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Abstract

The recent letter by Carotti and colleagues [1Carotti A. Piacentini G. Marino B. Ductal origin of the distal pulmonary artery in truncus arteriosus.Ann Thorac Surg. 2007; 83 (letter): 2262Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] addresses the association between a rare variant of truncus arteriosus and ductal origin of the distal pulmonary artery, which was not mentioned in our recent review [2Trivedi K.R. Karamlou T. Yoo S.J. Williams W.G. Freedom R.M. McCrindle B.W. Outcomes in 45 children with ductal origin of the distal pulmonary artery.Ann Thorac Surg. 2006; 81: 950-957Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar]. The modified Van Praagh classification [3Van Praagh R. Van Praagh S. The anatomy of common aorticopumonary trunk (truncus arteriosus communis) and its embryonic implications A study of 57 necrospsy cases.Am J Cardiol. 1965; 16: 406Abstract Full Text PDF PubMed Scopus (384) Google Scholar] describes a single origin of the pulmonary artery from the common arterial trunk (usually the right pulmonary artery), with either the ductus or collateral vessels supplying the contralateral side, classified as type A3. Others have described this morphologic type as hemitruncus [4Mee R.B. Surgical repair of hemitruncus: principles and techniques.J Card Surg. 1987; 2: 247Crossref PubMed Scopus (11) Google Scholar, 5Van der Horst R.L. Gotsman M.S. Type 3c truncus arteriosus Case report with clinical and surgical implications.B heart J. 1974; 36: 1046Crossref PubMed Scopus (6) Google Scholar] to emphasize the discontinuity of the pulmonary arteries.Although we are aware of this variant of truncus arteriosus, it is worth mentioning that overall, Van Praagh types A1 and A2 represent the majority of the morphologic spectrum of truncus arteriosus, comprising 86% of patients with truncus arteriosus in the GLH autopsy series and 89% in the Toronto series [6Calder L. Van Praagh R. Van Praagh S. et al.Truncus arteriosus communis Clinical, angiocardiographic, and pathologic findings in 100 patients.Am Heart J. 1976; 92: 23-38Abstract Full Text PDF PubMed Scopus (62) Google Scholar, 7Williams J.M. de Leeuw M. Blalck M.D. Freedom R.M. Williams W.G. McCrindle B.W. Factors associated with outcomes of persistent truncus arteriosus.J Am Coll Cardiol. 1999; 34: 545Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar]. Those patients with a true ductal origin of the distal pulmonary artery, as opposed to those with multiple collateral supply, represent an even more discrete subgroup, with only 2% of all patients with type A3 truncus arteriosus. Accordingly, we had no patients with hemitruncus in our series. This rarity notwithstanding, the morphology of hemitruncus is highly variable, and thus experience with each type is limited, making useful inferences problematic.We chose instead to concentrate on the morphologic spectrum present in our series of patients, although certainly the association mentioned by Carotti and colleagues [1Carotti A. Piacentini G. Marino B. Ductal origin of the distal pulmonary artery in truncus arteriosus.Ann Thorac Surg. 2007; 83 (letter): 2262Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] is relevant. Regarding surgical management, it is pragmatic to consider general principles used in the management of patients with ductal origin of the distal pulmonary artery that are described in our report. Specifically, those with pulmonary atresia and bilateral ducti in which unifocalization to create an intrapericardial pulmonary confluence followed by right ventricular outflow tract reconstruction was required. Or, our description of the importance of pulmonary overcirculation as a presenting sign in patients with type A3 truncus arteriosus. The association with deletion of chromosome 22q11 with truncus arteriosus (ie, roughly 33%) is an important point [8Goldmuntz E. Clark B.J. Mitchell L.E. Jawad A.F. et al.Frequency of 22q11 deletions in patients with conotruncal defects.J Am Coll Cardiol. 1998; 32: 492Abstract Full Text Full Text PDF PubMed Scopus (470) Google Scholar, 9Momma K. Ando M. Matsuoka R. Truncus arteriosus communis associated with chromosome 22q11 deletion.J Am Coll Cardiol. 1997; 30: 1067Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar]. However this genetic abnormality is not specific to ductal origin of the distal pulmonary artery, and therefore it was not mentioned in our report. The recent letter by Carotti and colleagues [1Carotti A. Piacentini G. Marino B. Ductal origin of the distal pulmonary artery in truncus arteriosus.Ann Thorac Surg. 2007; 83 (letter): 2262Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] addresses the association between a rare variant of truncus arteriosus and ductal origin of the distal pulmonary artery, which was not mentioned in our recent review [2Trivedi K.R. Karamlou T. Yoo S.J. Williams W.G. Freedom R.M. McCrindle B.W. Outcomes in 45 children with ductal origin of the distal pulmonary artery.Ann Thorac Surg. 2006; 81: 950-957Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar]. The modified Van Praagh classification [3Van Praagh R. Van Praagh S. The anatomy of common aorticopumonary trunk (truncus arteriosus communis) and its embryonic implications A study of 57 necrospsy cases.Am J Cardiol. 1965; 16: 406Abstract Full Text PDF PubMed Scopus (384) Google Scholar] describes a single origin of the pulmonary artery from the common arterial trunk (usually the right pulmonary artery), with either the ductus or collateral vessels supplying the contralateral side, classified as type A3. Others have described this morphologic type as hemitruncus [4Mee R.B. Surgical repair of hemitruncus: principles and techniques.J Card Surg. 1987; 2: 247Crossref PubMed Scopus (11) Google Scholar, 5Van der Horst R.L. Gotsman M.S. Type 3c truncus arteriosus Case report with clinical and surgical implications.B heart J. 1974; 36: 1046Crossref PubMed Scopus (6) Google Scholar] to emphasize the discontinuity of the pulmonary arteries. Although we are aware of this variant of truncus arteriosus, it is worth mentioning that overall, Van Praagh types A1 and A2 represent the majority of the morphologic spectrum of truncus arteriosus, comprising 86% of patients with truncus arteriosus in the GLH autopsy series and 89% in the Toronto series [6Calder L. Van Praagh R. Van Praagh S. et al.Truncus arteriosus communis Clinical, angiocardiographic, and pathologic findings in 100 patients.Am Heart J. 1976; 92: 23-38Abstract Full Text PDF PubMed Scopus (62) Google Scholar, 7Williams J.M. de Leeuw M. Blalck M.D. Freedom R.M. Williams W.G. McCrindle B.W. Factors associated with outcomes of persistent truncus arteriosus.J Am Coll Cardiol. 1999; 34: 545Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar]. Those patients with a true ductal origin of the distal pulmonary artery, as opposed to those with multiple collateral supply, represent an even more discrete subgroup, with only 2% of all patients with type A3 truncus arteriosus. Accordingly, we had no patients with hemitruncus in our series. This rarity notwithstanding, the morphology of hemitruncus is highly variable, and thus experience with each type is limited, making useful inferences problematic. We chose instead to concentrate on the morphologic spectrum present in our series of patients, although certainly the association mentioned by Carotti and colleagues [1Carotti A. Piacentini G. Marino B. Ductal origin of the distal pulmonary artery in truncus arteriosus.Ann Thorac Surg. 2007; 83 (letter): 2262Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] is relevant. Regarding surgical management, it is pragmatic to consider general principles used in the management of patients with ductal origin of the distal pulmonary artery that are described in our report. Specifically, those with pulmonary atresia and bilateral ducti in which unifocalization to create an intrapericardial pulmonary confluence followed by right ventricular outflow tract reconstruction was required. Or, our description of the importance of pulmonary overcirculation as a presenting sign in patients with type A3 truncus arteriosus. The association with deletion of chromosome 22q11 with truncus arteriosus (ie, roughly 33%) is an important point [8Goldmuntz E. Clark B.J. Mitchell L.E. Jawad A.F. et al.Frequency of 22q11 deletions in patients with conotruncal defects.J Am Coll Cardiol. 1998; 32: 492Abstract Full Text Full Text PDF PubMed Scopus (470) Google Scholar, 9Momma K. Ando M. Matsuoka R. Truncus arteriosus communis associated with chromosome 22q11 deletion.J Am Coll Cardiol. 1997; 30: 1067Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar]. However this genetic abnormality is not specific to ductal origin of the distal pulmonary artery, and therefore it was not mentioned in our report. Ductal Origin of the Distal Pulmonary Artery in Truncus ArteriosusThe Annals of Thoracic SurgeryVol. 83Issue 6PreviewWe read with interest the article by Trivedi and colleagues [1] on ductal origin of the distal pulmonary artery. Authors report on a series of patients with discontinuous pulmonary arteries and ductal origin of one of them not only as an isolated lesion, but also in association with tetralogy of Fallot, pulmonary atresia with ventricular septal defect, and heterotaxy. However there is no mention in their article about the possible association of ductal origin of distal pulmonary artery with truncus arteriosus. Full-Text PDF