© 2014, Wiley Periodicals, Inc. DOI: 10.1111/echo.12622
Echocardiography
Fetal Echocardiographic Characteristics of Fused Heart in Thoracopagus Conjoined Twins Yu Wu, M.D.,*,a Qing Lv, M.D.,*,a Ming-Xing Xie, M.D., Ph.D.,* Lin-Yuan Wan, M.D.,* Ping-Ping Ren, M.D.,* Andrew Ge,† and Shuping Ge, M.D.*‡ *Department of Ultrasonography, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Hubei Provincial Key Laboratory of Molecular Imaging, Wuhan, China; †Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and ‡The Heart Center, St. Christopher’s Hospital for Children and Drexel University College of Medicine, Philadelphia, Pennsylvania
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. (Echocardiography 2014;31:E218–E221) Key words: fetal echocardiography, conjoined twins, congenital heart defects
Conjoined twins (CT) are rare congenital malformations with unknown etiology. In a multicenter worldwide study, the total prevalence of CT was 1.47 per 100,000 births.1 It is characterized by soft tissue, bone, and/or internal organs that are joined in utero. The cardiac fusion is a critical determinant of viability, natural history, and the possibility and outcome for surgical intervention.2–4 Fetal echocardiography is an integral component for comprehensive assessment of the cardiovascular system of CT. It has increasingly been used to diagnose and assess cardiac fusion and intracardiac anatomy and associated defects to provide an opportunity to counsel the family and to plan for prenatal and perinatal care. Case Report: The patient was a 33-year-old G4P0 female who conceived through assisted reproductive technology. In the 23rd week of pregnancy, she was referred to our institution secondary to a diagnosis of CT by ultrasound examination. There was a These authors contributed equally to this work. Address for correspondence and reprint requests: Shuping Ge, M.D., The Heart Center, St. Christopher’s Hospital for Children/Drexel University College of Medicine, 3601 A Street, Philadelphia, PA 19134, USA. Fax: (215)-427-4822; E-mail: [email protected]
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no history of tuberculosis, hepatitis B virus, radiation exposure, or tobacco or alcohol usage during pregnancy. After hospitalization, maternal vital signs were stable. Fetal echocardiography demonstrated 2 heads, 2 vertebral columns (Fig. 1A), and 2 stomach bubbles (Fig. 1B). The twins, facing each other, were joined at the thorax and upper abdomen. The left-sided twin was defined as twin A and the right-sided twin as twin B. There was only a shared heart in the juncture. The greater part of the shared heart was located in the chest of twin A chest. Apex was pointed on the right side of twin A (Fig. 1C). There were a left-sided atrium and a rightsided atrium. Foramen ovale flaps in the leftsided atrium could be visualized (Fig. 1D). There were 3 atrioventricular valves in the shared heart. The atrioventricular valves were located in the left, right, and front of twin A, respectively (Fig. 1E and F). There were ventricular septal defects visualized. A great artery was observed as arising from the front ventricle in twin B (Fig. 1G). Another great artery originated from the right-sided ventricle in twin A (Fig. 1H). After the discussion that it was not feasible to septate the conjoint heart into 2 functional hearts, the patient opted to terminate pregnancy. The delivery of the male twins was
Fetal Echo for Thoracopagus Conjoined Twins
Figure 1. Fetal echocardiographic images of cardiac fusion of CT. A. Arrow: 2 stomach bubbles; B. Arrow: 2 vertebral columns; C. The shared heart D. Arrow: foramen ovale flaps (FOF); E. A left and a right atrioventricular valve (dash lines and arrow below) located in the right of twin A and the atrioventricular valve (dash lines and arrow above) located in twin A. F. A third front atrioventricular valve (dash lines and left arrow) located in the front of twin A; G. dash lines: the shared heart and an artery originating from the front ventricle; H. dash lines: the right-sided ventricle of the shared heart with an artery originating from the right-sided ventricle. CT = conjoined twins.
induced at 24 weeks of gestation. The combined weight was 1100 g. Autopsy (Fig. 2) confirmed the prenatal findings of twins with complex conjoined heart, except for the great arteries. Both twin A and twin B had 2 great arteries. The 2 arteries of twin A originated from the right-sided ventricle. And one of the arteries in twin B was too thin to find the origin.
Discussion: Conjoined twins are classified by the site of union. The common types are thoracopagus (joined in the thorax), omphalopagus (joined at their umbilical regions), cranipagus (joined at the head), and ischiopagus (joined at the hip). The earliest documented case of CT, joined laterally from hips to shoulders, dated back E219
Wu, et al.
A
B
C
D
E
Figure 2. Image of the thoracopagus twins after delivery by induced labor. A. The twins, facing each other, were joined at the thorax and upper abdomen; B. A shared heart in the juncture; C. Four auricular appendages; D. Three atrioventricular valves; E. A aorta and a pulmonary artery in both twin A and twin B, respectively, as shown by arrows.
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from the Maids of Biddendon in England in 1100.5 In 2011, a worldwide study showed that the total prevalence of CT was 1.47 per 100,000 births.1 Cardiac fusion of variable degree almost always occurs in thoracopagus, frequently in cephalopagus and parapagus, and never in ischiopagus, craniopagus or pygopagus.2 The extent of cardiac fusion is not only a risk factor for viability, natural history, and outcome,3 but also associated with the possibility of surgical partition.4 Fetal echocardiography is the modality of choice for diagnosis and assessment of CT with cardiac involvement as both a screening and confirmatory imaging method. In 1967, Leachman et al.6 classified CT on the basis of cardiac fusion: separate hearts and common pericardium (type A), fused atria with separate ventricles (type B), and fused atria and ventricles (type C). Afterward, Andrews et al.4 added twins with separate hearts and separate pericardium into the classification, which occurred in both thoracoomphalopagus and parapagus twins in the series. McMahon et al.7 reported a case of CT with separate atria and fused ventricles which should be a new type of this series. In the case of separate hearts with or without common pericardium, it is separable from a cardiac surgical standpoint. The survival can be 70% or more.5 In cases of high degree of cardiac fusion, separation would not be feasible.5,7–9 It was reported that there were almost no survivors in cases of CT in which the atria and ventricular chambers were fused.1,5 Our case is a type C malformation which suggested a poor prognosis. In type C, there were also various types of conjoined heart. Tongsong et al.2 reported a conjoined heart in thoraco-omphalopagus twins. The heart consisted of 3 atria and 2 ventricles, each twin having a single ventricle and right atrium but a fused left atrium. Ambar et al.10 reported another case of conjoined heart. The 2 hearts were fused at the atrial level. Right-sided heart had single atrial chamber communicating with a single ventricle. Left-sided heart was well developed with 2 atria and 2 ventricles. Fetal echocardiography provides an accurate diagnosis of cardiac fusion, including that of the atria and ventricles. In our case, autopsy confirmed all fetal echocardiographic findings related to the atria and ventricles, but there were discrepancies in the diagnosis of great arteries between fetal echocardiography and autopsy. It showed only one single great vessel, the aorta, in each twin by fetal echocardiography, but we had not visualized the pulmonary artery well. In fact, both twins had pulmonary arteries, one developed fair and the other was
Fetal Echo for Thoracopagus Conjoined Twins
dysplastic, demonstrating a limitation of fetal echocardiography in delineating small vascular structures. In conclusion, fetal echocardiography is feasible and accurate for diagnosis of cardiac, atrial and ventricular fusions and associated intracardiac defects in CT. It provides an important window of opportunity to counsel the families for their informed decision on pregnancy and to plan for prenatal and perinatal cardiac care. References
~ oz L, Amar E, et al: Conjoined 1. Mutchinick OM, Luna-Mun twins: A Worldwide Collaborative Epidemiological Study of the International Clearinghouse for Birth Defects Surveillance and Research. Am J Med Genet Part C Semin Med Genet 2011;157:274–287. 2. Tongsong T, Khunamornpong S, Piyamongkol W, et al: Prenatal sonographic delineation of the complex cardiac anatomy of thoraco-omphalopagus twins. Ultrasound Obstet Gynecol 2005;25:189–192.
3. Zhang YQ, Wu LP, Wu LJ, et al: Echocardiographic assessment of conjonined twins with congenital heart disease in Shanghai. Echocardiography 2009,26:691–698. 4. Andrews RE, McMahon CJ, Yates RW, et al: Echocardiographic assessment of conjoined twins. Heart 2006,92: 382–387. 5. O’Neill JA, Holcomb GW, Schnaufer L, et al: Surgical experience with thirteen conjoined twins. Ann Surg 1988;208:299–312. 6. Leachman RD, Latson JR, Kohler CM, et al: Cardiovascular evaluation of conjoined twins. Birth Defects 1967;3: 52–62. 7. McMahon CJ, Mullins CE, Vick W, et al: Cardiac catheterization in diagnosis and management of congenital heart disease in thoracopagus conjoined twins. Catheter Cardiovasc Interv 2000;51:159–167. 8. Brizot ML, Liao AW, Lopes LM, et al: Conjoined twins pregnancies: Experience with 36 cases from a single center. Prenat Diagn 2011;31:1120–1125. 9. Thomas Collins R, Weinberg PM, Gruber PJ, et al: Conjoined hearts in thoracopagus twins. Pediatr Cardiol 2012;33:252–257. 10. Ambar SS, Halkati PC, Patted SV, et al: Twin heart with a fused atria and separate ventricles in conjoined twins. Ann Pediatr Cardiol 2010;3:196–198.
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Echocardiography
Fetal Echocardiographic Characteristics of Fused Heart in Thoracopagus Conjoined Twins Yu Wu, M.D.,*,a Qing Lv, M.D.,*,a Ming-Xing Xie, M.D., Ph.D.,* Lin-Yuan Wan, M.D.,* Ping-Ping Ren, M.D.,* Andrew Ge,† and Shuping Ge, M.D.*‡ *Department of Ultrasonography, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Hubei Provincial Key Laboratory of Molecular Imaging, Wuhan, China; †Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and ‡The Heart Center, St. Christopher’s Hospital for Children and Drexel University College of Medicine, Philadelphia, Pennsylvania
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. (Echocardiography 2014;31:E218–E221) Key words: fetal echocardiography, conjoined twins, congenital heart defects
Conjoined twins (CT) are rare congenital malformations with unknown etiology. In a multicenter worldwide study, the total prevalence of CT was 1.47 per 100,000 births.1 It is characterized by soft tissue, bone, and/or internal organs that are joined in utero. The cardiac fusion is a critical determinant of viability, natural history, and the possibility and outcome for surgical intervention.2–4 Fetal echocardiography is an integral component for comprehensive assessment of the cardiovascular system of CT. It has increasingly been used to diagnose and assess cardiac fusion and intracardiac anatomy and associated defects to provide an opportunity to counsel the family and to plan for prenatal and perinatal care. Case Report: The patient was a 33-year-old G4P0 female who conceived through assisted reproductive technology. In the 23rd week of pregnancy, she was referred to our institution secondary to a diagnosis of CT by ultrasound examination. There was a These authors contributed equally to this work. Address for correspondence and reprint requests: Shuping Ge, M.D., The Heart Center, St. Christopher’s Hospital for Children/Drexel University College of Medicine, 3601 A Street, Philadelphia, PA 19134, USA. Fax: (215)-427-4822; E-mail: [email protected]
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no history of tuberculosis, hepatitis B virus, radiation exposure, or tobacco or alcohol usage during pregnancy. After hospitalization, maternal vital signs were stable. Fetal echocardiography demonstrated 2 heads, 2 vertebral columns (Fig. 1A), and 2 stomach bubbles (Fig. 1B). The twins, facing each other, were joined at the thorax and upper abdomen. The left-sided twin was defined as twin A and the right-sided twin as twin B. There was only a shared heart in the juncture. The greater part of the shared heart was located in the chest of twin A chest. Apex was pointed on the right side of twin A (Fig. 1C). There were a left-sided atrium and a rightsided atrium. Foramen ovale flaps in the leftsided atrium could be visualized (Fig. 1D). There were 3 atrioventricular valves in the shared heart. The atrioventricular valves were located in the left, right, and front of twin A, respectively (Fig. 1E and F). There were ventricular septal defects visualized. A great artery was observed as arising from the front ventricle in twin B (Fig. 1G). Another great artery originated from the right-sided ventricle in twin A (Fig. 1H). After the discussion that it was not feasible to septate the conjoint heart into 2 functional hearts, the patient opted to terminate pregnancy. The delivery of the male twins was
Fetal Echo for Thoracopagus Conjoined Twins
Figure 1. Fetal echocardiographic images of cardiac fusion of CT. A. Arrow: 2 stomach bubbles; B. Arrow: 2 vertebral columns; C. The shared heart D. Arrow: foramen ovale flaps (FOF); E. A left and a right atrioventricular valve (dash lines and arrow below) located in the right of twin A and the atrioventricular valve (dash lines and arrow above) located in twin A. F. A third front atrioventricular valve (dash lines and left arrow) located in the front of twin A; G. dash lines: the shared heart and an artery originating from the front ventricle; H. dash lines: the right-sided ventricle of the shared heart with an artery originating from the right-sided ventricle. CT = conjoined twins.
induced at 24 weeks of gestation. The combined weight was 1100 g. Autopsy (Fig. 2) confirmed the prenatal findings of twins with complex conjoined heart, except for the great arteries. Both twin A and twin B had 2 great arteries. The 2 arteries of twin A originated from the right-sided ventricle. And one of the arteries in twin B was too thin to find the origin.
Discussion: Conjoined twins are classified by the site of union. The common types are thoracopagus (joined in the thorax), omphalopagus (joined at their umbilical regions), cranipagus (joined at the head), and ischiopagus (joined at the hip). The earliest documented case of CT, joined laterally from hips to shoulders, dated back E219
Wu, et al.
A
B
C
D
E
Figure 2. Image of the thoracopagus twins after delivery by induced labor. A. The twins, facing each other, were joined at the thorax and upper abdomen; B. A shared heart in the juncture; C. Four auricular appendages; D. Three atrioventricular valves; E. A aorta and a pulmonary artery in both twin A and twin B, respectively, as shown by arrows.
E220
from the Maids of Biddendon in England in 1100.5 In 2011, a worldwide study showed that the total prevalence of CT was 1.47 per 100,000 births.1 Cardiac fusion of variable degree almost always occurs in thoracopagus, frequently in cephalopagus and parapagus, and never in ischiopagus, craniopagus or pygopagus.2 The extent of cardiac fusion is not only a risk factor for viability, natural history, and outcome,3 but also associated with the possibility of surgical partition.4 Fetal echocardiography is the modality of choice for diagnosis and assessment of CT with cardiac involvement as both a screening and confirmatory imaging method. In 1967, Leachman et al.6 classified CT on the basis of cardiac fusion: separate hearts and common pericardium (type A), fused atria with separate ventricles (type B), and fused atria and ventricles (type C). Afterward, Andrews et al.4 added twins with separate hearts and separate pericardium into the classification, which occurred in both thoracoomphalopagus and parapagus twins in the series. McMahon et al.7 reported a case of CT with separate atria and fused ventricles which should be a new type of this series. In the case of separate hearts with or without common pericardium, it is separable from a cardiac surgical standpoint. The survival can be 70% or more.5 In cases of high degree of cardiac fusion, separation would not be feasible.5,7–9 It was reported that there were almost no survivors in cases of CT in which the atria and ventricular chambers were fused.1,5 Our case is a type C malformation which suggested a poor prognosis. In type C, there were also various types of conjoined heart. Tongsong et al.2 reported a conjoined heart in thoraco-omphalopagus twins. The heart consisted of 3 atria and 2 ventricles, each twin having a single ventricle and right atrium but a fused left atrium. Ambar et al.10 reported another case of conjoined heart. The 2 hearts were fused at the atrial level. Right-sided heart had single atrial chamber communicating with a single ventricle. Left-sided heart was well developed with 2 atria and 2 ventricles. Fetal echocardiography provides an accurate diagnosis of cardiac fusion, including that of the atria and ventricles. In our case, autopsy confirmed all fetal echocardiographic findings related to the atria and ventricles, but there were discrepancies in the diagnosis of great arteries between fetal echocardiography and autopsy. It showed only one single great vessel, the aorta, in each twin by fetal echocardiography, but we had not visualized the pulmonary artery well. In fact, both twins had pulmonary arteries, one developed fair and the other was
Fetal Echo for Thoracopagus Conjoined Twins
dysplastic, demonstrating a limitation of fetal echocardiography in delineating small vascular structures. In conclusion, fetal echocardiography is feasible and accurate for diagnosis of cardiac, atrial and ventricular fusions and associated intracardiac defects in CT. It provides an important window of opportunity to counsel the families for their informed decision on pregnancy and to plan for prenatal and perinatal cardiac care. References
~ oz L, Amar E, et al: Conjoined 1. Mutchinick OM, Luna-Mun twins: A Worldwide Collaborative Epidemiological Study of the International Clearinghouse for Birth Defects Surveillance and Research. Am J Med Genet Part C Semin Med Genet 2011;157:274–287. 2. Tongsong T, Khunamornpong S, Piyamongkol W, et al: Prenatal sonographic delineation of the complex cardiac anatomy of thoraco-omphalopagus twins. Ultrasound Obstet Gynecol 2005;25:189–192.
3. Zhang YQ, Wu LP, Wu LJ, et al: Echocardiographic assessment of conjonined twins with congenital heart disease in Shanghai. Echocardiography 2009,26:691–698. 4. Andrews RE, McMahon CJ, Yates RW, et al: Echocardiographic assessment of conjoined twins. Heart 2006,92: 382–387. 5. O’Neill JA, Holcomb GW, Schnaufer L, et al: Surgical experience with thirteen conjoined twins. Ann Surg 1988;208:299–312. 6. Leachman RD, Latson JR, Kohler CM, et al: Cardiovascular evaluation of conjoined twins. Birth Defects 1967;3: 52–62. 7. McMahon CJ, Mullins CE, Vick W, et al: Cardiac catheterization in diagnosis and management of congenital heart disease in thoracopagus conjoined twins. Catheter Cardiovasc Interv 2000;51:159–167. 8. Brizot ML, Liao AW, Lopes LM, et al: Conjoined twins pregnancies: Experience with 36 cases from a single center. Prenat Diagn 2011;31:1120–1125. 9. Thomas Collins R, Weinberg PM, Gruber PJ, et al: Conjoined hearts in thoracopagus twins. Pediatr Cardiol 2012;33:252–257. 10. Ambar SS, Halkati PC, Patted SV, et al: Twin heart with a fused atria and separate ventricles in conjoined twins. Ann Pediatr Cardiol 2010;3:196–198.
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