Obstetrics Simplified - Diaa M. EI-Mowafi

Caesarean Section


An operative procedure to deliver a viable foetus or more (i.e. after 28 weeks or 20 weeks according to the ACOG) through an abdominal and uterine incisions.

Incidence

  • Increased from 5% in 1970 to 25% in 1990 due to:
  • Procedures as high forceps and difficult mid forceps are abandoned in favour of Caesarean Section (C.S.)
  • Increased C.S delivery in breech presentation.
  • Destructive operations are abandoned in favour of C.S.
  • Decreased morbidity and mortality due to C.S encourages its use.
  • Increased repeated C.S due to increased primary C.S.

Indications

  • (A) Maternal indications:
    • Contracted pelvis and cephalopelvic disproportion (see before).
    • Pelvic tumours especially if impacted in the pelvis or cancer cervix.
    • Antepartum haemorrhage (see before).
    • Hypertensive disorders with pregnancy (see before).
    • Abnormal uterine action (see before).
    • Previous uterine scar as hysterotomy or metroplasty.
    • Previous successful repair of vesico-vaginal fistula.
    • Previous caesarean section if,
      • the cause of the previous section is permanent e.g. contracted pelvis.
      • previous section was upper segment.
      • suspected weak scar as evidenced by:
        • History of puerperal infection after the previous section.
        • Hysterosalpingography or hysteroscopy done after the previous section reveals a defect in the scar.
        • Vaginal bleeding during current labour.
        • Marked tenderness over the scar during current labour.
      • Associated conditions as antepartum haemorrhage or malpresentations.
  • (B) Foetal indications:
    • Malpresentations and malposition (see before).
    • Prolapsed pulsating cord or foetal distress before full cervical dilatation.
    • Diabetes mellitus (see before).
    • Bad obstetric history as recurrent intrauterine foetal death in last weeks of pregnancy or repeated intranatal foetal death.
    • Post-mortem C.S. done within 10 minutes of maternal death to save a living baby.

Contraindications

  • Dead foetus: except in;
    • Extreme degree of pelvic contraction.
    • Neglected shoulder.
    • Severe accidental haemorrhage.
  • Disseminated intravascular coagulation: to minimise blood loss.
  • Extensive scar or pyogenic infection in the abdominal wall e.g. in burns.

Types of Caesarean Section

According to timing

  • Elective caesarean section: The operation is done at a pre-selected time before onset of labour, usually at completed 39 weeks.
  • Selective caesarean section: The operation is done after onset of labour.

According to the site of uterine incision

  • Upper segment caesarean section (classical C.S.): The incision is done in the upper uterine segment and it is always vertical.
  • Lower segment caesarean section (LSCS): It is the commoner type. The incision is done in the lower uterine segment and may be transverse (the usual) or vertical in the following conditions:
    • Presence of lateral varicosities.
    • Constriction ring to cut through it.
    • Deeply engaged head.

According to number of the operation

  • Primary caesarean section: for the first time.
  • Repeated caesarean section: with previous caesarean section(s).

According to opening the peritoneal cavity

  • Transperitoneal: The ordinary operation where the peritoneal cavity is opened before incising the uterus.
  • Extraperitoneal: The peritoneal cavity is not opened and the lower uterine segment is reached either laterally or inferiorly by reflecting the peritoneum of the vesico-uterine pouch . It is indicated in case of infected uterine contents as chorioamnionitis.

Advantages of elective C.S.

  • Pre - operative good preparation as regard sterilisation and antiseptic measures, fasting and bowel preparation.
  • The risk of puerperal sepsis is minimised.
  • The operation is scheduled and working is in ease.

Disadvantages of elective C.S.

  • The risk of immaturity of the foetus or its lung is present.
  • Higher incidence of respiratory distress syndrome.
  • The lower segment may be not well formed.
  • Postpartum haemorrhage is more liable to occur.
  • Imperfect drainage of lochia as the cervix is closed so it should be dilated by the index finger introduced abdominally through the uterine incision.

Procedure of Lower Segment Caesarean Section

  • Anaesthesia: General inhalation anaesthesia with nitrous oxide + oxygen (the most commonly used), epidural, spinal or rarely local infiltration anaesthesia.
  • Position: Tilting the patient 15o to the left in the dorsal position minimise the aorto-caval compression.
  • Skin incision: Pfannenstiel (transverse suprapubic) incision is the most commonly used, but midline or paramedian vertical suprapubic incisions may be used. If the patient had a previous C.S incise in the same incision with trimming of the fibrosed edges of the wound to help good healing.

Pfannenstiel incision has a better cosmetic appearance, better healing and less incidence of incisional hernia but it is more time consuming associated with more blood loss and gives less exposure.

  • The subcutaneous fat is incised.
  • The anterior rectus sheath is incised transversely in case of Pfannenstiel incision and longitudinally in case of vertical incisions.
  • The rectus muscles: are separated in the midline in Pfannenstiel incision or retracted laterally in case of vertical incisions.
  • The parietal peritoneum: is opened vertically.
  • The uterus is centralised, the bowel and omentum are packed off with moist laparotomy pads, however this is usually unnecessary.
  • The loose peritoneum over the lower uterine segment is held and incised transversely, for about 10 cm in a semilunar fashion with its edges directed upwards.
  • The bladder is dissected downward and is retained behind a Doyne retractor placed over the symphysis.
  • A stay suture may be taken superficially in the lower segment below the assumed site of uterine incision to help in its identification after evacuation of the uterus.
  • The uterus is incised: in the same semilunar fashion by one of the following methods:
    • A semilunar mark is made by the scalpel cutting partially through the myometrium for 10 cm. A short (3cm) cut is made in the middle of this incision mark reaching up to but not through the membranes. The incision is completed by the 2 index fingers along the incision mark. If the lower uterine segment is very thin, injury of the foetus can be avoided by using the handle of the scalpel or a haemostat (an artery forceps) to open the uterus.
    • The short (3cm) middle incision may be enlarged by a bandage scissors over 2 fingers introduced into the uterus to protect the foetus.
  • Membranes are ruptured by toothed or Kocher’s forceps.
  • The head is delivered by:
    • introducing the right hand gently below it and lifting it up helped by fundal pressure done by the assistant,
    • using one blade of the forceps or,
    • using Wrigley’s forceps.
    • If the head is deep in the pelvis it can be pushed up vaginally by an assistant.
    • The Doyen’s retractor is removed after the hand or forceps blade is applied and before head extraction.
  • Suction for the foetus is carried out before delivery of the head.
  • In breech or transverse lie the foetus is extracted as breech.
  • The placenta is removed.
  • Closure of the uterine incision is done in 3 layers.
    • The first is a continuous locking suture taking most of the myometrium but not passing through the decidua to guard against endometriosis and weakness of the scar.
    • The second is a continuous or interrupted one inverting the first layer.
    • The third is a continuous or interrupted layer to close the visceral peritoneum of the uterus. Closure of visceral and/or parietal peritoneum is omitted by some surgeons.
  • The abdomen is then closed in layers .

Upper Segment Caesarean Section

Indications

  • Dense adhesions, extensive varicosity or myoma in the lower uterine segment making its exposure or incising through it difficult.
  • Impacted shoulder presentation.
  • Anterior placenta praevia.
  • Defective scar in the upper segment.
  • Cancer cervix.
  • Rapid delivery is indicated.
  • If a concomitant tubal sterilisation will be done.
  • Previous successful repair of high vesico-vaginal or cervico-vaginal fistula.
  • Post-mortem hysterectomy.

Procedure

  • Abdominal incision: is vertical.
  • Uterine incision: 10 cm vertical incision is made in the midline of upper uterine segment without incising the peritoneal coat separately as it is adherent in the upper segment.
  • Extraction of the foetus: as a breech in cephalic presentation.
  • The last layer of the uterine incision closure includes the superficial part of the myometrium with the peritoneal covering.
  • The remainder of the procedure is as lower segment C.S.

Special problems encountered during caesarean section

Anterior placenta praevia

Try to pass beside the placenta to reach the foetus if this is impossible cut through it but severe bleeding will result which may affect the foetus.

Narrow uterine incision

Extension of the lower uterine segment incision may be done by:

  • "J" shaped or hockey-stick incision: i.e. extension of one end of the transverse semilunar incision upwards.
  • "U"- shaped or trap-door incision: i.e. extension of both ends upwards.
  • An inverted T incision: i.e. cutting upwards from the middle of the transverse incision. This is the worst choice because of its difficult repair and poor healing.

Advantages of the lower segment over the upper segment operation

  • Less blood loss: due to less vascularity and the placental bed is away from the incision.
  • Easier to repair.
  • The resultant uterine scar is stronger due to:
    • Better coaptation of the edges as the lower segment is thin.
    • Better healing as the lower segment is more passive during puerperium.
    • The scar is distant from the subsequent site of placental implantation which may penetrate it.
    • So subsequent rupture uterus is less (0.2% versus 2% in upper segment).
  • Less subsequent adhesions to the bowel and omentum.
  • Less liability to acute gastric dilatation and paralytic ileus.
  • Less liability to peritonitis due to better peritonization and healing.

Mode of Delivery in Subsequent Pregnancies

The rule that "caesarean always caesarean" had been replaced since a long time by "caesarean always hospital delivery". If the cause of the previous section is not permanent as contracted pelvis, vaginal delivery can be tried.

Caesarean Hysterectomy

Hysterectomy is carried out after caesarean section in the same sitting for one of the following reasons:

  • Uncontrollable postpartum haemorrhage.
  • Unrepairable rupture uterus.                   
  • Operable cancer cervix.
  • Couvelaire uterus.
  • Placenta accreta cannot be separated.      
  • Severe uterine infection particularly that caused by Cl. welchii.
  • Multiple uterine myomas in a woman not desiring future pregnancy although it is preferred to do it 3 months later.

Caesarean Sterilisation

Tubal sterilisation is usually advised during the fourth caesarean section.

Complications of Caesarean Section

  • Operative:
    • Primary maternal mortality is 4 times that of vaginal delivery which may be due to:
      • shock .
      • Anaesthetic complications particularly Mendelson’s syndrome
      • Haemorrhage usually due to extension of the uterine incision to the uterine vessels, atony of the uterus or DIC.
    • Injuries to the bladder or ureter.
    • Foetal injuries.
  • Post-operative:
    • Early:
      • Thrombosis and pulmonary embolism.
      • Acute dilatation of the stomach and paralytic ileus.
      • Wound infection, puerperal sepsis and burst abdomen.
      • Chest infection.
    • Late:
      • Rupture of the uterine scar.
      • Incisional hernia.

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Edited by Aldo Campana,