Abdominal wall defects

Although abdominal wall defects have been recognized and described since ancient times, virtually all significant anomalies of abdominal wall development were fatal until the last century. The first substantial advancement in the care of infants with large abdominal wall defects was the development by Gross of a staged technique for the closure of omphaloceles with skin flaps. The resulting ventral hernia defect and lateral displacement of abdominal wall musculature often caused considerable morbidity, but this was acceptable in light of the alternative. The second development that had a major impact on survival was the introduction of temporary coverage by prosthetic materials, allowing gradual reduction of the eviscerated structures and delayed fascial closure. Both of these techniques were applicable to omphaloceles with functional intestinal tracts protected by intact amniotic membranes. Improvements in survival for gastroschisis awaited the advent of techniques for parenteral nutrition to provide metabolic and nutritional support and allow time for the injured intestinal tract to become functional. Currently, survival with an acceptable quality of life is expected for most infants with isolated abdominal wall defects, and mortality is primarily related to associated anomalies. Embryology and pathogenesis Formation of the normal ventral abdominal wall requires the successful orchestration of many complex events that occur primarily from the fourth to the twelfth week of fetal development. These events include the folding, fusion, growth, and differentiation of embryonic tissues destined to become abdominal wall musculature, umbilicus, and the intestinal tract.