EPISIOTOMY AND

VAGINAL TEARS

Episiotomy

An episiotomy is a surgical incision through the perineum made to enlarge the vagina and assist childbirth.

Prior to an episiotomy, lignocaine is injected into the subcutaneous tissues of the perineum and vagina. A right mediolateral cut is then made and pressure on the fetal head is maintained so that the delivery is slow and the head remains flexed, minimizing the possibility of the incision extending.

At one time it was believed that episiotomies reduced the incidence of anal sphincter tears. There is, however, little good evidence to support this and there is certainly no evidence to support routine episiotomy in all deliveries as a preventive measure against third- or fourth degree tears. Episiotomy rates are falling (Figure 1.)

Figure 1. Falling Episiotomy Rates. A study involving 34,048 vaginal births at Thomas Jefferson University Hospital in Philadelphia, Pa, which showed a reduction in episiotomy rates from 69.6% in 1983 to 19.4% in 2000⁰²⁰¹

Midline episiotomy in particular does not protect the perineum or sphincters during childbirth and may impair anal continence. If an episiotomy is to be performed at all, a right (or less commonly left) posterolateral episiotomy is preferred (Figure 2).

Figure 2. A right medio-lateral episiotomy.

Diagrams and pictures of episiotomy and episiotomy repair are available at moondragon - Please note that we would recommend a continuous subcuticular suture to close the vaginal skin.

How is an episiotomy repaired?

These newer materials result in less short-term pain and less analgesic requirements than older materials such as catgut and non-absorbable sutures. Good perineal hygiene after delivery is likely to aid healing, and the use of ice packs. The perineum is infiltrated with 1% lignocaine unless an epidural is in situ or there has been a pudendal block or perineal infiltration prior to delivery. The apex of the vaginal incision or tear is identified and the first suture placed above this level.An episiotomy repair is demonstrated by Figures 3-5.Repair should be with an absorbable synthetic material (Dexon or Vicryl), using a continuous subcuticular technique to minimize short- and long-term problems.

Figure 3. The vaginal mucosal suture commences from just above the apex of the incision and the perineal musculature has an inverted suture.

Figure 4. The muscle is closed with a continuous suture.

Figure 5. The vaginal skin is closed with a continuous subcuticular suture.

Vaginal Tears

A tear may be less painful than an episiotomy and may also heal better.

Classification of spontaneous perineal tears:

First degree Injury to the vaginal epithelium and vulval skin only.
Second degree Injury to the perineal muscles, but not the anal sphincter.
Third degree Injury to the perineum involving the anal sphincter complex.
Fourth degree Injury to the perineum involving the anal sphincter complex and rectal mucosa.

Repairing a third or fourth degree tear.

This should ideally be by an experienced clinician, in theatre, with good analgesia, good lighting and the appropriate instruments. The anal mucosa should be repaired using interrupted dissolving sutures, with the knot of each suture in the lumen of the bowel. The internal sphincter is then identified and its ends approximated and sutured with a monofilament suture such as polydioxanone (PDS). Next, the ends of the external anal sphincter are identified and either approximated or overlapped, again with the monofilament suture. The rest is as described for episiotomy repair. Antibiotics, laxatives and fibre are important to allow healing. If secondary breakdown occurs, it may be necessary to perform a defunctioning colostomy before re-repairing.

Women delivering in the Swedish setting had a 23 times higher risk of OASR compared to Italy. An association between obstetric anal sphincter rupture and birth weight, gestational age, instrumental vaginal deliveries and duration of second stage was found. ⁰⁸⁰¹