Urologic Considerations in the Separation of Thoracoomphalopagus Conjoined Twins

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.

Hepatic separation of conjoined twins: Operative technique and review of three-dimensional model utilization

BACKGROUND

The separation of conjoined twins is a challenging and rare operation. Recent technological advances in imaging and three-dimensional printing (3DP) have allowed for enhancements in preoperative surgical planning and intraoperative anatomical orientation for complex operations. This report aims to consolidate the current clinical evidence utilizing 3DP models as an effective tool for surgical planning of conjoined twin separation and to detail our surgical approach for complex hepatic separation and management.

METHODS

A literature review was conducted for conjoined twin separations with preoperative use of 3D models including age at attempted separation, operative outcome, 3D modality, and postoperative course between 1998 and 2020. We also conducted a chart review of our electronic medical record for conjoined twin separations between January 2015 and December 2019.

RESULTS

We report two cases of conjoined twin separation with preoperative use of 3DP models from our institution: one set in the thoracoomphaloischiopagus orientation and the other set in the thoracoomphalopagus orientation with the presence of intrahepatic vascular anomalies. The literature review produced 10 case reports of conjoined twin separation with use preoperative 3D models accounting for 17 individual separation procedures. We summarize our preoperative radiological planning, the evidence of 3DP models as an educational and preoperative tool, ideal timing for separation, and our surgical approach for complex hepatic separation.

CONCLUSIONS

Conjoined twin separation requires a multidisciplinary effort to address the multisystem surgical and medical needs of these patients. These complex patients require extensive preoperative imaging for planning separation, and we strongly recommend utilizing 3D printed models when possible for better surgeon understanding of complex variable anatomy. We have found numerous reports of successful conjoined twin separation using 3DP technology in preoperative planning. The use of three-dimensional printed models for preoperative assessments is an invaluable tool and is rapidly improving in fidelity.

TYPE OF STUDY

Operative technique and case series.

LEVEL OF EVIDENCE

Level IV.

Prenatal and postnatal radiologic evaluation of conjoined twins

Imaging of conjoined twins requires the use of multiple modalities, in both the prenatal and postnatal setting. Prenatal imaging, including both ultrasound and magnetic resonance imaging, benefits from an organized, worksheet-based approach, careful labelling of all images, and adoption of supplemental techniques. Postnatal imaging should be informed by the prenatal imaging findings and should be thoughtfully planned prior to performance. Complete evaluation prior to planned surgical separation will require the use of complementary modalities and multidisciplinary review and discussion.