Main Findings
In spite of several preventive strategies, OASI is still a relatively common complication of vaginal delivery and associated with significant morbidity. The chance of anal incontinence following a primary repair is related to the degree of OASI (12)
Only 35% of our patients had a known primary OASI repair. Many of our patients were in the older age bracket and were not aware if they had a primary repair with their index delivery as this had not been well communicated to them, and some of our patients had occult OASI injuries.
Our study showed that the functional results of transvaginal AS repair have sustained satisfactory outcomes with almost 70% of patients having 5 points or more improvement of their St Mark score at 57 months. This outcome correlates with the fact that 70% of our women would recommend this procedure to a friend.
Our study indicated that 73% of women have persistent urgency post operatively, similar results of persistent urgency was also reported in a large Danish study with 220 months follow up (13). Ongoing urgency could be related to a persistent IAS defect. IAS defects are more difficult to identify and repair; particularly in a delayed setting, perhaps indicating that a sphincter repair should not be performed solely for faecal urgency.
Overall rates of surgical complications after a sphincteroplasty range from 5% to 27%. The most common adverse event after sphincteroplasty is wound infection, which occurs in 6–35% of cases. In our cohort we had a higher incidence of wound infection/perineal breakdown (45%). This could be due to the fact most of our complications were patient reported, the rates of infection may thus be overestimated as many of our patients present with vaginal discharge as part of the healing process, that does not necessarily indicate a wound infection. Interestingly in our group of women with concurrent fistula repair all of the women reported symptoms of infection. Importantly the presence of wound infection or perineal breakdown did not change the outcomes in our study.
Perineal wound infection is uncommon after vaginal repair but when an AS repair is performed, the proximity to the anal canal dramatically increases the risk of infection and breakdown. Possible preventive measures for breakdown may be the use of drains, although this may cause sinus formation. Prophylactic antibiotics may reduce infection but there is no current evidence that prolonged antibiotic prophylaxis beyond the intra operative dose has any added benefit (14).