Pediatric Omphalocele and Gastroschisis
- Author: James G Glasser, MD, MA, FACS; Chief Editor: Ted Rosenkrantz, MD more...
Ventral body wall defects comprise a group of congenital malformations that includes gastroschisis and omphalocele, which are relatively common, and ectopia cordis, bladder exstrophy, and cloacal exstrophy, which are extremely rare. The prevalence of gastroschisis is increasing; thus, it is the congenital anomaly most frequently encountered by pediatric surgeons.
Reported incidence of abdominal wall defects is as follows:
Gastroschisis - 1 case in 2000 births
Omphalocele - 1 case in 4000 births
Bladder exstrophy - 1 case in 40,000 births
Ectopia cordis - 1 case in 125,000 births
Cloacal exstrophy - 1 case in 200,000 births
Although the treatment of these babies is the task of neonatologists and pediatric surgeons, it behooves pediatricians to become familiar with the clinical spectrum of abdominal wall defects so that they are prepared to care for these children later in life. Sometimes, gastroschisis is as easy to repair as a surgical incision. In such cases, routine postnatal care may suffice; however, if multiple procedures are required or if the abdominal wall defect is one component of a multifaceted anomaly, further care by specialists familiar with the child's specific problems may be required.
A baby born with gastroschisis may have malabsorption, because in utero exposure of the intestine to amniotic fluid may cause mucosal or muscularis dysfunction, or the anatomic defect may constrict the mesentery causing ischemia and diminished intestinal length. In addition, there may be luminal obstruction from adhesions or bands associated with midgut malrotation, which accompanies all the anomalies in which the intestine remains outside the nascent abdominal cavity. Midgut volvulus, the complication most feared in babies with malrotation, is theoretically possible but unlikely, because of postsurgical adhesions. Atypical appendicitis may occur, however, if the abnormally located appendix is not removed. In addition, children with gastroschisis frequently have gastroesophageal reflux, which usually responds to medical therapy; fundoplication is rarely necessary. Hirschsprung disease, also, may contribute to these babies' intestinal dysfunction.
Initially, the embryo is a flat disk surrounded by the umbilical ring. Gastrulation proceeds in a cephalocaudal direction and converts the original two-layered disk into three germ layers. The dorsal layer is the ectoderm, which becomes either the central nervous system (CNS) or the skin and sensory organs. The middle layer is the mesoderm, which forms the skeleton, connective tissue, and the cardiovascular and urogenital systems. The ventral layer is the endoderm, which develops into the intestines, liver, gallbladder, and pancreas.
Proliferation of the neuroectoderm and the underlying mesoderm pushes the embryonic disk above the umbilical ring like a sprouting mushroom. The amnion bulges over the embryo and fuses with the yolk sac and body stalk. As the embryo elongates, longitudinal enfolding of its lateral walls creates the appearance of a ridged cylinder. Ventral enfolding separates the thoracic and abdominal cavities from the extra-embryonic space. With caudal enfolding, the embryo begins to resemble a fetus.
The yolk sac is incorporated into the hindgut and the allantois is incorporated into the urogenital sinus creating the cloaca. The cloacal membrane separates the coelom from the amniotic cavity.
The mesoderm invades the cloacal membrane and unites the genital tubercles to form the ventral wall of the urogenital sinus. As the hindgut elongates, condensation of mesoderm anteriorly forms the urorectal septum. The body folds (cephalic, caudal, and lateral) unite where the amnion invests the yolk sac and body stalk.
Fusion is a complex process that also occurs in formation of the neural tube, palate, and lip. In these areas, a surface glycoprotein promotes adhesion; then, planned cellular death (apoptosis) and migration create continuity between the opposing surfaces.
In an analogous fashion, the amnion and the lateral folds of the body wall coalesce about the attenuated yolk sac, constricting the umbilical ring. This process requires a "component separation and reorganization"” for the opposing sides to become a continuous layer. Development of the gut, suspended on its mesentery, occurs coincidentally with these events.
By the sixth week of intrauterine life, rapid growth of the liver and intestines causes herniation of the midgut through the umbilical ring.
By the tenth week, the abdominal cavity has enlarged sufficiently to accommodate the return of the midgut.
Rotation and fixation of the duodenum and the proximal colon occur as the intestine returns to the abdominal cavity.
Omphaloceles and gastroschisis
In babies with omphaloceles, this return to the abdominal never takes place; thus, the intestine stays within the confines of the umbilical ring. See the image below)
There is evidence to suggest that omphaloceles have a genetic etiology, as follows:
Omphaloceles are associated with increased maternal age.
Omphaloceles occur in twins, consecutive children, and different generations of the same family.
Omphaloceles are associated with trisomies 13, 18, and 21 (in 25-50 % of cases) and with Beckwith-Wiedemann Syndrome
In gastroschisis, there appears to be a weakness in the body wall—perhaps caused by defective ingrowth, cellular death, or impaired cellular fusion, such that the intestines are extruded through the defective area into the amniotic cavity. See the image below.
Gastroschisis is associated with young maternal age as well as low gravida, prematurity, and low birth-weight babies, secondary to in utero growth retardation.
Clustering of cases (number and severity) suggests a complex etiology, such as environmental factors acting upon susceptible hosts.
Other abdominal wall defects
There is a vast spectrum of body wall defects, which vary in their anatomic location and size of the defect. Issues to consider include the following:
Is a sac is present?
Is it ruptured?
Are there associated anomalies (which are four times more prevalent in omphalocele than gastroschisis)?
Other associated anomalies include the following:
Congenital heart disease
Patent omphalomesenteric duct remnant, creating an umbilical cord stoma
Hernias of the umbilical cord
In hernias of the umbilical cord, the umbilical ring is oversized, but the relation of the amnion to the yolk sac and connecting stalk is normal. See the image below.
Urachal remnants and omphalomesenteric duct malformations
The bladder develops between the fifth and ninth gestational weeks (postfertilization). By 10 weeks, urine is produced and mixes with the amniotic fluid; this is is crucial for normal lung development. In healthy babies, the bladder is visible on ultrasonography toward the end of the first trimester.
In patients with bladder exstrophy, the bladder image is a protruding, semi-solid mass inferior to an umbilical cord that is displaced caudally. The pelvis is shallow and flat; the lack of space displaces the developing bladder, urethra, vagina, and rectum anteriorly. Herniation of these organs interferes with the normal development of the lower abdominal wall. See the images below.
Prune-belly syndrome involves hydroureteronephrosis, megacystis, and undescended testes in addition to multiple other organ system defects. This syndrome is caused by increased "apoptotic" cell death in the body-wall placode or insufficient deposition of mesodermal cells with abnormal retention of the yolk sac.
Note the following:
There is attenuation of the abdominal musculature.
Muscle fibers are absent and are replaced by thick collagenous aponeuroses.
Hypoplasia of the abdominal wall contrasts with hypertrophy of the bladder wall, causing bladder neck obstruction and dilation of the ureters and renal collecting system.
Faulty intercellular conduction of electrical impulses causes disordered muscular contraction and ineffective ureteric peristalsis.
Approximately 95% of babies with prune belly syndrome are male; the absence of prostatic and seminal fluid precludes normal sperm development and causes infertility.
The urorectal septum divides the cloacae into the urogenital sinus and the rectum. Defective enfolding of the embryo's caudal pole and deficient incorporation of the yolk sac and allantois into the urogenital sinus leads to malformation of the external genitalia.
Without ingrowth of the mesoderm, the cloaca persists; differentiation of the genitourinary system and hindgut are arrested; and development of the lower abdominal wall obstructed. The result is cloacal exstrophy.
This anomaly is associated with mutations in the homeobox genes.
See the images below.
The combined incidence of omphalocele and gastroschisis is 1 case per 3,500 births. Epidemiologic data compiled over the last 40 years show that the incidence of omphalocele has remained constant, whereas that of gastroschisis is increasing.
Over the past 2 decades, the incidence of gastroschisis has increased three- to four-fold, whereas the incidence of omphalocele has remained constant. See the table below.
|Country||Time Period / Incidence||Time Period / Incidence|
|England and Wales||1987||1991|
|England and Wales||1995||2005|
The mortality of omphaloceles relative to gastroschisis is 8:1. Irreversible pulmonary hypertension/right heart failure is the usual terminal condition.
Factors adversely influencing the management of babies with gastroschisis are as follows:
Prematurity and low birth weight
Hypothermia (exposure of the intestine to the ambient environment)
Dehydration (gastrointestinal losses, in addition to the above factors)
Sepsis (open wound)
Hypoglycemia (stress with little metabolic reserve)
In utero growth restriction (protein loss from the extruded intestines)
Fetal distress and birth asphyxia
Injury to the intestines during delivery (tearing or cutting the bowel or mesentery)
Improvements in respiratory care, pharmacology (antibiotics and total parenteral nutrition), anesthesia, and surgery have increased the survival rates for these babies from 60% during the 1960s to more than 90% in more recent years.[6, 7, 9]
See the images below.
Long-term morbidity from gastroschisis is related to intestinal dysmotility (pseudo intestinal obstruction), malabsorption (mucosal injury), short gut, and gastroesophageal reflux disease. Difficulties in obtaining wound closure usually are reflected in intestinal morbidity. Poor healing of the abdominal wound causes an incisional hernia, which may require surgical repair.[10, 11, 12, 13]
The following scenarios may eventuate in short-gut syndrome, with which the baby has inadequate intestinal length:
An antenatal mesenteric vascular accident may cause intestinal atresia.
Constriction of the mesentery of the extruded intestine by a small abdominal wall defect may cause gut infarction ("closing gastroschisis").
An excessively tight closure of the abdominal wall defect may impede splanchnic blood flow and result in intestinal ischemia or necrosis.
Closed-loop obstructions, in which both efferent and afferent limbs of the intestine are blocked, occur in volvulus (rotation) of the entire midgut around its mesentery (the superior mesenteric artery and vein) or when a single loop of intestine flips on its mesentry or around an external point of fixation, such as an adhesion to the abdominal wall. This causes tense distention and ischemic injury of the intestines (ie, "strangulation obstruction").
The injury produced by antenatal exposure of the intestine to amniotic fluid (mucosal and muscular) leads to diminished absorptive and propulsive capacity of the gut and compounds the crippling effect of diminished length.
The care of babies with short-gut syndrome has improved with innovations in parenteral and enteral nutrition, venous access devices, prevention and early treatment of catheter sepsis, innovative surgical procedures to optimize gut length, and aggressive treatment of bacterial overgrowth in stagnant loops of intestine. Babies with short-gut syndrome from gastroschisis account for a substantial number of children undergoing intestinal transplantation.[15, 16]
See the images below.
Babies with giant omphaloceles usually have small, bell-shaped thoracic cavities and minimal pulmonary reserve. Repair of the omphalocele may precipitate respiratory failure, which may be chronic and require a tracheotomy and long-term ventilator support. The author recently treated (unsuccessfully) a baby with a giant omphalocele and a diaphragmatic hernia. Both conditions are associated with pulmonary hypoplasia, and, occurring together, they were of such severity as to preclude survival, despite extracorporeal membrane oxygenation (ECMO) support.
Even with successful repair of a giant omphalocele, the liver remains located in the midepigastrium, where it lacks the normal protection afforded by the lower rib cage and where it is more vulnerable to injury. See the image below.
A study by Corey et al indicated that compared with infants with gastroschisis, those with omphalocele have a higher incidence of other anomalies, are more likely to have pulmonary hypertension, and have a higher mortality rate. In the study, which involved 4687 infants with gastroschisis and 1448 with omphalocele, the investigators found that 35% of the patients with omphalocele had at least one other anomaly, compared with 8% of those with gastroschisis. The odds ratios for pulmonary hypertension and mortality in infants with omphalocele compared with those with gastroschisis were 7.78 and 6.81, respectively.
Neither gastroschisis nor omphalocele has a geographic or racial predilection. The Texas data indicate that gastroschisis occurs most commonly in Latinos, next in whites, and least frequently in African Americans.
The male-to-female ratio is 1.5:1.
Eggink BH, Richardson CJ, Malloy MH, Angel CA. Outcome of gastroschisis: a 20-year case review of infants with gastroschisis born in Galveston, Texas. J Pediatr Surg. 2006 Jun. 41(6):1103-8. [Medline].
Vermeij-Keers C, Hartwig NG, van der Werff JF. Embryonic development of the ventral body wall and its congenital malformations. Semin Pediatr Surg. 1996 May. 5(2):82-9. [Medline].
Suita S, Nagasaki A. Urachal remnants. Semin Pediatr Surg. 1996 May. 5(2):107-15. [Medline].
Moore TC. Omphalomesenteric duct malformations. Semin Pediatr Surg. 1996 May. 5(2):116-23. [Medline].
Duffy PG. Bladder exstrophy. Semin Pediatr Surg. 1996 May. 5(2):129-32. [Medline].
Suita S, Okamatsu T, Yamamoto T, et al. Changing Profile of Abdominal Wall Defects in Japan: Results of a National Survey. J Pediatr Surg. 2000. 35:66-72. [Medline].
Tan KH, Kilby MD, Whittle MJ, et al. Congenital anterior abdominal wall defects in England and Wales 1987- 93: retrospective analysis of OPCS data. BMJ. 1996 Oct 12. 313(7062):903-6. [Medline].
Srivastava V, Mandhan P, Pringle K, Morreau P, Beasley S, Samarakkody U. Rising incidence of gastroschisis and exomphalos in New Zealand. J Pediatr Surg. March 2009. 44(3):551-555. [Medline].
Puligandla PS, Janvier A, Flageole H, et al. Routine cesarean delivery does not improve the outcome of infants with gastroschisis. J Pediatr Surg. 2004 May. 39(5):742-5. [Medline].
Logghe HL, Mason GC, Thornton JG, Stringer MD. A randomized controlled trial of elective preterm delivery of fetuses with gastroschisis. J Pediatr Surg. 2005 Nov. 40(11):1726-31. [Medline].
McGuigan RM, Azarow KS. Is splanchnic perfusion pressure more predictive of outcome than intragastric pressure in neonates with gastroschisis?. Am J Surg. 2004 May. 187(5):609-11. [Medline].
Midrio P, Stefanutti G, Mussap M, D'Antona D, Zolpi E, Gamba P. Amnioexchange for fetuses with gastroschisis: is it effective?. J Pediatr Surg. 2007 May. 42(5):777-82. [Medline].
Olguner M, Hakguder G, Ates O, Caglar M, Ozer E, Akgur FM. Urinary trypsin inhibitor present in fetal urine prevents intraamniotic meconium-induced intestinal damage in gastroschisis. J Pediatr Surg. 2006 Aug. 41(8):1407-12. [Medline].
Dinatti LA, Meagher DP Jr, Martinez-Frontanilla LA. "Bucket handle" avulsion of intestine in gastroschisis. J Pediatr Surg. 28(6):840. [Medline].
Wada M, Kato T, Hayashi Y, et al. Intestinal transplantation for short bowel syndrome secondary to gastroschisis. J Pediatr Surg. 2006 Nov. 41(11):1841-5. [Medline].
Moon S , Jung S , Park K. Ruptured fetal omphalocele complicated by midgut volvulus with strangulation. January 2009. 44:1:303-304. [Medline].
[Guideline] Finnish Medical Society Duodecim. Ultrasound scanning during pregnancy. EBM Guidelines. 2008 Feb 15.
Pacilli M, Spitz L, Kiely EM, et al. Staged repair of giant omphalocele in the neonatal period. J Pediatr Surg. 2005 May. 40(5):785-8. [Medline].
Langer JC. Gastroschisis and omphalocele. Semin Pediatr Surg. 1996 May. 5(2):124-8. [Medline].
Cooney D. Defects of the Abdominal Wall. Pediatr Surg. 1998. 2:1045-1070.
Ledbetter DJ. Gastroschisis and omphalocele. Surg Clin North Am. 2006 Apr. 86(2):249-60, vii. [Medline].
Salihu HM, Boos R, Schmidt W. Omphalocele and gastrochisis. J Obstet Gynaecol. 2002 Sep. 22(5):489-92. [Medline].
Wakhlu A, Wakhlu AK. The management of exomphalos. J Pediatr Surg. 2000 Jan. 35(1):73-6. [Medline].
Dykes EH. Prenatal diagnosis and management of abdominal wall defects. Semin Pediatr Surg. 1996 May. 5(2):90-4. [Medline].
de Lorimier AA, Adzick NS, Harrison MR. Amnion inversion in the treatment of giant omphalocele. J Pediatr Surg. 1991 Jul. 26(7):804-7. [Medline].
De Ugarte DA, Asch MJ, Hedrick MH, Atkinson JB. The use of tissue expanders in the closure of a giant omphalocele. J Pediatr Surg. 2004 Apr. 39(4):613-5. [Medline].
Kilbride KE, Cooney DR, Custer MD. Vacuum-assisted closure: a new method for treating patients with giant omphalocele. J Pediatr Surg. 2006 Jan. 41(1):212-5. [Medline].
Bawazir OA, Wong A, Sigalet DL. Absorbable mesh and skin flaps or grafts in the management of ruptured giant omphalocele. J Pediatr Surg. 2003 May. 38(5):725-8. [Medline].
Vossoughi F, Reddy PP, Camps J. Acellular dermal tissue matrix in neonates. J S C Med Assoc. 2008 Apr. 104(4):96-7. [Medline].
Boutros J, Regier M, Skarsgard ED. Is timing everything? The influence of gestational age, birth weight, route, and intent of delivery on outcome in gastroschisis. J Pediatr Surg. May 2009. 44(5):912-917. [Medline].
Payne N R, Pfleghaar K, Assel B , Johnson A , Rich R H. Predicting the outcome of newborns with gastroschisis. J Pediatr Surg. May 2009. 44(5):918-923. [Medline].
Fok TF, Ng PC, Wong W, et al. High frequency oscillatory ventilation in infants with increased intra- abdominal pressure. Arch Dis Child Fetal Neonatal Ed. 1997 Mar. 76(2):F123-5. [Medline].
Houben C, Davenport M, Ade-Ajayi N, Flack N, Patel S. Closing gastroschisis: diagnosis, management, and outcomes. J Pediatr Surg. February 2009. 44(2):343-347. [Medline].
Marven S, Owen A. Contemporary postnatal surgical management strategies for congenital abdominal wall defects. Semin Pediatr Surg. 2008 Nov. 17(4):222-35. [Medline].
Ryckman J, Aspirot A, Laberge JM, Shaw K. Intestinal venous congestion as a complication of elective silo placement for gastroschisis. Semin Pediatr Surg. 2009 May. 18(2):109-12. [Medline].
Kim HB, Fauza D, Garza J, Oh JT, Nurko S, Jaksic T. Serial transverse enteroplasty (STEP): a novel bowel lengthening procedure. J Pediatr Surg. 2003 Mar. 38(3):425-9. [Medline].
Phillips TM. Spectrum of cloacal exstrophy. Semin Pediatr Surg. 2011 May. 20(2):113-8. [Medline].
Emil S, Canvasser N, Chen T, Friedrich E, Su W. Contemporary 2-year outcomes of complex gastroschisis. J Pediatr Surg. 2012 Aug. 47(8):1521-8. [Medline].
Keys C, Drewett M, Burge DM. Gastroschisis: the cost of an epidemic. J Pediatr Surg. 2008 Apr. 43(4):654-7. [Medline].
McClellan EB, Shew SB, Lee SS, Dunn JC, Deugarte DA. Liver herniation in gastroschisis: incidence and prognosis. J Pediatr Surg. 2011 Nov. 46(11):2115-8. [Medline].
Sadler TW. Langman, ed. Medical Embryology. 11th ed. Baltimore, Md: Lippincott, Williams and Wilkins; 2010.
Sadler TW. The embryologic origin of ventral body wall defects. Semin Pediatr Surg. 2010 Aug. 19(3):209-14. [Medline].
Venick RS, Calkins K. The impact of intravenous fish oil emulsions on pediatric intestinal failure-associated liver disease. Curr Opin Organ Transplant. 2011 Jun. 16(3):306-11. [Medline].
|Country||Time Period / Incidence||Time Period / Incidence|
|England and Wales||1987||1991|
|England and Wales||1995||2005|