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Pathological changes and myocardial remodelling related to the mode of shunting following surgical palliation for hypoplastic left heart syndrome*

Published online by Cambridge University Press:  01 August 2008

Massimo A. Padalino*
Affiliation:
Pediatric and Congenital Cardiovascular Surgery Unit, University of Padua, Medical School, Padua, Italy
Chiara Castellani
Affiliation:
Cardiovascular Pathology, University of Padua, Medical School, Padua, Italy
Silvia Toffoli
Affiliation:
Cardiovascular Pathology, University of Padua, Medical School, Padua, Italy
Mila Della Barbera
Affiliation:
Cardiovascular Pathology, University of Padua, Medical School, Padua, Italy
Ornella Milanesi
Affiliation:
Pediatric Cardiology, University of Padua, Medical School, Padua, Italy
Gaetano Thiene
Affiliation:
Cardiovascular Pathology, University of Padua, Medical School, Padua, Italy
Giovanni Stellin
Affiliation:
Pediatric and Congenital Cardiovascular Surgery Unit, University of Padua, Medical School, Padua, Italy
Annalisa Angelini
Affiliation:
Cardiovascular Pathology, University of Padua, Medical School, Padua, Italy
*
Correspondence to: Massimo A. Padalino, MD, PhD, Pediatric and Congenital Cardiovascular Surgery Unit, Centro “Vincenzo Gallucci”, University of Padua Medical School, Via Giustiniani 2, 35128 Padua, Italy. Tel: +39-049-8212427; Fax: +39-049-8212409; E-mail: [email protected]

Abstract

Background

The modification of placing the shunt from the right ventricle to the pulmonary arteries, also known as Sano procedure, has allegedly improved results over the short term in surgical palliation of hypoplastic left heart syndrome with the Norwood procedure. With this in mind, we reviewed autopsied specimens from neonates and children who did not survive after either a classic arterio-pulmonary shunt, or the modified procedure with the shunt placed from the right ventricle to the pulmonary arteries, so as to evaluate the pathological substrates of the remodelling of the systemic right ventricle, assessing any differences induced by the 2 techniques.

Methods

We obtained the hearts from 11 patients with neonatal diagnosis of hypoplastic left heart syndrome who died after the first or second stages of the Norwood sequence of operations, comparing them with 6 normal hearts matched for age and weight. Macroscopic, microscopic and morphometric analysis were performed on each specimen, evaluating the diameter of the myocytes, extracellular matrix remodelling in terms of fibrosis and type of collagen, and vascularization in terms of capillary density.

Results

Hypertrophy of the myocytes was significantly increased in the hearts from patients having either a classic arterio-pulmonary or the ventriculo-pulmonary modification of the shunt compared to controls (p < 0.05). Myocardial fibrosis was increased in those having a shunt placed from the right ventricle to the pulmonary arteries when compared to the other 2 groups. The ratio of collagen I to collagen III was similar in those undergoing a classic arterio-pulmonary shunt compared to controls (0.94), but was lower in those having a shunt placed from the right ventricle to the pulmonary arteries (0.61), with an increase in collagen type III. The density of capillaries was lower in those who had undergone a classic arterial shunt when compared to the others.

Conclusion

We have shown greater remodelling of the ventricular myocardial extracellular matrix in patients having a shunt from the right ventricle to the pulmonary arteries when compared to those having a classic arterio-pulmonary shunt, with this remodelling progressing even after the neonatal period. This may influence a later suboptimal ventricular performance.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2008

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Footnotes

*

Supported by Cardio-Cerebral Pathology Registry, Regione Veneto, Venice, Italy.

References

1.Norwood, WI, Lang, P, Hansen, DD. Physiologic repair of aortic atresia-hypoplastic left heart syndrome. N Engl J Med 1983; 308: 2326.CrossRefGoogle ScholarPubMed
2.Kishimoto, H, Kawahira, Y, Kawata, H, Miura, T, Iwai, S, Mori, T. The modified Norwood palliation on a beating heart. J Thorac Cardiovasc Surg 1999; 118: 11301132.CrossRefGoogle ScholarPubMed
3.Sano, S, Ishino, K, Kawada, M, et al. Right ventricle_pulmonary artery shunt in first stage palliation of hypoplastic left heart syndrome. J Thorac Cardiovasc Surg 2003; 126: 504510.CrossRefGoogle ScholarPubMed
4.Pizarro, C, Norwood, WI. Right ventricle to pulmonary artery conduit has a favourable impact on postoperative physiology after stage I Norwood: preliminary results. Eur J CardioThorac Surgery 2003; 23: 991995.CrossRefGoogle Scholar
5.Mair, R, Tulzer, G, Sames, E, et al. Right ventricular to pulmonary artery conduit instead of modified Blalock-Taussig shunt improves postoperative hemodynamics in newborns after the Norwood operation. J Thorac Cardiovasc Surg 2003; 126: 13781384.CrossRefGoogle ScholarPubMed
6.Maher, KO, Pizarro, C, Gidding, SS, et al. Hemodynamic profile after the Norwood procedure with right ventricle to pulmonary artery conduit. Circulation 2003; 108: 782784.CrossRefGoogle ScholarPubMed
7.Sano, S, Ishino, K, Kado, H, et al. Outcome of right ventricle to pulmonary artery shunt in first stage palliation of hypoplastic left heart syndrome: a multi-institutional study. Ann Thorac Surg 2004; 78: 19511958.CrossRefGoogle ScholarPubMed
8.Olivetti, G, Melissari, M, Balbi, T, Quaini, F, Sonnenblick, EH, Anversa, P. Myocite nuclear and possibile cellular hyperplasia contribute to ventricular remodelling in the hypertrofic senescent heart in humans. J Am Coll Cardiol 1994; 24: 140149.CrossRefGoogle Scholar
9.Bove, EL, Ohye, RG, Devaney, EJ. Hypoplastic left heart syndrome: Conventional surgical management. Ped Cardiac Surg Ann Semin Thorac Cardiovasc Surg 2004; 7: 310.CrossRefGoogle ScholarPubMed
10.Ashburn, DA, McCrindle, BW, Tchervenkov, CI, et al. Outcomes after the Norwood operation in neonates with critical aortic stenosis or aortic valve atresia. J Thorac Cardiovasc Surg 2003; 125: 10701082.CrossRefGoogle ScholarPubMed
11.Hoffman, GM, Ghanayem, NS, Kampine, JM, et al. Venous saturation and the anaerobic threshold in neonates after the Norwood procedure for hypoplastic left heart syndrome. Ann Thorac Surg 2000; 70: 15151521.CrossRefGoogle ScholarPubMed
12.Jobes, DR, Nicolson, SC, Steven, JM, Miller, M, Jacobs, ML, Norwood, WI Jr. Carbon dioxide prevents pulmonary overcirculation in hypoplastic left heart syndrome. Ann Thorac Surg 1992; 54: 150151.CrossRefGoogle ScholarPubMed
13.Bradley, SM, Simsic, JM, Atz, AM. Hemodynamic effects of inspired carbon dioxide after the Norwood procedure. Ann Thorac Surg 2001; 72: 20882093.CrossRefGoogle ScholarPubMed
14.Tweddell, JS, Hoffman, GM, Fedderly, RT, et al. Phenoxybenzamine improves systemic oxygen delivery after the Norwood procedure. Ann Thorac Surg 1999; 67: 161167.CrossRefGoogle ScholarPubMed
15.Fraser, CD, Mee, RBB. Modified Norwood procedure for hypoplastic left heart syndrome. Ann Thorac Surg 1995; 60: S546S549.CrossRefGoogle ScholarPubMed
16.Imoto, Y, Kado, H, Shiokawa, Y, Fukae, K, Yasui, H. Norwood procedure without circulatory arrest. Ann Thorac Surg 1999; 68: 559561.CrossRefGoogle ScholarPubMed
17. Pigula FA, Nemoto EM, Griffith BP, Siewers RD. Regional low-flow perfusion provides cerebral circulatory support during neonatal aortic arch reconstruction. J Thorac Cardiovasc Surg 2000; 119: 331–339.CrossRefGoogle Scholar
18.Ohye, RG, Ludomirsly, A, Devaney, EJ, Bove, EL. Comparison of right ventricle to pulmonary artery conduit and modified Blalock Taussig shunt hemodynamic after the Norwood operation. Ann Thorac Surg 2004; 78: 10901093.CrossRefGoogle ScholarPubMed
19.Pizarro, C, Malec, E, Maher, KO, et al. Right ventricle to pulmonary artery conduit improves outcome after stage I Norwood for hypoplastic left heart syndrome. Circulation 2003; 108: SII155160.CrossRefGoogle Scholar
20.Hughes, ML, Shekerdemian, LS, Brizard, CP, Penny, DJ. Improved early ventricular performance with a right ventricle to pulmonary artery conduit in stage 1 palliation for hypoplastic left heart syndrome: evidence from strain Doppler echocardiography. Heart 2004; 90: 191194.CrossRefGoogle ScholarPubMed
21.Tanoue, Y, Kado, H, Shiokawa, Y, Fusazaki, N, Ishikawa, S. Midterm ventricular performance after Norwood procedure with right ventricular-pulmonary artery conduit. Ann Thorac Surg 2004; 78: 19651971.CrossRefGoogle ScholarPubMed
22.Tabbutt, S, Dominguez, TE, Ravishankar, C, et al. Outcomes after the stage I reconstruction comparing the right ventricular to pulmonary artery conduit with the modified Blalock Taussig shunt. Ann Thorac Surg 2005; 80: 15821591.CrossRefGoogle Scholar
23.Hanna, B, Colan, SD, Bridges, ND, Mayer, JE, Castaneda, AR. Clinical and myocardial status after left ventriculotomy for ventricular septal defects closure [abstract]. J Am Coll Cardiol 1991; 17: 110A.CrossRefGoogle Scholar