Obstetrical anal sphincter injuries and outcome of primary repair

Abstract

INTRODUCTIONOASIs (obstetrical anal sphincter injuries) involve third and fourth degree perineal tears during the process of vaginal birth. A third degree perineal tear is a partial or complete disruption of the anal sphincter muscles. A forth degree tear is a disruption of anal sphincter muscles with a breech in rectal mucosa.1 OASIs is a serious complication having bearing on quality of life of the patient in future. The data regarding OASIs in developed countries is elaborately reviewed. The incidence in developed countries is on rise.2 Primiparous delivery, forceps delivery, macrosomic baby, Asian race are known high risk factors for obstetrical anal sphincter injuries. [3][4][5] Rise in incidence is reported to be due to improved recognition of tears following implementation of standardised classification of tears.2 We would like to study the incidence, etiology of OASIs in Indian population.The objective of this study was to determine the incidence of obstetrical anal sphincter injuries (OASIs), to determine the risk factors for development of OASIs and to assess success of primary repair of OASIs. ABSTRACTBackground: OASIs (obstetrical anal sphincter injuries) involve third and fourth degree perineal tears during the process of vaginal birth. It is a grave complication as it can affect quality of life. Incidence of OASIs is on rise in developed countries. We have analyzed OASIs data from a teaching institute in India. Methods: It was a retrospective study. Data was collected from delivery register, postnatal care OPD register and case sheets of patients with OASIs. Data was analyzed to determine incidence and risk factors. The outcome of primary suturing was assessed as per records in postnatal OPD. Results: OASIs was detected in 35 patients (incidence 0.42%), third degree perineal tear was seen in 31 patients, while four patients had forth degree tear. Out of these 35 patients 21 were nullipara. Sixteen patients were instrumental deliveries, 13 and 3 delivered by outlet forceps and ventouse respectively. Primary suturing of the tear was done in 34 patients under anaesthesia. Out of 24 patients who followed up in postnatal clinic at six weeks, 14 patients were asymptomatic. Two had faecal incontinence, while eight had perineal pain. Conclusions: Nulliparity, instrumental delivery, increasing birth weight were high risk factors for obstetrical anal sphincter injuries. Obstetrician needs to be more careful while delivering a patient with multiple risk factors for OASIs. Primary suturing of anal sphincter injury with good post-operative care has a favorable outcome.