Episiotomy: techniques and indications.

I n current obstetric practice episiotomy is generally taken to refer to an incision of the perineum and vagina to facilitate vaginal delivery. While the most precise definition of this incision is perineotomy, episiotomy is the generally employed terminology and thus is used in this article. The evolutionary background and historical perspective of this procedure have been reviewed extensively by Thacker and Banta l and are not reviewed here. This article reviews the techniques of the various types of episiotomies as well as their indications and contraindications. It also addresses the relative risks and benefits of episiotomy. Techniques The only types of episiotomy with any place in current obstetric practice are the midline and mediolateral procedures. Other techniques such as the lateral epi-siotomy are mentioned only for historical completeness and have no place in current (1986) practice. Midline Episiotomy Midline episiotomies are performed along the median raphe of the perineum and extend from the introitus down to, but not including, the fibers of the rectal sphincter capsule (Fig. 1). The incision divides the insertions of the superficial perineal muscles and avoids muscle fibers as well as major blood vessels. It should also involve 3-4 em of the vaginal mucosa above the hy-menal ring. This minimizes the risk of vagi-nallaceration. Midline episiotomy is most often performed with blunt surgical scissors but can also be performed with a scalpel. Care must be taken in the latter case to avoid fetal injury. Caution must be observed in both techniques that the rectum is not entered inadvertently. Despite controversy over the optimum timing of midline episiotomy,2.3 most authors and practitioners believe that the incision should be deferred until the presenting part has begun to distend the perineum. If it is performed too early, excess blood loss will probably occur. If performed too late, any protective benefit for the maternal perineum or fetal presenting part may be reduced. The recommendations of Buxton and Muran would seem appropriate for uncomplicated cases, namely, if an episiotomy is indicated it should be timed so that the fetus will be delivered within the next three to four contractions.