Pediatr Cardiol (2010) 31:1252–1253 DOI 10.1007/s00246-010-9784-8
IMAGES IN PEDIATRIC CARDIOLOGY
Inseparable Thoraco-Omphalopagus Twins Mohamed A. Hamdan • Muzibunnisa Begam Hisham M. Mirghani
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Received: 3 April 2010 / Accepted: 17 August 2010 / Published online: 8 September 2010 Ó Springer Science+Business Media, LLC 2010
Abstract Conjoined twins occur at the rate of 1 in 50 to 200,000 live births, and 75% of these share the thorax (thoracopagus) or the thorax and upper abdomen (thoracoomphalopagus), resulting in cardiac and hepatic sharing. Antenatal diagnosis can delineate the cardiac anatomy and provide parental counseling on whether separation is possible after birth. In the majority of cases, thoracopagus twins have a complex cardiac anatomy and share a common pericardial sac. Separation and survival depend on the extent to which the cardiac chambers and conduction system are fused. When the twins share the atria, ventricles, or both, death is inevitable even if surgical separation is occasionally attempted. Keywords Pediatrics
omphalopagus twins detected at the first trimester fetal ultrasound. Her pregnancy was spontaneous, and she had an unremarkable maternal medical and family history. The parents opted to continue the pregnancy at that time. Joined at the thorax and abdomen, the fetuses shared the heart and liver. Fetal echocardiography showed abnormal cardiac access, a common pericardial sac, atrial and ventricular fusion, and complex intracardiac anatomy (Fig. 1). These abnormalities were confirmed after delivery at 36 weeks
Echocardiography Congenital heart defects
A 41-year-old woman was referred to the fetal echocardiography laboratory at 34 weeks because of thoracoElectronic supplementary material The online version of this article (doi:10.1007/s00246-010-9784-8) contains supplementary material, which is available to authorized users. M. A. Hamdan (&) Department of Pediatrics, Tawam Hospital, P.O. Box 15258, Al Ain, United Arab Emirates e-mail:
[email protected] M. Begam Department of Obstetrics and Gynecology, Tawam Hospital, P.O. Box 15258, Al Ain, United Arab Emirates H. M. Mirghani Department of Obstetrics and Gynecology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
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Fig. 1 Fetal echocardiogram at 34 weeks showing a common pericardial sac (arrows) as well as atrial and ventricular sharing. The numbers refer to the twins. ASD atrial septal defect, IAS interatrial septum IVS1 interventriculr septum in twin 1, IVS2 interventricular septum in twin 2, LA1 left atrium in twin 1, LV2 left ventricle in twin 2, RV1 right ventricle in twin 1, RV2 right ventricle in twin 2, VSD ventricular septal defect
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Fig. 2 Thoraco-omphalopagus twins
Fig. 4 Cardiac anatomy in both twins. AAo ascending aorta, ASD atrial septal defect, IVC inferior vena cava, LA1 left atrium in twin 1, LA2 left atrium in twin 2, LV1 left ventricle in twin 1, LV2 left ventricle in twin 2, MPA main pulmonary artery, PDA patent ductus arteriosus, RA1 right atrium in twin 1, RA2 right atrium in twin 2, RV1 right ventricle in twin 1, RV2 right ventricle in twin 2, SVC superior vena cava, VSD ventricular septal defect
Fig. 3 Two-dimensional echocardiogram after birth depicting atrial and ventricular fusion. ASD atrial septal defect, LA2 left atrium in twin 2, LV2 left ventricle in twin 2, RA1 right atrium in twin 1, RA2 right atrium in twin 2, RV1 right ventricle in twin 1, RV2 right ventricle in twin 2, VSD ventricular septal defect
(Figs. 2, 3 and Supplementary Movie 1). Twin 1 had unbalanced complete atrioventricular (AV) septal defect, hypoplastic left AV valve and left ventricle (LV), and double-outlet right ventricle with side-by-side great arteries (the aorta was more posterior) (Fig. 4 and Supplementary Movies 2 and 3). The pulmonary veins were draining anomalously into the innominate vein. Twin 2 had hypoplastic left heart syndrome, with a hypoplastic mitral valve and LV, aortic atresia, and a hypoplastic ascending aorta (Fig. 4 and Supplementary Movie 4). The tricuspid valve was dysplastic and had moderate regurgitation. A 12-lead electrocardiogram obtained simultaneously from the twins showed identical heart rhythm, confirming a common conduction system (Fig. 5). The parents were counseled regarding the inseparable hearts and the fatal outcome. They opted for comfort care, and the twins died of progressive metabolic acidosis at the age of 50 days after
Fig. 5 Simultaneous electrocardiogram recording from twins 1 (a) and 2 (b) depicting the same cardiac rhythm
ductal closure. Postmortem examination was declined by the parents.
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