J Thorac Cardiovasc Surg 2004;127:606-607
© 2004 The American Association for Thoracic Surgery
Heterotopic right heart transplantation
Antonio F. Corno, MD, PD, FECTS, FRCS
Service de Chirurgie Cardio-vasculaire, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
To the Editor:
In a recent issue of the Journal, Elefteriades and coworkers1 published their interesting short-term experimental study with the technique for isolated accessory right heart transplantation. The idea is definitely clever, and this technique will open new potential approaches in the management of patients with congenital heart defects.
According to the suggestions of the authors, this technique should be taken into consideration as a potential alternative treatment in two groups of patients1: (1) children with congenital heart defects and right heart malformation not allowing a biventricular type of repair because of the presence of a right ventricle that is either underdeveloped or malfunctioning and (2) patients with congenital heart defects and either right ventricular failure after biventricular repair in the presence of elevated pulmonary vascular resistance, or failure of Fontan type of procedure because of the presence of mild to moderate increase of pulmonary vascular resistance.
Despite the authors' acknowledgement that cardiac surgeons will have to consider this new technique as simply another tool in their armamentarium to face complex situations, it probably is worthwhile to consider other options not discussed in this article. For the patients of group 1, the alternative of one-and-a-half ventricular repair should be always ruled out before considering accessory right heart transplantation. In most children with complex congenital heart defects, it is possible to use a hypoplastic or malfunctioning right ventricle to pump the inferior vena cava venous return into the pulmonary circulation, deviating the venous return from the superior vena cava directly into the pulmonary circulation with an end-to-side anastomosis to the right pulmonary artery (bidirectional Glenn). This approach of one-and-a-half ventricular repair, which is of course suitable only in the presence of normal pulmonary vascular resistance, has been proved successful in various reported experiences.2-4
For patients in group 2, with elevated pulmonary vascular resistance, not suitable for a Fontan type of procedure or with failing Fontan procedure, the authors did not provide any proof that their technique with the two right ventricles will allow the heart to overcome elevated pulmonary vascular resistance. They did demonstrate that the system with two right ventricles can work in the short term, but they did not provide any data regarding the possibility for this combination with an unprepared donor right ventricle of supporting either a right ventricular volume overload or a pressure overload.
At this point, if we have a donor heart available and wish to consider a donor ventricle to pump against elevated pulmonary vascular resistance in heterotopic position, we consider it much better to use a donor left ventricle. A left ventricle is definitely able to overcome very high pulmonary vascular resistance, at least up to a systemic level.
This idea was tested in an acute experimental study performed when I was at University of California, Los Angeles, and we were able to prove that our heterotopic right heart assist transplant (heart with two left ventricles) was able to function against pulmonary vascular resistance artificially elevated to the systemic level.5 Although this technique requires a little more complicated surgical approach and understanding, as the technique reported by Elefteriades and coworkers1 does not require cardiopulmonary bypass, it could potentially applied to a much larger patient population, particularly including children with severe pulmonary hypertension.
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References
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- Elefteriades J, Lovoulos C, Edwards R, Tittle S, Riley T, Tang P, et al. Novel technique for isolated accessory right heart transplantation for congenital heart disease. J Thorac Cardiovasc Surg. 2003;125:1283–1290[Abstract/Free Full Text]
- Corno AF. Surgical treatment of complex cardiac anomalies: the "one and one half ventricle repair". [editorial]Eur J Cardiothorac Surg. 2002;22:436–437
- Corno AF, Chassot PG, Payot M, Sekarski N, Tozzi P, von Segesser LK. Ebstein's anomaly: one and a half ventricular repair. Swiss Med Wkly. 2002;132:485–488[Medline]
- Stellin G, Vida VL, Milanesi O, Rubino M, Padalino MA, Secchieri S, et al. Surgical treatment of complex cardiac anomalies: the "one and one half ventricle repair". Eur J Cardiothorac Surg. 2002;22:1043–1049[Abstract/Free Full Text]
- Corno AF, Laks H, Davtyan H, Flynn WM, Chang P, Drinkwater DC. The heterotopic right heart assist transplant. J Heart Transplant. 1988;7:183–190[Medline]
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