Aim: Structural anal sphincter damage may be secondary to obstetric anal sphincter injury, perineal trauma or anorectal surgery. We reviewed the spectrum of anal sphincter injuries and their outcomes in a tertiary care colorectal unit.
Methods: Data of patients who underwent anal sphincter repair between 2004 and 2008 were analyzed retrospectively. Outcomes were compared with respect to etiology, type of repair, previous attempts at repair and manometry findings. Outcomes were defined as good or poor based on patient satisfaction as the primary criteria.
Results: Thirty-four patients underwent anal sphincter repair. Twenty-two injuries were obstetric, eight traumatic, and four iatrogenic. All patients underwent overlap sphincteroplasty with six additional anterior levatorplasty and seven graciloplasty. Twenty-three (67.6%) patients had a good outcome while nine (26.4%) had a poor outcome. All patients who had augmentation anterior levatorplasty had a good outcome. Fifty percent of patients with a previous sphincter repair and 42.9% requiring augmentation graciloplasty had a poor outcome. Median resting and squeeze anal pressures increased from 57.5 to 70 cmH₂O and 90.25 to 111 cmH₂O in those with a good outcome.
Conclusions: Overlap sphincteroplasty has a good outcome in majority of the patients with incontinence due to a structural sphincter defect. Additional anterior levatorplasty may improve outcomes. Previous failed repairs or use of a gracilis muscle augmentation may have a worse outcome secondary to poor native sphincter muscle. Improvement in resting and squeeze pressures on anal manometry may be associated with a good outcome.