The Abdominal Wall

Normal Anatomy of the Abdominal Gastroschisis/ 224 Wall/ 209 Body Stalk Anomaly/ 226 Diaphragmatic Hernia/ 211 Bladder Exstrophy and Cloacal Omphalocele/ 220 Exstrophy/ 228

Normal Anatomy of the Abdominal Wall

The superior wall of the abdominal cavity is formed by the diaphragm. This muscle can be seen as a hipoechogenic line separating the lung and fetal liver (Fig. 6-1). In cases of severe hydrops, the structure appears as a hyperechogenic sheet between the pleural effusion and the ascites. When a massive Pleural effusion is present, the muscle can be inverted. The floor of the abdominal cavity is formed by the pelvic diaphragm. The pelvic bones (iliac crests, ischial ossification centers) and pelvic muscles can be imaged with ultrasound but have limited diagnostic interest (Fig. 6-2). The anterior abdominal wall is formed by the skin, subcutaneous tissue, and muscles. The muscles are visible as hypoechogenic structures (Fig. 6-3). In the past, the image of the muscles has been confused with ascites and referred to as "pseudoascites."1,2 The entrance of the umbilical cord into the fetal abdomen should always be imaged to screen for the presence of an omphalocele (Fig. 6-4). Examination of the anterior abdominal wall should include visualization of its infraumbilical portion in order to rule out caudal fold defects (e.g., bladder exstrophy). Figure 6-5 shows the Figure 6-1. Coronal section of a third trimester fetus. The normal contours of the lower portion of the anterior diaphragm appears as a hypoechogenic line between the thorax and the abdomen. L, lung; H, heart. abdominal wall. The posterior wall of the abdomen can be easily REFERENCES imaged. Structures that can be identified include the spine and the paraspinal muscles. 1. Rosenthal SJ, Filly RA, Callen PW, et al.: Fetal pseudoascites. Radiology 131:195, 1979. 2. Hashimoto BE, Filly RA, Callen PW: Fetal pseudoascites: Further anatomic observations. J Ultrasound Med 5:151, 1986.

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Figure 6-2. Coronal scan of a male fetal pelvis. A curved Figure 6-4. Longitudinal scan showing the insertion of the arrow points to the right ileopsoas muscle. IW, iliac wings; IT, umbilical cord in the abdomen of a first trimester fetus. ischial tuberosities.

Figure 6-3. Transverse section of the abdomen of a third Figure 6-5. Longitudinal scan of the fetal abdomen between trimester fetus. The abdominal muscles appear as the insertion of the umbilical cord (UC) and the gender. B, hypoechogenic structures (arrowheads). bladder; P, penis.

Diaphragmatic Hernia

Definition septum tranversum is a mesodermal structure that Diaphragmatic hernia consists of protrusion of the migrates from the cranial portion of the embryo to the abdominal organs into the thoracic cavity through a definitive location of the diaphragm. It gives origin to diaphragmatic defect. It includes posterolateral the central tendon of the diaphragm. The dorsal diaphragmatic hernia, Bochdalek hernia, retrosternal esophageal mesentery contributes to the median portion diaphragmatic hernia, Morgagni hernia, and eventration of the organ. The pleuroperitoneal membranes are of the diaphragm. structures that close the pleuroperitoneal cavity. Although they form a large segment of the embryonal Incidence diaphragm, their contribution to the final and fully The incidence of diaphragmatic hernia varies developed diaphragm is relatively small. The depending on the type of study. The best estimates participation of the body wall is limited to a narrow vary from 0.033 to 0. 05 percent of births. 11, 19,31,47 peripheral segment corresponding to the insertion of the Neonatal surgical series report a frequency of 0.012 muscle to the ribs and sternum (Fig. 6-6). The percent.67 This difference is due to an underestimation diaphragm is completely formed by the end of the 8th of the incidence of the disease because of its week of conceptional age. However, modeling association with stillbirths and early neonatal deaths.36 continues throughout gestation. Expansion of the lungs The male to female ratio in the two largest series to results in the formation of the costodiaphragmatic date varies between 0.67 and 0.77.11,19 recesses, which have a dome-shaped configuration. The normal diaphragm allows the passage of organs, Etiology and Risk of Recurrence vessels, and nerves from the thoracic to the abdominal cavity. This is accomplished by three main orifices, Congenital diaphragmatic hernia can be both a sporadic allowing passage for the aorta, esophagus, and inferior and a familial disorder. The pattern of inheritance for vena cava (Fig. 6-7). The thoracic duct and azygos familial cases is unknown, but a multifactorial type of vein cross through the aortic foramen, and the vagal inheritance has been suggested,17,57,58 indicating a nerves use the esophageal foramen. The right phrenic recurrence risk for siblings of 2 percent.57 Familial nerves cross through the inferior vena cava orifice. cases have a higher male to female ratio (M:F=2.10 Congenital diaphragmatic hernias occur when a versus 0.67), a higher incidence of bilateral defects (20 diaphragmatic defect allows the protrusion of percent versus 3 percent), and a lower incidence of life- abdominal visceral content into the thoracic cavity. threatening malformations than sporadic cases.17 The spectrum of embryologic defects is wide, ranging However, no specific features allow identification of a from complete absence of the diaphragm through familial case. Diaphragmatic hernia has been pathologic orifices (Bochdaleck foramen) to congenital associated with Fryns syndrome,49 Beckwith- hiatal hernia, in which the viscera protrude through a Wiedemann syndrome (see p. 221),68 Pierre Robin physiologic orifice. syndrome, and congenital choanal atresia.22 The defect Congenital diaphragmatic hernias are classified has been associated with chromosomal defects (see according to the location of the diaphragmatic defect: section on associated anomalies).

The etiology of sporadic cases is largely unknown. 1 Posterolateral defect, or Bochdaleck hernia, Maternal ingestion of bendectin,10 thalidomide,43 occurring through the primitive communication of the quinine,46 and antiepileptic drugs40 has been reported in pleuroperitoneal canal or foramen of Bochdaleck association with diaphragmatic hernia. In animal 2 Parasternal defect, or Morgagni hernia, located in models, hypovitaminosis A was able to induce the anterior portion of the diaphragm between the diaphragmatic hernia in rats.1,72 The etiologic role of costal and the sternal origins of the muscle (foramen of diabetes is considered weak.45 Morgagni or sternocostal hiatus) 3 Septum transversum defects, occurring because of Embryology and Anatomy of the Diaphragm a defect of the central tendon The diaphragm is a dome-shaped septum dividing the 4 Hiatal hernias, occurring through a congenitally thoracic and abdominal cavities. It consists of a central large esophageal orifice or aponeurotic segment and a peripheral or muscular one. It is formed by the fusion of four different Another pathologic entity, eventration of the structures: (1) the septum transversum, (2) the dorsal diaphragm, is frequently considered with congenital esophageal mesentery, (3) the pleuroperitoneal 25 ,55 ,65 diaphragmatic hernias because they have a similar membrane, and (4) the body wall. The pathophysiologic sequence. However, eventration of

212 THE ABDOMINAL WALL

abdominal viscera would prevent complete closure of the diaphragm. An alternative hypothesis suggests that a primary defect occurs in the formation of the diaphragm, and this creates the condition for a subsequent migration of the abdominal organs into the thoracic cavity. The negative pressure created by fetal thoracic wall movements (fetal breathing) could be responsible for migration of the viscera into the thorax. Two observations support the first hypothesis. (1) In some cases, organs firmly attached to the abdomen in late fetal life, such as the pancreas, can be found in the thorax. This implies a precocious migration of abdominal organs into the thoracic cavity. (2) The discrepancy between the size of the defect and the dimensions of the herniated organs also suggests an early migration of the viscera and secondary partial closure of the defect. The main cause of death of infants with congenital Figure 6-6. Development of the diaphragm (viewed from below). diaphragmatic hernia without associated anomalies is A. sketch of a lateral view of a 5-week embryo (actual size), indicating the level of the section. B. Transverse section showing respiratory failure due to pulmonary hypoplasia. This can the pleuroperitoneal membranes not yet fused. C. Same section be easily understood if it is considered that development of at the end of the 6th week; the pleuroperitoneal membranes the normal lung is an active process from the 5th week of have fused with the other two diaphragmatic components. D. gestation.44,61 The fetal lung goes through four different Same section at 12 weeks; the fourth diaphragmatic component has formed from the body wall. E. view in the newborn, stages (Figs. 6-8, 6-9): (1) embryonic period, from indicating the probable embryologic origin of the different conception to the 5th week, (2) pseudoglandular period, components. (Reproduced from Moore: The Developing Human, from the 5th to the 17th week, (3) canalicular period, from 3d ed. Philadelphia, Saunders, 1982.) the 17th to the 24th week, and (4) terminal sac period, from the 24th week until term. By the 16th week of gestation, the development of the conductive part of the airways is the diaphragm consists of an upward displacement of the completed (from trachea to terminal bronchioles). From abdominal content into the thoracic cavity because of a this time until birth, respiratory airways are fully developed. congenitally weak diaphragm, which is virtually reduced This includes respiratory bronchioles and saccules. Most to an aponeurotic sheet. alveolar development is a postnatal event. Their number The mechanisms responsible for the origin of a increases until the age of 7 years, and their size keeps up diaphragmatic hernia are unknown. The two main with changes in thoracic volume until maturity. The hypotheses are (1) delayed fusion of the diaphragm and development of the pulmonary circulation follows that of (2) a primary diaphragmatic defect. The bowel normally the airways. The total adult complement of blood vessels returns to the abdominal cavity between the 10th and irrigating the conducting portion of the airways (also known 12th weeks of gestation, at which time formation of the as preacinar) is completed by 20 weeks of gestation. The diaphragm should be completed. Delayed closure of the alveolar or intraacinar portion devel- communication between the abdomen and the thorax would allow part of the abdominal contents to pass into the thorax, and

Figure 6-7. View of a diaphragm from below, showing the position of the normal orifices. (Reproduced with permission from Thompson: Core Textbook of Anatomy. Philadelphia, Lippincott, 1977.)

DIAPHRAGMATIC HERNIA 213

Figure 6-8. Development of the bronchial tree. Lobar bronchi appear at 6 weeks of gestation, and by 16 weeks all nonrespiratory airways are present. Most respiratory airways appear between 16 weeks and birth. Cartilage and glands appear later, with extension complete by 24 weeks of gestation. On the vertical axis: number of generations. (Reproduced with permission from Bucher, Reid: Development of intrasegmental bronchial tree: The pattem of branching and development of cartilage at various stages of intrauterine life. Thorax 16.-207, 1961.)

ops postnatally. Knowledge of changes in the thickness and on a thorough pharmacologic treatment aimed at and extension of the muscular component of the media is dilating the pulmonary vascular bed and at preventing important in order to understand the development of acidosis and hypoxia.7,16,31,54,73 postsurgical pulmonary hypertension. The muscle of these vessels is limited to the terminal bronchioles during Pathology fetal life. Postnatally, there is progressive extension Among the previously described varieties of congenital peripherally to the respiratory bronchioles, alveolar ducts, diaphragmatic hernia, the three most common are and alveolar vessels. There is also a progressive decrease posterolateral or Bochdalek type, parasternal or in the thickness of the muscle wall (Figs. 6-10, 6-11). Infants with diaphragmatic hernia have profound changes in both the respiratory and the vascular components of the lungs. These are more pronounced in the ipsilateral than in the contralateral lung, depending on the timing and the degree of herniation.20 An early insult (before 16 weeks) could reduce the number of conducting airways. After this time, it also impairs the development of respiratory airways. After surgical correction, gains can be achieved in respiratory airways as their normal development continues postnatally. However, catchup growth cannot occur in conducting airways, and therefore, the total number of alveoli is diminished (pulmonary hypoplasia). The vascular changes in congenital diaphragmatic hernia include a reduction in the number of vessels, an increase in arterial medial wall thickness, and an extension of muscle peripherally into smaller preacinar arteries.39,48,56 These morphologic changes are the basis for the occurrence of pulmonary hypertension in the postoperative period, which can be triggered even by mild acidosis, hypoxia, or hypercapnia and can lead to right-to- left shunt and persistent fetal circulation.7,16,20,21,24,53,62,64 The presence of a transitory, postoperative, asymptomatic period shows that the cause of death is not lung hypoplasia but intense pulmonary vasospasm. Survival in these cases is related to surgical ligation of the ductus Figure 6-9. Development of the acinus. TB, terminal bronchiole; l5,16 RB, respiratory bronchiole; TD, transitional duct; S, saccule; TS, arteriosus terminal saccule; AD, alveolar duct; At, atrium; AS, alveolar sac. (Reproduced with permission from Hislop, Reid: Development of the acinus in the human lung. Thorax 29:90, 1974.)

Figure 6-11. Pulmonary artery structure at distal end. Complete muscle coat (muscular artery) gives way to spiral of muscle (partially muscular artery) before it completely disappears, leaving nonmuscular artery. In cross-section, vessels within the spiral region have a crescent of muscle. Figure 6-10. Bar graph showing progression of muscle in the (Reproduced with permission from Reid: AJR 129:777, 1977) walls of arteries within the acinus. In fetuses, there is no muscle within the acinus. With age, there is gradual extension into the acinar region, but, even at 11 years, muscular arteries have not reached the alveolar wall, where they are found in though on occasion rupture occurs, leaving little trace adults. (Reproduced with permission from Reid: AJR 129:777, 1977.) of the sac. Herniation into the pericardial cavity has been reported rarely. The heart may herniate through the foramen of Morgagni into the epigastric area.4 Morgagni type, and eventration. Hiatal hernia has little Eventration of the diaphragm occurs in 5 percent of relevance for prenatal diagnosis. diaphragmatic defects.19 It is five times more common Bochdalek type is the most common, accounting for in the right side than in the left, and some bilateral 85 to 90 percent of all congenital diaphragmatic defects instances have been reported. All or part of the found in the neonatal period.11,19 It occurs in the left hemidiaphragm is involved. The disorder can be side in 80 percent of cases, in the right side in 15 considered a failure of muscularization of the percent of cases, and is bilateral in the rest.11,19,28 An diaphragm, which appears thin and lacks, either explanation for this predominance is that the right partially or totally, muscle fibers. Acquired eventration pleuroperitoneal canal closes before the left. A true sac can be caused by paralysis of the phrenic nerve, and is present in only 5 to 10 percent of patients. The small injury of this nerve during delivery may account for bowel is involved in about 90 percent of cases, the some cases of eventration in the neonatal period. In stomach in 60 percent, the spleen in 54 percent, and the congenital eventration, the phrenic nerve is normal. colon in 56 percent. Less frequently, the pancreas (24 The frequency of malrotation of the intestine in percent), liver, adrenal glands, and even kidneys (12 congenital eventration suggests that this disorder can percent) may be found.,1 In the chest, the heart and occur during fetal life. mediastinum are shifted generally to the right. When the hernia is located in the right side, the main organs Associated Anomalies include the liver and gallbladder. Incomplete rotation Congenital diaphragmatic hernia has been associated of the intestine and anomalous mesenteric attachment consistently with a high incidence of other anomalies, are the rule. excluding lung hypoplasia and gut malrotation, which Morgagni hernia accounts for only 1 to 2 percent of are implied in the diaphragmatic hernia sequence. 19 congenital diaphragmatic hernias. It is most Three major studies have reported a remarkably similar frequently located in the right side and can also be incidence of major anomalies, ranging from 50 to 57 52 bilateral. This type of hernia is considered to be the percent.11,19,47 These studies have included both result of failure of muscle to develop from the stillbirths and neonatal deaths. The incidence of transverse septum. The content of the hernia is usually anomalies is much lower in survivors.9,28 Congenital liver; other organs, such as colon, small bowel, and diaphragmatic hernia has been considered as part of the stomach, may follow as well. The hernia is usually schisis type of abnormalities, which include neural tube small because the liver may limit the degree of defects (anencephaly, cephaloceles, spina bifida), oral herniation. A peritoneal sac is always present, al- cleft (lip and palate),

DIAPHRAGMATIC HERNIA 215

genital diaphragmatic hernia.33 Greenwood et al. found 2 cases of trisomy 21 in 48 patients.26 David and Illingworth reported 3 cases (2 trisomy 18 and I trisomy 21) in 143 patients.19 Boles and Anderson found 3 genetic anomalies (including 2 Down syndrome babies) in 58 infants.9 Other reports have suggested an association between trisomy 21 and Morgagni congenital diaphragmatic hernia.2,19 It is controversial whether eventration of the diaphragm is associated with a higher incidence of trisomy 18.3,71

Diagnosis The diagnosis of congenital diaphragmatic hernia has been made in utero several times.5,12,14,23,33,42,51 A definitive diagnosis can be made if abdominal organs are seen in the thoracic cavity. Visualization of fluidfilled bowel at the level of the four chamber view of the heart is diagnostic (Figs. 6-12, 6-13, 6-14). The ribs and the inferior margin of the scapula can be used as landmarks when trying to establish the intrathoracic location of viscera. The visualization of these organs in the chest is difficult in early pregnancy. In late pregnancy, they can be seen as fluidfilled cystic structures that may peristalte in the thoracic cavity. We have found that the most sensitive sign of the presence of a congenital diaphragmatic hernia is a shift in the position of the heart within the chest. Polyhydramnios is common and thought to be secondary to bowel obstruction. However, this mechanism does not explain the presence of polyhydram-

and omphalocele. It is associated with these anomalies more frequently than is expected by chance.18,57 However, other anomalies have also been reported. Table 6-1 illustrates the associated anomalies in the largest reported series in the literature. The central nervous system is the most frequently involved. Cardiovascular abnormalities have been found in 23 percent of newborn babies with congenital diaphragmatic hernias excluding eventration.26 Ventricular septal defects and tetralogy of Fallot were the most common anomalies. Less frequent anomalies include coarctation of the aorta, ectopia cordis, atrial septal defects, absence of pericardium, and tricuspid atresia. Half of the infants with cardiac anomalies (5 of 11) had other extracardiac anomalies compared to those without cardiac disease (4 of 37, p < 0.05). Congenital diaphragmatic hernia has been reported in Figure 6-12. Transverse scan at the level of the heart in a fetus association with chromosomal abnormalities. Hansen with diaphragmatic hernia. There is a striking mediastinal shift with reported one trisomy 21, one trisomy 18, and one ring 4 in deviation of the heart to the right. The left hemithorax is occupied by a complex mass (arrows) with cystic components (c). Sp, spine; 75 newborns.28 Harrison reported 2 cases (trisomies 18 and LV, left ventricle; RV, right ventricle; LA, left atrium; RA, right atrium; 13) in 20 patients with con- Ant, anterior; Post, posterior; L, left; R, right.

216 THE ABDOMINAL WALL

Figure 6-13. Longitudinal scan of the fetus shown in Figure 6-12. The diagnosis is suspected by the visualization of a cystic mass (C) at the level of the heart (H). nios in right hernias or left hernias in which intestinal transit is not impaired. The diagnosis of right diaphragmatic hernia is extremely difficult because of the similar echogenicity of liver and lung. Figure 6-15. Amniogram of a fetus with a diaphragmatic A helpful hint is the identification of the gallbladder, which is hernia. The fetus has swallowed the contrast medium, which is frequently herniated into the chest. The presence of a pleural visualized as dilated loops of bowel in the fetal chest (arrows). effusion and ascites may also aid in the differentiation between lung and liver. The mechanism for fluid accumulation in serous cavities is thought to be related to an duodenal atresia by realizing that there was malrotation obstruction of venous return. We made the diagnosis of right of the stomach (see Fig. 7.5). diaphragmatic hernia in one patient with a Small congenital diaphragmatic hernias may not be detected in utero. Presumably, these would have a better prognosis. In cases of uncertainty, other diagnostic maneuvers, such as amniography (Fig. 6- 15)5,17 and computed tomography,14,33 can be used. This would be helpful in the differential diagnosis of cystic lesions of the chest, such as cystic adenomatoid malformation of the lung and mediastinal cystic processes (neuroenteric cysts, bronchogenic cysts) (see Table 5.1). The presence of a normally placed stomach can help to distinguish these two conditions. A diagnosis of diaphragmatic hernia mandates a careful examination of the fetal anatomy.

Prognosis The prognosis of congenital diaphragmatic hernia is poor. Infants with congenital diaphragmatic hernia are at risk for antepartum and neonatal death.36 In a retrospective review of such infants, 35 percent were 11 stillbirths. Associated anomalies are thought to be Figure 6-14. Diaphragmatic hernia in a 23-week-old fetus. responsible for most antenatal deaths, and they were Transverse scan of the chest shows deviation of the heart (H) and a present in 90 percent of stillbirths. An earlier study cystic structure (C). Sp, spine; Ant, anterior; Post, posterior; L, left; R, right. noted that abnormalities severe enough to account

DIAPHRAGMATIC HERNIA 217 for death were most frequently located in the CNS Overall, the prognosis for infants with congenital (anencephalus, iniencephalus, Dandy-Walker diaphragmatic hernia diagnosed in utero is extremely malformation, Arnold-Chiari malformation).11The other poor. Harrison reported a mortality of 100 percent in frequent location of lethal anomalies is the nine consecutive patients.33 We have made 10 prenatal cardiovascular system.53 A significant number of diagnoses of diaphragmatic hernia and have had only 1 infants die within the first few hours of life. In Butler's survivor, in whom diagnosis was made at 23 weeks of series, 35 percent of all neonatal deaths occurred 1 hour gestation. The poor prognosis for infants diagnosed in after birth.11The causes of immediate neonatal death are utero may reflect a selection bias, as smaller hernias severe pulmonary insufficiency and associated may not be detectable with ultrasound. congenital anomalies.11,53 Of infants who survive the Abnormally low lecithin:sphingomyelin (L:S) ratios immediate neonatal period and go to surgery, the have been reported in infants with congenital 50 5,6,33,41 mortality rate varies between 29 percent and 53 diaphragmatic hernia. Such observation has been percent.69 The following are prognostic factors. attributed to decreased surfactant production by a hypoplastic lung.41 However, it has not been Age in Hours at Time of Operation. Infants who established whether a mature L:S ratio has prognostic clinically manifest respiratory failure immediately after value for infants diagnosed in utero. birth have a poor prognosis. In fact, the survival rate is One study provided information in long-term follow- almost 100 percent in infants operated on 24 hours after up of 21 infants with congenital diaphragmatic hernia birth,15,50,63,73 but it drops to 38 to 64 percent in infants operated on within 24 hours of life.9 Infants were less than 24 hours old.9,28,50,63,64,69,73 Unfortunately, followed for an average of 8 1/2 years, and they were most of the babies treated surgically are in the latter found to be in good health, vigorous, active, and group.53,63,64 without evidence of growth failure. Although some infants had respiratory problems in the first 3 to 4 years Blood Gas Data. Infants with acidosis, hypercapnia, 8,9,15,29,53,63,69 of life (2 had pneumonia, 2 had recurrent upper and hypoxemia have a poor prognosis. The respiratory infections, I was said to have "chronic predictive value of blood gas determinations does not asthma"), all complaints subsequently disappeared. seem to be purely dependent on the volume of lung Other authors have performed pulmonary function tests parenchyma, since no correlation has been found in infants with congenital diaphragmatic hernia and between lung weight and blood gas data in dead 59,63 have found residual defects in ventilatory functions and infants. impaired blood flow to the lung in the side of the hernia, but normal airway resistance and distribution of 75 Chest X-ray Data. The presence of a pneumothorax, ventilation. Interpretation of some long-term follow- location of the stomach above the diaphragm, and up studies is difficult because they have included 13,60,75 volume of aerated ipsilateral and contralateral lungs 69 infants operated on at different ages. In one study have prognostic value. On the other hand, the degree involving 30 infants, 3 had evidence of mental of mediastinal shift and the amount of visceral retardation that was attributed to hypoxia after birth, distention have not been found to be statistically although no evidence was presented to support this different between surviving and nonsurviving groups. contentions

Associated Anomalies. The presence of additional Obstetrical Management major malformations, excluding gut malrotation and Before viability the option of pregnancy termination patent ductus arteriosus, which are often part of the 28 should be offered to the parents. Karyotype disease process, portends a poorer outcome. In one determination and echocardiography should be series, the postsurgery mortality rate was significantly performed in each infant in whom a diagnosis of higher (p < 0.02) in infants with cardiac abnormalities diaphragmatic hernia is made. There are no data to (73 percent) than in those without cardiac disease (27 26 justify delivery before fetal maturity or to alter the percent). In another series, the death rate among mode of delivery. Labor should occur in a tertiary infants with associated serious congenital anomalies center where a neonatologist and a pediatric surgeon was higher (70.6 percent) than the overall mortality rate 9 are immediately available. (36 percent). Diaphragmatic hernia is one of the conditions for After excluding infants with associated anomalies, which there is solid experimental basis for in utero fetuses with congenital diaphragmatic hernia do not surgery. 32,35,70 An animal model for this condition has seem to be at higher risk for preterm delivery and 17,33 been developed in the fetal lamb by inflating an intrauterine growth retardation. intrathoracic balloon 27,34,37 or by producing a dia-

218 THE ABDOMINAL WALL phragmatic defect surgically.30,35,66 The ventilatory and 17. Crane JP: Familial congenital diaphragmatic hernia: hemodynamic changes observed in the lamb are similar Prenatal diagnostic approach and analysis of twelve to those seen in affected human fetuses.27,34,37,66 families. Clin Genet 16:244, 1979. Furthermore, intrauterine correction by deflation of the 18. Czeizel A: Schisis association. Am J Med Genet 10:25, 37 30,35 1981. intrathoracic balloon or by closure of the defect 19. David TJ, Illingworth CA: Diaphragmatic hernia in the has been associated with a favorable outcome. This South-west of England. J Med Genet 13:253, 1976. procedure has been attempted in the human fetus at the 20. Dibbins AW: Congenital diaphragmatic hernia, time of this writing, with poor results. hypoplastic lung, and pulmonary vasoconstriction. Clin Perinatol 5:93, 1978. REFERENCES 21. Dibbins AW, Wiener ES: Mortality from neonatal diaphragmatic hernia. J Pediatr Surg 9:633, 1974. 1. Andersen DH: Effect of diet during pregnancy upon the 22. Evans JNG, MacLachlan RF: Choanal atresia. J Laryngol incidence of congenital hereditary diaphragmatic hernia 85:903, 1971. in the rat. Am J Pathol 25:163, 1949. 23. Fleischer AC, Killam AP, Boehm FH, et al.: Hydrops 2. Baran EM, Houston HE, Lynne HB, et al.: Foramen of fetalis: Sonographic evaluation and clinical Morgagni hernias in children. Surgery 62:1076, 1967. implications. Radiology 141:163, 1981. 3. Barash BA, Freedman L, Optiz JM: Anatomic studies 24. Geggel RL, Reid LM: The structural basis of PPHN. Clin in the 18-trisomy syndrome. Birth Defects 6:3, 1970. Perinatol 2:525, 1984. 4. Behrman RE, Vaughn VC: Nelson's Textbook of 25. Gray SW, Skandalakis JE: The diaphragm. In: Pediatrics, 11th ed. Philadelphia, Saunders, 1983, pp Embryology for Surgeons. The Embryological Basis for 988-990. the Treatment of Congenital Defects. Philadelphia, 5. Bell MJ, Ternberg JL: Antenatal diagnosis of Saunders, 1972, pp 359-385. diaphragmatic hernia. Pediatrics 60:738, 1977. 26. Greenwood RD, Rosenthal A, Nadas AS: Cardiovascular 6. Berk C, Grundy M: "High-risk" lecithin/sphingomyelin abnormalities associated with congenital diaphragmatic ratios associated with neonatal diaphragmatic hernia. hernia. Pediatrics 57:92, 1976. Case Reports. Br J Obstet Gynaecol 89:250, 1982. 27. Haller JA, Signer RD, Golladay ES, et al.: Pulmonary and 7. Bloss RS, Aranda JV, Beardmore HE: Congenital ductal hemodynamics in studies of simulated diaphragmatic hernia: Pathophysiology and diaphragmatic hernia of fetal and newborn lambs. J pliarmacologic support. Surgery 89:518, 1981. Pediatr Surg 11:675, 1976. 8. Boix-Ochoa J, Natal A, Canals J, et al.: The important 28. Hansen J, James S, Burrington J, et al.: The decreasing influence of arterial blood gases on the prognosis of incidence of pneumothorax and improving survival of congenital diaphragmatic hernia. World J Surg 11:783, infants with congenital diaphragmatic hernia. J Pediatr 1977. Surg 19:385, 1984. 9. Boles ET, Anderson G: Diaphragmatic hernia in the 29. Hardesty RL, Griffith BP, Debski RJ, et al.: newborn: Mortality, complications, and long term Extracorporeal membrane oxygenation. Successful follow up observations. In: Kiesewetter WB (ed). treatment of persistent fetal circulation following repair of Long Term Follow Up in Congenital Anomalies. congenital diaphragmatic hernia. J Thorac Cardiovasc Pediatric Surgical Symposium, September 14-15, 1979, Surg 81: 556, 1981. Pittsburgh, PA, pp 13-22. 30. Hardy KJ, Auldist AW, Shulkes A: Congenital 10. Bracken MB, Berg A: Bendectin (Debendox) and diaphragmatic hernia. Intrauterine repair in fetal sheep. congenital diaphragmatic hernia. Lancet 1:586, 1983. Med J Aust 2:223, 1982. 11. Butler NR, Claireaux AE: Congenital diaphragmatic 31. Harrison MR, de Lorimier AA: Congenital diaphragmatic hernia as a cause of perinatal mortality. Lancet 1:659, hernia. Surg Clin North Am 61:1023, 1981. 1962. 32. Harrison MR, Golbus MS, Filly RA: Management of the 12. Campbell S, Pearce JM: The prenatal diagnosis of fetal fetus with a correctable congenital defect. JAMA 246: structural anomalies by ultrasound. Clin Obstet 774, 1981. Gynaecol 10:475, 1983. 33. Harrison MR, Golbus MS, Filly RA: The Unborn Patient. 13. Chatrath RR, El Shafie M, Jones RS: Fate of Prenatal Diagnosis and Treatment. Orlando, FL, Grune & hypoplastic lung after repair of congenital Stratton 1984, pp 257-275. diaphragmatic hernia. Arch Dis Child 46:633, 1971. 34. Harrison MR, jester JA, Ross NA: Correction of 14. Chinn DH, Filly RA, Callen PW: Congenital congenital diaphragmatic hernia in utero. 1. The model: diaphragmatic hernia diagnosed prenatally by Intrathoracic balloon produces fatal pulmonary ultrasound. Radiology 148:119, 1983. hypoplasia. Surgery 88:174, 1980. 15. Collins DL, Marks L, Edwards D: Management of 35. Harrison MR, Ross NA, de Lorimier AA: Correction of infants with diaphragmatic hernia. West J Med congenital diaphragmatic hernia in utero. III. 127:479, 1977. Development of a successful surgical technique using 16. Collins DL, Pomerance JJ, Travis KW, et al.: A new abdominoplasty to avoid compromise of umbilical blood approach to congenital posterolateral diaphragmatic flow. J Pediatr Surg 16:934, 1981. hernia. J Pediatr Surg 12:149, 1977. 36. Harrison MR, Bjordal RJ, Langmark F, et al.: Congen-

DIAPHRAGMATIC HERNIA 219

ital diaphragmatic hernia: The hidden mortality. J 57. Norio R, Kaariainen H, Rapola J, et al.: Familial Pediatr Surg 13:227, 1978. congenital diaphragmatic defects: Aspects of etiology, 37. Harrison MR, Bressack MA, Churg AM, et al.: prenatal diagnosis, and treatment. Am J Med Genet Correction of congenital diaphragmatic hernia in utero. 17:471, 1984. II. Simulated correction permits fetal lung growth with 58. Pollack LD, Hall JG: Posterolateral (Bochdalek's) survival at birth. Surgery 88:260, 1980. diaphragmatic hernia in sisters. Am j Dis Child 38. Harrison MR, Goibus MS, Filly RA, et al.: Fetal 133:1186, 1979. surgical treatment. Pediatr Ann 11:896, 1982. 59. Raphaely RC, Downes JJ Jr: Congenital diaphragmatic 39. Haworth SG, Reid L: Persistent fetal circulation: Newly hernia:Prediction of survival. J Pediatr Surg 8:815, recognized structural features. J Pediatr 88:614, 1976. 1973. 40. Hill RM, et al.: Infants exposed in utero to antiepileptic 60. Reid IS, Hutcherson RJ: Long-term follow-up of patients drugs. Am J Dis Child 127:645, 1974. with congenital diaphragmatic hernia. J Pediatr Surg 41. Hisanaga S, Shimokawa H, Kashiwabara S, et al.: 11:939, 1976. Unexpectedly low lecithin/sphingomyelin ratio 61. Reid L: The lung: Its growth and remodeling in health associated with fetal diaphragmatic hernia. Am J Obstet and disease. AJR 129:777, 1977. Gynecol 149:905, 1984. 62. Rudolph AM: Fetal and neonatal pulmonary circulation. 42. Hobbins JC, Grannum PAT, Berkowitz RL, et al.: Annu Rev Physiol 41:383, 1979. Ultrasound in the diagnosis of congenital anomalies. 63. Ruff SJ, Campbell JR, Harrison MW, et al.: Pediatric Am J Obstet Gynecol 134:331, 1979. diaphragmatic hernias. An 11-year experience. Am J 43. Hobolth N: Drugs and congenital abnormalities. Lancet Surg 139:642, 1980. 2:1332, 1962. 64. Shochat SJ, Naeye RL, Ford WDA, et al.: Congenital 44. lnselman LS, Mellins RB: Growth and development of diaphragmatic hernia. New concept in management. the lung. J Pediatr 98:1, 1981. Ann Surg 190:332, 1979. 45. Kucera J: Rate and type of congenital anomalies among 65. Snell RS: Clinical Embryology for Medical Students, 3d offspring of diabetic women. J Reprod Med 7:73, 1971. ed. Boston, Little, Brown, 1983, pp 177-194. 46. Kup J: Zwerchfelldefekt nach Abtreibungsversuch mit 66. Starret RW, de Lorimer AA: Congenital diaphragmatic Chinin. Munch Med Wschr 27:2582, 1967. hernia in lambs: Hemodynamic and ventilatory changes 47. Leck I, Record RG, McKeown T, et al.: The incidence with breathing. J Pediatric Surg 10:575, 1975. of malformations in Birmingham, England, 1950-1959. 67. Stauffer UG, Rickham PP: Congenital diaphragmatic Teratology 1:263, 1959. hernia and eventration of the diaphragm. In: Rickham 48. Levin DL: Morphologic analysis of the pulmonary PP, Lister JP, Irving TM (eds): Neonatal Surgery,'2d ed. vascular bed in congenital left-sided diaphragmatic London, Butterworths, 1978, pp 163-178. hernia. J Pediatr 92:805, 1978. 68. Thorburn MJ, Wright ES, Miller CG, et al.: 49. Lubinsky M, Severn C, Rapoport JM: Fryns syndrome: Exomphalosmacro-glossia-gigantism syndrome in A new variable multiple congenital anomaly (MCA) Jamaican infants. Am J Dis Child 119:316, 1970. syndrome. Am J Med Genet 14:461, 1983. 69. Touloukian RJ, Markowitz RI: A preoperative x-ray 50. Marshall A, Sumner E: Improved prognosis in scoring system for risk assessment of newborns with congenital diaphragmatic hernia: Experience of 62 cases congenital diaphragmatic hernia. J Pediatr Surg 19:252, over 2-year period. J Roy Soc Med 75:607, 1982. 1984 51. Marwood RP, Davison OW: Antenatal diagnosis of 70. Turley K, Vlahakes GJ, Harrison MR, et al.: Intrauterine diaphragmatic hernia. Case report. Br J Obstet cardiothoracic surgery: The fetal lamb model. Gynaecol 88:71, 1981. Presented at the Eighteenth Annual Meeting of the 52. Merten DF, Bowie JD, Kirks DR, et al.: Anteromedial Society of Thoracic Surgeons, January 11-13, 1982. diaphragmatic defects in infancy: Current approaches to 71. Warkany J: Congenital Malformations. Notes and diagnostic imaging. Radiology 142:361, 1982. Comments. Chicago, Year Book, 1971, pp 10, 303- 53. Mishalany HG, Nakada K, Wooley MW: Congenital 310, 751-757. diaphragmatic hernias. Eleven years' experience. Arch 72. Warkany J, Roth CB: Congenital malformations induced Surg 114:1118, 1979. in rats by maternal vitamin A deficiency. J Nutr 35:1, 54. Moodie DS, Telander RL, Kleinberg F, et al.: Use of 1948. tolazoline in newborn infants with diaphragmatic hernia 73. Wiener ES: Congenital posterolateral diaphragmatic and severe cardiopulmonary disease. J Thorac hernia: New dimensions in management. Surgery Cardiovasc Surg 75:725, 1978. 92:670, 1982. 55. Moore KL: The Developing Human. Clinically 74. Williams R: Congenital diaphragmatic hernia: A review. Oriented Embryology, 3d ed. Philadelphia, Saunders, Heart Lung 11:532, 1982. 1982, pp 172-175. 75. Wohl MEB, Griscom NT, Strieder DJ, et al: The lung 56. Naeye RL, Shochat SJ, Whitman V, et al.: Unsuspected following repair of congenital diaphragmatic hernia. J pulmonary vascular abnormalities associated with Pediatr 90:405, 1977. diaphragmatic hernia. Pediatrics 58:902, 1976.

220 THE ABDOMINAL WALL

Omphalocele

Synonym isolated omphalocele. Defective fusion of the caudal Exomphalos. fold results in cloacae exstrophy of the bladder.

Definition Pathology Omphalocele is a ventral wall defect characterized by The defect is located in the midline, and the protrusion of herniation of the intraabdominal contents into the base the intraabdominal contents occurs through the base of of the umbilical cord, with a covering amnioperitoneal the umbilical cord. Bowel loops, stomach, and liver are membrane (Fig. 6-16). the most frequently herniated organs and are covered by Pentalogy of Cantrell is a term used to describe the a membrane made up of two layers:internally the peri- association of five anomalies: (1) midline toneum and externally the amnion. The umbilical cord supraumbilical abdominal defect, (2) defect of the inserts into the sac. The size of these defects is lower sternum, (3) deficiency of the diaphragmatic variable, ranging from a very small hernia containing a pericardium, (4) deficiency of the anterior diaphragm, few bowel loops to a very large mass containing most of and (5)intracardiac abnormality.27 the visceral organs. The Beckwith-Wiedemann syndrome is charac- With pentalogy of Cantrell, the diaphragmatic terized by the association of macroglossia, defect is embryologically different from the hernia of visceromegaly, and omphalocele. Morgagni. The lesion is located in the anterior portion of the diaphragm and is rarely associated with Incidence Omphalocele is estimated to occur in 1 in 5800 to 1 in 5130 live births.2,15 Beckwith-Wiedemann syndrome has an incidence of 1 in 13,700 live births.3 Pentalogy of Cantrell is a very rare disorder.

Etiology Most cases of omphalocele are sporadic. Often the condition is associated with chromosomal aberrations, such as trisomies 13 and 18. The familial occurrence of this anomaly with a sex- finked or autosomal pattern of inheritance has been reported.10,20,23 The recurrence risk for isolated omphalocele cases appears to be less than 1 percent. However, when an omphalocele is identified in association with trisomies, a careful evaluation of the karyotype should exclude the possibility of a balanced translocation, which increases the recurrence risk. Although most cases of Beckwith-Wiedemann syndrome are sporadic, familial occurrence has been described, suggesting autosomal dominant, recessive, sex-linked, and polygenic patterns.3,20 Cantrell's pentalogy is also a sporadic condition.

Embryology The development of the anterior abdominal wall depends on the fusion of four ectomesodermic folds (cephalic, caudal, and two laterals). Failure of the cephalic fold to fuse with the other folds usually results in the association of omphalocele with ectopia cordis Figure 6-16. Typical omphalocele in a newborn. The lesion and sternal and diaphragmatic defects. Failure of the occurs in the midline and is covered by a membrane. (Courtesy of Dr. Pobert Touloukian.) lateral folds to meet in the midline (between the 3d and 4th weeks) leads to the formation of an

diac anomalies (ventricular and atrial septal defects, tetralogy of Fallot) are found in up to 47 percent of patients,4,6,19 genitourinary abnormalities in up to 40 percent,19,23 and neural tube defects in up to 39 percent.2,16 Gastrointestinal anomalies, either primary or secondary (e.g., bowel obstruction), are a frequent finding. Intrauterine growth retardation has been reported in 20 percent of patients.2

Diagnosis The diagnosis of omphalocele relies on the demonstration of a mass adjacent to the anterior ventral wall representing the herniated visceral organs (Figs. 6-17 through 6-20). Differential diagnosis is mainly with gastroschisis.21 Figure 6-17. Prenatal diagnosis of an omphalocele at 15 weeks of Omphaloceles are located in the midline. The umbilical gestation. Transverse scan of the abdomen at the level of the umbilicus demonstrating the lesion (*) Sp, spine. cord enters into the hernia, and the herniated organs are covered by a membrane that is continuous with the umbilical cord. Gastroschisis is a lateral defect, devoid of a surrounding membrane and separated from the umbilical herniation of intraabdominal organs into the thoracic cord insertion. These signs permit an accurate differential cavity, although bowel loop protrusion inside the 27 diagnosis in almost all patients. A possible exception may pericardial sac has been documented. The most frequent be those cases of omphalocele in which rupture of the cardiac abnormalities are atrioventricular septal defects, amnioperitoneal sac occurs in utero, an exceedingly rare ventricular septal defects, and tetralogy of Fallot. In a complication. 8 Pentalogy of Cantrell can be suspected in review of 36 patients, the incidence of these three cardiac the presence of ectopia cordis.24 In many cases, the defect defects was 50 percent, 18 percent, and 11 percent, 27 in the diaphragm at the level of the pericardium is small respectively. and cannot be demonstrated by prenatal sonography. The Beckwith-Wiedemann syndrome is a constellation Suspicion should arise when the apex of the heart deviates of clinical abnormalities, including combinations of inferiorly (under nor- omphalocele, macroglossia, natal or postnatal gigantism, nephromegaly, facial flame nevus, hepatomegaly, ear lobe abnormalities, hemihypertrophy, and neonatal polycythemia. The most prominent features are exomphalos (E), macroglossia (M), and gigantism (G); hence, the condition is also known as "EMG syndrome."25 Neonatal hypoglycemia is found in 50 percent of patients. Cardiac abnormalities occurred in 12 of 13 patients reported by Greenwood et al.7 Seven of the 12 patients (58 percent) had structural abnormalities, and 5 had isolated cardiomegaly. No specific pattern of congenital heart disease has been described. Ten percent of infants with Beckwith-Wiedemann syndrome may develop malignant tumors, including nephroblastoma, hepatoblastoma, and adrenal tumor.26 In a review of cases of omphalocele, Irving estimated that 11.7 percent of all cases were 12* associated with the BeckwithWiedemann syndrome The syndrome has no obligatory anomalies and has been diagnosed in the absence of macroglossia or omphalocele.3

Associated Anomalies

The frequency of trisomies in infants with omphalocele 4,9,16,17,19 varies between 35 and 58 percent. Chromosomal aberrations include trisomy 13 and 18. Car- Figure 6-18. A large omphalocele in a third trimester fetus. * Our review of the literature indicates that this syndrome accounts for 4 Transverse scan of the abdomen at the level of the umbilicus. The percent of all cases of omphalocele. amniotic peritoneal membrane is seen covering the lesion (white arrows). The liver (L) is herniated into the sac. The umbilical vein (uv) is visible. St, stomach.

tions, and prematurity.Kirk and Wah have reported 38 cases of omphaloceles, with a mortality rate of 29 13 percent. Of the 11 deaths, 5 occurred in infants with multiple congenital anomalies and 3 in infants with associated congenital heart disease. Carpenter et al. reported an overall mortality rate of 40 percent.2 Among the infants who died, two had trisomies, two had other severe anomalies (esophageal atresia, tetralogy of Fallot, pulmonary hypoplasia), and three had pentalogy of Cantrell. Cephalic fold defects carry a worse prognosis than do the lateral and caudal fold defects. In the series by Carpenter et al., the mortality rate among cephalic fold defects was 78 percent versus 19 percent in the lateral fold defects.2 In a review of the literature by Toyama, the Figure 6-19. Omphalocele in a third trimester fetus. The herniated organs are the liver (L) and bowel (B). The amniotic survival rate among individuals with pentalogy of 27 peritonea membrane is seen (arrows). hv, hepatic vein. Cantrell was only 20 percent. Since this report is based on data collected before 1970, it is quite likely that the mal circumstances, the heart is horizontal within the outcome for infants with this condition has improved due thoracic cavity) and bulges under the skin of the chest to advances in cardiothoracic surgery. due to the sternal defect. Infants with Beckwith-Wiedemann syndrome have A specific prenatal diagnosis of Beckwith- respiratory and feeding difficulties because of the large Wiedemann syndrome has not been reported. The tongue. The oral cavity may grow with time, and the condition should be suspected when an omphalocele is tongue eventually fits inside the mouth. In some patients, associated with visceromegaly and macroglossia. glossectomy has been required. The excessive rate of Nomograms are available for assessing the size of growth often slows down after the first few years.27 kidneys, heart, and spleen. However, the value of these Neonatal hypoglycemia is a serious complication, which measurements in the diagnosis of BeckwithWiedemann has been implicated in the mild to moderate mental syndrome has not been tested. This condition has been deficiency noted in some of these infants. Steroids have 14,28 prenatally visualized twice, but a specific diagnosis of been used to control hypoglycemia. Ten percent of these Beckwith-Wiedemann syndrome was not made before infants develop neoplasms. In a review of 17 cases of birth. Polyhydramnios is a frequent finding and is Beckwith- probably responsible for the increased incidence of premature labors. Ventral wall defects may result in an elevation of the maternal serum alpha-fetoprotein (MSAFP). It has been reported that MSAFP screening has a sensitivity of 52 percent in the detection of anterior wall defects and 42 percent for omphaloceles.16 Therefore, the evaluation of the anterior abdominal wall is an important part of the monographic assessment of pregnancies with elevated AFP. Since an increased incidence of neural tube defects has been found in infants with omphalocele, identification of the latter lesion should not result in overlooking the fetal spine.

Prognosis A small defect can be repaired in a one-stage operation. Larger defects usually require a two-stage operation, generally using a Silastic or Teflon membrane to cover and reduce the herniation of the intraabdominal organs.22 Prognosis of omphalocele depends largely on the presence of associated anomalies. Losses are mainly due Figure 6-20. Small omphalocele in a fetus with hydrops. The to cardiac abnormalities, chromosomal aberra- insertion of the umbilical cord (uc) in the abdomen is interrupted by a lesion that contains small bowel (b). The amniotic peritoneal membrane is outlined by the short arrows. Ascites is present in the peritoneal cavity. B, intraabdominal bowel loops.

Wiedemann syndrome associated with tumors, a 47 fetus with an abdominal wall defect. In: The Unborn percent mortality rate was reported.26 Patient. Prenatal Diagnosis and Treatment. Orlando, FL, Grune & Stratton, 1984, pp 217-234. 9. Hauge M, Bugge M, Nielsen J: Early prenatal diagnosis Obstetrical Management of omphalocele constitutes indication for amniocentesis. Identification of a fetal omphalocele should prompt a Lancet 2:507, 1983. careful search for associated anomalies. Fetal 10. Havalad S, Noblett H, Speidel BD: Familial occurrence of 18 karyotyping and echocardiography are indicated. omphalocele, suggesting sex-linked inheritance. Arch Diagnosis before viability may allow parents to opt for Dis Child 54:142, 1979. pregnancy termination. In continuing pregnancies and 11. Hoyme HE, Jones MC, Jones KL: Gastroschisis: in those cases diagnosed after viability, serial Abdominal wall disruption secondary to early gestational ultrasound monitoring is indicated to look for signs of interruption of the omphalomesenteric artery. Sem intestinal obstruction and intrauterine growth Perinatol 7:294, 1983. 12. Irving I: Exomphalos with macroglossia: A study of 11 retardation. In recent years, the optimal mode of cases. J Pediatr Surg 2:499, 1967. delivery of fetuses with omphalocele has been a subject 13. Kirk EP, Wah RM: Obstetric management of the fetus of debate. Some authors have suggested that delivery with omphalocele or gastroschisis: A review and report of of these infants should be performed by cesarean one hundred twelve cases. Am J Obstet Gynecol section to avoid birth injury with rupture of the 146:512, 1983. amnioperitoneal sac. However, in two large 14. Koontz WL, Shaw LA, Lavery JP: Antenatal sonographic retrospective and uncontrolled series, no benefits of appearance of Beckwith-Wiedemann syndrome. J Clin cesarean section versus vaginal delivery could be Ultrasound 14:57, 1986. documented.2,13 15. Lindham S: Omphalocele and gastroschisis in Sweden 1965-1976. Acta Paediatr Scand 70:55, 1981. The major limitation of these studies is their design. 16. Mann L, Ferguson-Smith MA, Desai M, et al.: Prenatal The incidence of complications in infants delivered assessment of anterior abdominal wall defects and their vaginally seems to be small. However, we believe that prognosis. Prenat Diagn 4:427, 1984. there is a sub roup of patients who may benefit from a 17. Mayer T, Black R, Matlak ME, et al.: Gastroschisis and cesarean section. An example of this is the large omphalocele. An eight-year review. Ann Surg 192:783, omphalocele with external protrusion of a large part of 1980 the liver.1 A careful search for associated anomalies is 18. Nicolaides KH, Rodeck CH, Gosden CM: Rapid indicated also in those cases diagnosed in the third karyotyping in non-lethal fetal malformations. Lancet trimester. Omphalocele may be accompanied by 1:283, 1986. 19. Nivelon-Chevallier A, Mavel A, Michiels R, et al.: anomalies incompatible with life (e.g., trisomies 13 and Familial Beckwith-Wiedemann syndrome: Prenatal 18), and the recognition of such disorders could alter echography diagnosis and histologic confirmation. J obstetrical management. Genet Hum 5:397, 1983. 20. Osuna A, Lindham S: Four cases of omphalocele in two REFERENCES generations of the same family. Clin Genet 9:354, 1976. 21. Redford DHA, McNay MB, Whittle MJ: Gastroschisis 1. Bartolucci L: Discussion in Kirk EP, Wah RM: Obstetric and exomphalos: Precise diagnosis by midpregnancy management of the fetus with omphalocele or ultrasound. Br J Obstet Gynaecol 92:54, 1985. gastroschisis: A review and report of one hundred twelve 22. Rickham PP: Exomphalos and gastroschisis. In: Rickham cases. Am J Obstet Gynecol 146:512, 1983. PP, et al. (eds): Neonatal Surgery. New York, Appleton- 2. Carpenter MW, Curci MR, Dibbins AW, et al.: Perinatal Century-Crofts, 1969, p 254. management of ventral wall defects. Obstet Gynecol 23. Rott HD, Truckenbrodt H: Familial occurrence of 64:646, 1984. omphalocele. Hum Genet 24:259, 1974. 3. Cohen MM, Ulstrom RA: Beckwith-Wiedemann 24. Seeds JW, Cefalo RC, Lies SC, et al.: Early prenatal syndrome. In: Bergsma D (ed): Birth Defects monographic appearance of rare thoraco-abdominal Compendium, 2d ed. New York, Alan R. Liss, 1979, pp eventration. Prenat Diagn 4:437, 1984. 140-141. 25. Smith DW: Recognizable Patterns of Human 4. Crawford DC, Chapman MG, Allan LD: Malformations. Genetic, Embryologic and Clinical Echocardiography in the investigation of anterior Aspects, 3d ed. Philadelphia, Saunders, 1982, p 130. abdominal wall defects in the fetus. Br J Obstet Gynecol 26. Sotelo-Avila C, Gooch M: Neoplasms associated with the 92:1034, 1985. Beckwith-Wiedemann syndrome. Perspect Pediatr Pathol 5. Gosden C, Brock DJH: Prenatal diagnosis of extrophy of 3:255, 1977 the cloaca. Am J Med Genet 8:95, 1981. 27. Toyama WM: Combined congenital defects of the 6. Greenwood RD, Rosenthal A, Nadas AS: Cardiovascular anterior abdominal wall, sternum, diaphragm, malformations associated with omphalocele. J Pediatr pericardium and heart: A case report and review of the 85:818, 1974. syndrome. Pediatrics 50:778, 1972. 7. Greenwood RD, Sommer A, Rosenthal A, et al.: 28. Weinstein L, Anderson C: In utero diagnosis of Cardiovascular abnormalities in the Beckwith- Beckwith-Wiedemann syndrome by ultrasound. Wiedemann syndrome. Am J Dis Child 131:293, 1977. Radiology 134:474, 1980. 8. Harrison MR, Golbus MS, Filly RA: Management of the

Gastroschisis

Definition the amniotic fluid of these fetuses. Its presence Gastroschisis is a paraumbilical defect of the anterior probably reflects intestinal irritation.2,14 At birth, infants abdominal wall associated with evisceration of have low serum albumin and total protein levels, which abdominal organs. probably indicate intestinal chronic sclerosing peritonitis. Incidence The incidence of gastroschisis ranges from 1:10,000 to Associated Anomalies 1:15,000 live births.1,2,8 In contrast to omphalocele, gastroschisis is not associated with an increased incidence of other Etiology anomalies. However, in 25 percent of patients, Most cases are sporadic. Familial occurrence has been gastrointestinal problems secondary to the vascular documented in five families.1,9,10,13,15 The findings in impairment and adhesions are found, including bowel two families indicate the possibility of an autosomal malrotation, atresia, and stenosis.3 Intrauterine growth dominant inheritance, with variable expressivity. retardation has been reported in up to 77 percent of infants.2 Embryology and Pathogenesis Gastroschisis is a defect resulting from vascular Diagnosis compromise of either the umbilical vein or the The diagnosis of gastroschisis relies on the omphalomesenteric artery.5,6 demonstration of a mass adjacent to the anterior ventral Human embryos initially bear both left and wall representing the herniated visceral organs. right umbilical veins. Involution of the right umbilical Differential diagnosis from omphalocele can be made vein occurs between the 28th and the 32d day after in almost all cases because, in gastroschisis, (1) the conception. Premature involution may lead to ischemia defect is usually located in the right paraumbilical area, and to the resultant mesodermal and ectodermal (2) the umbilical cord is normally connected to the defects. abdominal wall, and (3) the herniated organs are not The omphalomesenteric arteries (OMAS) covered by a membrane but float freely in the amniotic branch from the primitive dorsal aorta and extend to the cavity (Figs. 6-21, 6-22). An omphalocele is a central right along the omphalomesenteric duct toward the yolk defect surrounded by a membrane on which the sac. The left OMA involutes, whereas the right one is umbilical cord is inserted.12 A possible exception may transformed into the superior mesenteric artery. The be those cases of omphalocele in which rupture of the terminal portion extends into the extraembryonic amnioperitoneal sac occurs in utero, an exceed- coelom, which is now located in the body stalk. Disruption of the distal segment could result in right- sided periumbilical ischemia and the paramedian defect characteristic of gastroschisis. Ischemic injury to the territory of the superior mesenteric artery may account for the high incidence of jejunal atresia found in association with gastroschisis.,5,6,11

Pathology Gastroschisis is characterized by a full-thickness defect of the abdominal wall, usually located to the right of the umbilical cord, which has a normal insertion. The defect in the abdominal wall is generally quite small (3 to 5 cm). The herniated organs include mainly bowel loops covered by an inflammatory exudate possibly resulting from chemical irritation by exposure to .3 amniotic fluid They appear edematous and are not Figure 6-21. Newborn with gastroschisis. There is no protected by a membrane. Hepatic herniation is less covering membrane, and the defect is on the right frequent with gastroschisis than with omphaloceles. paraumbilical area, (Courtesy of Dr. Robert Touloukian.)

Meconium is frequently found in

GASTROSCHISIS 225

fetuses with ventral wall defects has been a subject of debate. Some authors have suggested that delivery of these infants should be performed by cesarean section to avoid birth injury to the herniated visceral organs. However, in two large series, no benefits of cesarean section versus vaginal delivery could be documented.2,7 The major limitation with such studies is their retrospective and uncontrolled design. The incidence of complications in infants delivered vaginally seems to be small. Delivery in a tertiary care center is recommended.

REFERENCES

Figure 6-22. Sagittal scan of a 20-week fetus with a 1. Baird PA, MacDonald EC: An epidemiologic study of gastroschisis. Bowel is seen floating in the amniotic cavity congenital malformations of the anterior abdominal wall (curved arrow). The normal insertion on the umbilical vessels in more than half a million consecutive live births. Am J is demonstrated. UC, umbilical cord inserting into the anterior Hum Genet 33:470, 1981. abdominal wall; Sp, spine. 2. Carpenter MW, Curci MR, Dibbins AW, et al.: Perinatal management of ventral wall defects. Obstet Gynecol ingly rare complications.4 Polyhydramnios is a frequent 64:646, 1984. finding, and it is probably related to impaired 3. Grybowski J, Walker WA: Gastrointestinal problems in gastrointestinal transit. the infant. Philadelphia, Saunders, 1983, pp 284-287. Ventral wall defects may result in elevation of the 4. Harrison MR, Golbus MS, Filly RA: Management of the MSAFP. It has been reported that MSAFP screening fetus with an abdominal wall defect. In: The Unborn Patient. Prenatal Diagnosis and Treatment. Orlando, FL, will identify 77 percent of these fetuses.10 Therefore, Grune & Stratton, 1984, pp 217-234. examination of the anterior abdominal wall is an 5. Hoyme HE, Higginbotton MC, Jones KL: The vascular important part of the monographic evaluation of pathogenesis of gastroschisis: Intrauterine interruption of pregnancies with elevated AFP. the omphalomesenteric artery. J Pediatr 98:228, 1981. 6. Hoyme HE, Jones MC, Jones KL: Gastroschisis: Prognosis Abdominal wall disruption secondary to early gestational In three different series, the mortality rate ranged from interruption of the omphalomesenteric artery. Semin 7.6 percent to 28 percent.2,7,14 Death was caused by Perinat 7:294, 1983. prematurity, sepsis, and intraoperative complications. 7. Kirk EP, Wah RM: Obstetric management of the fetus with omphalocele or gastroschisis: A review and report of In one series, herniation of the liver was associated one hundred twelve cases. Am J Obstet Gynecol with a higher mortality rate (50 percent versus 7 7 146:512, 1983. percent). 8. Lindham S: Omphalocele and gastroschisis in Sweden 1965-1976. Acta Paediatr Scand 70:55, 1981. Obstetrical Management 9. Lowry RB, Baird PA: Familial gastroschisis and The critical issue is the differential diagnosis from an omphalocele. Am J Hum Gen 34:517, 1982. omphalocele, since this defect is associated with a 10. Mann L, Ferguson-Smith MA, Desai M, et al.: Prenatal higher incidence of associated anomalies and carries a assessment of anterior abdominal wall defects and their worse prognosis. In the past, the consensus was that prognosis. Prenat Diagn 4:427, 1984. 11. Moore TC: Gastroschisis and omphalocele: Clinical fetal karyotyping was not indicated in gastroschisis. differences. Surgery 82: 561, 1977. We have recently seen two cases with karyotype 12. Redford DHA, McNay MB, Whittle MJ: Gastroschisis abnormalities. When the diagnosis is made before and exomphalos: Precise diagnosis by midpregnancy viability, the parents may opt for termination of ultrasound. Br J Obstet Gynaecol 92:54, 1985. pregnancy. In continuing pregnancies and in those 13. Salinas CF, Bartoshesky L, Othersen HB, et al.: Familial cases diagnosed in the third trimester, serial ultrasound occurrence of gastroschisis. Am J Dis Child 133:514, examinations are recommended to detect intrauterine 1979. growth retardation and early signs of bowel 14. Seashore JH: Congenital abdominal wall defects. Clin obstruction. Polyhydramnios is a frequent finding and Perinatol 5:61, 1978. 15. Ventruto V, Stabile M, Lonardo F, et al.: Gastroschisis in may contribute to the onset of premature labor. In this two sibs with abdominal hernia in maternal grandfather situation, tocolytic agents and amniotic fluid drainage and great-grandfather. Am J Med Genet 21:405, 1985. are indicated to prolong the gestation. In recent years, the optimal mode of delivery of

extraembryonic coelom (chorionic cavity). The amnion Body Stalk Anomaly then fuses with the chorion peripherally and forms the covering of the umbilical cord centrally. Body stalk Definition anomaly results from severe maldevelopment of This is a severe abdominal wall defect due to failure of cephalic, caudal, and lateral embryonic body folds. formation of the body stalk and characterized by absence of The failure of complete extraembryonic coelom the umbilicus and umbilical cord. obliteration accounts for the absence of umbilical cord formation and the wide-based insertion of the Incidence amnioperitoneal membrane onto the placental chorionic The incidence of body stalk anomaly is 1 in 14,273 births.2 plate. The intraabdominal contents persist in the extraembryonic coelom. Fusion of the amnion and Embryology chorion takes place only at the margin of the placenta. During the third week of embryonic life the flat trilaminar embryo is transformed into a cylindrical fetus by a parallel Pathology set of contiguous body folds: cephalic, lateral, and caudal. The abdominal organs lie in a sac outside the Folding separates the intraembryonic coelom (peritoneal abdominal cavity (Fig. 6-23). This sac is covered by cavity) from the amnion and placenta and is attached directly to the placenta.

Figure 6-24. The umbilical vessels run along the wall of the sac.

Figure 6-23. Body stalk anomaly. The placenta is attached to the herniated viscera without an intervening umbilical cord.

The umbilical vessels are short and run along the sac walls (Fig. 6-24). The absence of the umbilical cord results in the fetus lying directly against the placenta and the uterine wall. This may lead to malposition and skeletal deformities, including kyphosis and scoliosis (Fig. 6-25).

Etiology The disorder is sporadic in most cases, but concordance for this anomaly has been noted in twins.2

Diagnosis This diagnosis should be suspected when the fetus is attached to the placenta and uterine wall and a large defect of the anterior abdominal wall allows protrusion of the viscera (Fig. 6-26). Prenatal diagnosis of this condition has been reported using MSAFP and ultrasound.1,2

Associated Anomalies Anomalies, including neural tube defects, intestinal atresias, genitourinary and skeletal defects, anoma-

Figure 6-26. Sonogram of the fetus shown in Figures 6-24 and 6- 25. Note that the viscera is herniated and in proximity with the placenta. The condition was suspected because the infant was constantly apposed to one uterine wall. L, liver; K, kidney; B, bowel loops; H, heart; T, thorax; P, placenta. (Reproduced with permission from Lockwood et al: Am J Obstet Gynecol 155:1049, 1986.)

lies of the chest wall, pericardium, heart, liver, and lungs, are nearly always present. One umbilical artery is usually absent.3

Prognosis Potter and Craig3 and Mann et al.2 have stated that this condition is uniformly fatal.2,3

Obstetrical Management The option of pregnancy termination for this uniformly lethal condition could be offered to the parents anytime the diagnosis is made.

REFERENCES

1. Lockwood CJ, Scioscia AL, Hobbins JC: Congenital absence of the umbilical cord resulting from maldevelopment of embryonic body folding. Am J Obstet Gynecol 155:1049, 1986. 2. Mann L, Ferguson-Smith MA, Desai M, et al.: Prenatal Figure 6-25. Severe scoliosis in a fetus with body stalk anomaly. assessment of anterior abdominal wall defects and their prognosis. Prenat Diagn 4:427, 1984. 3. Potter EL, Craig JM: Pathology of the Fetus and the Infant, 3d ed. Chicago, Year Book, 1975, p 388.

Bladder Exstrophy and Cloacal Exstrophy

Definition Embryology Exstrophic anomalies are a group of disorders derived The cloaca is a blind pouch that receives the midgut by a maldevelopment of the caudal fold of the anterior and the allantoic duct. The anterior wall of the cloaca abdominal wall. In bladder exstrophy, the anterior wall is formed by the cloacal membrane, which extends of the bladder is absent, and the posterior wall of this from the two lateral mesodermal ridges to the body organ is exposed. Cloacal exstrophy is a more complex stalk (the primordium of the umbilical cord). By the anomaly in which there is involvement of both the 6th week of conception, the cloaca is divided by a urinary and intestinal tracts caused by a defect in the proliferating mesodermal ridge (the urorectal septum) formation of the urorectal septum. into a urogenital sinus anteriorly and a hindgut posteriorly. The urorectal septum divides the cloacal Incidence membrane in an anterior portion, or urogenital Exstrophy of the bladder occurs in 1:30,000 deliveries, membrane, and a posterior one, or anal membrane (Fig. with a male to female ratio of 2.3:1.5 Exstrophy of the 6-27). cloaca has an incidence of 1:200,000 live births without Normally, the two mesodermal ridges fuse in the a sex preponderance.2,11 midline to form the genital tubercle, and the cloacal membrane retracts downward toward the perineum. Etiology The lower portion of the anterior abdominal wall is Most cases of bladder exstrophy are sporadic. Familial reinforced by the tissues derived from the mesodermal cases have been reported, and the risk of recurrence in a ridges (Fig. 6-28A). If the cloacal membrane does not given family is 1 percent.4 The risk of having an retract normally, the two mesodermal ridges fuse affected offspring if one parent has bladder exstrophy is inferiorly, and the cloacal membrane becomes the 1 in 70 live births, which is 500 times greater than the anterior wall of the bladder. By the 9th week, the risk of the general populations Presumably, cloacal cloacal membrane disappears and the posterior wall of exstrophy is also a sporadic disorder, although affected the bladder is exposed, giving rise to bladder exstrophy individuals have not reproduced. (Figs. 6-28B, 6-29). If the membranes disappear before the urorectal septum divides the primitive cloaca, both bladder and rectum will be exposed, leading to cloacal exstrophy (Fig. 6-30).

Figure 6-27. A-D. Developmental changes of the cloaca and cloacal membrane in the 4 to 16 mm embryo. Arrows show the direction of growth of the urorectal septum. (Reproduced with permission from Muecke: In Campbell's Urology. Philadelphia, Saunders, 1986, pp 1856-1880.)

Associated Anomalies Associated anomalies are rare in bladder exstrophy. In contrast, associated anomalies are very frequent in cloacal exstrophy.9 Renal anomalies (renal agenesis, hydronephrosis, multicystic kidney, hydroureter, ureteric atresia) are present in 60 percent of patients. Skeletal defects other than separation of pubic bones were noted in 72 percent of patients. Spina bifida is by far the most common.11Anomalies of the cardiovascular and gastrointestinal tract occur in 16 percent and 10.5 percent, respectively. Omphaloceles are present in 87 percent of patients. A double vena cava is also frequent.9

Diagnosis The prenatal diagnosis of bladder exstrophy has been reported.8 This condition was suspected because of the presence of a solid mass (47 mm in diameter) in the lower part of the fetal abdomen (Fig. 6-34). The mass did not contain cystic areas, and the bladder could not be identified. The penis was extremely short, and a normal amount of amniotic fluid was present. The diagnosis should be suspected any time a bladder cannot be visualized in a fetus with a

Figure 6-28. Schematic view of regression of cloacal membrane and formation of the primitive phallus. A. Normal sequential events. B. Genesis of the exstrophy group of anomalies by a persistent cloacal membrane impeding mesodermal flow. The paired genital folds fuse inferiorly, carrying the thin cloacal membrane along the anterior surface of the enlarging phallus. A weak, membranous anterior body wall persists, leading to the eventual catastrophic event of exstrophy. (Reproduced with permission from Muecke: In Campbell's Urology. Philadelphia, Saunders, 1986, pp 1856- 1880.)

Pathology In bladder exstrophy, there are protrusion of the posterior vesical wall, separation of pubic bones, low set umbilicus, incomplete descent of the testes, short penis pointing upward and epispadias in males, and cleft clitoris in females (Fig. 6-31). The size of the everted bladder is quite variable, ranging from a small area of the trigone to complete eversion of the posterior wall of the organ. The perineum is short and broad. Divergent elevator ani- and puborectal muscles may result in rectal incontinence and anal prolapse. In cloacal exstrophy, there are two hemibladders each with its own ureteral orifice, separated by an area of intestine. This bowel mucosa probably corresponds to the cecum, since it receives the ileum superiorly. Other Figure 6-29. Diagram of events leading to classic exstrophy. structures that can be observed include an umbilical (Reproduced with permission from Muecke: In Campbell's hernia and diphallus (separation of the two corpora) Urology. Philadelphia, Saunders, 1986, pp 1856-1880.) (Figs. 6-32, 6-33).

Figure 6-30. Diagram of eventration of the cloaca, forming cloacae exstrophy. (Reproduced with permission from Muecke: In Campbell's Urology. Philadelphia, Saunders, 1986, pp 1856-1880.) normal amount of amniotic fluid. The differential diagnosis includes omphalocele, gastroschisis, and cloacal exstrophy. Visualization of a normal bladder Figure 6-32. Descriptive drawing of classic exstrophy of the and the relationship of the mass to the fetal abdomen bladder in a female child. (Reproduced with permission from Muecke: In Campbell's Urology. Philadelphia, Saunders, 1986, are helpful hints in the differentiation of bladder pp. 1856-1880.) exstrophy from the first two defects. A prenatal diagnosis of cloacal exstrophy with ultrasound has not cally by the performance of a primary bladder closure, been reported. Elevated amniotic fluid AFP has been 1 reconstruction of the bladder neck, and epispadias repair. reported in one case of exstrophy cloaca. Alternatively, the approach may consist of a urinary diversion, cystectomy, and epispadias repair. An optimal Prognosis surgical treatment between these two alternatives has not The main problems of bladder exstrophy are urinary been established, and there are merits to both approaches. incontinence, presence of an abdominal wall defect, The genital defects in the male are quite serious, and sex and the cosmetic consequences of the lesion in the reassignment may be required in 1 in 50 to 1 in 100 male genitalia. These problems can be treated surgi- patients in whom an adequately functional penis cannot be created.5 Genital defects in the female are less complex. Approximation of the hemiclitoris can generally be accomplished. Vaginal dilatation and perineoplasty may be required for satisfactory sexual intercourse. Patients with bladder exstrophy grow into adulthood and have an acceptable social adjustment.7,13 Fertility is decreased in both males and females.10 Pregnancy is possible, although there is an increased likelihood of uterine prolapse postpartum.6 This complication is due to hypoplasia of the cardinal ligaments. Cloacal exstrophy is a very serious anomaly associated with a 55 percent mortality rate.3 The most common associated anomaly is a neural tube defect. Untreated infants frequently die from sepsis, short bowel syndrome, or renal or central nervous system defects. The correct surgical approach consists of a series of operations including repair of the omphalocele, functional bladder closure (neonatal period), antiincontinence and antireflux surgery at age 2 to 3 years, and vaginal reconstruction at Figure 6-31. Descriptive drawing of classic exstrophy of the age 14 to 18 years. Tank and Lindenauerl2 have bladder in a male child. (Reproduced with permission from Muecke: In Campbell's Urology. Philadelphia, Saunders, 1986, recommended the conversion of males to females because pp 1856-1880.) of the

©1987-2002 Romero-Pilu-Jeanty-Ghidini-Hobbins BLADDER EXSTROPHY AND CLOACAL EXSTROPHY 231 uniformly disappointing results when trying to create a functionally acceptable penis. Gonadectomy is performed 12 when sexual reassignment has been selected.

Obstetrical Management If a diagnosis of bladder exstrophy is suspected before viability, the option of pregnancy termination should be offered. After this point, no change in standard obstetrical management is required. There is no evidence that altering the mode of delivery changes the prognosis for these infants. After birth, the exposed bladder mucosa is very friable and easily denuded. Jeffs and Lepor 5 have recommended that the umbilical cord be tied closely to its area of

Figure 6-34. Sonogram of a fetus with bladder exstrophy. Oblique and longitudinal scans through the caudal aspect of the fetus, demonstrating fetal genitalia (closed arrow), with a solid mass (open arrow) projecting anteriorly. (Reproduced with permission from Mirk et al.: J Ultrasound Med 5.-291, 1986.)

insertion so that a long cord does not add trauma to the bladder mucosa. It is preferable to tie the cord with a suture as opposed to the standard clamp, which may also traumatize the defect. The bladder mucosa may be covered with a nonadherent film of plastic wrap to prevent the mucosa from sticking to clothing. The traditional petroleum jelly gauze should be avoided, since it may lift the bladder epithelium when removed.

REFERENCES

1. Gosden C, Brock DJH: Prenatal diagnosis of exstrophy of the cloaca. Am J Med Genet 8:95, 1981. 2. Gravier L: Exstrophy of the cloaca. Ain Surg 34:387, 1968. 3. Howell C, Caldamone A, Snyder H, et al.: Optimal management of cloacal exstrophy. J Pediatr Surg 18:365, 1983. 4. Ives E, Coffey R, Carter CO: A family study of bladder exstrophy. J Med Genet 17:139, 1980 5. Jeffs RD, Lepor H: Management of the exstrophy-epispadias complex and urachal anomalies. In Walsh PC (ed): Campbell's Urology, 5th ed. Philadelphia, Saunders, 1986, pp 1882-1921. 6. Krisiloff M, Puchner PJ, Tretter W, et al.: Pregnancy in women with bladder exstrophy. J Urol 119:478, 1978. Figure 6-33. Diagrams of cloacal exstrophy in the newborn 7. Lattimer JK, Beck L, Yeaw S, et al.: Long-term follow-up after emphasizing characteristic anatomic features: two hemibladders with exstrophy closure. Late improvement and good quality of life. their ureteral orifices, cecumlike exstrophied intestine receiving the J Urol 119:664, 1978. terminal ileum superiorly and the tailgut inferiorly, paired appendiceal 8. Mirk P, Calisti A, Fileni A: Prenatal monographic diagnosis of diverticula, two hemipenises or corpora cavernosa. (Reproduced with bladder exstrophy. J Ultrasound Med 5:291, 1986. permission from Muecke: In Campbell's Urology. Philadelphia, Saunders, 1986, pp 1856-1880.)

9. Muecke EC: Exstrophy, epispadias and other anomalies 11. Soper RT, Kilger K: Vesico-intestinal fissure. J Urol of the bladder. In Walsh PC (ed): Campbell's Urology, 92:490, 1964. 5th ed. Philadelphia, Saunders, 1986, pp 1856-1880. 12. Tank ES, Lindenauer SM: Principles of management of 10. Shapiro E, Lepor H, Jeffs RD: The inheritance of the exstrophy of the cloaca. Am J Surg 119:95, 1970. exstrophy epispadias complex. J Urol 132:308, 1984. 13. Woodhouse CRJ, Ransley PC, Williams DI: The patient with exstrophy in adult life. Br J Urol 55:632, 1983.