18.8 Symphysiotomy

Cutting a patient’s symphysis allows the two halves of her pelvis to separate 2 to 2.5 cm. This increases its diameter by 0.6 to 0.8 cm, which is enough to overcome mild or moderate CPD, and so avoid Caesarean section. After delivery, its circumference remains wider by about 1.5 cm, and its diameter by about 0.5 cm, so that her next deliveries may be normal. Symphysiotomy is thus particularly valuable if she wants a large family.

This is one of the most contentious operations in this book. One school of thought considers it a ‟barbarous operation done by expatriate doctors on the mothers of the developing world”Another school, which includes all our contributors who practise obstetrics, considers it an invaluable operation which needs to be reinstated and given its proper place: (1) Unlike Caesarean section, especially with unskilled anaesthesia, it is never fatal, and seldom produces complications, particularly serious ones. (2) It does not leave a mother with a scar in her uterus which may rupture if she does not deliver in hospital when she is pregnant next time. (3) It may save her life if she delivers in a health centre and cannot be referred. Like many other medical procedures it has been evaluated by personal experience rather than by formal trials, and there is a particular lack of good data on how effective it is in the hands of paramedical staff on a community scale. We encourage you to investigate this, since, like the destructive operations, it is one of the few practical procedures which might really alleviate maternal mortality from obstructed labour.

Symphysiotomy has fallen into disrepute because there was a time when it was used to overcome gross CPD, which led to serious complications. It is not used at all in parts of the world where CPD hardly exists, where trends are set—and where most textbooks are written. But, in countries where CPD is common, symphysiotomy is excellent—if it is used for borderline cases only. If CPD is marked, a mother needs a Caesarean section. The skill is to recognize the difference. You will not need to do a symphysiotomy very often, and you will find that deciding when to do one needs more judgement than deciding when to section a mother. If a symphysiotomy fails you can still do a Caesarean section: but you should look upon this as an error of judgement, and try to do better next time.

The indications for symphysiotomy in a hospital and a health centre are different:

In hospital, symphysiotomy is used to its best advantage: (1) At the strategic moment in a well-planned trial of labour, in which there is borderline CPD, and before there are any signs of fetal distress. If the indications are right, it is better than Caesarean section, and it avoids a difficult vaginal delivery. (2) In neglected obstructed labour it avoids a major abdominal operation in a high-risk mother. (3) It is occasionally useful in a breech delivery when the aftercoming head is arrested (9.8). Symphysiotomy is usually done in a primip, but you can do it in a multip. It is especially useful if a mother is isolated and cannot easily attend for antenatal care, if she is infected, and if your anaesthetic facilities are poor. In a health centre a symphysiotomy is an emergency method of delivering a mother, and securing a live baby, when she cannot be referred. It should never be an elective procedure there, because she cannot have a Caesarean section in a hurry if she needs one.

There are two ways of doing a symphysiotomy, either: (1) Open through an incision which is large enough for you to see and feel exactly what you are doing, as described below. Or, (2) closed through an incision which is only just large enough to admit the blade of a scalpel, as described in Primary Mother Care. Opinions differ as to which is best. Of those obstetricians who do the operation, the large majority favour the closed method and some think that we should not even have described the open one. One exceptionally able and experienced contributor is however strongly in favour of it. However you do it, you must divide the symphysis through its cartilage, exactly in the midline, because incisions which involve the bone to one side are more likely to lead to chronic pubic osteitis and long-standing pain, both of which are fortunately rare. Local infection in the soft tissue and cartilage is not important and heals without trouble.

Experts can do a closed symphysiotomy through a very small skin incision. If you are not an expert, do it open. Use an ordinary scalpel to cut through the skin and subcutaneous tissue in the midline. Then, when you have found the cartilage, cut through its exact centre with a solid scalpel, or a short ordinary one. Be sure to support the patient’s legs as described below, and don’t fail to insert a catheter before you cut!