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350 Congenital Anterior Abdominal Wall Defects: Exomphalos and Gastroschisis Congenital Anterior Abdominal Wall Defects: Exomphalos and Gastroschisis
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diaphragm, and oedematous or dusky lower limbs due to poor venous Conservative Treatment
return. The fascial layer and skin are closed separately, with possible Conservative treatment involves nonoperative measures aimed at
constuction of an umbilicus. Muscle flaps are sometimes created by escharisation of the sac, which progressively contracts the scar, and
making a release incision on the sides of the peritoneal cavity and encouraging rapid epithelisation from the edge. Various materials have
mobilising the muscle medially to obtain fascial closure. been used, including mercurochrome solution, dilute silver nitrate solu-
Staged abdominal wall closure tion, and 70–90% alcohol. The effect and complications on the baby
have caused these solutions to be used less frequently. A useful method
If closure of the fasciomuscular layer is not possible due to undue pres-
of conservative treatment is the application of closed dressing, which
sure on the diaphragm, only the skin may be undermined, stretched,
is applicable only for an intact sac. When the sac is ruptured, the silo
and closed. This will heal, leaving a ventral hernia that can be closed
is preferable.
at a later age.
For the dressing, the whole abdomen is cleaned with a plain
Postoperatively, the child is monitored for adequate respiration
antiseptic lotion and dried. A layer of Sofratulle is laid to cover the
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and urine output. Oral feeds are commenced as soon as the child can
whole sac. Two or three layers of soft cotton gauze are placed to cover
tolerate them.
the whole lesion. A soft crepe bandage, 4 or 6 inches, is applied around
Skin stretching may need to be attempted to increase the surface
the circumference of the abdomen, thus maintaining uniform pressure
area of the abdominal skin wall. This is usually possible and reduces
respiratory stress. Skin flaps are sometimes created by making release on the omphalocele (Figure 56.4). The dressing is kept on for 24–48
incisions on the sides of the abdomen and mobilising the skin medially hours and repeated with fresh materials. If the sac appears moist,
without attempting to appose the fascia and muscles. the dressing should be done once every day. If there is evidence of
infection, the dressing should be done twice a day.
Secondary abdominal wall closure By this method, the baby can be kept in the hospital for a shorter
Secondary abdominal wall closure is repair of the ventral hernia by time than for other methods, usually 7–10 days, and can be discharged
achieving fascial closure with native body wall and, where not possible, to continue further dressing on an outpatient basis.
the use of a prosthetic material (Gor-Tex , Surgisis , Permacol™) fol- By the time the omphalocele heals, there is a ventral abdominal
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lowed by skin closure. hernia (Figure 56.5). This is repaired at a later stage, as described above.
The general condition of the child must be good, with good
nutritional status and haemoglobin of at least 10 gm/dl. General
anaesthesia is used. The scar of the healed omphalocele is excised. The
skin is undermined, the fascial edge identified, and the fascia mobilised
and muscle edge identified. Any adherent viscera are released. The
peritoneum is closed without tension. The fascia is then closed
longitudinally with monofilament-interrupted sutures. The effect of
the closure on respiration should be monitored by the anaesthetist. If
there is respiratory compromise, the sutures should be released and the
use of a prosthetic material, such prolene mesh, Gor-Tex, Surgisis, or
Permacol, should be considered, followed by skin closure.
Application of silo
Silo material is silicon or prolene or other nonirritant synthetic mate-
rial that is nonporous and not adhesive. The mesh is constructed into a
bag to fit firmly around the bowels and sutured tightly to the circum-
ference of the fascia and subcutaneous tissues of the defect (Figure
56.3). Bogota bags or intravenous solution bags may be used as silos. Figure 56.4: Conservative management of omphalocele.
Preformed silo bags are now available that can be placed on the ompha-
locele and applied firmly on the circumference; however, these are
expensive. The baby is nursed in an incubator in supine position with
the bag suspended from the roof of the incubator.
The baby is usually comfortable. Broad-spectrum antibodies are
administered. The circumference suture area is firmly packed and
monitored for soaking, infection, or evidence of detaching. Over the
days that follow, the bowel content gradually reduces into the abdominal
cavity. The bag can get loose on the omphalocele. Further sutures or
bands are then applied on the bag to keep it firm on the bowels; this
may be required every 2 days. By 7 to 10 days, the omphalocele can
be reduced sufficiently to enable closure. The most serious difficulties
with silos are infection and detachment at the suture line.

Figure 56.5: Ventral hernia formation.

Figure 56.3: Traditional silo bag.