Diagnosis and Treatment of Obstetric Anal Sphincter Injuries: New Evidence and Perspectives

Abstract

Perineal injury during childbirth is a common event with important morbidity associated in particular with third-and-fourth degree perineal tears (also referred to as obstetric anal sphincter injuries—OASIS). Early diagnosis of these damages is mandatory to define a prompt therapeutic strategy and thus avoid the development of late-onset consequences, such as faecal incontinence. For this purpose, various diagnostic exams can be performed after a thorough clinical examination. The management of OASIS includes several measures and should be individualized according to the timing and features of the clinical presentation.

Comparison of the outcomes of overlapping and direct apposition sphincteroplasty techniques in anal sphincter repair

“…Obstetric anal sphincter injuries (OASIS) are referred to also as third-and fourth-degree spontaneous perineal tears (14). The incidence of OASIS has been reported to be between 0.5% and 17% in the literature (15)(16)(17)(18)(19)(20). Primiparous women (5.7%) are at greater risk than multiparous women (1.5%) with no previous OASIS (21).…”

“…The overlapping technique can be used only for full-thickness lacerations, as two free ends of anal sphincter muscle are required for a tension-free overlapping repair. The torn ends of the EAS are brought together, and 1-1.5 cm of the muscle ends are overlapped and sutured (15). In a meta-analysis, no significant difference has been found between the direct apposition and overlapping repair techniques in terms of flatus incontinence, dyspareunia and perineal pain, although those undergoing overlapping surgery have been shown to have lower faecal urgency and anal incontinence scores than those treated with the direct apposition technique (26).…”

Update and Trend in Episiotomy Practice

“…A delay of up to 12 h is allowable if resources for repair are not available. A secondary repair can be done later when tissue edema has subsided for cases diagnosed later or if injuries have been unrepaired for more than 12 h, and this is referred to as secondary repair [39].…”

“…The aim of sphincter repair (either primary or secondary) is to restore a functioning anal canal by reconstruction of a muscular cylinder that is at least 2 cm thick and 3 cm long [39]. OASI; (a) third-degree perineal tear, (b) fourth-degree perineal tear.…”

“…Key: IAS, internal anal sphincter; EAS, external anal sphincter. Meticulous hemostasis and anatomic approximation with a multilayer closure of all disrupted tissue layers are the key principles for preventing complications and restoring fecal continence and two recognized methods for the repair of OASI: end-to-end (approximation) and overlap repair [39] are important depending on the extent of the injuries as illustrated in Figure 3.…”