The two most common types of episiotomy are the midline episiotomy and the medio-lateral episiotomy. There has been significant debate about the advantages and disadvantages of these two types of episiotomy. In the U.S., midline episiotomy is by far more common, while medio-lateral episiotomies are more common in and other parts of the world.
A midline episiotomy refers to an episiotomy where the incision of the vaginal opening is directly in the midline, straight down toward the anus. The advantages of a midline episiotomy include easy repair and improved healing. This type is also less painful and is less likely to result in long-term tenderness or problems with pain during intercourse. There is often less blood loss with a midline episiotomy. The main disadvantage of a midline episiotomy is the likelihood for this type of incision to extend (continue tearing) and involve the anal sphincter or the lining of the rectum. When this happens, injury to the sphincter can result in long-term problems, such as fecal incontinence or the development of a recto-vaginal fistula (a small channel that connects the rectum with the vagina).
A right medio-lateral episiotomy begins at the vaginal opening in the midline with the incision directed toward the right buttocks at a 45-degree angle. The main advantage of the medio-lateral episiotomy is that it is less likely to extend into or involve the anal sphincter and the rectum. Disadvantages of the medio-lateral episiotomy are significant and include increased blood loss, increased pain, difficult repair, and an increased risk of long-term discomfort, especially during intercourse.
Both midline and medio-lateral episiotomies are easy to perform-they involve the simple incision of the opening of the vagina. The episiotomy should be performed when 3 or 4 centimeters (cms) of the baby's head is visible at the vaginal opening. If the mother has not received anesthesia in the form of an epidural block, local anesthesia may be given at the site of the episiotomy. The area is cleaned with soap. The provider then inserts two fingers into the vaginal opening to protect the baby's head (the fingers should be inserted between the baby's head and the tissue of the vaginal opening). One blade of the scissors is then inserted between the two fingers and a small incision, approximately 2 to 3 cms in length, is made. The incision may be made in the midline or medio-laterally.
After the incision has been made, the physician gently supports the episiotomy site to prevent further tearing by pinching the tissue just below the incision. Gentle pressure is also placed against the top of the baby's head to prevent the head from rapidly or abruptly delivering. A controlled delivery is preferred because it is easier to prevent tearing during a slow and steady delivery of the baby's head.
After delivery of the baby and the placenta, the vagina and perineum are cleaned and carefully examined. The physician must be sure that there has been no tearing of the vaginal walls or cervix. The doctor or midwife may use a special instrument (a metal retractor) to adequately visualize the vagina and cervix. Once the provider is certain there has been no further tearing, the episiotomy itself will be visualized. The physician may wash the area with sterile water or an antibacterial soap solution. If the incision has involved the lining of the rectum or the anal sphincter (a doughnut shaped muscle that controls the anus and prevents the leakage of stool), sterile fluids may be used to wash out the wound. In most cases, the episiotomy will involve only the vaginal lining and the tissue directly below the vagina. However, if the episiotomy does extend into the anal sphincter or the rectal lining, these portions should be repaired first.
All repairs are performed with suture (surgical thread) that absorbs into the body and does not require removal. A very thin suture is used to bring together and close the rectal mucosa and larger and stronger sutures are used to repair the anal sphincter. After the rectal mucosa and the anal sphincter have been repaired, a simple repair of the remaining episiotomy is required. Several stitches may be required to bring together the deeper tissues below the vaginal lining; a continuous suturing of the vaginal mucosa and the skin outside the vagina is required to completely close the incision.
The severity or extent of a vaginal laceration or episiotomy is often referred to in degrees as discussed below.
Degrees of vaginal tears:
First Degree -The smallest or most simple episiotomy, extending only through the vaginal mucosa. It does not involve the underlying tissues.
Second Degree -This is the most common type of episiotomy. It extends through the vaginal mucosa and into the submucosal tissues, but does not involve the rectal sphincter or mucosa.
Third Degree -A third degree episiotomy involves the vaginal mucosa, submucosal tissues, and a partial or complete transection of the anal sphincter muscle.
Fourth Degree -The most severe type of episiotomy includes incision of the vaginal mucosa, submucosal tissues, and anal sphincter, and it also involves of the lining of the rectum.
The severity of the episiotomy is directly associated with the amount and seriousness of postpartum and long-term complications. As the degree of the episiotomy increases, there is more potential for infection, postpartum pain, and other complications, such as leakage of stool and development of recto-vaginal fistula.