Chapter 17 Caesarean section

David T Y. Liu, Mentor: Alexander Omu

CHAPTER CONTANTS

Indications for caesarean section 145

Preoperative care 146

Postoperative care 146

Types of incision 146

Abdominal incisions 146

Subumbilical midline incision 146

Transverse (Pfannenstiel’s) incision 147

Uterine incisions 147

Lower segment caesarean section 147

Classical caesarean section 147

Krönig–Gellhorn–Beck incision 147

Other situations 148

Operative steps for caesarean section 148

Caesarean section: specific issues 148

Communication 148

Vaginal birth after caesarean section 148

Signs of uterine scar rupture 149

Management for uterine rupture 150

Caesarean section after intrauterine fetal death 150

Difficulty with delivery of the fetal head 151

Caesarean hysterectomy 151

Classical caesarean section 152

Holding stitch 152

Bleeding lower segment uterine angles 152

Sterilisation 152

Caesarean section describes the surgical procedure for delivery of the fetus by incisions through the abdomen and uterus. The attendant risk of a surgical procedure must be considered. In the UK direct deaths following all caesarean sections is 82.3 per 1 000 000. For elective procedures this is 38.5 per 1 000 000. Death rate following vaginal delivery is 16.9 per 1 000 000 maternities (Department of Health (DoH) 2001). Pulmonary embolism, hypertension haemorrhage and sepsis continue to be salient causes of mortality. Inappropriate delegation, inadequate facilities and poor communication contribute to substandard care and necessitate improvement.

Sequelae of vaginal birth such as rectal and urinary incontinence, the question of choice, increased safety for caesarean section, more older women having babies and ready redress to litigation for complications with operative vaginal deliveries are factors leading to an increase in the rates of caesarean sections.

INDICATIONS FOR CAESAREAN SECTION

Caesarean sections can be subdivided into elective, scheduled or planned of varying emergency, unplanned emergency and peri-mortem and post-mortem categories to facilitate audit. Clearly complications and mortality attributed to the surgical procedure must be distinguished from contributions by obstetric complications and maternal medical problems.

Caesarean sections are performed to:

• overcome cephalo-pelvic disproportion and abnormal uterine activity

• expedite delivery for maternal or fetal reasons

• reduce fetal trauma (for example the small pre-term breech) and fetal infection (for example risk of transmitting herpetic infection or the human immunodeficiency virus (HIV))

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• reduce maternal risk (for example certain cardiac disorders, intracranial lesions or cervical malignancy)

• allow women to exercise their informed choice.

PREOPERATIVE CARE

• Ensure reasons for surgery are valid. There should be input by senior colleagues and clear discussion with the woman and her partner. Document clearly for medicolegal reasons.

• Past obstetric and medical history must be reviewed. Check gestation (usually not before 39 weeks if elective surgery).

• Discuss mode of anaesthesia with the anaesthetist and the woman. Ideally, mode of anaesthesia or analgesia should be discussed in advance at a joint clinic with the anaesthetist. Regional anaesthesia is safer for the woman and the baby.

• Inform the paediatrician in good time.

• Check that cross-matched blood is available. Most labour wards now reserve 2 units of 0 Rhesus negative blood for emergencies. Cross-match 4 or more units if increased bleeding is likely, e.g. placenta praevia. Use cell saver for heavy loss or women refusing blood transfusion.

• Give an antacid (see Chapter 9).

• Obtain written consent. This includes discussion of need and procedure, risks, inadvertent damage to bladder and fetus.

• Introduce indwelling catheter.

• Administer prophylactic antibiotics. This is particularly relevant in emergency caesarean sections. Assess need for prophylaxis against thromboembolism following recommendations from the Royal College of Obstetricians and Gynaecologists’ Working Party Report (Department of Health 1995). Women with three or more moderate risk factors such as age more than 35, obesity of more than 80 kg, para 4, gross varicose veins, concurrent infection, pre-eclampsia, 4 days immobility prior to surgery, labour over 12 hours, major medical disease, extended pelvic surgery, personal or family history of venous thrombosis or pulmonary embolism (thrombophilia) and presence of antiphospholipid antibody will need heparin prophylaxis and leg stockings.

POSTOPERATIVE CARE

Presence of obstetric or medical complications mean some women will need close observation following caesarean section. The labour ward can serve as an area for recovery and care. Intensive or high dependency care facilities must be readily available in the same hospital. General care for all women includes:

• Assess vital signs at regular intervals (15 minutes). Make sure condition is stable.

• Watch fundal height, any bleeding from wound and amount of lochia. This is particularly important if the labour is prolonged, when the uterus has been distended by polyhydramnios or multiple pregnancies and where there is a threat of coagulation defects, for example, after antepartum haemorrhage and pre-eclamptic toxaemia. Infuse oxytocin for 4–6 hours.

• Maintain fluid balance.

• Ensure adequate analgesia. Continued use of epidural analgesia is particularly useful.

• Address specific requirements which prompt indication for caesarean section, e.g. medical conditions such as diabetes.

• Early physiotherapy and ambulation if there is no contraindication.

• Remember thrombo-prophylaxis. Early ambulation and attention to hydration suffice for low risk women with uncomplicated pregnancies and no risk factors. Avoid use of dextran 70. Subcutaneous heparin or mechanical methods are required where risk is considered moderate. Where risk of thromboembolism is high, heparin and leg stockings should be used for 5 days following surgery or until full mobilisation. For past histories of venous thromboembolism in pregnancy or the puerperium thrombo-prophylaxis should be continued for 6 weeks post partum.

• Before discharge an opportunity should be made available to examine events and address questions.

• Schedule an opportunity for postnatal review to ensure complete recovery, to discuss subsequent pregnancies and ensure follow-up care for medical conditions.

TYPES OF INCISION

Abdominal incisions

Essentially these are the subumbilical midline and transverse lower abdominal incisions (Figure 17.1).

Figure 17.1 Abdominal incisions: (a) subumbilical midline and (b) transverse ‘Pfannenstiel’s’.

Subumbilical midline incision

This incision is easy and quick. Access is good with minimal bleeding. It is useful when access to the lower segment is difficult, for example severe kyphoscoliosis or anterior lower segment fibroid. The scar however, is unsightly, there is more postoperative discomfort and dehiscence is more likely compared with transverse incisions.

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Where extension upwards into the abdomen is likely a left or right paramedian incision can be performed.

Transverse (Pfannenstiel’s) incision

This is the current incision of choice. It is cosmetically pleasing, is less likely to dehisce and being less uncomfortable, allows better postoperative mobility. The incision can be technically more difficult especially in repeat surgery. It can be associated with greater blood loss and poorer access.

Variations include the Joel Cohen incision (placed higher up the abdomen) and Misgav Ladach (emphasises preservation of anatomical structures).

Uterine incisions

Entry into the uterus can be through a midline or a transverse lower segment incision (Figure 17.2).

Figure 17.2 Uterine incisions: (a) lower segment (b) classical and (c) Krönig–Gellhorn–Beck.

Lower segment caesarean section (Figure 17.2a)

This is the most common approach. The transverse incision is placed in the lower segment of the gravid uterus behind the uterovesicle peritoneum. Advantages include:

• The site is less vascular hence less blood loss.

• It contains spread of infection into abdominal cavity.

• It is in the less contractile part of the uterus hence scar rupture in subsequent pregnancies is less likely.

• Healing is better with fewer postoperative complications such as adhesions.

• Implantation of the placenta over the uterine scar is less likely in subsequent pregnancies.

Disadvantages include:

• Access may be limited.

• Proximity to the bladder increases risk of damage particularly in repeat procedures.

• Extension into the lateral angles or behind the bladder can increase blood loss.

Classical caesarean section (Figure 17.2b)

This incision is placed vertically in the midline of the uterine body. Indications for use include:

• Early gestation, when the lower segment is poorly developed.

• When access to the lower segment is prevented by adhesions or uterine fibroids.

• When the fetus is impacted in the transverse position.

• Where the lower segment is vascular because of an anterior placenta praevia.

• When there is cervical carcinoma.

• When speed is essential, for example following death of the mother.

Disadvantages include:

• Haemostasis is more difficult with a thick vascular incision.

• Adhesions to surrounding organs are more likely.

• The anterior placenta may be encountered during entry.

• Healing is impaired because of myometrial involution.

• There is more risk of uterine rupture in subsequent pregnancies.

Krönig–Gellhorn–Beck incision (Figure 17.2c)

This is a midline incision in the lower segment. It is used in preterm deliveries where the lower segment is poorly formed or in situations where extension into the upper uterine segment is anticipated to provide more access. It has fewer of the complications associated with a classical Caesarean section. This incision need not preclude vaginal delivery.

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Other situations

An inverted T incision or a J incision may on occasion be required when access is found to be inadequate despite a lower segment incision.

These incisions are best avoided. Like classical caesarean sections subsequent pregnancies will need to be delivered by elective caesarean section.

OPERATIVE STEPS FOR CAESAREAN SECTION

1. Open the abdomen through a midline or transverse Pfannenstiel’s incision. In the Pfannenstiel approach a transverse skin incision is placed above the symphysis pubis. This is followed by division of the rectus sheath and separation of the rectus muscles prior to opening the abdominal peritoneum.

2. After opening the abdomen a Doyen retractor is inserted to hold the incision open for access into the lower uterine segment. Check the rotation of the uterus.

3. Identify and pick up loose peritoneum (Figure 17.3a) over the lower uterine segment and open transversely (Figure 17.3b). Replace the Doyen retractor to displace the peritoneum and bladder away from the intended uterine incision. Avoid excessive dissection behind the bladder otherwise troublesome venous bleeding may occur.

4. Incise the lower uterine segment transversely over an area of 2–3 cm until the amniotic cavity or membranes are identified. Extend the incision laterally with fingers until there is adequate room for delivery (Figure 17.3c). Bleeding is common when the lower segment is incised and care is needed to avoid fetal damage.

5. Remove the retractor. Insert a hand into the uterine wound below the breech or the fetal head. The presenting part is gently brought out (Figure 17.3d) through the uterine and abdominal incision. A characteristic hiss may be heard when the vacuum effect is lost. Facilitate delivery by fundal pressure (use the free hand or that of an assistant). An impacted presenting part can be dislodged by an assistant gently pushing through the vagina.

6. Once the fetal head is delivered, clear the airways (mouth first). Carefully deliver the shoulders to avoid further extension of the incision at the lateral angles. Syntocinon (5 units) or ergotamine (0.25 mg) is given. Clamp and cut the cord. Take arterial and venous cord blood samples to assess fetal pH and base excess. (Particularly relevant for emergency caesarean sections.) The placenta is removed manually. Ensure the uterine cavity is empty. Pass a digit through the cervical os to facilitate discharge of lochia.

7. Identify the lateral angles and secure bleeding vessels with clamps.

8. Identify the lower edge of the uterine incision, secure the lateral angles and close the uterine wound in two layers with continuous sutures (Figure 17.3e).

9. Exteriorise the uterus if needed to facilitate uterine wound closure (warn the anaesthetist if a spinal or epidural is used for anaesthesia). When haemostasis is achieved close the peritoneum with continuous suture.

10. Remove blood and clots from the peritoneal cavity. Check normality of salpinges and ovaries. Remove abdominal packs if used. Use a drain if oozing is a cause for concern.

11. Close the abdominal wound in layers. Current practice does not require closure of the parietal peritoneum. Likewise when there is no bleeding, the subcutaneous layer need not be sutured. Catgut is not used in contemporary surgery.

12. All steps of the procedure should be clearly documented. All complications must be highlighted to support counselling for subsequent pregnancies.

Figure 17.3 The peritoneum is (a) picked up and opened (b) before the lower segment is incised transversely (c). The fetal head (d) is delivered and the uterine wound is closed in two layers (e).

See Box 17.1 for a summary of the dos and do nots of caesarean section.

Box 17.1 Dos and do nots of caesarean section

Do

• Place the woman in a 15° left lateral tilt (using a wedge) to overcome caval compression.

• Check the fetal heart before surgery. Operation may be contraindicated if the fetus is dead.

• If possible place the fetus into a longitudinal lie by external version.

• Once the fetus is delivered quickly the safety of the mother and her subsequent obstetric career must govern the tempo of surgery.

• The average blood loss is 400–600 ml. Consider replacement of blood if there is excessive bleeding.

• Ensure lochia can drain especially after elective caesarean section. Pass a finger or artery forceps from above through the cervix before closing the uterine incision.

• Insert drains if haemostasis is considered unsatisfactory or oozing is anticipated.

• If uterine infection is suspected take uterine swabs for culture.

• Ensure there is adequate width of the abdominal wound in a repeat transverse incision. Scar tissue is less compliant compared with normal tissue and may not stretch to allow easy delivery of the fetus.

• A thorough toilet of the abdominal cavity reduces the risk of postoperative ileus.

• Make sure the uterus is contracted.

• Clean the vagina. This procedure removes a nidus for infection and allows early recognition of postoperative bleeding.

• Document clearly difficulties encountered or complication with the surgery. A plan for management of subsequent deliveries should be included.

• Wear double gloves if the woman has a viral infection, e.g. HIV.

• Encourage early contact of mother and baby.

Do not

• Conduct trial of labour after a caesarian section.

• Vaginal delivery is usually contraindicated after two caesarean sections.

• Do not hesitate to use a subumbilical midline incision if a previous transverse lower abdominal incision is considered unsatisfactory.

• Do not place the uterine lower segment incision too close to the bladder.

CAESAREAN SECTION: SPECIFIC ISSUES

Communication

Apart from issues of consent and good practice of forewarning team members such as anaesthetists and neonatologists it is important to define the degree of urgency for need to deliver the baby. In an emergency the current accepted decision to delivery interval is 30 minutes or less. This is however, not an evidence-based standard. Regular drills will ensure smooth assembly for urgent surgical delivery.

Vaginal birth after caesarean section (VBAC)

Vaginal delivery is contraindicated after a classic caesarean section and if there is need to extend the transverse uterine incision (T, J incisions). Where there is no recurrent indication for caesarean section, vaginal delivery reduces maternal mortality and morbidity. There is however, a 0.3% rate of uterine rupture associated with trial of scar. There is 25% perinatal mortality and a 25% need for hysterectomy following uterine rupture. Although a quarter to a third of women with prior caesarean section can successfully deliver vaginally, the following must be satisfied.

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• The woman gives informed consent.

• The woman is well and there is no obstetric complication. The fetus is of normal size.

• The pelvis is adequate. A trial of labour is not acceptable.

• There is no complication following the previous caesarean section, e.g. extension of uterine scar or infection following surgery.

• Delivery must be conducted in a safe environment where appropriate care and continuous surveillance such as fetal heart rate monitoring is available.

• A successful vaginal delivery following caesarean section need not indicate reduction in risk for a second vaginal delivery.

• The second stage should not be prolonged.

• No new complication develops (after mutually agreed VBAC).

Signs of uterine scar rupture

Mothers with a classic uterine scar may experience uterine rupture prior to onset of labour. The low vertical uterine incision does not contribute an increased risk to uterine rupture compared with the low transverse uterine incision. Signs of uterine rupture are:

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• Fetal heart rate – signs of compromise.

• Suprapubic pain present between contractions and often felt despite presence of epidural analgesia.

• There is exquisite tenderness on palpation of the lower uterine segment.

• The presence of a rising maternal pulse rate.

• There is intrapartum vaginal bleeding.

• Sudden cessation of uterine contractions.

• Abdominal palpation detects malpresentation and fetal parts are easily palpable.

• Vaginal examination may reveal the presenting part has moved up into the pelvis.

• There may be maternal shock and collapse.

Management for uterine rupture

Maternal mortality for uterine rupture was 2.3 per 1 000 000 maternities (Confidential Enquiries into Maternal Deaths in the United Kingdom, 1994–1996). Correct planning of delivery and induction (judicious prostaglandin usage after one dose), delivery in an appropriate setting, and involvement of experienced obstetric staff in intrapartum care can contribute to improved outcome.

When scar rupture is suspect:

• Perform immediate laparotomy.

• Following assisted delivery or where manual removal of the placenta is required the lower segment following a previous caesarean section can be examined by an experienced surgeon. The lower segment is identified by locating the thick upper uterine segment and then withdrawing the examining finger towards the cervix. Integrity of the loose thinner lower segment is best examined by running the finger gently from side to side (Figure 17.4). For small dehiscence with no bleeding no further action is necessary apart from close observation. Future deliveries must be by elective caesarean section. For large rupture, especially when bleeding continues, laparotomy and repair are necessary.

Figure 17.4 Examination for uterine scar integrity.

Caesarean section after intrauterine fetal death

This is necessary when vaginal delivery is not feasible (for example impacted shoulders, fetal abnormality) or for the mother’s welfare (for example abruptio placentae, with severe bleeding and fetal death). Exclude coagulation defects. Additional psychological support will be required.

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Difficulty with delivery of the fetal head

Caesarean section following a trial of labour or trial of forceps may find the fetal head impacted or deep in the pelvis. Delivery of the presenting part is facilitated by:

• Displacement of the presenting part up into the pelvis by an assistant pushing through the vagina.

• Turning the fetal head into the occipitoposterior position.

• Wrigley’s forceps. A single blade can be employed as a lever (Figure 17.5) or both blades can be applied to effect delivery (Figure 17.6). Forceps are useful to bring a high head through the uterine incision.

• Extended uterine incision, e.g. inverted ‘T’ (Figure 17.7).

Figure 17.5 Use of single forceps blade to assist delivery of the fetal head.

Figure 17.6 Forceps delivery in caesarean section: forceps such as Wrigley’s are applied to the fetal head in the direct occipitoposterior position (a), changing to position (b) to lift head through the uterine wound and complete delivery by directing forceps towards the mother’s head (c).

Figure 17.7 Inverted T incision.

Caesarean hysterectomy

Indications include gross uterine rupture or uncontrollable haemorrhage. The woman’s condition is usually compromised hence speed and experience are required. Consider the following:

• Time is saved if the uterus is removed before tying the pedicles.

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• There may be difficulty in differentiating between the oedematous lower segment, the cervix and surrounding tissues. A subtotal hysterectomy is advised when damage and bleeding are confined to the uterine body.

• Bilateral ligation of the internal iliac artery may be required.

• Repair the ruptured uterus if the mother is stable, surgical expertise is available and fertility has to be preserved.

Classical caesarean section

Remember to check the rotation of the uterus. If possible start at the lower half of the upper uterine segment and extend if required. The uterine wall should be closed in three layers. The herringbone suture technique for closure of the superficial layer minimises oozing.

Holding stitch

• Rate of fetal scalpel laceration is about 2%.

• A holding stitch can help lift the lower segment away from tight application to the fetus. Traction on the stitch will allow incising without damage to the fetus (Figure 17.8). The stitch can also help identify the distal lower segment flap if difficulty is anticipated.

Figure 17.8 A holding stitch.

Bleeding lower segment uterine angles

• A drier field and better control of bleeding is achieved if the uterus is delivered through the abdomen wound. Warn the anaesthetist if this procedure is intended.

Sterilisation

• Consent for this procedure from both partners should be obtained well in advance. Use of an epidural or spinal anaesthesia will allow opportunities for discussion at time of surgery.

• The couple should be fully counselled in terms of irreversibility of the procedure, increased failure rates and technique used.

• The isthmic portion of salpinges are usually excised and the cut ends ligated. The excised segments should be dispensed for histological verification. Clips are less reliable because the salpinges are enlarged by pregnancy.

References

Department of Health. Report on Confidential Enquiries into Maternal Deaths in the United Kingdom 1997–1999. London: HMSO, 2001.

Department of Health. Report on Confidential Enquiries into Maternal Deaths in the United Kingdom, 1994–1996. London: HMSO, 1998.

Royal College of Obstetricians and Gynaecologists. Report of the Working Party on Prophylaxis Against Thromboembolism in Gynaecology and Obstetrics. London: RCOG Press, 1995.

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