Emergency separation of conjoined twins

Emergency Separation of Extreme VLBW Omphalopagus Twins: Case Report

The classification of conjoint twins is based according to the site of attachment. The challenges in management of such anomalies span the entire continuum of care from delivery to resuscitation to separation and finally discharge. Scheduled separation is ideal, occasionally the caring team is faced with no option but to perform an emergent separation. Omphalopagus is a type of conjoined twinning characterized by union of the peritoneal cavities through an infraumbilical abdominal wall defect. In this report we describe our experience with a successful emergency separation of extremely preterm omphalopagus twins.

This is the first case of conjoint twins in Kuwait, we highlight the challenges faced, stressing the importance of adhering to antenatal care as well as management by a multidisciplinary team.

Conjoined twins: Pre-birth management, changes to NRP, and transport

The management of conjoined twins is complex and requires careful preparation. Pre-birth management includes prenatal counseling, which is important due to the overall poor prognosis. In instances of trial of life, the delivery must be tailored to address the anticipated anatomy based on prenatal imaging and anticipated physiology. A multidisciplinary team is essential to anticipate and address the ergonomic challenges and medical issues related to organ fusion, cross-circulation and associated anomalies. There are several suggested modifications to the current Neonatal Resuscitation Program algorithm including modifications to initial assessment, airway management, administration of chest compressions, obtaining emergency access, and medication dosing. Simulation is essential to address challenges, practice Neonatal Resuscitation Program modifications, delineate clear roles during delivery and practice communication. This paper offers a discussion of unique issues associated with delivery of conjoined twins and recommendations on how to approach these challenges based on our experience and available literature.

Minimally Conjoined Omphalopagus Twins with a Body Stalk Anomaly

Introduction This report will discuss a case of minimally conjoined omphalopagus twins (MCOTs) with a body stalk anomaly (BSA). Case Report We experienced monochorionic diamniotic (MD) twins born at 31 weeks. One infant was suspicious of BSA before birth, and another infant was normal. But normal infant had anal atresia with small intestine which was inserted behind the umbilicus. Twins had very short common umbilicus and infant with BSA had intestinal conjunction, two appendixes at the site of the colon, and a blind-ending colon. We diagnosed MCOTs. Discussion On the basis of the Spencer hypothesis, the etiology of MCOTs was that MD twins shared a yolk sac. However, this could not explain the presence of a BSA. It is necessary to consider the possible reasons for a singleton BSA. In addition, intestinal fusion occurred unequally in this case, although two appendixes were found in the same place, which might have occurred because of the balanced fusion.

Familial recurrence of gastroschisis: literature review and data from the population-based birth registry "Mainz Model"

BACKGROUND

Familial forms of gastroschisis are considered rare. A search for these forms in a population-based birth registry in 1993 found a recurrence risk of 3.5% among first-degree relatives. Since then, similar investigations in population-based registries have led to contradictory results.

METHODS

A search of the population-based birth registry "Mainz Model" for familial cases of gastroschisis and a systematic review of the literature were performed.

RESULTS

The Mainz Model database yielded 1 familial recurrence out of 27 gastroschisis cases. From the literature, 37 affected families could be retrieved. Among 412 gastroschises from population-based registries, 10 familial recurrences have been found. These translate into a recurrence risk of 2.4%, with a strong tendency toward underestimation.

CONCLUSION

The existing data support the hypothesis that familial recurrence of gastroschisis is much more likely than previously thought.

Development of gastroschisis: review of hypotheses, a novel hypothesis, and implications for research

Gastroschisis, a ventral body wall defect, is a continuing challenge and concern to researchers, clinicians, and epidemiologists seeking to identify its cause(s) and pathogenesis. Concern has been renewed in recent years because, unlike most other birth defects, rates of gastroschisis are reportedly increasing in many developed and developing countries. No tenable explanation or specific causes have been identified for this trend. Rates of gastroschisis are particularly high among pregnancies of very young women. Such an intriguing association, not observed to this degree with other birth defects, may afford clues to the defect's cause. Understanding the causes of gastroschisis may provide insight to the defect's origin. In pursuing such causal studies, it would be helpful to understand the embryogenesis of gastroschisis. To date, four main embryologic hypotheses have been proposed: (1) Failure of mesoderm to form in the body wall; (2) Rupture of the amnion around the umbilical ring with subsequent herniation of bowel; (3) Abnormal involution of the right umbilical vein leading to weakening of the body wall and gut herniation; and (4) Disruption of the right vitelline (yolk sac) artery with subsequent body wall damage and gut herniation. Although based on embryological phenomena, these hypotheses do not provide an adequate explanation for how gastroschisis would occur. Therefore, we propose an alternative hypothesis, based on well described embryonic events. Specifically, we propose that abnormal folding of the body wall results in a ventral body wall defect through which the gut herniates, leading to the clinical presentation of gastroschisis. This hypothesis potentially explains the origin of gastroschisis as well as that of other developmental defects of the ventral wall.

Diamniotic conjoined fetuses in a triplet pregnancy: an insight into embryonic topology

We present a case of triplets, 2 of whom were monochorionic diamniotic conjoined fetuses, and the other triplet was in a separate chorion. The pregnancy followed in vitro fertilization with 2 embryo transfers and the conjoined fetuses developed from a single embryo. An early ultrasound showed 2 embryos attached to 1 yolk sac. Further monitoring of the pregnancy showed these 2 triplets to be diamniotic with a short umbilical cord/body stalk anomaly. After fetal loss a postmortem examination demonstrated that these fetuses were conjoined with a body stalk anomaly/short umbilical cord syndrome with fusion of the coelomic cavities and small bowel (minimally united/conjoined twins). There were dividing amniotic membranes. This case demonstrates the development of an unusual type of conjoined twin with characteristic features. Conjoined fetuses with this pattern have fused small bowel and cloacal anomalies and often diamniotic placentation, when this is recorded. Various terms including minimally united/conjoined omphalopagus/ischiopagus have been used for this characteristic pattern, but this pattern may warrant a specific term. "Diamniotic vitellopagus" may best reflect the pathogenesis of this pattern.

Association of cloacal anomalies, caudal duplication, and twinning

Cloacal anomalies exhibit a wide variety of morphologic types and accompanying clinical severity. The association of malformations of the cloaca with partial, complete, or conjoined twinning has been appreciated for some time, but, with the advent of prenatal ultrasound technology, appears to occur with a greater frequency than once thought. This observation has important implications for pathogenesis. We present 2 representative cases, a 19-week-old female fetus with duplication of several caudal structures and a 21-week-old male fetus with cloacal exstrophy variant and demised co-twin with lower abdominal wall defect, extruded intestinal tract, absent external genitalia, and imperforate anus. These findings and previously published theories suggest that certain models of monozygotic twinning may apply to the pathogenesis of cloacal anomalies. Specifically, the partial or complete duplication of the organizing center within a single embryonic disc may increase the risk of mesodermal insufficiency and thus account for the failure of complete development of the cloacal membrane and consequent exstrophy or other aberration.

Necrotizing enterocolitis in omphalopagus conjoined twins

Female omphalopagus twins underwent laparotomy on the second day of life after an antenatally diagnosed high jejunal bowel obstruction. Bowel resection and choldocho-enterostomies were performed. Despite recovery from laparotomy, the development of severe necrotizing enterocolitis (NEC) in one twin led to rapid deterioration and the death of both infants on day 34. The elucidation of the combined biliary tree, the dilemma of NEC in conjoined twins, and the possibilities of emergency separation are discussed. Consideration should be given to emergency separation of conjoined twins in the event of potentially lethal complications.

Minimally united ischiopagus twins: infraumbilical union with cloacal anomalies

In researching the embryology and pathological anatomy of conjoined twins, more than 1,200 cases were reviewed from the literature of the past 100 years; a few additional cases were obtained by personal communications. One hundred twenty-eight were classified as ischiopagus, the typical cases having union in the perineum, the pelvis, and the lower abdominal wall. Eighteen atypical ischiopagus cases, however, were conjoined only in the infraumbilical abdominal wall, none with union in the perineum or the bony pelvis but all with anomalies of the cloaca. Twelve infants survived surgery in nine of the ten cases separated since 1964. The malformations of the cloaca were not immediately life-threatening, but the death of one twin or an associated gastroschisis or ruptured omphalocele in some cases required prompt attention. The invariable involvement of the urachus and/or bladder and the shared distal ileum and colon led to the conclusion that the anomalies in these twins arose from union of the allantois and the caudal portion of the yolk sac.

[Conjoined omphalopagous twins separated at fifteen days of age]

BACKGROUND

Conjoined (siamese) twins represent a rare situation which may occur in 1 of every 50,000 births. A prenatal diagnosis usually leads to stopping pregnancy. We report a case with successful surgical separation at the age of 15 days.

CASE REPORT

Ultrasonographic examination at 20 weeks of gestation showed omphalopagus siamese joined at the abdomen from the xiphoid process to the umbilicus. Conjoined structures included liver. There was a multicystic right kidney in one twin, without other malformation. Karyotype was normal, 46XX. The mother refused interruption of her pregnancy. Both girls were born by cesarean section. Angiography, magnetic resonance imaging and intravenous urography confirmed the ultrasound examination. There was no cross circulation into the liver and the gastrointestinal tract was not conjoined. The twins were separated at 15 days of age with right heminephrectomy of the multicystic kidney. The girls are now 16 months old and are in very good health.

CONCLUSION

Prognosis of siamese twins depends on the nature of joined structures and presence of malformations. Ultrasonographic examination during pregnancy shows the possibility of surgical separation, which is performed by a double anesthetic and surgical pediatric team. Preoperative investigations must include MRI.

Minimally conjoined omphalopagi: a consistent spectrum of anomalies

Omphalapagus twins constitute less than one third of all siamese twins. Most omphalopagi are attached by a skin bridge that often contains hepatic tissue. Only four cases of omphalopagi attached by an intestinal bridge have been reported. The authors present two additional cases of conjoined twins minimally attached by a small bowel and bladder bridge. In both instances, the spectrum of anomalies included a ruptured omphalocele and imperforate anus with cloacal anomalies. The attachment consisted of an open urachal remnant joining the two bladders, and the short small bowel of twin A attached to the terminal ileum of twin B. Separation was uneventful. For one set of twins, the case part of the proximal colon of twin B was used to lengthen the bowel of twin A. Three of the twins survived and underwent additional procedures for repair of the cloacal anomalies. All four previously reported cases of minimally conjoined omphalopagi presented with a remarkably similar spectrum of anomalies. All had ruptured omphaloceles, imperforate anus with cloacal anomalies, and urachal anomalies. Intestinal connection was consistently at a point corresponding to the Meckel diverticulum site of twin B, with blood supply to the small bowel of twin A, probably via the vitelline artery. The consistent spectrum of anomalies encountered with minimally conjoined omphalopagi allows planning of separation. Caution is required to avoid overlooking the patent urachus, and intestinal lengthening procedures based on the vitelline artery become an important consideration.

Monozygotic twins discordant for gastroschisis: case report and review of the literature of twins and familial occurrence of gastroschisis

We describe a pair of monozygotic (MZ) female twins discordant for gastrochisis. To our knowledge, this is the first such case reported. The zygosity was verified by DNA analysis using highly polymorphic microsatellites. There was no family history of gastroschisis. During pregnancy there was no suspicion of any exposure responsible for the malformation. The number of twin cases described so far does not allow any conclusion as to hereditary factors in the cause of gastroschisis, but the number of families reported with familial gastroschisis suggests that the recurrence risk is higher than previously thought.

Anatomic basis of pathology of the urachus

The urachus, derived partly from the allantoic canal, tethers the apex of the bladder to the umbilical ring. This vestigial structure, though constant in man, is formed by a whole series of embryologic mechanisms which are still controversial. Total or partial persistence of the lumen of the urachal canal, when sufficiently extensive, becomes manifested by characteristic clinical features. Moreover, it is frequently associated with malformational urogenital involvement, which must be routinely sought. The sole form of treatment consists of total surgical excision of the urachus.