Background
The anal sphincter is anatomically well protected by the fat tissue in
the ischiorectal fossa and by the gluteal muscles and pelvic structures
[1]. The injuries are thus not frequent, and are mostly caused
iatrogenically (surgery, childbirth), or by sexual injuries, or war
injuries from bullets, fragments, etc [2-4]. The commonest cause of
anal sphincter damage is child birth injury and the site is always the
anterior midline and easily treated as the external anal sphincter
muscles are mainly shifted laterally [4]. Complete division of the
sphincter ring is followed by retraction of the cut ends to about half a
circle and, during the subsequent healing the gap is filled by fibrous
tissue which only contracts a little and leaves a long non-contractile
segment. Clinical assessment of traumatic anal injury may suffice in
determining the sphincter defect in resource-limited settings where
endoanal ultrasonograpy is not available [5, 6]. The aim of surgical
repair is to remove this segment and recreate a long anal canal
surrounded by active sphincter muscle [5]. Traumatic perineal
injuries resulting in anal sphincter disruption often occur with severe
associated life-threatening injuries. Once stabilized, assessment during
the secondary survey will identify perineal and/ or anal injuries. The
general principles of injury prioritization, perineal debridement and
diversion of the faecal stream in cases of associated rectal laceration
are important [2, 3].