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Journal of the Anatomical Society of India

Omphalocoele, Exstrophy of Cloaca, Imperforate Anus and Spinal Defects (OEIS Complex): A Case Report and Review of Literature

Author(s): Yuvaraj Bhosale,Lakshmi Rajgopal, Y.S. Nandanwar

Vol. 56, No. 1 (2007-01 - 2007-06)

Yuvaraj Bhosale, Lakshmi Rajgopal, Y.S. Nandanwar

Seth GS Medical College and KEM Hospital, Parel, Mumbai.


The defects that occur due to improper closure of the ventral abdominal wall form a spectrum ranging from the simple epispadias to the moderate ectopia vesicae to the complex association of exomphalos (omphalocoele) and exstrophy of cloaca. We present here a case which had Omphalocoele, Exstrophy of cloaca, Imperforate anus and Spinal defects – called as OEIS complex. We discuss the theories regarding the embryological basis of these defects and also present a review of literature pertaining to the varied clinical presentation of this complex.

Key Words: Exomphalos, Cloacal exstrophy, Kyphoscoliosis, Calcaneovalgus deformity

Case History:

A stillborn full-term foetus, born to a 21 years old mother, was referred to the department of Anatomy. The mother had had non-consanguineous marriage and had a normal male child as her firstborn. She did not have any antenatal history of drug intake or infection. Antenatal ultrasonography had revealed the fetus to have omphalocoele with polyhydramnious and kyphosis of lumbar spine. Birth weight of the foetus was 990 grams.

On external examination, the head circumference of the baby was 30 cm. The crown-rump length was 24 cm and the crown-heel length was 37 cm. The sex was indeterminate as the genital swellings were unfused and genital tubercle was split. The baby had brachycollis, kyphoscoliosis of lumbar spine, and bilateral congenital dislocation of the hips and bilateral calcaneovalgus deformity of the feet. There was imperforate anus with only a dimple seen in the perineum.

The ventral abdominal wall was found to be defective with the liver, stomach, spleen and loops of intestine lying outside and these were partially covered by a thin membrane (Fig. 1) suggesting omphalocoele. Just above the spit genital tubercle, there was a patch of cherry red mucosa showing two ureteric orifices and on squeezing the loop of intestine a speck of meconium was found to appear in the upper part of the mucosa between the ureteric orifices suggesting exstrophy of cloaca (Fig. 2). Further examination of the eviscerated organs revealed the liver to have an accessory lobe though the liver itself was found to be in the midline. The situs was normal because stomach and spleen were to the left of the liver. First part of the duodenum was atretic (Fig. 3). Rest of the small intestinal loops was not matted. Appendix was present and just distal to that a small stump of colon was present and beyond that the large intestine was absent. Kidneys and ureters were normal. Ureters could be traced upto the exposed cloacal mucosa. The gonads could not be traced and there were no Mullerian duct, uterus or fallopian tubes. The diaphragm was normal. On thoracotomy, the lungs and thymus were found to be normal. The heart showed ventricular septal defect of the membranous part, tricuspid atresia and absent trabeculae carneae of both the ventricles. The rest of the body including the upper limbs was normal.

Fig.1 Omphalocoele and Caloacaneovalgus deformity

Omphalocoele and Caloacaneovalgus deformity

Fig.2 Exstrophy of cloace

Exstrophy of cloace

Fig. 3 Duodenal Atresia

Duodenal Atresia


The complex occurrence of Omphalocoele, Exstrophy of cloaca, Imperforate anus and Spinal defects (OEIS Complex) has been documented as a group of closely associated anomalies and a clearly defined entity in a population study (Kallen K et al., 2000). The defects due to defective migration of mesoderm in the caudal part of the embryo span a spectrum from simple epispadias to complex exomphalos and exstrophy of cloaca. The incidence of OEIS complex has been reported to be 1 in 200,000 to 1 in 400,000 pregnancies and is not of clearly known aetiology (Smith NM et al., 1992). One of the causes put forth is a single localized defect in the early development of the mesoderm that later contributes to the formation of infraumbilical mesenchyme, cloacal septum and caudal vertebrae (Chen CP et al., 1997). Of the four components of OEIS complex, cloacal exstrophy, also known as vesicointestinal fissure or exstrophia splanchnica is the severest ventral abdominal wall defect. Exstrophy of cloaca was first described by Littre in 1709 and later by Meckel in 1812 (Gray SW and Skandalakis JE, 1972; Jeffs RD, 1994).

Embryological Basis:

There are different embryological explanations given for the occurrence of exstrophy of cloaca. According to Patten and Barry, caudal displacement of the paired primordia of the genital tubercle is the basic abnormality and it results in the persistence of the cloacal membrane cranial to the fused phallus. Disparity between the timing of the caudal displacement of the phallus and that of the rupture of the cloacal membrane results in varying degrees of exstrophy. Marshall and Muecke, however, believe that an overdeveloped cloacal membrane is the basic defect and this prevents the migration of the mesoderm between the ectodermal and endodermal layers. Rupture of this unduly large cloacal membrane before the descent of the urorectal septum results in the entire cloaca being exposed to the exterior (Gray SW and Skandalakis JE, 1972; Jeffs RD, 1994). Muecke proved this in chick embryo by inserting a silastic shield and called this as ‘wedge effect’. Because of the constant association of the diastasis of the pubic bones with these defects, some suggest (Beaudoin S et al., 1997) that failure of rotation of pelvic bone primordia results in failure of final closure of the ventral abdominal wall and formation of pubic symphysis resulting in varying degrees of exstrophy. Overall it appears that there is a basic defect in the gastrulation in the caudal part of the embryo which in turn affects the tail-folding of the embryo and this explains an oversized cloacal membrane, caudal displacement of phallus and defective urorectal septum formation, all of which lead to exstrophy of cloaca. Lack of mesoderm in the infraumbilical abdominal wall results in omphalocoele. Cloacal exstrophy precludes the development of proctodaeum and hence imperforate anus. Caudal dysgenesis affects somite formation in the caudal part of the embryo and results in vertebral defects. The teratogenic influence causing these must be occurring in the late 3rd and early 4th week of embryogenesis. A developmental field defect involving the intraembryonic mesoderm suggests a possible aetiologic role for homeobox genes such as HLXB9 with mutations. The sporadic occurrence of OEIS complex suggests that both environmental and genetic factors may be playing a role in the aetiology (Keppler-Noreuil KM, 2002).

Clinical Presentation

There have been many attempts to classify congenital abdominal wall defects. One classification notes four different types: Primary thoracoabdominoschisis, Omphalocoele, Body wall dysplasia and Secondary thoraco-abdominoschisis (Vermeii-Keers C et al., 1996). A classical presentation of cloacal exstrophy consists of an omphalocoele superiorly with an open plate of mucosa inferiorly consisting of two posterior walls of hemibladder on either side with a central strip of intestinal epithelium. In the central plate, sometimes the small bowel may prolapse producing the so-called elephant trunk deformity. Sometimes the appendiceal orifices may be duplicated and present in the central strip. In our case, there was a superiorly placed omphalocoele, below which was a cherry-red mucosal patch showing two ureteric orifices. Between the ureteric orifices, a speck of meconium appeared on squeezing the intestine.

Male genitalia are usually represented as bifid penis on widely separated pubic bones. In female fetuses, the Mullerian duct orifices may be exstrophied below the bladder mucosa and duplicate vagina and bifid clitoris may be present (Ziegler MM et al., 1986). In our case, there was ambiguous genitalia with diphallia and the gonads could not be traced. However, a Leishman’s stain of the peripheral blood of this foetus revealed no Barr body thereby identifying the genetic sex as male.

Rarely, the abdominal viscera including liver, stomach, spleen, pancreas, intestine etc. may be present in an extraembryonic sac directly attached to the placenta without an umbilical cord. Referred to as “Body Stalk anomaly” (Giacoia GP, 1992) or as “Dysplasia Umbilicofoetalis” (Ullrich K and Bohm N, 1977), it is caused very early in embryonic life i.e. at 7 mm stage corresponding to the end of 3rd week of gestation.

The congenital vertebral malformations associated with cloacal exstrophy vary from congenital scoliosis, kyphosis, abnormal lumbosacral segmentation, sacral agenesis, interpedicular lumbar widening (Loder RT and Dayioglu MM, 1990) to hemivertebra, spina bifida occulta and myelomeningocoele (Schober JM et al., 2002). The limb anomalies may vary from talipes equinovarus, calcaneovalgus (rocker-bottom feet) to congenital hip dislocations (Schober JM et al., 2002; Langer JC et al., 1992). In our case, the limb and vertebral anomalies seen were bilateral calcaneovalgus deformity of the feet, bilateral congenital hip dislocation, kyphoscoliosis and brachycollis.

There are reports of OEIS complex occurring in association with Oculo-Auriculo-Vertebral (OAV) sequence comprising of hydrocephalus, hypertelorism and microotia (Haldar A et al., 1994). Cardiac defects in association with OEIS complex are reported to be very rare (Kant SG et al., 1997) but in our case there were ventricular septal defect and tricuspid atresia.


Even though this complex entity was once thought to be hopeless, this is no longer the case. Prompt prenatal diagnosis with appropriate surgery for bladder (Mitrofanoff operation) and bowel reconstruction (Lund DP and Hendren WH, 2001) and proper assignment of gender would see these children have a good quality of life.


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