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Interrupted aortic arch with ventricular septal defect: an unsuspected fatal congenital anomaly in forensic pathology
Journal of Clinical Forensic Medicine (2002) 9, 185–188 Ó 2002 Elsevier Science Ltd and APS. All rights reserved. doi:10.1016/S1353-1131(02)00125-6, available online at http://www.idealibrary.com on
CASE REPORT
Interrupted aortic arch with ventricular septal defect: an unsuspected fatal congenital anomaly in forensic pathology P. M. NgÕwalali, Y. Ohtsu, S. Tsunenari Department of Forensic Medicine, Kumamoto University School of Medicine, Kumamoto, Japan SUMMARY. Interrupted aortic arch (IAA) is a relatively rare cardiovascular anomaly worldwide and is very rarely encountered in forensic pathology. A case of clinically unsuspected fatal IAA in a 5-day old neonate is described. A full term female baby was declared dead on arrival at an emergency hospital few hours after having been discharged from a maternity hospital following delivery. There were no noticeable signs and symptoms reported during the short postnatal period. Antenatal medical history was unremarkable and there were no abnormalities noticed at birth. Autopsy revealed an unsuspected IAA arch with ventricular septal defect (VSD) as cause of sudden unexpected death. Although amenable to surgical intervention, IAA may not produce obvious clinical symptoms as was the case for this baby. Such sudden unexpected deaths raise medico-legal questions as to the manner and the precise cause of death. The importance of a full forensic autopsy to clarify such a sudden death was re-emphasized. Ó 2002 Elsevier Science Ltd and APS. All rights reserved. Journal of Clinical Forensic Medicine (2002) 9, 185–188
INTRODUCTION
CASE HISTORY
Interrupted or congenitally absent aortic arch (IAA) is defined as a complete anatomical separation of the ascending and descending aorta. It is a rare congenital anomaly accounting for only about 1% of all congenital cardiovascular anomalies1 and was found in only 24 of the 2251 infants registered in the New England Regional Infant Cardiac Program (NERICP) between 1969 and 1974.2 In an experience with 53 IAA cases over a period of 9 years, Loffredo et al.3 encountered an average of one case per year in each of the participating six pediatric cardiology centers. The prognosis for IAA patients is extremely poor, and without surgical intervention 76% will die in the newborn period and 90% will die in the first year of life.4 A fatal case of clinically unsuspected IAA in a 5day neonate is presented.
A full-term female baby was born at 0200 h. The antenatal period had been unremarkable, the mother had taken iron supplements. At birth the baby had no noticeable abnomalities, she had normal sucking reflex and appeared to sleep well. On the third day after birth at 2330 h, the baby was reluctant to feed on expressed breast milk (EBM) at two occasions. On day 4 at 1100 h, the baby was discharged home. Attempts to feed the baby at home with EBM and artificial formula at 1230 h and 1420 h respectively on the day of discharge were unsuccessful. By this time the baby was said to be immobile with cold upper and lower limbs. The baby was brought to an emergency hospital where he was pronounced dead on arrival. As no clinical diagnosis had been made, an autopsy was requested to clarify the circumstances surrounding the case. At autopsy the body was that of a full term female neonate weighing 3230 g and measuring 53 cm in length. Neither gross abnormalities nor cyanosis were noted externally. The heart was normal in size and weight. However, the ductus arteriosus was widely patent measured 0.5 cm in diameter and continued as a descending aorta (Fig. 1). Since the site of the
Received 3 August 2002 Accepted 3 October 2002 P. M. NgÕwalali MD, D Med Sci, Y. Ohtsu BMedTech, S. Tsunenari MD, Department of Forensic Medicine, Kumamoto University School of Medicine, 2-2-1 Honjyo, Kumamoto 860-0811, Japan. Correspondence to: Dr. P. M. NgÕwalali, Tel.: +81-96-373-5123; Fax: +81-96-373-5123; E-mail: [email protected] 185
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Journal of Clinical Forensic Medicine
Fig. 1 The pulmonary trunk (PT) in continuity with the patent ductus arteriosus (PDA) and the descending aorta (DAo). The ascending aorta (Ao) is not connected to the DAo. Lsc, left subclavian artery; Lct, left common carotid; Rct, right common carotid artery; Rsc, right subclavian artery.
interruption of the aortic arch in the present case was distal to the left subclavian artery, the interruption was determined as IAA Type A (Fig. 2). Fig. 3 shows a ventricular septal defect (VSD) which was subpul-
monary in the infundibular septum. The stomach contained about 10 g of milk-curd. The other organs showed no pathological changes and the histological examination was unremarkable.
Fig. 2 Schematic presentation of the three IAA types; Types A, B and C. a, ascending aorta; b, right subclavian artery; c, right common carotid; d, left common carotid; e, left subclavian artery; f, pulmonary trunk; g, right pulmonary artery; h, left pulmonary artery; I, descending aorta. Revised from Celoria and Patton.8
Interrupted aortic arch with venticular septal defect
187
Fig. 3 The subpulmonary ventricular septal defect (arrow) lying within the substance of the infundibular septum. PT, pulmonary trunk.
DISCUSSION IAA is a rare and usually fatal cardiovascular anomaly that requires early medical and surgical care of affected infants. As with by this case, the prognosis of IAA patients is extremely poor. Without surgical intervention most of the infants die within the first month of life.5 From data of 30 IAA infants 9 (30%) patients who did not undergo surgery, 8 (89%) died at a median age of four days.6 Survival beyond the first year of life has been reported only in patients without intracardiac lesions. Twenty patients have been reported to survive beyond the age of 15 years, the oldest presenting with isolated IAA at the age of 56 years.7 The pathogenesis of IAA is not clear. Research advances have provided a new focus on IAA in relation to certain genetic, embryologic, and morphogenetic disturbances. The first concerned the anatomic characterization of the anomaly based on the location of the interruption in relation to the origins of the great arteries. Reviewing 28 IAA cases, Celoria and Patton8 classified the anomalies according to the anatomical site of the interruption; Type A: interruption of the arch distal to the left subclavian artery, Type B: interruption of the arch distal to the left common carotid artery, and Type C: interruption distal to the innominate artery. The second significant advance was in cardiac embryology. Kirby et al.9 discovered that neural crest cells contribute to the normal development of aorticopulmonary septation and to the formation of aortic arch system. The third expansion of knowledge resulted from the recognition of typical multiorgan
anomalies involving the thymus, parathyroid and aortic arch system; all the structures have a common origin from the third and fourth pharyngeal arches.10 The fourth phase of knowledge was the recognition of chromosomal abnormalities. Deletion of 22q11 chromosome is reported to associate with IAA type B.3 Most IAA patients have associated intracardiac defects; a patent ductus arteriosus (PDA) almost always connects the pulmonary trunk to the descending aorta. With rare exceptions, IAA patients have either VSD (80–90%) or an aorticopulmonary window (10– 20%).11 Being the commonest associated anomaly in IAA, VSD was present in our case. Theoretical argument is given for the interruption of the aorta in these cases; namely obstruction of the left ventricular outflow tract and diversion of the fetal circulation across the VSD into the pulmonary circulation may lead to IAA. Our literature searches revealed several cases of IAA, but fatal IAA cases had not been reported in medico-legal literature. The absence of such reports in medico-legal literature may be explained by the following aspects: Most IAA cases are diagnosed and managed early in life, when death in such cases occurs later there are no medico-legal questions. In addition to being a rare congenital cardiovascular anomaly, our IAA case presented no symptoms to guide investigations and hence diagnosis and subsequent clinical management. Such sudden unexpected deaths always raise medico-legal questions as to the manner and the precise cause of death. The present case re-emphasizes the importance of a complete forensic autopsy for better clarification of
188
Journal of Clinical Forensic Medicine
the full circumstances surrounding the case of sudden unexpected natural death.
REFERENCES 1. Neye-Bock S, Fellows KE. Aortic arch interruption in infancy: radio- and angiographic features. Am J Roentgenol 1980; 135: 1005–1010. 2. Report of the New England Regional Infant Cardiac Program. Pediatrics 1980;65(Suppl):377–461. 3. Loffredo CA, Ferencz C, Wilson PD, Lurie IW. Interrupted aortic arch: an epidemiological study. Teratology 2000; 61: 368–375. 4. Baysal T, Kutlu R, Sarac K, Karaman I. Ruptured intracranial aneurysm associated with aortic arch interruption. Neuroradiology 2000; 42: 842–844. 5. Kocis KC, Midgley FM, Ruckman RN. Aortic arch complex anomalies: 20-year experience with symptoms,
6. 7. 8. 9. 10. 11.
diagnosis, associated cardiac defects, and surgical repair. Pediatr Cardiol 1997; 18: 127–132. Collins-Nakai RL, Dick M, Parisi-Buckley L, Fyler DC, Castaneda AR. Interrupted aortic arch in infancy. J Pediatr 1976; 88: 959–962. Hu WY, Sevick RJ, Tranmar BI, Maitland A, Gray RR. Aortic arch interruption associated with ruptured cerebral aneurysm. Can Assoc Radiol J 1996; 47: 20–23. Celoria GC, Patton RB. Congenital absence of the aortic arch. Am Heart J 1959; 58: 407–413. Kirby ML, Gale TF, Stewart DE. Neural crest cells contribute to normal aorticopulmonary septation. Science 1983; 220: 1059–1061. DiGeorges AM. Congenital absence of the tymus, and its immunological consequences: occurrence with congenital hypoparathyroidism. BirthDefects Orig ArtSer 1968;4: 116–121. Friedman WF, Silverman N. Congenital heart disease in infancy and childhood. In: Braunwald E, Zipes DP, Libby P (eds.) Heart disease: a textbook of cardiovascular medicine, vol. 2. Philadelphia, Toronto: Saunders, 2001;1505–1591.
CASE REPORT
Interrupted aortic arch with ventricular septal defect: an unsuspected fatal congenital anomaly in forensic pathology P. M. NgÕwalali, Y. Ohtsu, S. Tsunenari Department of Forensic Medicine, Kumamoto University School of Medicine, Kumamoto, Japan SUMMARY. Interrupted aortic arch (IAA) is a relatively rare cardiovascular anomaly worldwide and is very rarely encountered in forensic pathology. A case of clinically unsuspected fatal IAA in a 5-day old neonate is described. A full term female baby was declared dead on arrival at an emergency hospital few hours after having been discharged from a maternity hospital following delivery. There were no noticeable signs and symptoms reported during the short postnatal period. Antenatal medical history was unremarkable and there were no abnormalities noticed at birth. Autopsy revealed an unsuspected IAA arch with ventricular septal defect (VSD) as cause of sudden unexpected death. Although amenable to surgical intervention, IAA may not produce obvious clinical symptoms as was the case for this baby. Such sudden unexpected deaths raise medico-legal questions as to the manner and the precise cause of death. The importance of a full forensic autopsy to clarify such a sudden death was re-emphasized. Ó 2002 Elsevier Science Ltd and APS. All rights reserved. Journal of Clinical Forensic Medicine (2002) 9, 185–188
INTRODUCTION
CASE HISTORY
Interrupted or congenitally absent aortic arch (IAA) is defined as a complete anatomical separation of the ascending and descending aorta. It is a rare congenital anomaly accounting for only about 1% of all congenital cardiovascular anomalies1 and was found in only 24 of the 2251 infants registered in the New England Regional Infant Cardiac Program (NERICP) between 1969 and 1974.2 In an experience with 53 IAA cases over a period of 9 years, Loffredo et al.3 encountered an average of one case per year in each of the participating six pediatric cardiology centers. The prognosis for IAA patients is extremely poor, and without surgical intervention 76% will die in the newborn period and 90% will die in the first year of life.4 A fatal case of clinically unsuspected IAA in a 5day neonate is presented.
A full-term female baby was born at 0200 h. The antenatal period had been unremarkable, the mother had taken iron supplements. At birth the baby had no noticeable abnomalities, she had normal sucking reflex and appeared to sleep well. On the third day after birth at 2330 h, the baby was reluctant to feed on expressed breast milk (EBM) at two occasions. On day 4 at 1100 h, the baby was discharged home. Attempts to feed the baby at home with EBM and artificial formula at 1230 h and 1420 h respectively on the day of discharge were unsuccessful. By this time the baby was said to be immobile with cold upper and lower limbs. The baby was brought to an emergency hospital where he was pronounced dead on arrival. As no clinical diagnosis had been made, an autopsy was requested to clarify the circumstances surrounding the case. At autopsy the body was that of a full term female neonate weighing 3230 g and measuring 53 cm in length. Neither gross abnormalities nor cyanosis were noted externally. The heart was normal in size and weight. However, the ductus arteriosus was widely patent measured 0.5 cm in diameter and continued as a descending aorta (Fig. 1). Since the site of the
Received 3 August 2002 Accepted 3 October 2002 P. M. NgÕwalali MD, D Med Sci, Y. Ohtsu BMedTech, S. Tsunenari MD, Department of Forensic Medicine, Kumamoto University School of Medicine, 2-2-1 Honjyo, Kumamoto 860-0811, Japan. Correspondence to: Dr. P. M. NgÕwalali, Tel.: +81-96-373-5123; Fax: +81-96-373-5123; E-mail: [email protected] 185
186
Journal of Clinical Forensic Medicine
Fig. 1 The pulmonary trunk (PT) in continuity with the patent ductus arteriosus (PDA) and the descending aorta (DAo). The ascending aorta (Ao) is not connected to the DAo. Lsc, left subclavian artery; Lct, left common carotid; Rct, right common carotid artery; Rsc, right subclavian artery.
interruption of the aortic arch in the present case was distal to the left subclavian artery, the interruption was determined as IAA Type A (Fig. 2). Fig. 3 shows a ventricular septal defect (VSD) which was subpul-
monary in the infundibular septum. The stomach contained about 10 g of milk-curd. The other organs showed no pathological changes and the histological examination was unremarkable.
Fig. 2 Schematic presentation of the three IAA types; Types A, B and C. a, ascending aorta; b, right subclavian artery; c, right common carotid; d, left common carotid; e, left subclavian artery; f, pulmonary trunk; g, right pulmonary artery; h, left pulmonary artery; I, descending aorta. Revised from Celoria and Patton.8
Interrupted aortic arch with venticular septal defect
187
Fig. 3 The subpulmonary ventricular septal defect (arrow) lying within the substance of the infundibular septum. PT, pulmonary trunk.
DISCUSSION IAA is a rare and usually fatal cardiovascular anomaly that requires early medical and surgical care of affected infants. As with by this case, the prognosis of IAA patients is extremely poor. Without surgical intervention most of the infants die within the first month of life.5 From data of 30 IAA infants 9 (30%) patients who did not undergo surgery, 8 (89%) died at a median age of four days.6 Survival beyond the first year of life has been reported only in patients without intracardiac lesions. Twenty patients have been reported to survive beyond the age of 15 years, the oldest presenting with isolated IAA at the age of 56 years.7 The pathogenesis of IAA is not clear. Research advances have provided a new focus on IAA in relation to certain genetic, embryologic, and morphogenetic disturbances. The first concerned the anatomic characterization of the anomaly based on the location of the interruption in relation to the origins of the great arteries. Reviewing 28 IAA cases, Celoria and Patton8 classified the anomalies according to the anatomical site of the interruption; Type A: interruption of the arch distal to the left subclavian artery, Type B: interruption of the arch distal to the left common carotid artery, and Type C: interruption distal to the innominate artery. The second significant advance was in cardiac embryology. Kirby et al.9 discovered that neural crest cells contribute to the normal development of aorticopulmonary septation and to the formation of aortic arch system. The third expansion of knowledge resulted from the recognition of typical multiorgan
anomalies involving the thymus, parathyroid and aortic arch system; all the structures have a common origin from the third and fourth pharyngeal arches.10 The fourth phase of knowledge was the recognition of chromosomal abnormalities. Deletion of 22q11 chromosome is reported to associate with IAA type B.3 Most IAA patients have associated intracardiac defects; a patent ductus arteriosus (PDA) almost always connects the pulmonary trunk to the descending aorta. With rare exceptions, IAA patients have either VSD (80–90%) or an aorticopulmonary window (10– 20%).11 Being the commonest associated anomaly in IAA, VSD was present in our case. Theoretical argument is given for the interruption of the aorta in these cases; namely obstruction of the left ventricular outflow tract and diversion of the fetal circulation across the VSD into the pulmonary circulation may lead to IAA. Our literature searches revealed several cases of IAA, but fatal IAA cases had not been reported in medico-legal literature. The absence of such reports in medico-legal literature may be explained by the following aspects: Most IAA cases are diagnosed and managed early in life, when death in such cases occurs later there are no medico-legal questions. In addition to being a rare congenital cardiovascular anomaly, our IAA case presented no symptoms to guide investigations and hence diagnosis and subsequent clinical management. Such sudden unexpected deaths always raise medico-legal questions as to the manner and the precise cause of death. The present case re-emphasizes the importance of a complete forensic autopsy for better clarification of
188
Journal of Clinical Forensic Medicine
the full circumstances surrounding the case of sudden unexpected natural death.
REFERENCES 1. Neye-Bock S, Fellows KE. Aortic arch interruption in infancy: radio- and angiographic features. Am J Roentgenol 1980; 135: 1005–1010. 2. Report of the New England Regional Infant Cardiac Program. Pediatrics 1980;65(Suppl):377–461. 3. Loffredo CA, Ferencz C, Wilson PD, Lurie IW. Interrupted aortic arch: an epidemiological study. Teratology 2000; 61: 368–375. 4. Baysal T, Kutlu R, Sarac K, Karaman I. Ruptured intracranial aneurysm associated with aortic arch interruption. Neuroradiology 2000; 42: 842–844. 5. Kocis KC, Midgley FM, Ruckman RN. Aortic arch complex anomalies: 20-year experience with symptoms,
6. 7. 8. 9. 10. 11.
diagnosis, associated cardiac defects, and surgical repair. Pediatr Cardiol 1997; 18: 127–132. Collins-Nakai RL, Dick M, Parisi-Buckley L, Fyler DC, Castaneda AR. Interrupted aortic arch in infancy. J Pediatr 1976; 88: 959–962. Hu WY, Sevick RJ, Tranmar BI, Maitland A, Gray RR. Aortic arch interruption associated with ruptured cerebral aneurysm. Can Assoc Radiol J 1996; 47: 20–23. Celoria GC, Patton RB. Congenital absence of the aortic arch. Am Heart J 1959; 58: 407–413. Kirby ML, Gale TF, Stewart DE. Neural crest cells contribute to normal aorticopulmonary septation. Science 1983; 220: 1059–1061. DiGeorges AM. Congenital absence of the tymus, and its immunological consequences: occurrence with congenital hypoparathyroidism. BirthDefects Orig ArtSer 1968;4: 116–121. Friedman WF, Silverman N. Congenital heart disease in infancy and childhood. In: Braunwald E, Zipes DP, Libby P (eds.) Heart disease: a textbook of cardiovascular medicine, vol. 2. Philadelphia, Toronto: Saunders, 2001;1505–1591.