SYMPHYSIOTOMY

INDICATIONS. Mild or moderate CPD associated with any of these problems, most of which are interrelated:

(1) A failed trial of vacuum extraction when failure has occurred by a small margin. It will not work if CPD is gross, and vacuum extraction was done on the wrong indication. This is the most common indication. It is difficult to be sure that vacuum extraction won’t work without having a try!

Figure 18.10: OPEN SYMPHYSIOTOMY. A, the position of the symphysis on the anterior abdominal wall. B, the position of the symphysis in relation to the clitoris. C, the structures to cut. D, the incision in relation to the urethra and the bladder.

(2) Obstructed labour with a live baby. If his head is deeply jammed into his mother’s pelvis, perhaps with caput visible at her vulva, symphysiotomy will be safer for her. If you try to section her, his head will be difficult to deliver, and infection of her deeper tissues is more likely.

(3) A difficult vacuum extraction may succeed, but only after prolonged traction and the risk of damaging the baby. Symphysiotomy will make delivery easier and safer for him.

(4) A prolonged second stage. If the criteria for symphysiotomy are met, and vacuum extraction alone is unlikely to succeed, symphysiotomy is better than trying vacuum extraction first.

(5) Mild or moderate CPD with a live baby, particularly in a primigravida, when his head is 1/5 or 2/5 above the brim, and is too tightly held for vacuum or low forceps alone.

(6) To deliver the arrested aftercoming head of a breech—if you are quick!

CAUTION! Symphysiotomy is normally done at full dilatation, but you can do it when there is still a 1 or 2 cm ring of cervix. Another contributor considers that you should never do this!

CONTRAINDICATIONS. (1) Severe CPD. (2) Malpresentations, with the exception of the aftercoming head of a breech (19.8). (3) A dead baby; if there is CPD he should be delivered by craniotomy or section, if there is no CPD a symphysiotomy is unnecessary. (5) A previous Caesarean section. (6) Abnormalities of a mother’s legs or spine. (7) Severe obesity is a relative contraindication. (8) A baby more than 4 kg as estimated by the fundal height being >40 cm (who is too big to deliver by symphysiotomy), or less than 2.5 kg (who does not need one). (9) Poor uterine action in spite of an oxytocin drip, especially if dilatation is not complete. (10) A fetal head which remains >3/5 above the brim after rupture of the membranes.

OPEN SYMPHYSIOTOMY

Do a vaginal examination to check the dilation of the mother’s cervix, and the descent and position of her baby’s head. At this point decide if symphysiotomy is indicated or not.

If his head is 1/5 above the brim a symphysiotomy is unnecessary. If it is 2/5 above symphysiotomy may be indicated. If it is 3/5 above, try to insert a finger vaginally between his head and her pelvis. If your finger passes too easily symphysiotomy is unnecessary. If it passes with difficulty, symphysiotomy is indicated. If it does not pass at all, CPD is too great, so section her. Note that this is somewhat less conservative than the indication for closed symphysiotomy given in Primary Mother Care, which advises that midwives should not attempt it, if the head is more than 2/5 above the brim.

Listen to the fetal heart to make sure that he is alive. Put her into the lithotomy position, with her legs outside the lithotomy poles.

CAUTION! Find two assistants and ask them to support each of her legs, so that her symphysis opens only to a maximum of 3 cm. This must be their only job; they must do nothing else. If they allow her legs to flop apart, the fibres of her sacroiliac joint may rupture, and she will have much postoperative pain. You will need these assistants anyway, even if you have lithotomy poles, to prevent too much abduction.

Pass a stiff rubber or plastic catheter. Clean her skin with iodine and spirit. Palpate the bony margins of her symphysis pubis. Infiltrate the skin and subcutaneous tissue over her symphysis with 20 ml of 1% lignocaine with adrenalin (this is a very vascular area). Allow 3 minutes to pass for it to act. Place the index and middle fingers of your left hand in her vagina, to displace the catheter in her urethra to her right side.

CAUTION! You MUST displace her urethra, or you will cut it. This would be a major disaster!

Incise the skin and subcutaneous tissue over her symphysis pubis in the midline, and find the exact position of the cartilage of the joint. Try locating it with a hypodermic needle first. Then use a standard scalpel to cut down on to it throughout its length. Clamp any superficial bleeding arteries.

When you have exposed the joint throughout its length (it is better felt as a depression rather than seen), divide it using a sharp solid scalpel, or a standard one with a No. 20 or 21 blade. Cut it little by little with your right hand, keeping her urethra to the side with your left hand. Mop up any blood. When the joint is almost divided, it will begin to open. Continue cutting its fibres until it opens fully. Two cm is ideal, it should never open more than 3 cm. Its infrapubic fibres may rupture spontaneously, or need cutting. Judge this by how much it opens. If separation is inadequate, cut more joint fibres, usually the superior and posterior ones.

CAUTION! (1) Always keep her urethra to one side with your left hand. (2) Don’t cut above her symphysis pubis, because her uterus or bladder may be protruding there. A small cut in her uterus is not such a tragedy as cutting her urethra. (3) Never do a symphysiotomy without also doing an episiotomy.

If you have operated on the right indications, she will deliver easily—usually after bearing down with 3 or 4 contractions. If she does not deliver spontaneously, apply the vacuum extractor. Give her ergometrine with the birth of the anterior shoulder.

CAUTION! Don’t apply forceps after symphysiotomy, they may stretch her sacroiliac joint too much.

If she bleeds from the incision, apply pressure. Suture her subcutaneous tissue, tie the vessels with 2/0 catgut, and suture her skin with 2/0 or 1/0 monofilament.

Leave a self retaining catheter in place. Leave this in for 48 hours only, provided her urine is not blood-stained (the usual cause of this is obstructed labour), and release it 4-hourly. Keep her in bed for 48 hours—walking will be painful. Allow her to walk on the 3rd to the 5th day. Some patients can do this easily, others, especially the heavier ones, fail to walk until the 5th or 7th day. Remove her sutures on the 7th day. Most patients are walking well, and fit for discharge, on the 10th day. There is no need to bind her pelvis, her symphysis will heal to leave her pelvis larger that it was before.

DIFFICULTIES WITH OPEN SYMPHYSIOTOMY

If she has FEVER postoperatively, suspect urinary infection due to the catheter.

If she DOES NOT PASS URINE when the catheter is removed on the 3rd day, replace it and try on the 5th day.

If she is INCONTINENT OF URINE, especially on standing, it may be partial so that she also passes urine, or it may be total. Insert a catheter and leave it in for 2 weeks. She will probably recover completely or partly. If she still has trouble it is likely to be partial. Advise her to empty her bladder 4- hourly. Incontinence rarely lasts more than 3 months. If necessary (rare), refer her for a sling operation. Loss of the normal angle where the bladder joins the urethra is probably the cause of temporary incontinence. As she heals this angle returns.

If her wound shows signs of LOCAL INFECTION (common), give her ampicillin or chloramphenicol. Insignificant quantities will reach her baby, but avoid tetracycline or sulphonamides, which may harm him. Careful preparation of her skin with iodine and spirit reduces the incidence of infection.

If she BLEEDS from the branches of her epigastric vessels, watch for a haematoma of her wound,,, which may spread up into her abdominal wall. This is said to be more likely when the closed method is used. If necessary, drain it by removing one or two sutures.

If, later, she develops chronic PAIN and DISCHARGE, she has chronic pubic OSTEITIS (rare). Treatment is difficult, treat her pain symptomatically. It probably only occurs when the incision involves bone, so keep strictly to the midline in the fibrocartilage of the joint. This is easier to achieve in the open method than in the closed one.

If you INJURE HER URETHRA, which should never happen, see Section 18.19D.