Which kind of Caesarean section?

Caesarean section is the commonest emergency procedure in a district hospital. If you are inexperienced it will also be the one which you will be most frightened of doing. In unskilled hands it is often fatal, as the result of: (1) the inhalation of gastric contents, (2) the supine hypotensive syndrome, (3) haemorrhage, or (4) sepsis.

There are several kinds of Caesarean section:

(1) Classical Caesarean section, is done through a vertical incision in the upper segment of the uterus (18.12). It is largely outmoded, but there are some rare occasions when it may be indicated.

(2) A lower segment Caesarean section approaches the uterus through a transverse incision in the peritoneum over the lower segment. It has long been the standard operation because: (a) a scar here ruptures ten times less often than the scar from a classical incision, (b) when it does rupture it does so less dangerously, (c) the incision in the uterus heals better, (d) the danger of spreading infection is reduced, (e) the placenta is less often directly underneath the uterine incision, (f) the gut is less likely to stick to the scar in the uterus, and (g) there are fewer postoperative complications.

But: (a) A lower segment operation needs more skill. (b) It is dangerous if there is intrauterine infection, although less so than a classical one. (c) You may injure the patient's bladder. (d) Bleeding from the ends of the incision is more difficult to control, especially if there are lateral extension tears, as may happen if the lower segment is thin and distended, or the baby is an awkward position, as in a transverse lie. These tears may bleed severely, and in trying to control bleeding you may tie or cut her ureters. (e) You may find it difficult to extract a distorted presenting part through a lower segment incision, and tear it as you do so. A tear will be dangerous, and the only way to avoid ]]one, once you have begun a lower segment operation, is to extend it as an inverted-T incision. Unfortunately, this does not heal well, and is a very bad incision to have to make. So only make the standard transverse incision if it is safe. It is because of these dangers, that we describe the following three alternatives:

(3) The de Lee incision (18.9) is a vertical incision, two-thirds of which are in the lower segment, and one- third in the upper one. It is thus a cross between the classical upper segment operation, and the ordinary lower segment one. Make a de Lee incision if a lateral tear is likely, as can happen if the lower segment is very thin, or the baby is in an abnormal position, as in a transverse lie.

(4) A transverse incision in the upper segment is occasionally needed if there is a transverse lie, or a contraction ring (Bandl's ring).

(5) Extraperitoneal Caesarean section (18.13) is indicated if there is established or potential intrauterine infection. It greatly reduces the incidence of peritonitis, especially if you do not have antibiotics, particularly metronidazole.

(6) Caesarean hysterectomy is occasionally necessary for rupture of the uterus (18.17), when you have to remove the uterus (usually subtotally), and the baby (usually dead). It is also occasionally indicated when the lower segment is severely bruised, or major uterine vessels have been torn, or there is is established or potential uterine infection.

If you enter the abdomen through a lower midline incision, you need not decide whether to do a standard or a de Lee operation, until you get inside. But, if you are going to do an extraperitoneal Caesarean section, you will have to decide to do this before you open the abdomen.

WHICH KIND OF CAESAREAN SECTION? The indications as to when to do Caesarean section are discussed in Sections 18.1, 18.2, and 18.4, and in M 22.12. Here we are concerned with what kind of Caesarean section you do. One indication which is not accepted, is the need to tie a mother's Fallopian tubes. There are easier and safer ways of doing this (15.3).

Always do the ordinary lower segment operation unless one of these others is indicated.

CLASSICAL SECTION is indicated if neither a lower segment operation, nor a transverse incision in the upper segment are possible (unusual). This may happen if: (1) The lower half of the patient's upper segment is very vascular, or inaccessible as the result of adhesions from a previous operation joining her lower segment to her abdominal wall. (2) She has had a previous classical incision, which has healed poorly. (3) She has a very vascular lower segment, with many thick veins on it. This may occur with placenta praevia (Type Four, or Types One or Two if the placenta is anterior), or it may sometimes occur with a normally placed placenta. She will bleed much, if you do a lower segment incision in a uterus like this, so a classical one is better. (4) A poorly developed lower segment which does not allow a transverse incision of adequate length. For some special points concerning Caesarean section in placenta praevia, see Section 18.10. (5) You are very inexperienced indeed. Alternatively, make a transverse incision half-way up her upper segment, and as you gain experience, transfer the incision to her lower segment. (6) As a preliminary to Caesarean hysterectomy.

CAUTION ! Don't let her wish to have her tubes tied favour the decision to do a classical section.

DE LEE SECTION. Do this if her lower segment is likely to tear, because it is thin and distended, or because there is a transverse lie.

EXTRAPERITONEAL SECTION. Do this if the contents of her uterus are infected and antibiotics are scarce.