problem with most studies is the lack of a follow-up ultrasonography to determine whether the repair was still intact. The effect of pudendal nerve function on overlapping sphincteroplasty is somewhat controversial. Significantly lower success rates have been shown in a comparison of those with normal pudendal nerve terminal motor latencies to those with abnormal latencies (63% vs. 17%; P < .01) (120). Other studies have confirmed this finding (79,89,106,107,121,122), but the more recent studies fail to show a difference based on preoperative neurophysiologic testing (116,118). Other controversial factors that may affect outcome include age, duration of fecal incontinence, size of the defect, and anal manometry results.
Although there are many controversial aspects to overlapping sphincteroplasty, the literature is in agreement that diverting colostomy is not necessary; bowel confinement does not improve outcomes; clinical improvement correlates with postoperative endoanal ultrasonography results; and prior sphincteroplasty does not affect outcomes (114,116,120,123–128).