IJCS | Volume 33, Nº1, January / February 2019

103 Ponce Complete interruption of aortic arch Int J Cardiovasc Sci. 2020;33(1):102-106 Case Report Case report A multiparous 43-year-old woman in prenatal care with negative serological tests for infectious diseases was referred for fetal cardiovascular evaluation at 33 weeks of gestation. Her past medical and family histories were unremarkable. A morphology ultrasound in the third trimester showed a hydrops fetus with probable atrioventricular septal defect (AVSD) and heart failure with pericardial effusion in utero. Fetal echocardiography was not performed. Based on perinatal outcomes, amniocentesis for fetal karyotyping was recommended, but the parents declined. Examination during the 35 weeks’ follow-up visit revealed that the fetus had died. A female stillborn infant was delivered vaginally. Permission for autopsy was obtained from the parents. Autopsy findings An autopsy was performed based on the guidelines of the Committee of the College of American Pathologists. 7 The stillborn weighed 1,510 grams and measured 40 cm in length. The pertinent findings were as follows: macerated skin, hydrops fetalis facies and no other external malformation. At this time, the umbilical cord bloodwas already clotted, not allowing a suitable sample for the karyotype. The cephalic, thoracic, and abdominal organs showed moderate autolysis. The heart was dilated and had increased weight for the gestational age, with 20.5 g (mean reference value [mRV]; 14.5 ± 3.7 g) and discrete hydropericardium. The ascending aorta ended at the innominate and left common carotid arteries (Figure 1A). The descending thoracic aorta was a continuation of the pulmonary artery with a widely dilated ductus arteriosus (Figure 1B). The left subclavian artery originated from the descending aorta (Figure 1B). There was a complete absence of the segment of aorta between the origin of the left common carotid and the left subclavian arteries (absence of the aortic isthmus). The venous return to the heart was normal. The aortic and pulmonary valves showed no abnormalities (Figure 2A and 2B). Proximally to the pulmonary artery opening, we noticed the ostium of the left pulmonary artery and distally the ostium of the right pulmonary artery (Figure 2A), and a single coronary artery ostium was identified (Figure 2B). There was a complete AVSD, Rastelli’s type A, 8 with both atrial and ventricular septal defect and common atrioventricular valve that bridges both sides of heart (Figure 2B). The lungs were immature. The liver was enlarged, weighing 111.5 g (mean reference value [mRV]; 81.8 ± 22.3 g). No other syndromic features or other malformations were noted. The placenta weighed 220 grams previously fixed in formaldehyde was received in the Pathology Laboratory, which precluded a karyotype test. Histological sections stainedwith hematoxylin and eosin (H&E) revealed acute purulent inflammation of the fetal membranes and large areas of placental infarction. No changes were detected in the umbilical cord. Discussion IAAwas anatomically classified by Celoria and Patton in 1959 9 according to the level of arch interruption: type A, IAA distal to the left subclavian artery, accounting for approximately 30% – 40% of cases; type B, IAA between the left common carotid and left subclavian arteries; it is the most common form, representing 53% of cases; and type C the arch is interrupted between the innominate and left common carotid arteries. This is the most uncommon, accounting for about 4% of cases. 2,4 The case reported herein can be classified as type B based on the site of aortic arch interruption. This subtype is found when the left fourth arch segment regresses early, prior to cephalad migration of the left subclavian artery. 4 IAA type B is usually syndromic; it is the most common cardiac defect occurring inDiGeorge syndrome, which is associated with microdeletions of the segment 22q11.2. 3,6 Although fetal karyotyping was indicated by the medical team, the parents did not agree with it. In our case, the blood from the vena cava emptied into the right atrium and then into the right ventricle. Because of complete AVSD, part of this blood passed into the left atrium and into the left ventricle. From the pulmonary artery, some of this blood flew into the branches of this vessel, and the other part emptied through the ductus arteriosus into the descending aorta. 1,4,5 In intrauterine life, the fetus receives the oxygenated blood from the placenta through the umbilical vein. The intercavitary flow promoted by septal defect and ductus arteriosus allows a mixed-blood condition sine qua non for survival. 6 However, in the case described here, the septal defect and the large ductus arteriosus exerted no positive effect on gestational outcome. Chorioamnionitis is an inflammation of the fetal membranes due to infection. The presence of polymorphonuclear leukocytes indicates acute