Perineal tears are normally prevented by adequate episiotomy, but can nevertheless occur in certain circumstances such as delivery of a big baby, occipitoposterior position, face presentation, forceps or precipitate delivery, and narrow pelvic outlet or subpubic angle.
Tears predispose to postpartum haemorrhage. Cervical and vaginal lacerations bleed profusely. In postpartum haemorrhage, bleeding is unlikely to come from a contracted uterus, so the patient should instead be examined for tears. Inspection of the cervix for tears is routine after any type of vaginal delivery.
If blood loss has been profuse, the patient may be hypovolaemic. Perineal tears are visible on local examination: a speculum and swabs held with sponge forceps can be helpful in examining lacerations. Perineal tears are classified according to the degree of damage. In a first-degree tear, the fourchette is torn, together with only a small part of the vaginal and perineal skin. In a second-degree laceration, the perineal body is torn, together with the posterior vaginal wall, to a variable degree. In a third-degree tear, the damage extends beyond the anal sphincter into the anal canal. Tears due to direct trauma have ragged edges with surrounding abrasions and contusions.
See tray for Episiotomy, Annex 1 and add a vaginal speculum, No. 1 and 2/0 chromic catgut sutures, and 2/0 plain catgut sutures.
All tears should be sutured immediately unless they are already infected. Infected tears should be cleaned and dressed, but should not be sutured until the infection has cleared; appropriate antibiotics should be administered.
For the repair of first-degree and second-degree tears, place the patient in the lithotomy position and infiltrate a local anaesthetic in the region of the tear. Expose the tear (Fig. 4.1A). Suture the vagina first with continuous 0 chromic catgut; then the perineal body with three or four interrupted stitches of No. 1 chromic catgut; and finally the perineal skin with interrupted stitches of 2/0 plain catgut (Fig. 4.1B - D). Apply a sterile pad.
Repair a third-degree perineal rear with the patient under general anaesthesia. First close the muscle wall of the rectum and the anal canal with interrupted or continuous 0 chromic catgut, placing the sutures so as to avoid the bowel mucosa (Fig. 4.1E). Identify the torn ends of the anal sphincter and approximate them with two or three mattress sutures of 2/0 chromic catgut (Fig. 4.1F). The repair of the vagina, perineal body, and the skin can then be carried out as described above. Apply a sterile pad.
Fig. 4.1. Repair of perineal tears. Exposing a perineal tear (A); suturing a tear of the vagina (B); suturing the perineal body (C); suturing the skin (D). Third-degree tear: closing the muscle wall of the rectum (E) and suturing the anal sphincter (F).
Infiltrate a local anaesthetic in the region of the tear. Expose the tear and catch both its edges with sponge forceps. Stitch the edges together with mattress sutures of 0 chromic catgut. Take the highest stitch about 1 cm above the apex to include any retracted vessels, after inserting a preliminary stay suture lower down. Apply a sterile pad.
After infiltrating a local anaesthetic, stitch a vaginal tear as described above for a perineal tear and apply a sterile pad. Tears of the anterior vaginal wall involve the tissues close to the urethral meatus; the torn edges lie in apposition, and suturing is necessary only when there is free bleeding. Bladder catheterization is necessary if there is retention of urine as a result of muscle spasm and swelling.
Clean and dress the wound daily and after each passage of stool.
Possible complications such as haematoma in the parametrium, residual recto-vaginal fistula, and dyspareunia can be prevented by proper surgical techniques.