Anal sphincter function and integrity after primary repair of third-degree tear: Uncontrolled prospective analysis

Background: The purpose of the present paper was to determine the anatomical integrity and functional effect of a tear to the anal sphincter in women after vaginal delivery. Methods: A prospective review of third- and fourth-degree vaginal tears over a 3 year period at Lyell McEwin and Queen Elizabeth Hospitals, Adelaide. Obstetric details were obtained from the records. All were counselled by a continence advisor and offered consultation with a colorectal surgeon. The integrity of the anal sphincter was assessed by endoanal ultrasound. Results: During the study period there were 6875 vaginal deliveries. There were 89 women (1.3%) who had a third- or fourth-degree tear. Fifty-one (57%) agreed to participate. Primiparity (67%), episiotomy (49%), forceps delivery (29%) and instrumental delivery were common in women sustaining a tear. Symptoms of anal incontinence (mild) or faecal urgency were described in 23 women (45%). Except for three women with an anovaginal fistula none required surgery for the management of faecal incontinence. A sphincter defect was seen in 27 women (53%) on endoanal ultrasound. The presence or absence of a sphincter defect was not significantly associated with symptoms but a trend was suggested (χ² = 3.21; P = 0.07). Conclusions: Third-degree tear after vaginal delivery was a significant intrapartum event, yet associated only with minimal symptoms (excluding patients with anovaginal fistula) even in the presence of a sphincter defect on anal ultrasound.