Ann Thorac Surg 2008;85:1451-1453. doi:10.1016/j.athoracsur.2007.10.078
© 2008 The Society of Thoracic Surgeons
Case Reports
Interruption of the Ascending Aorta: A Hitherto Undescribed Lesion
Michael Weidenbach, MDa,*,
Ingo Daehnert, MDa,
Vit Razek, MDa,
Alexandra Beller, MDc,
Jan Janousek, MDa,
Martin Kostelka, MDb,
Robert H. Anderson, MDd
a Department of Pediatric Cardiology, Heart Center Leipzig, Leipzig, Germany
b Department of Cardiac Surgery, Heart Center Leipzig, Leipzig, Germany
c Department of Pathology, University of Leipzig, Leipzig, Germany
d Cardiac Unit, Institute of Child Health, University College, London, United Kingdom
Accepted for publication October 23, 2007.
* Address correspondence to Dr Weidenbach, Department of Pediatric Cardiology, Heart Center Leipzig, Struempellstr. 39, Leipzig, 04107, Germany (Email: michael.weidenbach{at}medizin.uni-leipzig.de).
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Abstract
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We are describing a most unusual variant of aortic arch interruption. The ascending aorta was atretic above the sinutubular junction forming a blind-ending pouch. The coronary arteries were the only vessels arising from the aortic trunk. All the brachiocephalic vessels were perfused in retrograde fashion through the arterial duct. The aortic valve itself was dysplastic, stenotic, and permitted severe regurgitation. There was no subaortic obstruction. A modified first stage Norwood palliation was performed. Due to myocardial insufficiency transthoracic extracorporeal membrane oxygenation had to be commenced at the end of surgery. Unfortunately the child died due to severe intracranial hemorrhage.
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Introduction
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Interruption of the aortic arch is well recognized and is usually stratified as suggested by Celoria and Patton [1] as long ago as 1959. The least frequent pattern is seen when the arch is interrupted between the brachiocephalic and the left common carotid arteries, the so-called type C. We have now encountered a most unusual variant in which there is interruption between the ascending aorta and the brachiocephalic artery. As far as we are aware, this lesion has not been previously described.
The child was born by normal vaginal delivery at term. Evaluation by echocardiography and cardiac catheterization revealed usual atrial arrangement with concordant atrioventricular and ventriculo-arterial connections. There was a small patent foramen ovale. Both ventricles and atrioventricular valves were of normal size, albeit with a large perimembranous ventricular septal defect, but in the absence of any subaortic obstruction. However, the orifice of the aortic valve was hypoplastic, and the leaflets were dysplastic, stenotic, and permitted severe regurgitation. The ascending aorta was atretic above the sinutubular junction, forming no more than a blind-ending pouch (Figs 1A and 2A). The coronary arteries were the only vessels arising from the aortic trunk, with both arteries arising from a single left-sided orifice. Due to the severe aortic regurgitation, the diastolic pressure in the pouch was equal to the diastolic pressure in the left ventricle. All the brachiocephalic vessels were perfused in retrograde fashion through a wide persistently patent arterial duct (Fig 1B). The pulmonary trunk, valve, and arteries were all normal. The morphology is depicted in Figure 1C. The electrocardiogram showed unspecific changes of repolarization with depressed and descending ST segments and negative T waves in the precordial leads. However, the cardiac enzymes were within normal limits. Clinically, the preoperative course was uncomplicated. The arterial duct was kept open by continuous infusion of prostaglandins. On day 15 of life, we proceeded with a modification of the first stage of Norwood palliation with cardiopulmonary bypass in deep hypothermia and selective cerebral perfusion. In addition to ductal cannulation, we also cannulated the aortic pouch, as the latter was needed to provide adequate coronary arterial perfusion. It proved difficult to infuse cardioplegia because of the run-off through the insufficient aortic valve, along with the unusual coronary arterial pattern; so the solutions were delivered through the orifice of the left coronary artery and also retrogradely through the coronary sinus. During surgery, the aortic valve was closed and the pulmonary trunk dissected proximal to the branches. Due to distance between the proximal and distal segments of the aorta, it proved impossible to reconnect the ascending aorta with the aortic arch. Therefore, we created a proximal anastomosis between the stump of the pulmonary trunk and the aortic pouch, and a distal anastomosis between the pulmonary arterial stump and the descending aorta (Fig 2B). The arterial duct was resected, and a conduit of 5 mm diameter was placed between the right ventricle and the pulmonary arteries. It then proved impossible to decannulate due to myocardial insufficiency occurring after acute dilation of the heart on bypass. We commenced transthoracic extracorporeal membrane oxygenation, but this was complicated by severe intracranial haemorrhage on postoperative day 6, making urgent weaning necessary. This was tolerated hemodynamically, but unfortunately the neonate died the next day due to the hemorrhage that involved the complete left frontoparietal lobe. Autopsy examination confirmed the surgical findings, including the presence of a single left coronary arterial orifice, albeit that an accessory infundibular branch was found arising from a slit-like orifice in the right coronary aortic sinus, the artery feeding the anterior aspect of the right ventricle.
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Fig 1. (A) Angiogram of ascending aorta reveals that this trunk supplies only the coronary arteries. (B) Angiogram of descending aorta, having advanced the catheter through the arterial duct, shows retrograde filling of the brachiocephalic arteries. (C) Drawing showing the anatomy. The shaded area marks the aortic pouch. (*Left coronary artery; **right coronary artery; ***accessory infundibular branch arising from the right coronary sinus; AD = arterial duct; Ao arch = aortic arch; PT = pulmonary trunk.)
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Fig 2. (A) Anatomy as seen during the surgical procedure. (B) Arrangement after reconstruction of the aortic arch. (*Native ascending aorta; **neoaorta; arrow represents distal anastomosis; arrowhead represents anastomosis from pulmonary trunk to aortic pouch.)
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Comment
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As far as we are aware, ours is the first description of interruption of the ascending aorta proximal to the origin of the brachiocephalic artery. When interruption is found within the aortic arch, then it is associated in a substantial number of cases with subaortic stenosis [2]. Severe aortic valvar stenosis or dysplastic aortic valves are less frequently described [3]. In the majority of neonates, primary complete repair can be safely done, even in more complex cases [3, 4]. We considered primary biventricular repair in our patient. This would have needed reconstruction of the arch, closure of the ventricular septal defect, and a Ross procedure [5], or interventricular re-routing [6]. However, because of the length of atretic segment, it was not possible to construct a direct anastomosis between the ascending and descending components of the aorta, so we opted to create a functionally univentricular circulation using a modification of the first stage of the Norwood sequence, and by inserting a conduit from the right ventricle to the pulmonary arteries.
Interruption of the aorta proximal of the brachiocephalic artery has major implications for both preoperative management and the subsequent surgical strategy. In this setting, the ascending aorta is part of the systemic circulation, usually with normal systemic blood pressures ensuring adequate coronary arterial perfusion during diastole. In our patient, the pressures in the ascending aorta were equal to ventricular pressures due to the severe aortic regurgitation and lack of any aortic elastic reservoir (Windkessel function). This compromised coronary arterial perfusion. However, the abnormal coronary arterial anatomy, coupled with the severe aortic regurgitation, made it difficult to instill the cardioplegic solutions, further compromising coronary arterial perfusion. All of these events almost certainly contributed to the myocardial insufficiency noted at the end of the surgical procedure.
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References
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- Celoria GC, Patton RB. Congenital absence of the aortic arch Am Heart J 1959;58:407-413.[Medline]
- Fulton JO, Mas C, Brizard CPR, Cochrane AD, Karl TR. Does left ventricular outflow tract obstruction influence outcome of interrupted aortic arch repair? Ann Thorac Surg 1999;67:177-181.[Abstract/Free Full Text]
- Steger V, Heinemann MK, Irtel von Brenndorff C, Ziemer G. Combined Norwood and Rastelli procedure for repair of interrupted aortic arch with subaortic stenosis Thorac Cardiovasc Surg 1998;46:156-158.[Medline]
- Kostelka M, Walther T, Geerdts I, et al. Primary repair for aortic arch obstruction associated with ventricular septal defect Ann Thorac Surg 2004;78:1989-1993discussion 1993.[Abstract/Free Full Text]
- Hirooka K, Fraser Jr CD. Ross-Konno procedure with interrupted aortic arch repair in a premature neonate Ann Thorac Surg 1997;64:249-251.[Abstract/Free Full Text]
- Takabayashi S, Kado H, Shiokawa Y, Fukae K, Nakano T. Long-term outcome of left ventricular outflow tract after biventricular repair using Damus-Kaye-Stansel anastomosis for interrupted aortic arch and severe aortic stenosis J Thorac Cardiovasc Surg 2005;130:942-944.[Free Full Text]
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Abstract
Introduction
