Omphalocele (exomphalos)

Not uncommonly, a child is born with a defect in his abdominal wall which involves his umbilicus, and leaves his viscera covered only by a translucent layer of peritoneum and amnion. In omphalocele minor there are only a few loops of gut in the sac, but in omphalocele major, it may contain most of his abdominal organs, including even his liver. Often he has no other defects, so he is well worth saving.

The sac of an omphalocele is weak, and easily ruptures or becomes infected, causing peritonitis. If it ruptures during delivery, surgery is urgent. If it survives delivery intact, you have the choice between operative and non-operative treatment. Surgery is the usual method; non-operative treatment needs particularly good nursing care.

If you can reduce the contents of the sac, he has omphalocele minor, which you can treat without difficulty. If you cannot reduce them, he has omphalocele major, which has to be managed surgically in two stages: (1) Undermine skin flaps to make an artificial hernia, and bring them together over his herniated viscera, which will then lie subcutaneously. (2) At nine months to a year, his abdominal cavity should have grown enough to allow you, or an expert, to reduce the hernia into it.

Fig. 28-9 OMPHALOCELE. A, this hernia is too large to reduce in a single stage (omphalocele major); its sac is intact. B, incise the skin 5 mm below the edge of the defect. C, separate skin flaps with scissors. D, extend the incision superiorly and inferiorly. E, hold up the skin flaps with haemostats applied to the subcutaneous tissue to reduce the viscera. F, close the flaps. G, and H, early and late stages in the non-operative treatment with spirit dressings. Partly after Ravitch et al., ''Paediatric Surgery'. Yearbook Medical, permission requested.

OMPHALOCELE [s8](exomphalos) As soon as the child is born, apply warm saline soaks to the omphalocele, to keep it moist and to prevent him getting cold. Wrap him up well.

If his omphalocele has ruptured, or is threatening to do so, operate betwen 6 and 24 hours. If its covering appears stable, you can wait a few days. If possible refer him, especially if his omphalocele is large.

NON-OPERATIVE TREATMENT [s7]FOR OMPHALOCELES If the sac is intact and its coverings are fairly strong (common with small omphaloceles, but not with large ones), you can, if necessary, treat omphaloceles of any degree this way. It is however second best, so repair them if you can.

Clean the sac with an antiseptic, and dress it with spirit. Don't use mercurochrome. Apply spirit to the sac hourly for the first 48 hours, and then less often as an eschar forms. This will separate from the periphery, as epithelialisation takes place, but it may take several weeks. He will then be left with a large skin-covered ventral hernia (H, Fig. 28-9) which will need repair later.

THE SURGICAL REPAIR [s7]OF OMPHALOCELES ANTIBIOTICS. Always give these if the sac ruptures before or during the operation. Give him ampicilllin 10 mg/kg 6- hourly, and metronidazole 7.5 mg/kg 8-hourly.

ANAESTHESIA. Set up a scalp vein drip or do a cut-down. Give him a general anaesthetic (A 18.1) or ketamine, tracheal intubation, and suxamethonium (18.2). You can use local anaesthesia for a small omphalocele (not easy), but not for a large one because you need muscular relaxation. If he has an omphalocele major, have blood available, and replace any blood he loses meticulously (3-1).

REPAIRING AN OMPHALOCELE MINOR INDICATIONS. His omphalocele is small enough for you to be able to: (1) reduce it while he is anaesthetized and breathing spontaneously, and (2) bring the edges of the sac together, without embarrassing his respiration. If it is embarrassed, do a two-stage repair.

REDUCTION. Prepare his skin, including the hernial sac and drape him. Tie and divide his cord, as it emerges from the sac, with ''0' chromic catgut (monofilament cuts through too easily).

Try to reduce the contents of the sac into his abdominal cavity. If you fail, manage him as an omphalocele major. If you succeed, incise the skin 0.5 cm, or less, from the edge of the defect (B, in Fig. 28-9). Find and tie his umbilical arteries in the 5 and 7 o'clock positions; tie his umbilical vein superiorly in the 12 o'clock position. Expose the edge of his fascia and peritoneum, and remove a ring of tissue. Excise any tissue of doubtful viability from the sac wall.

Reduce his hernia, and close the defect in three layers. If necessary, hold up the edges of the defect with haemostats (E). Close his peritoneum with 3/0 catgut. Close his fascia with 2/0 monofilament mattress sutures. Close his skin with simple sutures of 2/0 monofilament.

Postoperatively, feed him with expressed breast milk by nasogastric tube, until he is sucking well, usually in 2 or 3 days.

REPAIRING AN OMPHALOCELE MAJOR This is an omphalocele which you cannot reduce in a single stage (A, in Fig 28-9).

FIRST STAGE. Incise his skin and subcutaneous tissue 0.5 cm or less from the edge of the sac (B). Find and tie the vessels as above. Excise any tissue of doubtful viability from the wall of the sac, including the stumps of the vessels. Extend the incision in the midline superiorly and inferiorly (D). Use scissors to extensively undermine a superficial layer of skin and subcutaneous tissue, and separate this from the muscles of his abdominal wall and the aponeurotic layer. Reduce dissection over his thorax to the absolute minimum that will provide enough skin cover. The flaps must cover the hernia without undue tension.

Hold the edges of the wound up in haemostats applied to the subcutaneous tissue, and reduce the contents of the sac so that they lie subcutaneously. Close the wound in two layers. Use 2/0 chromic catgut for the subcutaneous tissue and 2/0 monofilament for the skin.

Postoperatively, care for him as for omphalocele minor, but continue tube feeding for longer.

SECOND STAGE. Do this at nine months or a year, and refer him for it if you can.

If you cannot refer him, give him a general anaesthetic, and try to reduce the contents of the sac into his abdominal cavity. If you cannot reduce most of them, delay the operation and try again six months later.

If you can reduce all the contents, excise the sac, as for the first operation. Disssect out skin flaps down to the edge of the defect in his abdominal wall. Divide any adhesions between the subcutaneous tissue of the flaps and the sac, or his abdominal organs. Define the peritoneum and fascia at the edge of the defect. Then close the peritoneum and fascia longitudinally if you can (unusual).

If you cannot reduce all the contents into his abdominal cavity, reduce what you can. This will help his abdominal cavity to enlarge. Make his hernia smaller by suturing his subcutaneous tissue to the muscles of his abdominal wall with catgut. Then close his subcutaneous tissue and his skin as before. Operate again about a year later. The greater volume of his abdominal contents will help his abdominal cavity to enlarge.

Fig. 28-9a BILE-DUCT ATRESIA. A, normal. B, total atresia of all ducts. C, atresia of all ducts except the gall-bladder. D, intrahepatic atresia. E, atresia of the common ducts. F, atresia of the common bile-duct and gall-bladder. G, segmental atresia of the distal common bile-duct. After Seymour I. Schwartz, ''Surgical Disease of the Liver', (1964). McGraw-Hill, permission requested. page485