Surgical experience with thirteen conjoined twins

Postnatal imaging of conjoined twins: a customized multimodality approach

Medical imaging plays a crucial role in the management of conjoined twins. The role of imaging is to explore the anatomy, outline the shared organs and determine whether surgery is feasible. It also serves as a roadmap for successful separation. Additionally, imaging helps with counseling parents about prognosis. This review aims to illustrate recent advances in different imaging modalities and their role in the management of the various types of conjoined twins with an emphasis on relevant tips for optimal imaging.

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.

Emergency separation of conjoined twins in a tertiary hospital in Indonesia: three case reports

BACKGROUND

Emergency separation of conjoined twins is performed when one twin is already dead or dying and threatens the survival of the other. The particular decision to perform an emergency separation of conjoined twins provides an ethical dilemma that needs special attention. Adding to the complexity of surgical and postsurgical management in emergency separation, ethical and sociocultural aspects further complicate decision-making.

CASE PRESENTATION

From 1987 to 2022, 18 conjoined twin separations were performed in our centre. This paper describes three conjoined twin emergency separations. In the first case of thoracoomphalopagus babies at nine days of age, one baby was diagnosed with necrotizing enterocolitis with frequent desaturation and seizures, and the other baby was healthy. Emergency separation was performed on the twelfth day of age; unfortunately, neither baby survived the surgery. In the second case, emergency separation was performed on the 110th day of life due to sepsis in one baby. The nonseptic twin passed away six hours after surgery, while the septic twin died 12 days after surgery due to wound dehiscence and abdominal sepsis. The third case was of an omphalopagus conjoined twin with a parasitic twin. The healthy baby was deemed nonviable but found to be healthy upon birth. Immediate emergency separation was performed at 2 h of age. The living baby survived the surgery but passed away two months later.

CONCLUSIONS

When separation is deemed necessary to save one twin, it becomes difficult to apply standard ethical medical reasoning. The decision to separate results in most cases in very high-risk surgeries with poor outcomes during surgery and postsurgery. Compounded by the complexity of the case, sociocultural and religious aspects further add to the dynamics of decision-making. A multidisciplinary team must work together with a health ethics committee and navigate through this ethical conundrum with the patient and family at its decision-making centre to decide on the best plan of care.

Conjoined Twins in Guinea Pigs: A Case Report

Simple Summary

Cases of newborn connected twins, so-called Siamese twins, are well known in humans, laboratory mammals, domestic and wild birds, reptiles, amphibians and fish. This report describes a unique case of newborn conjoined twins in guinea pigs (Cavia aperea f. porcellus). Connected twins in guinea pigs have been very rare, and there are only a few previous reported cases. This report is only the fourth described case of the birth of conjoined guinea pigs. They were born in breeding in the Czech Republic in 2020. The conjoined twins were males connected in the upper body by a cephalopagus-type connection, which has occurred in all three previous reports. The skeletons of both the bodies were connected by a broad shared skull and sternum. Both of the fused bodies had their own hearts and livers, but the lungs were mutual. The issue of this anomaly has not yet been clearly explained.

Abstract

The report describes a unique case of newborn conjoined twins in guinea pigs (Cavia aperea f. porcellus). Connected twins in guinea pigs have been very rare, and there are only a few previous reported cases. The newborns were stillborn in breeding in the Czech Republic in 2020 as two bodies conjoined into one. The external and internal structure of the body and the type of connection of both of the bodies are described. The weights of selected internal organs of the twins are compared with those of normally developed newborn guinea pigs.

Conjoined Twin Separation: Review of 30-Year Case Experience and Lessons Learned

BACKGROUND

Conjoined twinning is a rare medical phenomenon, and numerous challenges remain with respect to surgical separation and reconstruction. The purpose of this study is to present a detailed discussion of the authors' institutional experience with eight conjoined twin separations over the past three decades, focusing on challenges and lessons gleaned from these cases.

METHODS

The records of all patients who underwent conjoined twin separation at The Hospital for Sick Children in Toronto, Ontario, Canada, from 1984 to 2018 were retrospectively reviewed.

RESULTS

Eight sets of conjoined twins were analyzed. Half of the sets [ n = 4 (50 percent)] were female. There were four sets (50 percent) of ischiopagus twins, three sets (37.5 percent) of omphalopagus twins, and one set (12.5 percent) of craniopagus twins. The median age at separation was 6.75 months. The mean durations of intensive care unit and hospital stay were 14.1 ± 12.9 days and 4.9 ± 4.8 months, respectively. Mean length of follow-up was 6.7 ± 4.4 years. Three deaths occurred in our series, with an overall survival rate of 81 percent. Two sets of twins experienced expander-related complications such as infection and bowel perforation. Three twins required reoperation because of flap necrosis or dehiscence after separation.

CONCLUSIONS

The authors' results highlight the unique nature of each operation and the great ingenuity required in managing the particular considerations of each case and also adhering to a systematic approach of evaluation and planning. A number of novel strategies were used at the authors' center and have now become commonplace. The lessons learned from such procedures may improve care for future generations of patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Ventrally Fused Conjoined Twins (Omphaloischiopagus): A Roadmap to Successful Separation

Conjoined twining is one of the most fascinating and challenging situations which a pediatric surgeon may face in his career. Only few surgeons may have the opportunity to share in separation of such cases. In this report, we aim to share our experience with the successful separation of ventrally fused male conjoined twins (omphaloischiopagus). The case was thoroughly studied via preoperative cross-sectional imaging modalities (magnetic resonance imaging [MRI] and computed tomography [CT] angiography), complemented by data obtained from reviewing similar cases in the literature. A clear delineation of the complex anatomy was achieved preoperatively which proved to be well consistent with the operative findings. A detailed description of the operative procedure to divide/redistribute the shared abdominal/pelvic organs between both twins is provided. To the best of our knowledge, this is the first report to describe the detailed and unique internal anatomy of a common central phallus associating ischiopagus conjoined twins. The penis was centrally located in the perineum in between both twins with an open urethral plate. This common phallus had a peculiar configuration with four crura anchoring ischial bones of both twins together.

Conjoined Thoracopagus Twins - Our Experience of Successful Separation

Conjoined twin is an extremely rare condition and needs a thorough knowledge of anatomy and a multidisciplinary approach is essential to successfully separate, the twins. Thoracopagus are the twins attached by chest and umbilicus and are the commonest among all the varieties but carries a poor survival rate. We describe our approach and experience of management of thoracopagus twins who were separated at eighty-three day of life and are alive and well after 4 years of follow up. The most important decisive parameter for successful separation is the extent of sharing of organs between twins but the role of a motivated multidisciplinary team is also indispensable.

A case report describing the successful separation of ischiopagus tetrapus conjoined twins in Vietnam

Ischiopagus conjoined twinning is a rare congenital defect. The surgical separation of conjoined twins is difficult because of the complex anatomy and physiology. Careful preoperative assessment, planning, and effective surgical teams are critically important for achieving a good outcome. We describe the successful separation of ischiopagus tetrapus conjoined twins as a representative case demonstrating the growth of pediatric surgery in southern Vietnam.

Use of local perforator flaps for closure of a thoraco-omphalopagus conjoined twin defect after separation during the COVID-19 pandemic

Introduction

Conjoined twins are a rare medical phenomenon that poses unique challenges for surgeons. Separation of conjoined twins involves multidisciplinary teamwork, complex medical management and surgical planning, and multi-stage operations and often still has a high mortality and morbidity rate. In the times of the COVID-19 pandemic, separation of conjoined twins pose even greater challenges. Aiming for the best outcome possible, while minimizing the risk of COVID transmission and ensuring the safety of the personnel, is paramount. This case report presents thoraco-omphalopagus twins who were successfully separated at 4 months of age. The preoperative planning, operative details, postoperative follow-ups, and outcomes are discussed.

Methods

The absence of a tissue expander and the inability to acquire it due to travel restrictions from COVID-19 further complicated the management on this patient. A Routine Polymerase Chain Reaction (PCR) swab test was performed on the patients and personnel. Standardized personnel protective equipment (PPE) was worn during ward and surgical care. After separation of the twins by cardiothoracic and pediatric surgeons, one twin underwent immediate skin closure using a double keystone perforator island flap and a lower abdominal perforator flap. Due to extensive defects, closure was delayed for the second twin. After a series of dressing changes, eventually local perforator flaps could be raised to close the defect using staged tension sutures and skin grafts for secondary defects.

Results

Both twins were discharged with no significant morbidity, and no personnel were exposed to COVID-19 infection during the management.

Conclusion

Preoperative coordination and planning, multidisciplinary effort, adherence to screening protocols for COVID, and strict use of standardized PPE all contributed to the successful separation of thoraco-omphalopagus conjoined twins during the COVID-19 pandemic.

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.

Airway management protocol for conjoined twins delivery

OBJECTIVE

Conjoined twin deliveries require collaborative preparation by multiple specialties for successful airway management. Literature regarding neonatal airway management after conjoined twin delivery is limited to case reports. We present a case series of conjoined twins and introduce an airway management protocol for conjoined twin delivery.

METHODS

The medical records of conjoined twins and their mothers at a tertiary care center were reviewed from April 2016 to December 2018. The NCBI database was queried for literature regarding preparation for neonatal airway management after conjoined twins delivery.

RESULTS

Five sets of conjoined twins were delivered. Of 10 neonates, all required bag valve mask ventilation. Other airway interventions included continuous positive airway pressure (7), endotracheal intubation (6), and direct laryngoscopy with telescopic video evaluation (1). No patients required ex-utero intrapartum treatment or emergent tracheostomy. A protocol for airway management is described and special considerations are discussed, including anatomic variations, equipment list, operating room staffing and layout, multidisciplinary prenatal conference, and airway imaging review.

CONCLUSION

Conjoined twin deliveries have significant implications for the otolaryngologist and require multidisciplinary collaboration. An airway management protocol allows for a standardized process to secure the neonatal airway and optimize patient outcomes.

Epigastric heteropagus and omphalocele

We report a case of epigastric heteropagus twins with omphalocele. The parasite had two lower limbs, genitalia with developed phallus and scrotum but absent testis and absent anus. An omphalocele was present just below the attachment of the parasitic twin. No kidney or ureter but only a bladder filled with urine seen during exploration. The parasite bowel was attached to an omphalocele sac prolapsing through it and there was connection to the autosite liver, which forms the main source of its blood supply. Surgery was performed in the neonatal period (Day 12 after birth) for both excision of epigastric heteropagus and omphalocele repair.

Preoperative Evaluation of Craniopagus Twins: Anatomy, Imaging Techniques, and Surgical Management

Craniopagus twins are a rare congenital malformation in which twins are conjoined at the head. Although there is high prenatal and postnatal mortality for craniopagus twins, successful separation has become more common due to advances in neuroimaging, neuroanesthesia, and neurosurgical techniques. Joined brain tissue, shared arteries and veins, and defects in the skull and dura make surgery technically challenging, and neuroimaging plays an important role in preoperative planning. Drawing on our experience from consultation for multiple successful separations of craniopagus twins, we discuss what radiologists need to know about the anatomy, classification, imaging techniques, and surgical management of craniopagus twins.

Successful Surgical Separation of Thoraco-Omphalopagus Symmetrical Conjoined Twins in Iran: Two Case Reports

Conjoined twins are derived from the division of a single fertilized ovum; a phenomenon accompanied with multiple congenital anomalies. Such twins are identical, of the same sex, and more likely to be female. Most twins die during the embryonic period, and only 18% survive longer than 24 hours. There are complex anomalies in thoraco-omphalopagus twins that makes them unlikely to live long enough to undergo separation. Treatment of this uncommon condition presents both surgical and anesthetic challenges. The management of rare anomalies is difficult even for skilled surgeons. Therefore, it is logical to use the knowledge gained from previous experiences. We herein present the first successful surgical separation of two pairs of thoraco-omphalopagus conjoined twins at the Pediatric Surgery Center of Namazi Hospital (Shiraz, Iran). In both cases, the neonates had separate hearts and common pericardium. Contrast-enhanced computed tomography of two sets of twins showed fusion of sternum, pericardium, diaphragm, and left lobe of liver. Critical steps of the surgical separation were identified and contingency plans were made for possible partial liver donation and cross-circulation between twins. The separation procedure and reconstruction of the abdominal wall were successfully performed. Both pairs of twins, now 6- and 8-year-old, are healthy and have normal growth and are under follow-up.

Our experience with anesthetic management of conjoined twins' separation surgery

Conjoined twins are one of the most fascinating human malformations. Here, we report the anesthetic management and challenges faced in performing the successful separation surgery of 4-day-old thoraco-omphalopagus conjoined twins, born at term to a multigravida by elective caesarean section weighing 3.5 kg with APGAR score of more than 7. Computerized tomography scan revealed fused anterior surface of the left lobe of liver with common left portal vein. Confirmation of cross-circulation between the twins was done by giving intravenous midazolam to one of the conjoined twins, but no effect seen in the other one. We highlighted the responsibility of anesthesia team in anesthetizing sequentially the two patients who are joined together, technical difficulty of intubating the twins facing each other, need of careful monitoring, anticipation of complications such as massive blood loss, hemodynamic instability, desaturation, and hypothermia, and preparedness for their management and vigilant postoperative care.

The growth of pediatric neurosurgery in southern Vietnam and the first separation of pygopagus twins: case report

Conjoined twins are a rare congenital abnormality with an estimated incidence of 1:50,000 pregnancies and 1:200,000 live births. Pygopagus twins are characterized by sacrococcygeal fusion that is commonly associated with perineal and spinal abnormalities. Management of this complex disease requires a well-developed surgical system with multidisciplinary capacity and expertise.A decade ago there were no dedicated pediatric neurosurgeons in southern Vietnam. This has changed within a few short years; there are now 10 dedicated pediatric neurosurgeons with continually expanding technical capacity. In August 2017 a multidisciplinary surgical and anesthetic team successfully separated female pygopagus twins with fused sacrum and spinal cord with associated myelomeningocele defect.The authors present here the first successful separation of pygopagus twins in Vietnam as a representative case of gradual and sustainable pediatric neurosurgical scale-up.

Body Wall Reconstruction for Conjoined Twins: Our Experience and Lessons Learned

BACKGROUND

Conjoined twinning is a rare congenital malformation, and the resultant huge body wall defects after separation of conjoined twins represent a real challenge to surgeons.

METHODS

From 2004 to 2009, authors performed body wall reconstruction for 2 pairs of thoraco-omphalopagus twins and 1 pair of ischiopagus tetrapus twins. Before separation, the techniques of tissue expansion and tractive training were adopted to acquire sufficient skin for final coverage. After separation, the defects of thoracic cage and abdominal myofascial system were repaired with synthetic materials. The closure of the wounds was performed with artificial skin temporarily or by the use of local flaps in 1 stage.

RESULTS

The first pair of thoraco-omphalopagus twins died of circulatory and respiratory failure after emergency surgery, and the other 2 pairs of conjoined twins survived. The second pair of thoraco-omphalopagus twins had wound dehiscence and partial flap necrosis after surgery. The expanded polytetrafluoroethylene mesh in 1 sister of the ischiopagus twins was removed because of local infection 4 years after surgery.

CONCLUSIONS

Compressive anatomical understandings and advanced skills in plastic surgery are required for body wall reconstruction in the separation of conjoined twins. In addition, the multidisciplinary team approach has an important role for obtaining satisfactory final surgical outcome.

Symmetric and ventrally conjoined twins: prenatal evaluation by ultrasound and magnetic resonance imaging and postnatal outcomes

OBJECTIVE

To review the perinatal and long-term outcomes of symmetric and ventrally conjoined twins evaluated prenatally by ultrasound and fetal magnetic resonance imaging (MRI).

METHODS

From March 2010 to January 2019, cases of symmetric and ventrally conjoined twins, who were prenatally diagnosed and referred to the Clínica Diagnóstico por Imagem (CDPI), Rio de Janeiro, Brazil, for prenatal evaluation by ultrasound and MRI were selected. The postnatal information was collected from hospitals where the twins were born and/or treated and from parents' verbal and written information.

RESULTS

Four cases of symmetrical and ventrally conjoined twins were selected. Of these, two were omphalopagi and two thoracopagi. One pair of thoracomphalopagus died early in utero and the other died 6 days after birth. The outcome of the two omphalopagus pairs were separation in emergency surgeries after birth, with neonatal demise of one of the twins due to congenital malformations. In cases of omphalopagi, fetal MRI presented important information of the twins' anatomy before emergency separation of both pairs.

CONCLUSION

Despite the apparently similar conditions of twins with ventral fusion, ventrally attached twins have very different outcomes, most adverse for thoracomphalopagus and related to the singular anatomy of the pair, associated malformations and the extension of the adhesion, requiring individual evaluation of the cases. Fetal MRI is as an important tool for the postnatal surgery management of twin neonates, providing crucial information in cases where urgent separation is required.

Gemelo Heterópago

Los gemelos parásitos o heterópagos son aquellos unidos asimétricos con  partes deformes del parásito que se unen en diferentes regiones del gemelo normal (autosite), del cual depende para su soporte nutricional y crecimiento. Presentamos el caso de un gemelo heterópago con las extremidades inferiores y rudimentos de las superiores del parásito unidas al periné y glúteo derecho del autosite. Aunque no compartían órganos pélvicos, la compresión extrínseca de estructuras óseas del parásito causaron estenosis del recto, lo que obligó a la corrección quirúrgica. Los estudios por imágenes permitieron planificar la cirugía, lo cual facilitó la separación exitosa y lograr la sobrevida del paciente con muy buena calidad de vida. A pesar de ser reportados desde épocas ancestrales, aún generan gran interés debido a la variabilidad en su presentación clínica y al desconocimiento en su etiopatogénesis.

Anesthesia and perioperative challenges for surgical separation of thoraco-omphalopagus twins: case report

Background and objectives

Conjoined twins are monozygotic twins physically joined at some part of the body. This is a rare phenomenon, estimated between 1:50,000 and 1:200,000 births. The objective of this report is to present the anesthetic management and the perioperative challenges for a separation surgery.

Case report

Thoraco-omphalopagus twins were diagnosed by ultrasound and were followed by the fetal medicine team of the service. After 11 h of cesarean surgery, the pediatric surgical team chose to separate the twins. They were monitored with cardioscopy, oximetry, capnography, nasopharyngeal thermometer, urinary output, and non-invasive blood pressure. We chose inhaled induction with oxygen and 4% Sevoflurane. T1 patient was intubated with a 3.5 uncuffed endotracheal tube, and, after three unsuccessful intubation attempts of patient T2, a number 1 laryngeal mask was used. After securing the twins’ airway, the induction was supplemented with fentanyl, propofol, and rocuronium. Mechanical ventilation in controlled pressure mode (6 mL.kg⁻¹) and lumbar epidural (L1–L2) with 0.2% ropivacaine (2.5 mg.kg⁻¹) were used. The pediatric surgical team initiated the separation of the twins via sternotomy, ligation of hepatic vessels. After 2 hours of procedure, the separation was completed, continuing the surgical treatment of T1 and the support of T2 until his death.

Conclusions

Conjoined twin separation surgery is a challenge, which requires planning and coordination of a multidisciplinary team during all stages.

Therapy services and specialized devices for conjoined twins: Unique challenges with conjoined twins and the importance of physical and occupational therapy

Conjoined twins are a rare occurrence that offer unique challenges and circumstances to therapists. The overall goal of physical and occupational therapy treatment is to provide care that promotes developmental progression to two conjoined individuals with distinct personalities and potentially different physical and medical needs. The unique presentation of conjoined twins must be considered in determining therapeutic goals, interventions and plans of care. Providing therapeutic interventions throughout the NICU stay is a dynamic, evolving process, which challenges the therapy team to work together to find solutions. This paper aims to highlight the considerations, challenges, and strategies used to address barriers in the therapeutic care of conjoined twins.

An ethically-justifiable, practical approach to decision-making surrounding conjoined-twin separation

Conjoined twins present unique ethical and palliative care challenges. We present an ethically-justifiable, practical approach to decision-making with regards to surgical separation. These decisions must account for the short- and long-term prognoses for each infant prior to, and after, separation. Other considerations include the benefits and burdens of separation and the family's values and goals. Caregivers should recognize that decisions surrounding separation may be unduly influenced by social biases. The palliative care team aids in developing goals of care to guide decision-making by promoting communication between the medical team and family. They play an important role in supporting families regardless of the planned course of treatment. This support may be social or spiritual in nature, and is promoted by the interdisciplinary structure of the team. Early involvement of palliative care services facilitates complex decision making and can aid in the transition from cure-oriented therapies to support if needed during and after the dying process.

Nutritional considerations in the care of conjoined twins

Conjoined twins represent an interesting nutritional challenge as nutrient delivery and absorption is greatly affected by anatomy and, therefore, unique to each twin pair. Nutritional support is essential to optimize growth and development in the neonatal period; however, very little data exists on the topic in this population. Conjoined twins require individualized nutritional assessment that focuses on the interaction between the metabolic rate, nutrient uptake, and nutrient delivery of each twin in the dyad. This report describes one center's experience with monitoring growth, establishing nutrient requirements, and determining substrate utilization in three sets of conjoined twins.

[Anesthesia and perioperative challenges for surgical separation of thoraco-omphalopagus twins: case report]

BACKGROUND AND OBJECTIVES

Conjoined twins are monozygotic twins physically joined at some part of the body. This is a rare phenomenon, estimated between 1:50,000 to 1:200,000 births. The objective of this report is to present the anesthetic management and the perioperative challenges for a separation surgery.

CASE REPORT

Thoraco-omphalopagus twins were diagnosed by ultrasound and were followed by the fetal medicine team of the service. After 11hours of cesarean surgery, the pediatric surgical team chose to separate the twins. They were monitored with cardioscopy, oximetry, capnography, nasopharyngeal thermometer, urinary output, and noninvasive blood pressure. We chose inhaled induction with oxygen and 4% Sevoflurane. T1 patient was intubated with a 3.5 uncuffed endotracheal tube, and, after three unsuccessful intubation attempts of patient T2, a number 1 laryngeal mask was used. After securing the twins' airway, the induction was supplemented with fentanyl, propofol, and rocuronium. Mechanical ventilation in controlled pressure mode (6mL.kg^-1) and lumbar epidural (L1-L2) with 0.2% ropivacaine (2.5mg.kg^-1) were used. The pediatric surgical team initiated the separation of the twins via sternotomy, ligation of hepatic vessels. After 2hours of procedure, the separation was completed, continuing the surgical treatment of T1 and the support of T2 until his death.

CONCLUSIONS

Conjoined twin separation surgery is a challenge, which requires planning and coordination of a multidisciplinary team during all stages.

Conjoined Twin Separation: Integration of Three-Dimensional Modeling for Optimization of Surgical Planning

Conjoined twinning is a rare anomaly, with an incidence of approximately 1 in 100,000 live births. There is a high perinatal mortality rate, but twins who survive pose reconstructive challenges that require meticulous preoperative planning. The authors describe the senior surgeon's career experience with conjoined twin separation, and the evolution of medical modeling and 3-dimensional imaging as a critical component in presurgical planning.The authors performed a retrospective review of all consecutive patients of conjoined twin separation at a single institution from January 2004 to December 2013. Data were collected related to patient demographics, comorbidities, operative technique, perioperative complications, survival, long-term outcomes, and the type of medical modeling system used for preoperative planning.Five sets of conjoined twins underwent separation during the 10-year study period. There were 3 sets of thoraco-omphalopagus twins, 1 set of pyopagus twins, and 1 set of ischiopagus tetrapus twins. The mean age at separation was 70 days, with a mean of 3.5 surgical procedures performed per patient during the first year of life. One set of twins experienced postseparation complications that warranted immediate return to the operating room. The overall survival rate after separation was 70%. The imaging methods used were computed tomography scan with 3-dimensional reconstruction, plaster molds, medical modeling with composite printing, and virtual surgical planning.The use of imaging and medical modeling in presurgical planning has proven to be an important element in optimizing the outcomes for patients with this rare anomaly.

Conjoined twins - role of imaging and recent advances

INTRODUCTION

Conjoined twins are identical twins with fused bodies, joined in utero. They are rare complications of monochorionic twinning. The purpose of this study is to describe the various types of conjoined twins, the role of imaging and recent advances aiding in their management.

MATERIAL AND METHODS

This was a twin institutional study involving 3 cases of conjoined twins diagnosed over a period of 6 years from 2010 to 2015. All the 3 cases were identified antenatally by ultrasound. Only one case was further evaluated by MRI.

RESULTS

Three cases of conjoined twins (cephalopagus, thoracopagus and omphalopagus) were accurately diagnosed on antenatal ultrasound. After detailed counseling of the parents and obtaining written consent, all the three cases of pregnancy were terminated. Delivery of the viable conjoined twins was achieved without any complications to the mothers, and all the three conjoined twins died after a few minutes.

CONCLUSION

Ultrasound enables an early and accurate diagnosis of conjoined twins, which is vital for obstetric management. MRI is reserved for better tissue characterization. Termination of pregnancy when opted, should be done at an early stage as later stages are fraught with problems. Recent advances, such as 3D printing, may aid in surgical pre-planning, thereby enabling successful surgical separation of conjoined twins.

LDT classification and therapeutic strategy of congenital body wall defects

BACKGROUND

Repairing body wall defects is a critical step in the treatment of some congenital deformities, and this procedure may need the help from plastic surgeons. Although there are many articles about congenital deformities, body wall defects of these malformations are rarely studied as independent targets.

METHODS

In this article, the authors present an LDT classification for congenital body wall defects according to the position of the defects, the tissue layers involved, and the surgical urgency, each of which is represented by letters L, D, and T, respectively. That is, the defects in different areas (L), full-thickness (D₁), or partial (D_0A, D_0B) defects, defects needing instant repair (T₂), semi-elective repair (T₁), or elective repair (T₀). Based on this classification system, the authors have performed body wall reconstruction on two pairs of thoraco-omphalopagus twins, one pair of ischiopagus tetrapus twins, and an infant and an adult, both of whom were diagnosed with pentalogy of Cantrell associated with ectopia cordis.

RESULTS

Except for one pair of thoraco-omphalopagus twins who died after emergency separation, all the other patients survived. Another pair of thoraco-omphalopagus twins suffered from wound dehiscence and partial flap necrosis, respectively, after surgery. An expanded polytetrafluoroethylene mesh in one sister of the ischiopagus twins was removed because of infection.

CONCLUSIONS

LDT classification not only can help doctors categorise different congenital body wall defects rapidly and easily, but can also guide the reconstruction of these defects. It may have clinical value to plastic surgeons to some extent.

Freeform fabrication of tissue-simulating phantom for potential use of surgical planning in conjoined twins separation surgery

Preoperative assessment of tissue anatomy and accurate surgical planning is crucial in conjoined twin separation surgery. We developed a new method that combines three-dimensional (3D) printing, assembling, and casting to produce anatomic models of high fidelity for surgical planning. The related anatomic features of the conjoined twins were captured by computed tomography (CT), classified as five organ groups, and reconstructed as five computer models. Among these organ groups, the skeleton was produced by fused deposition modeling (FDM) using acrylonitrile-butadiene-styrene. For the other four organ groups, shell molds were prepared by FDM and cast with silica gel to simulate soft tissues, with contrast enhancement pigments added to simulate different CT and visual contrasts. The produced models were assembled, positioned firmly within a 3D printed shell mold simulating the skin boundary, and cast with transparent silica gel. The produced phantom was subject to further CT scan in comparison with that of the patient data for fidelity evaluation. Further data analysis showed that the produced model reassembled the geometric features of the original CT data with an overall mean deviation of less than 2 mm, indicating the clinical potential to use this method for surgical planning in conjoined twin separation surgery.

Conjoined twins: From conception to separation, a review

Conjoined twins are suggested to result from aberrant embryogenesis. The two main theories proposed to explain the phenomena are fission and fusion. The incidence rate is 1 in 50,000 births; however, since about 60% of the cases are stillborn, the true incidence is approximated at 1 in 200,000. There is a higher predisposition towards female than male gender with a ratio of 3:1. Conjoined twins are classified based upon the site of attachment. The extent of organ sharing, especially the heart, determines the possibility and prognosis of a separation procedure. Meticulous preoperative evaluation, planning, and preparedness of the team are crucial for a successful separation. Separation of conjoined twins poses several technical, legal, and ethical issues. Clin. Anat. 30:385-396, 2017. © 2017 Wiley Periodicals, Inc.

Thoracic heteropagus conjoined twins associated to an omphalocele: Report of a case and complete review of the literature

Heteropagus twins are an extremely rare event with an incidence of 1-2 million live births that represents, sometimes, a real challenge for paediatric surgeons. The majority of cases have complete or partial duplication of the pelvis and/or lower extremities. Thoracic heteropagus conjoined twins is a rare condition in which a grossly defective foetus (the parasite) is attached to the thorax of the main foetus (the autosite). We describe a case of a parasitic heteropagus attached at the chest wall with a rare presentation of giant exomphalos on the autosite. In this situation, the separation procedure was simple after a well-done anatomic study using X-ray, ultrasonography, magnetic resonance and echocardiogram are performed.

Delayed presentation of a heteropagus (parasitic) twin: a case report of a 17-year-old patient

Conjoined twins are rare, but well-described, anomalies. The heteropagus (parasitic) variant, in which there is a fully functioning autosite and a partially formed parasite, is even more rare. Typically, patients with this condition are discovered and treated as neonates or infants. We present an unusual case of an ischiopagus patient presenting at 17 years of age, which appears to be the oldest recorded presentation for surgery of a heteropagus twin in the English literature. The patient had two additional developed lower extremities along with two additional rudimentary upper extremities. The challenges and lessons learned from this rare and complex surgery are discussed.

Classification and clinical evaluation

Conjoined twins represent a great challenge for most pediatric specialists including pediatric surgeons, anesthetists, neonatologists, urologists, neurosurgeons, and orthopedic surgeons. This anomaly can be classified according to the type of twins׳ fusion. Various organs can be fused making the separation difficult. Conjoined twins are usually diagnosed antenatally by ultrasound. Detailed fetal echocardiography is necessary to counsel the parents during pregnancy. Postnatally, the majority of the conjoined twins can be thoroughly investigated using various imaging techniques. This allows careful planning of the operation. However, in approximately one-third of the patients an urgent operation is required at birth without a complete assessment of the joining. This is associated with a poorer outcome.

Urological management

The pediatric urologists role is confined to ischio-, para-, and pygopagus conjoined twins. The aim is to preserve renal function, to address problems with urinary continence, and to optimize genital issues with particular reference to sexual and reproductive function. Full urological imaging is essential prior to separation for planning and for the operation itself.

Anesthetic management for separation of thoracopagus twins with complex congenital heart disease: a case report

Although thoracopagus twins joined at the upper chest are the most common type of conjoined twins, the separation surgery in these cases has a higher mortality rate. Here, we describe an anesthetic management approach for the separation of thoracopagus conjoined twins sharing parts of a congenitally defective heart and liver. We emphasize the importance of vigilant intraoperative hemodynamic monitoring for early detection of unexpected events. Specifically, real-time continuous monitoring of cerebral oximetry using near-infrared spectroscopy allowed us to promptly detect cardiac arrest and hemodynamic deterioration.

Fetal echocardiographic characteristics of fused heart in thoracopagus conjoined twins

Conjoined twins (CT) are rare with possible serious malformations in which soft tissue, bone, or some organs are joined in utero. The extent of cardiac fusion and intracardiac anatomy of CT determine the viability, natural history, and outcome of potential surgical intervention. Early prenatal diagnosis and assessment may provide a window of opportunity to counsel the family for their informed decision on the pregnancy and to plan for prenatal and perinatal care. In this report, we describe a case of thoracopagus twins diagnosed by fetal echocardiography at 23-week gestation. The 2 hearts fused at the atrial and ventricular levels. The outcome and review of literature on fetal echocardiographic characteristics of this malformation are discussed.

Anesthetic management of conjoined twins undergoing one-stage surgical separation: A single center experience

OBJECTIVE

To summarize our experience in the anesthetic management of conjoined twins undergoing one-stage surgical separation.

METHODOLOGY

Medical records of conjoined twins admitted to our hospital for treatment and considered for surgical separation from 1996 to present were retrospectively reviewed. Four cases of conjoined twins underwent one-stage surgical separation under general anesthesia. Preoperative evaluation was performed to determine the extent of anatomical conjunction and associated anomalies. Anesthesia was simultaneously induced in all conjoined twins. The intubation procedure was successfully performed with the head slightly rotated to each baby's side, followed by the administration of vecuronium. Anesthetic agents were administered according to the estimated weight of each baby. One case of conjoined twins underwent surgical separation with cardiopulmonary bypass due to shared hearts. Results : All conjoined twins were successfully separated. No significant respiratory or cardiac events occurred during surgery except for one twin, which died after separation because of complicated congenital heart disease. Conclusions : Accurate preoperative evaluation, respiratory and circulatory management, and close cooperation of the multidisciplinary team are important aspects of anesthetic management of conjoined twins surgery.

Gluteal flap for omphalocele repair in a case of epigastric heteropagus: A novel approach for surgical management

Epigastric heteropagus is an extremely rare congenital anomaly, in which there is asymmetrical conjoined twinning, with the parasitic twin attached to the epigastrium. A 2-day-old male, with epigastric heteropagus and omphalocele, was operated in our institution. After excision of the parasitic twin, omphalocele was covered with a gluteal skin flap available from the parasitic twin. Post-operative course was uneventful, except for infection along the edges of the skin flaps, which was managed conservatively. Only 44 cases of epigastric heteropagus twins have been reported previously in world literature. We present a novel surgical approach for the repair of the omphalocele in a case of epigastric heteropagus twins, probably the 45(th) case to be reported in the world literature.

Technical challenges of a term delivery in a separated ischiopagus twin

BACKGROUND

Conjoined twins occur in one in 100,000 live births. Successful term pregnancy in a separated conjoined twin is rare.

CASE

We present a 27-year-old woman, gravida 2 para 0, former ischiopagus conjoined twin with successful separation at 12 days of life. We report a successful term gestation delivered by cesarean without complications.

CONCLUSION

Term pregnancy is possible in a previous conjoined twin patient having undergone surgical separation. We recommend a multidisciplinary approach with close evaluation of maternal anatomy to achieve a successful pregnancy outcome while minimizing the risk of complications.