An attempt to separate xiphopagus twins sharing a common heart, liver, and duodenum

Conjoined thoracopagus twins: A systematic review of the anomalies and outcome of surgical separation

Introduction

Conjoined twin is an extremely rare condition and requires a thorough knowledge of anatomy, and a multidisciplinary approach is essential to successfully separate the twins. Thoracopagus twins lie face to face and are attached from chest to upper abdomen. They are the most common among all the varieties but have a poor survival rate.

Materials and Methods

This study is a review of literature from 2019 to the oldest via PubMed and Google Scholar using keywords: Conjoined twins, Thoracopagus twins, Thoracoomphalopagus and Thoraco-omphalopagus twins. The articles were reviewed for the description of the anatomy of shared organs, management and outcome of these twins.

Results

One hundred and fifty-eight sets of thoracopagus and thoraco-omphalopagus twins including our twins were included in this study. Out of 158 reported thoracopagus twin sets in literature, with M: F ratio of 1:2.3, 71 sets were found to be non-operable and all of them subsequently expired; 82 sets were operated upon, out of which 83 babies survived, suggesting an overall surgical success rate of about 50%.

Conclusion

Thoracopagus twins have a dismal prognosis. The most important decisive parameter for successful separation is the extent of sharing of organs between twins. The role of a motivated multidisciplinary team is also indispensable and cannot be overemphasised.

The Outcomes of Surgical Separation in Thoracopagus Twins with Conjoined Hearts: An Analysis of the Literature

We sought to perform a comprehensive review of reported cases of conjoined thoracopagus twins with cardiovascular conjunction to determine the overall survival after separation and factors that might be associated with survival. We performed a systematic review of cases of thoracopagus twins with conjoined cardiovascular systems reported in the English medical literature using Embase, PubMed, Web of Science, and Scopus. We employed standard statistical methods to analyze differences among groups. We identified 102 unique cases of thoracopagus twins (69% female) with some degree of cardiovascular conjunction who had undergone surgical separation. We identified 6 distinct types of cardiovascular union. Median age was 47 days (IQR 12, 120). Survival to at least hospital discharge occurred in 51% (105/204). Median age at separation was lower in emergent (9 days, IQR 1, 25) versus elective cases (93 days, IQR 49, 180) (p < 0.0001). Survival to hospital discharge was higher in those who underwent elective separation (70%, 93/132 total children versus 17%, 12/72) (p < 0.0001). Survival was associated with the type of cardiovascular union (p < 0.0001). The separation of thoracopagus twins with cardiovascular conjunction is higher than expected. Increased survival is associated with elective separation, older age, and shared pericardium only. These findings suggest survival could be improved with better delineation of degree of union and delayed separation.

Congenital heart defects in conjoined twins: outcome after surgical separation of thoracopagus

In this study, we correlated cardiac malformations in the various types of conjoined twins with the proposed site of embryologic union and evaluated the possibility of survival after surgical separation. We conclude that surgical separation is only very rarely successful in twins with united hearts, whereas survival in twins with separate hearts is more dependent on the malformations of other viscera. This report deals primarily with conjoined twins in whom anomalies of the heart are the major factor in deciding whether surgical separation is feasible.

Biliary tract anomalies in thoraco-omphalopagus conjoined twins

Thoraco-omphalopagus conjoined twins were separated urgently on the ninth day of life because of bowel obstruction and impending intestinal perforation. Preoperative studies clarified the cardiac, intestinal, and hepatic parenchymal anomalies, but the precise biliary anatomy remained obscure. Operative cholangiogram through the single gallbladder visualized only the extrahepatic biliary anatomy in twin A. At reoperation for abdominal patch removal, exploration in twin A found biliary atresia. Because of the unusual duodenal anatomy and extreme short bowel, the authors elected to treat the biliary atresia in twin A with an appendix portoenterostomy. Twin B had no gallbladder and a profoundly hypoplastic biliary tree. Both twins have normal bilirubin and liver function at 18 months of age. The anatomic details of 8 additional cases of complex biliary tract anomalies in thoraco-omphalopagus conjoined twins are reviewed. In all cases, the complex biliary anatomy has been associated with conjoined duodenum. In most cases the preoperative technetium 99m HIDA scan has been inconclusive or misleading.

Anatomical study of five prenataly diagnosed sternopagus twins

Among conjoined twins (1 out 50000 births), thoracopagus occurs most frequently and is generally lethal. Our anatomical study of five sets of sternopagus twins (3 female, 2 male) was performed to determine the ability of prenatal sonography to detect these anomalies. Autopsy in four cases revealed identical malformations: common sternum, single malformed heart, joined hepatic parenchyma, and a common small bowel leading to a cystic dilatation situated on the ileal segment at the end of the superior mesenteric artery. The diagnosis of conjoined twins was made in all cases by prenatal sonography at the mean time of 24.6 gestation weeks (range 19-34). The malformations detected by prenatal sonography were a single cardiac mass (all cases), joined hepatic parenchymas (3 cases), and an ileal cystic dilatation (1 case). Pregnancy was terminated in four cases. In one case cesarean delivery was performed, and the infants died 48 hours later. Prenatal sonography currently seems to be the best examination for diagnosis of sternopagus twins and the detection of lethal malformations thus allowing interruption of pregnancy.

Successful separation of a conjoined biliary tract in a set of omphalopagus twins

Omphalopagus twins were separated in the first 48 hours of life. Preoperative evaluation did not disclose either their conjoined intestines or their conjoined biliary tract; intraoperative evaluation, including an operative cholangiogram, was required to determine if separation was possible. The intestines were divided to give each infant an equal share, and an hepaticoenterostomy was constructed in each of the twins.

Management of xiphopagus conjoined twins with small bowel obstruction

A set of xiphopagus conjoined twins with prematurity, exomphalos, and intestinal obstruction was separated successfully. Preoperative evaluation included computerised axial tomography, 99mTc-HIDA scan, and barium enema. Major hepatobiliary and gastrointestinal anomalies were encountered. One twin is alive and well today. The other twin died one week postoperatively from sepsis. Postmortem studies showed she had a severe cardiac anomaly incompatible with normal life.