Neonatal abdominal wall defects

Gastroschisis and omphalocele are the two most common congenital abdominal wall defects. Both are frequently detected prenatally due to routine maternal serum screening and fetal ultrasound. Prenatal diagnosis may influence timing, mode and location of delivery. Prognosis for gastroschisis is primarily determined by the degree of bowel injury, whereas prognosis for omphalocele is related to the number and severity of associated anomalies. The surgical management of both conditions consists of closure of the abdominal wall defect, while minimizing the risk of injury to the abdominal viscera either through direct trauma or due to increased intra-abdominal pressure. Options include primary closure or a variety of staged approaches. Long-term outcome is favorable in most cases; however, significant associated anomalies (in the case of omphalocele) or intestinal dysfunction (in the case of gastroschisis) may result in morbidity and mortality.     

Anterior abdominal wall defects.

A total of 48 infants with abdominal wall defects referred to the South West Regional Neonatal Surgical Centre over a period of six years were reviewed. There were 27 (56%) infants with gastroschisis and 21 (44%) infants with exomphalos. At the regional centre, four pregnancies with gastroschisis were terminated following a prenatal diagnosis, one child was stillborn, and one with exomphalos and trisomy 13 died soon after birth. Of the remaining 42 live births, the one year survival for babies born with a gastroschisis was 95% (21/22) and with an exomphalos was 81% (17/20). All deaths, except one, were due to factors other than the abdominal defect. The effect on outcome of prenatal diagnosis, parental counselling, in utero transfer, mode of delivery, and methods of surgical closure was reviewed.     

Anterior abdominal wall defects and biliary obstruction

Three infants with anterior abdominal wall defects (gastroschisis and exomphalos) who presented with obstructive jaundice secondary to biliary obstruction, are described. All three infants had abnormal biliary systems, with mechanical distortion of the biliary tree. Biliary obstruction secondary to structural biliary anomalies should be considered in patients with abdominal wall defects and cholestasis, as prolonged unrelieved biliary obstruction may lead to biliary cirrhosis and portal hypertension.     

Risk factors for abdominal wall defects

In the last decades, the prevalence of gastroschisis (GS) has increased worldwide. The purpose of this study was to identify maternal risk factors explaining the described gain and to identify differences between GS and omphalocele (OC). A case-control design was used to compare GS (n = 36) and OC (n = 18) mothers to control group (CG; n = 30) matched for maternal age. Specialized questionnaires and mothers' prenatal records were used, and participants completed a structured interview. Focus was on medical history, changing nutrition, drug consumption, and external risk factors. The local ethics committee approved this study. GS mothers were significantly younger (mean 23.00; median 24; SD ±5) than OC (P = 0.007; mean 28.61; median 28, 19-41; SD ±5.1) and CG (P = 0.001; mean 30.77; median 31, SD ±6.2). Mothers with abdominal wall defects (AWD) ingested antibiotics more often (P = 0.008) than CG. Socioeconomic characteristics, for example, level of profession, of GS mothers was significantly lower than OC (P = 0.039) and CG (P = 0.05) mothers, and their cohabitation time was shorter (P < 0.05; mean 35 month/median 24 month, SD ±35.8). Incidence of OC significantly increased after hormonal treatment (P = 0.022) and invasive prenatal diagnostics (P < 0.05) compared to GS. GS mothers took folic acid prophylaxis less often than OC (P = 0.02). Smoking, illicit drugs, and external risks like herbicides showed no influence, but GS mothers drink significantly more often alcohol (P = 0.05). We confirmed an increased risk for GS if several factors such as young maternal age, short cohabitation time, and usage of antibiotics coincide with alcohol consumption and associated immune diseases. OC increased after hormonal treatment and invasive prenatal diagnostics.     

Anatomy and embryology of tracheo-esophageal fistula

Anomalies in tracheo-esophageal development result in a spectrum of congenital malformations ranging from, most commonly, esophageal atresia with or without trachea-esophageal fistula (EA+/-TEF) to esophageal web, duplication, stricture, tracheomalacia and tracheal agenesis. Despite the relative frequency of EA, however, the underlying etiology remains unknown and is likely due to a combination of genetic, epigenetic and environmental factors. In recent years, animal models have dramatically increased our understanding of the molecular and morphological processes involved in normal esophageal development during the key stages of anterior-posterior regionalization, dorsal-ventral patterning and morphogenic separation. Moreover, the use of animal models in conjunction with increasingly advanced techniques such as genomic sequencing, sophisticated live imaging studies and organoid models have more recently cast light on potential mechanisms involved in EA pathogenesis. This article aims to unravel some of the mysteries behind the anatomy and embryology of EA whilst providing insights into future directions for research.     

Evisceration through multiple abdominal wall defects following blunt abdominal injury

We report an unusual case of a posttraumatic evisceration of small and large bowel through 2 holes in the anterior abdominal wall after a motor vehicle accident. Prompt adequate management consists of reestablishing the perfusion of the eviscerated organ if the blood supply is compromised, performing a full laparotomy to exclude intra-abdominal organ injury and meticulous cleaning of the eviscerated organs before reducing them in the abdomen and closing the abdomen in layers.     

Decentralized surgery of abdominal wall defects in Germany

Pediatric Surgery International - Neonatal surgery for abdominal wall defects is not performed in a centralized manner in Germany. The aim of this study was to investigate whether treatment for...     

Cryptorchidism in boys with congenital abdominal wall defects

Cryptorchidism (CPT) has been suggested to be common in boys with congenital abdominal wall defects (CAWD). It has been hypothesized that the low intra-abdominal pressure in both omphalocele (OMP) and gastroschisis (GS) and brain malformations in patients with OMP contribute to the high incidence of CPT. To determine the incidence of CPT in boys with OMP and GS and to assess the relationship of CPT to the size of the AWD, prematurity, and concomitant anomalies, the hospital records and autopsy reports of 113 boys with CAWD (OMP n = 75; GS n = 38) were reviewed. Twelve (16.0%) boys with OMP had undescended testes; 5 (41.0%) of those had bilateral and 4 (23.5%) intra-abdominal undescended testes. The occurrence of CPT in OMP patients did not correlate with the size of the AWD, birth weight, or gestational age. However, congenital cardiac anomalies and cleft lip and palate were significantly more common (P < 0.05) among those with CPT. Two (5.0%) boys with GS, both of whom were born prematurely, had inilateral CPT. In patients with OMP, the incidence of CPT was significantly higher than that of healthy children. There was a correlation between CPT and congenital midline defects such as cardiac anomalies and cleft lip and palate. In patients with GS, the incidence of CPT only slightly exceeded that of normal children and may have been related to prematurity. Accepted: 6 January 1997     

Muscular flaps for closure of giant abdominal wall defects

In this article we describe the use of muscle flaps in closing giant abdominal wall defects. The technique used to take the flaps from the anterior rectum, internal and external oblique muscles are shown. We emphasize the advantages of using this technique, which avoids the use of synthetic materials, such as Teflon and Marlex mesh. Correspondence to: Antonio F. Gallardo Meza     

Myocutaneous sartorius flap for major congenital abdominal wall defects

Management of giant omphalocele/gastroschisis remains unsatisfactory: primary fascial closure is not always possible, prosthetic applications lead to problems of infection and separation, and escharification or skin closure results in ventral hernias. We have therefore investigated the possible use of myocutaneous flaps in such situations. The myocutaneous flap, comprising a skin pedicle isolated along with the underlying muscle, has two major attractions: (1) the good blood supply minimises risks of infection and flap separation; and (2) the muscle pedicle provides a strong fascial-muscular closure. The flap has to fulfill four criteria: (1) it is viable; (2) it provides adequate coverage; (3) it reaches the defect; and (4) its transposition does not result in functional disability of the organ from which it originates. Based on an anatomical study of 20 post-mortem specimens in eight neonates and two adults, including contrast injections, we have found the sartorius musculocutaneous flap to be the ideal solution. The sartorius muscle is relatively more bulky in neonates than in adults. The major blood supply, which enters between its upper third and lower two thirds, can maintain a 7 × 3-cm flap. With the hips immobilised in flexion, the flap can reach the xiphisternum without tension. Our study suggests that it is feasible to repair neonatal abdominal wall defects of up to 7 × 6 cm by sartorius musculocutaneous flaps. In particular, this approach appears ideally suited for reconstruction in cloacal exstrophy and for secondary repair of ventral hernias resulting from escharification, skin closure alone, or failed prosthetic applications in giant omphalocele/gastroschisis.Offprint requests to: P. K. H. Tam     

Pulmonary hypoplasia in infants with giant abdominal wall defects

The medical records of 114 infants with abdominal wall defects, including 35 infants examined at autopsy, were reviewed to determine if giant (liver-containing) defects are associated with a narrow thoracic cage deformity and pulmonary hypoplasia. The study included 48 infants with gastroschisis, 60 with omphalocele, two with a lower midline syndrome (cloacal exstrophy) and four with an upper midline syndrome (Cantrell's pentalogy). A giant abdominal wall defect was present in 33 infants, including one with gastroschisis, 27 with omphalocele, two with a lower midline syndrome, and three with an upper midline syndrome. A thoracic cage deformity, characterized by a narrow chest and down-slanting ribs, was identified radiographically in 42% (14 of 33) of infants with giant abdominal wall defects. Among the 35 infants examined at autopsy, 14 infants with giant omphaloceles had mean chest circumference to occipital frontal circumference ratio and lung weight to body weight ratios that were significantly below the means for infants with gastroschisis or small omphalocele. Lung weight to body weight ratios indicated marked pulmonary hypoplasia in three of 12 (25%) of infants who had a narrow thoracic cage deformity, and radial alveolar counts indicated mild pulmonary hypoplasia in four additional infants. Prematurity (four infants), diaphragmatic abnormalities (seven infants), and congenital heart disease (four infants) potentially contributed to the respiratory distress experienced by these 12 infants. Infants with giant abdominal wall defects and narrow thoracic cages are at increased risk for pulmonary hypoplasia and respiratory distress.     

Teratogens inducing congenital abdominal wall defects in animal models

Congenital abdominal wall defects are common anomalies which include gastroschisis, omphalocele and umbilical cord hernia. Recent reports indicate that gastroschisis is increasing in prevalence, whereas omphalocele has remained steady, suggesting that environmental factors may play a part in their pathogenesis. The aim of this study is to review animal teratogen studies resulting in abdominal wall defects to investigate their possible causes. Each report was examined not only for the teratogens causing the defects, but also to carefully identify the defect occurring and its correlation with the known clinical anomalies. We found many discrepancies between the nomenclature used by animal teratology investigators and that used by clinicians. We were able to confirm the induction of gastroschisis by 22 teratogens, omphalocele by 9 teratogens and umbilical cord hernia by 8. There is no doubt that environmental factors may be responsible, at least in part, for all three of the clinical abdominal wall defects. Future studies should take care to appreciate the differences between these anomalies and describe them in detail, so that accurate and meaningful conclusions can be obtained.     

Morbidity in infants with antenatally-diagnosed anterior abdominal wall defects

 The aims of this study were to compare the morbidity of infants with gastroschisis (GS) with that of infants with exomphalos (EX) without lethal abnormalities and to identify factors predictive of adverse outcome: a requirement for parenteral nutrition (PN) for over 1 month and hospital admission for over 2 months. The medical records of 45 infants with anterior wall defects (32 with GS) diagnosed antenatally who consecutively received intensive care in one institution from 1993 were reviewed. Both the GS and EX infants had a median gestational age of 37 weeks, but the former were lighter at birth (P < 0.01). Fourteen infants (all with GS) were able to start feeds only after 2 weeks; 10 (8 with GS) developed liver dysfunction; and 5 (all with GS) died. The GS compared to the EX infants required a longer period of PN (median 20 vs 10 days, P < 0.01) and longer hospital admission (median 40 vs 25 days, P < 0.01). In the GS group the time to start feeding related independently to prolonged hospital stay, and the existence of structural bowel abnormalities (SBA) related independently to both measures of adverse outcome, with a positive predictive value of 100%. We conclude that infants with GS, particularly those with SBA, suffer greater morbidity than infants with EX without lethal abnormalities. Accepted: 8 October 1999     

Lower abdominal wall flap for closure of large diaphragmatic defects

A method of closure of diaphragmatic herniae with large defects is described in two children using a muscle flap of internal oblique and transversus abdominus from the inferior aspect of the wound. The advantages are that the flap is large, easily accessible, autologous, assists in resultant wound closure, and requires no separate incision. It differs from previously described flaps as it is taken from below the subcostal wound and is not limited in size or length by the costal margin. Correspondence to: W. D. A. Ford     

Review of the evidence on the closure of abdominal wall defects

Infants with congenital abdominal wall defects pose an interesting and challenging management issue for surgeons. We attempt to review the literature to define the current treatment modalities and their application in practice. In gastroschisis, the overall strategies for repair include immediate closure or delayed operative repair. The best level of data for gastroschisis is grade C and appears to support that there is no major difference in survival between immediate closure or delayed repair. In patients with omphalocele, the management techniques are more varied consisting of immediate closure, staged closure or delayed closure after epithelialization. The literature is less clear on when to use one technique over the other, consisting of mostly grade D and E data. In patients with omphalocele, a registry to collect information on patients with larger defects may help determine which of the management strategies is optimal.