Caesarean section is the delivery of a child through incisions in the anterior abdominal wall and uterus. The origin of the word, ‘caesarean’ is uncertain but probably derives from the Latin verb ‘caedere’ meaning ‘to cut’. The oldest authenticated record of a live child being born by this method occurred in Sicily in 508 BC. Up to the sixteenth century the operation was mainly carried out after death to save the life of the child, and this is still necessary today on rare occasions.

The first verifiable caesarean section on a living woman was performed in Wittenberg in Germany by Trautmann in 1610; the patient died 25 days later. The first such operation in Great Britain occurred in Edinburgh in 1737: the baby was stillborn and the mother died shortly afterwards. Mary Donelly, an Irish midwife, is credited with performing the first caesarean section in the British Isles in which the mother survived, in 1738. A 14-year-old woman carried out the first recorded procedure in the United States on herself in 1822. The first of the twins she was carrying was born normally but the second was born after she opened her own abdomen with a razor. The fate of the illegitimate twins is unknown but the woman survived after two doctors closed the abdominal wound.

It was not until the late nineteenth century that the uterine incision became routine, with a consequent improvement in maternal mortality. The first satisfactory method for suturing the upper segment incision was described by Sanger in 1822. Vertical incision of the uterus through the lower, rather than the upper, segment was first described by Osiander from Gottingen in 1805. Kehere, also in 1882, described the precursor of the transverse lower segment operation. This was subsequently championed by Munro Kerr, the Scottish obstetrician, who first used the transverse lower segment incision in 1911. However, it was almost 40 years before the reduced maternal mortality associated with the approach was generally accepted in Great Britain.

An elective caesarean section is performed when a prior decision to effect delivery by this route has been made before the onset of labour. All the rest are, rather unsatisfactorily, classified as emergency caesarean section (although some will be carried out as greater ‘emergencies’ than others) and are the subject of this chapter.

Figure 1 1469 shows the marked variation in caesarean section rates for the United States, England and Wales, and the Netherlands between 1965 and 1989. Between 1968 and 1988 the incidence of caesarean section increased by factors of 4.6, 3.0, and 3.2 in the United States, England and Wales, and the Netherlands respectively. Lomas and Enkin have analysed the variations in the operative delivery rates in general and in caesarean section in particular and have shown that they are hard to justify. For example, in 1980 the incidence of caesarean section for breech presentation in Sweden was twice that for demographically, economically, and culturally similar Norway. Table 1 423 gives some of the suggested determinants of the variation in rates with comments on each.

About one-third of all maternal deaths in the United Kingdom directly attributable to childbirth are associated with caesarean section (Fig. 2) 1470. Despite a fall in the overall fatality rate from 0.78 per 1000 procedures in 1970 to 0.24 per 1000 in 1984, emergency caesarean section caused four and eight times more direct maternal deaths than the elective procedure in the periods 1982–84 and 1985–87, respectively. Table 2 424 shows the immediate cause of death in women undergoing emergency caesarean section between 1982 and 1987. Table 3 425 illustrates the extent to which ‘substandard care’ contributed to the outcome.

An increasing caesarean section rate is one of the many inappropriate exports of Western-style medicine in developing countries. Although true figures for the incidence of this method of delivery and for associated maternal mortality and morbidity are not known, haemorrhage (in the absence of a reliable blood transfusion service) and too late recourse to operation in obstructed labour are significant problems in the developing world.

There are two types of procedure—the ‘classical’ caesarean section, in which the upper uterine segment is incised longitudinally, and the lower segment caesarean section. In the latter the lower uterine segment is usually incised transversely, although a longitudinal incision starting in the lower segment is sometimes necessary.

Caesarean section must not be carried out without good reason. It is justified when risk to the life and health of the baby and/or mother is greater if the pregnancy continues and if vaginal delivery cannot be achieved safely.

This situation can arise as a result of problems with uterine contractions, with the dimensions of the bony pelvis, or with the fetus. The specific reasons given for carrying out an emergency caesarean section include fetal distress, which is difficult to define and is frequently an uncorroborated statement about concern for fetal welfare; and failure to progress in labour, which often includes other indications, such as failed induction of labour, ‘abnormal uterine action’, cephalopelvic disproportion, prolonged labour and ‘maternal distress’ (there is a strong iatrogenic element in both causation and interpretation in this category); antepartum haemorrhage, including both placenta praevia and placental abruption; failed ‘trial of labour’ with a breech presentation; other malpresentations, such as transverse lie, face or brow presentation; cord presentation or prolapse; severe pre-eclampsia or eclampsia; and actual or impending death of the mother. Fetal brain damage will begin about 8 to 10 min after failure of maternal circulation. If life-support can be continued, or if a post-mortem caesarean section can be performed within that time, an attempt to save the fetus is justifiable.

Classical caesarean section is rarely necessary in modern practice. This option may, however, be used when a structurally abnormal or space-occupying lesion (e.g. a fibroid) makes the lower segment approach impossible. It is also applicable when the fetus is trapped in a transverse lie after rupture of the membranes and all the liquor has drained away, in some cases of anterior placenta praevia when the lower segment is excessively vascular, if hysterectomy is scheduled at the same time (very rare), or when the woman is already dead or moribund and rapid delivery of the baby is vital.

Several important conditions should, if at all possible, be fulfilled before proceeding. The woman, her partner, the surgeon, the anaesthetist, the paediatrician, the midwife, and all the nurses involved must know why the operation is thought to be necessary, and the paediatrician must be present in theatre for the delivery. If the operation is being carried out by an obstetrician in training, the case should be discussed with the senior obstetrician in charge of the woman's care or with the senior obstetrician on call. Written informed consent should be obtained from the woman. If her consciousness is obtunded consent should be obtained from the next of kin. A fully conscious and otherwise competent woman has the right to refuse permission for surgery.

The woman's partner may ask to be present in theatre during the procedure in order to support her. This is usually acceptable if regional anaesthesia is being used and the woman, is therefore, awake, and if someone is available to look after him. He must understand that his presence is a privilege and not a right and he must agree to leave the operating theatre if asked to do so. Presence during surgery under general anaesthesia is less acceptable because the primary reason for attendance (i.e. support of his partner) cannot be fulfilled and it may be traumatic to see his partner unconscious and paralysed on a surgical table. Theatre staff are also more fully occupied and may not be able to look after him.

Premedication is not routinely necessary before emergency caesarean section but an H&sub2; blocking agent or omeprazole must be given to all patients (even if regional anaesthesia is planned) to reduce the risk of pulmonary aspiration of acidic gastric contents. Magnesium trisilicate is ineffective. A recommended regimen for patients undergoing emergency caesarean section consists of 30 ml 0.3 M sodium citrate orally and 50 mg ranitidine given intravenously, and a further 30 ml sodium citrate just before induction of anaesthesia. Nasogastric tubes are not effective in emptying the stomach and, if not withdrawn before induction of anaesthesia, may increase the risk of aspiration.

Routine crossmatching of blood is not necessary provided that the woman's blood group and a recent haemoglobin concentration are known and a least 2 units of group O RhD-negative, Kell-negative blood are immediately available within the maternity unit. A blood sample should be sent to the blood transfusion laboratory in case cross-matching needs to be undertaken later. Prior cross-matching of blood will be necessary under some circumstances, such as significant placental abruption.

Aseptic catheterization of the bladder should be performed in theatre (before induction of general anaesthesia) but an indwelling catheter is not routinely necessary. If a fetal scalp electrode is in place it should be removed. The operating table must be adjustable to allow head down tilt. The mother should be placed on it with a 10° left lateral tilt to reduce the risk of maternal supine hypotension and fetal compromise. If the woman is considered to be at high risk of carrying hepatitis B virus or human immunodeficiency virus the surgeon and assistant(s) are advised to take appropriate precautions.

The abdominal wall should be painted with a suitable antiseptic preparation from xiphisternum to midthigh and sterile towels draped around the area of the incision. Towel clips should not be fixed to the skin.

Factors that affect the conduct of anaesthesia during pregnancy include the physiological adaptations to pregnancy, which include an increased tendency to coagulation, smooth muscle relaxation, which increases the risk of oesophageal reflux, and more rapid development of hypoxia during apnoea. There may be aorta-caval compression caused by the gravid uterus, and delayed stomach emptying in the patient who has been in labour. The need to maintain uterine tone in order to avoid catastrophic haemorrhage prevents the use of volatile anaesthetic agents, while the risk of depressing fetal function also limits the choice of drugs. The choice of anaesthetic procedure for emergency caesarean section is determined by the skill of the anaesthetist and surgeon, the degree of urgency, and informed patient preference.

This has the advantages of rapidity of onset, a low failure rate, and operator control over respiratory, cardiovascular, and central nervous systems. However, its disadvantages include risks of failed intubation, gastric aspiration, maternal awareness, and depression of fetal activity. General anaesthesia is indicated if the patient is hypovolaemic, semiconscious or convulsing, or if urgent surgery is required. It is contraindicated in the presence of maternal disease such as myasthenia or malignant hyperpyrexia.

For general anaesthesia to be used with the maximum degree of safety, an intravenous line must be established, induction should take place in a fully equipped and staffed operating theatre, the patient should be preoxygenated for 3 to 4 min, cricoid pressure must be applied properly during induction, and must be maintained until the endotracheal tube balloon is inflated to avoid aspiration, and a failed intubation drill must be established.

The risks of general anaesthesia are avoided, unless total or high spinal block occurs, blood loss is decreased and mother-infant bonding and breastfeeding are facilitated. However, the block may fail, be inadequate, or may be too extensive. Regional anaesthesia is preferred if intubation has previously been difficult, if the patient has experienced an allergic response to previous general anaesthetic, or if a functioning block has been established earlier.

In order to make the procedure as safe as possible, both anaesthetist and assistant must be trained in the techniques to be used, full facilities must be prepared for induction of general anaesthesia and resuscitation, the patient must be prepared as if for general anaesthesia, patients should be given an intravenous ‘preload’ of 1 1 of crystalloid, and the sensory block should cover from S4 to T4. A combination of subarachnoid and epidural anaesthesia is becoming popular, but the decision to use one or other (or both) must be determined by the available facilities and skills, and then needs of the individual patients.

There are many safe ways of performing a caesarean section: the techniques are best learnt from an experienced obstetrician.

The skin incision can be transverse or vertical (Figs. 3(a)–(b)) 1471. The transverse incision may bleed more, but it is less painful, heals more quickly, is less liable to herniate, and the scar is usually hidden beneath the hairline. It is, therefore, generally preferred. A suprapubic midline incision may be useful for the delivery of three of more infants and is necessary for classical section.

If a transverse skin incision (Fig. 3(a)) 1471 is used a straight incision (10–12 cm) is made approximately two finger-breadths above the symphisis pubis. The subcutaneous tissue and rectus sheath are divided transversely and haemostasis secured (Fig. 4(a)) 1472. Subaponeurotic dissection of the sheath is then carried out and perforating vessels are ligated or diathermied. The rectus muscles are separated digitally in the midline to expose the parietal peritoneum (Fig. 4(b)) 1473.

Midline incision (Fig. 3(b)) 1471 is performed as for other lower abdominal surgery. The parietal peritoneum is divided vertically (Fig. 4(c)) 1474, taking care not to damage bowel or bladder. Abdominal packs are unnecessary. A Doyen retractor is inserted suprapubically to widen access to the visceral peritoneum and retract the bladder. The lower uterine segment can now be seen (check for dextrorotation). The loose uterovesical peritoneum is divided transversely and the upper border of the bladder freed digitally and displaced caudally. The Doyen retractor is slipped into the retrovesical space. Using a scalpel, an 8- to 10-cm superficial incision (with a slight upward curve) is made in the lower segment (Fig. 5(a)) 1475. This is this is then deepened in the midline until the cavity is entered and fully extended by stretching with both index fingers (Fig. 5(b)) 1476. The Doyen retractor is then removed.

Undue haste makes extension of the uterine incision and heavy bleeding more likely. If the head presents a hand is passed inside the uterus below and behind it to lift and guide it through the incision (Fig. 6) 1477. Suction of the mouth can now be performed. Fundal pressure may be exerted by the assistant once the head is free. Short obstetric forceps may be used for controlled delivery. If the head is moulded deeply in the pelvis it may be pushed up from below by an assistant.

All presentations other than cephalic are best delivered by the breech. The feet are grasped and delivered, and the trunk is delivered by traction and rotated slightly to the patient's left. This brings the left arm into view which is delivered by hooking a finger into to elbow. The right arm is delivered similarly after rotating the trunk to the right. The face will now appear in the wound and oral suction can be performed. It is important to control delivery of the head, using short obstetric forceps.

The baby is placed on the maternal abdomen (to prevent blood draining towards the placenta) where the umbilical cord is clamped and cut. The baby is then passed to the gowned paediatrician.

Syntocinon 5 units should be given intravenously when the head is delivered and the placenta should then be delivered by cord traction when the uterus contracts. Manual removal can be performed if necessary. The uterine cavity should be explored using a gauze swab wrapped around a finger to confirm complete removal of placenta and membranes.

Closure can be facilitated by eventrating the uterus on to the anterior abdominal wall but this may be painful if epidural anaesthesia is being used. Otherwise, reinsertion of the Doyen retractor gives access.

The upper and lower borders and the lateral extremities (angles) of the incision are identified and held by Green Armytage forceps. Care is needed—the upper edge will now be much thicker than the lower because of uterine retraction and the posterior wall is sometimes confused with the anterior edge of the incision. The uterus should be closed in two layers using No. 1 chromic catgut on round bodied needles (Fig. 7(a-c)) 1478,1479,1480. The first suture is placed to secure the right angle: it is cut long and held in the artery forceps. The left angle is then sutured and, with the short end held, the suture is continued across the inner two-thirds of the myometrium and tied into the suture on the right angle. The second suture starts at the left angle. An invaginating (Lembert type) suture can be used. The eventrated uterus is returned to the abdominal cavity and the incision is checked for persistent bleeding points which are sutured to secure haemostasis. The visceral peritoneum is closed with a continuous suture as above. The fallopian tubes and ovaries are inspected and swabs and instruments are checked.

The peritoneal cavity should be swabbed clear of blood and amniotic fluid, paying particular attention to the paracolic gutters. The abdomen is then closed in the conventional manner. The suture material used for closure is a matter for personal preference. Careful technique and scrupulous attention to haemostasis are far more important. Some operators advise routine subcutaneous and/or subfascial drainage of transverse incisions. A subcuticular stitch to the skin using prolene or one of the newer absorbable materials gives a good cosmetic result.

The uterus is approached through a midline incision with the rectus sheath and peritoneum incised vertically. The upper segment of the uterus is incised in its lower half and in the less vascular midline. It is, therefore, necessary to check the position of the fundus and for dextrorotation before making the incision. Delivery of the baby is easier by the breech method whatever the presentation. Closure of the incision is as for the lower segment, except that three layers of suture are necessary, and conventional abdominal closure procedures are followed.

This vertical incision starting in the lower segment if the latter is undeveloped, for example, when very preterm delivery by caesarean section is required.

A midline skin incision may be best. The lower segment is approached routinely and the visceral peritoneum incised transversely. The upper flap is reflected upwards and the bladder downwards. A small vertical incision is made in the lower segment down to the membranes and the incision carefully enlarged caudally and cranially by scissors. Care must be taken to deliver the very premature baby as atraumatically as possible. Closure is performed as for the conventional lower segment procedure.

If a conventional lower segment caesarean section has been embarked upon in the presence of a transverse lie with ruptured membranes it may not be possible to deliver the baby through the transverse uterine incision because the shoulder is likely to be impacted. On no account must the arm be delivered into the wound: this renders safe delivery impossible. An inverted ‘T’ incision into the upper segment should be made, although the scar heals less well than in either the transverse or vertical uterine incisions. Transverse lie with ruptured membranes is, therefore, a possible indication for a classical caesarian operation.

This seldom causes major problems for delivery, even if it is anterior. It is best to avoid incising the anterior placenta. The placental site in the lower segment tends to bleed heavily because it does not contract so well, but hot packs, pressure, and patience are usually sufficient to control the bleeding.

Rarely, the placenta is morbidly adherent because of excessive invasion of the trophoblast (placenta accreta). This can give rise to major haemorrhage and should be dealt with as described below.

The average blood loss at caesarean section is about 1000 ml. Haemorrhage is best prevented by precise and unhurried surgery and by careful delivery of the fetal head. An effective protocol to deal with obstetric haemorrhage must be laid down and known. Excessive bleeding is often due to trauma to the uterine vessels: deep and wide sutures usually control the bleeding but the ureters must be identified to prevent damage (see below). Hot packs and pressure should be applied for sufficient time to allow haemostasis and for preparations to be made to deal with major haemorrhage. If not already present a senior obstetrician and anaesthetist should be called for and, if the situation is not under control, they must attend. The key to successful haemostasis is calm and purposeful action. Aortic pressure is useful as a temporary measure and can be life-saving.

Ligation of the internal iliac (hypogastric) arteries and/or hysterectomy should be considered in patients who require intraoperative blood transfusion in the presence of significant continuing haemorrhage. These procedures must not be performed too late, but neither should they be undertaken too early.

A coagulation defect may be the primary cause of the haemorrhage (as in severe placental abruption) or may develop secondarily: this must be considered and dealt with. Other management is as for any major haemorrhage associated with surgery.

A thin or fibrous lower segment may be torn during delivery of the baby, particularly in patients who have undergone a previous caesarean section. The tear is usually in the midline towards the cervix and below the bladder, which must be dissected free and inspected for damage before repair of the tear.

The bladder may be accidentally damaged during opening of the parietal peritoneum (particularly in patients who have had previous surgery), or after previous caesarean section. It may also be damaged if the lower segment tears. The damage must be recognized and repaired if fistula formation is to be avoided. Continuous bladder drainage is necessary for up to 10 days.

Damage to the ureters is uncommon but usually occurs during attempts to stop haemorrhage from uterine vessels or during repair of a damaged bladder. Recognition and immediate repair are vital.

The same principles apply as for general surgery. Aspiration and hypoxia must be prevented. Adequate pain relief is important, and early mobilization should be the aim, since this reduces the risk of thromboembolism. In the absence of postoperative complications and if the baby is well the woman can expect to go home about 5 days after delivery. Before discharge she should be counselled about contraception and management of any future deliveries.

Poor postoperative observation with failure to appreciate the degree of intra-abdominal and/or vaginal haemorrhage, failure to control it, and inadequate replacement are among the most common causes of serious sequelae of caesarean section.

Sepsis, which contributes significantly to morbidity, can be minimized by proper attention to sterility and surgical technique. Prophylactic administration of antibiotics reduces infective morbidity: broad-spectrum penicillins (e.g. amoxycillin with clavulanic acid) are as effective as cephalosporins. A higher incidence of side-effects and poorer compliance with longer courses have to be balanced against the lesser efficacy of short courses of drugs.

Women are at risk of thromboembolism after caesarean section, particularly if there is a past history of thrombosis, severe pre-eclampsia, or if the patient is obese. Early mobilization is important for prevention, and prophylactic low-dose heparin should be given to high-risk patients. Management of established deep vein thrombosis or pulmonary embolism is described elsewhere. If possible iodine-125 should be avoided for diagnosis because iodine is excreted in breast milk. Warfarin is not excreted in breast milk to any significant extent.

This is generally preventable by good surgical technique. It is usually due to inadequate haemostasis and failure to drain ‘oozing’ wounds.

Postoperative distension of the abdomen is usually associated with caesarean section performed after very prolonged labour. Paralytic ileus is managed by gastric suction and administration of parental fluids until resolution is complete. Failure to treat may result in caecal perforation.

The combination of emergency caesarean section and severe pre-eclampsia is a significant contributor to maternal mortality (Table 2) 424: the altered haemodynamics in pre-eclampsia are often not appreciated and proper precautions are not taken. Since it is a high-output state with reduced plasma volume, infusion of excessive fluid causes pulmonary oedema, which can be fatal. All patients with severe pre-eclampsia who are undergoing caesarean section must be carefully monitored postoperatively in a high dependency area using at least a central venous pressure line and possibly a Swann-Ganz catheter. Intravenous infusion of crystalloid must be controlled very carefully. Oliguria is to be expected initially: diuretics are contraindicated since they merely reduce the circulating volume further.

Advice must be taken from a haematologist about women with an acquired coagulation defect or bleeding diathesis. Warfarin therapy is best avoided antenatally because it cannot be readily reversed (and is associated with fetal anomalies). Subcutaneous heparin does not increase the risk of bleeding and the action of intravenous heparin is reversible on administration of protamine sulphate.

The risk of surgery to the mother must not be underestimated. Meticulous anaesthetic and surgical technique and access to intensive care facilities are vital.

Special anaesthetic precautions need to be taken for women taking corticosteroids, &bgr;-agonists and antagonists, and antihypertensive agents.

These are rarely severe enough to cause surgical problems. Classical caesarean section or a longitudinal incision in the narrow segment may be necessary if the uterus is not properly formed or is too narrow for safe transverse incision.

This can usually be dealt with by lower segment caesarean section, but a midline skin incision is advisable for higher order multiples (triplets and above). The risks of maternal supine hypotension and postpartum haemorrhage are increased. Conjoined twins are very rare, but the possibility should be checked by ultrasound when twins are diagnosed. Classical caesarean section is necessary: if found unexpectedly the ‘inverted T’ incision (see above) will be necessary.

A major hydrocephalus may make decompression of the head necessary before delivery. The diagnosis should have been made by preoperative ultrasound examination: a large but normal head may be mistaken for hydrocephalus and radiography may give a false-positive diagnosis.

Tubal ligation is a simple surgical addition to caesarean section but must be used sparingly because there is an increased risk of subsequent request for reversal. Prior counselling is mandatory and written permission from the woman absolutely necessary.

Caesarean hysterectomy is usually performed for control of major haemorrhage: the difficult decision must be made before it is too late for the patient to survive (see above). It should be avoided for other indications if at all possible and is not justifiable for sterilization. The temptation to remove subserous fibroids at caesarean section (myomectomy) must be resisted because bleeding from the incised pregnant uterus is difficult to control.

An accident to an ovarian cyst (such as rupture or torsion of a teratoma) is a rare cause of an acute abdomen during pregnancy. If it occurs after about 28 weeks caesarean section is likely to be necessary to gain access. During such an operation for obstetric reasons both ovaries should be checked visually. Neoplastic cysts should be removed but the surgery should be the least possible until a full histological diagnosis is made when, if necessary, definitive surgery can be planned. Histological examination of frozen sections is prone to overdiagnose malignancy in these circumstances.

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