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Myocardial preservation for heart transplantation in children
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MYOCARDlAL PRESERVATION FOR HEART TRANSPLANTATION IN CHILDREN Ph. Pouard’ MD, Ph. Mauriat’ MD, P. Jayais’ MD, P. R. Vouhe** M.D, D. Journois’ MD, F. Leca” MD Department of ANAESTHESIOLOGY, LAENNEC, NECKER-ENFANTS MAtiDES ** Department of Cardiothoracic Surgery LAENNEC Hospital, Paris, FRANCE. ??
INTRODUCTION. Most children undergoing heart transplantation have end stage heart disease with pulmonary hypertension (PHT). This PHT may lead to acute right ventricular graft failure. Right ventricular failure or biventricular failure may be exacerbated by an inadequate myocardial preservation resulting in ischaemla and a decrease of the myocardial function. Due to distant procurement ischaemic time is usually prolonged. (mean ischaemic time was 166f 50 min in our serie). This finding enables us to enhance myocardial preservation by using diluted cold oxygenated dilute blood cardioplegic solution (COBC) alone or COBC associated with warm blood reperfusion as we do for prolonged operative ischaemic times. To evaluate the differences between these two methods of myocardial protection we reviewed the 32 heart, and heart and lung transplantations performed in children In our lnsitution since 1987 (divided into 3 groups below). METHODS. The patients ranged in age from three weeks to 13 years (mean age f SD, 5.7 years f 4.7). Recipients and donnors were only matched for weight and ABO compatibility. Before graft excision all donnor hearts were perfused with a cold hyperkaliemic crystalloid solution (CC). After excision they were placed in an iced saline solution for transport. In the operating room, the first four patients had nothing except the initial cardioplegia (groupe I), 20 received a COBC (group II) and in the 8 final cases (goupe Ill) the COBC was associated with warm reperfusion (WR) before aortic unclamping. The following data were analysed: rate of spontaneous rhythm rs covery, duration of assistance in cardiopulmonary bypass (CPB), need for inotropic support and early mortality. Occurences of spontaneous rhythm recovery, rhythm troubles, and need of an inotropic support were compared in the 3 groups using a contingency Khi square test. Anova test was used to compare inotropic doses. A p value of 0.05 was considered as significant to reject the null hypothesis. RESULTS. Spontaneous rhythm recovery: In group I, 50% of the patients had a spontaneous rhythm recovery (25% sinus rhythm, 25% heart block). This was increased to 95% in group II (65% sinus rhythm, 30% nodal rhythm) and 100% in group Ill (75% sinus rhythm, 13% nodal rhythm and 12% heart block) (p < 0.05). Duration of CPB assistance: time between aortic unclamping and discontinua-
tion of CPB was 66 f 2 minutes In group I, 57 f 29 minutes In group II, and 52 f 10 in group Ill. Need for inotropic support: In group I. 75% of the patients received double inotropic support, 25% had none. In group II, 10% had double inotropic support, 70% single inotropic support and 20% received nothing (p c 0.05). In group Ill, 70% had single inotropic support and 30% had no inotropic support. The mean doses of dobutamine were 2M5 pg/kg.min in group I, 126 pg/kg.min in group II and Qf2 pglkg.min in group Ill. Early mortality: there were six (19%) premature deaths, one acute graft rejection, two cases of inadequate graft preservation, and three cases of irreversible pulmonary hypertension. DISCUSSION. Paediatric heart transplantation remains controversial. Both for ethical (long term survival time in children is unknown) and technical reasons : (high rate of pulmonary hypertension leading to graft failure). However heart transplantation is often the only effective therapy for end stage cardiac failure in children and Is now accepted. Prolonged myocardial preservation remains also controversial. As It has been demonstrated, crystalloid cardioplegic solution may be inappropriate in children [l]. The benefits of cold oxygenated dilute blood cardioplegia have been established In adults by Dagett and al [2] and in children during routine use in our Institution [3]. Furthermore, it has been reported that using an infusion of cardioplegic solution when the donnor heart has just been implanted may decrease the need for inotropic support [4]. In addition, blood reperfusion is known to enhance recovery of preservated associating diluted blood cardioplegic hearts [5]. By solution and warm blood reperfusion our preliminary results suggest a better myocardial recovery of grafts. REFERENCE: l- Pedro J. del Nido, Donald A.G. Mickle, M.D., Gregory J. Wilson M.D. et al. Inadequate myocardial protection with cold cardioplegic arrest during repair of tretralogy of Fallot. J Thorac Cardiovasc Surg, 1988, 95: 223-g. 2- Will&d M. Daggett, Jr., M.D., John D. Randolph, M.D., et al. The superiority of cold oxygenated dilute blood cardioplegia. Ann Thorac Surg 43: 397-402, Apr 1887. 3- Gilles D. Touati M.D., Pascal R. Vouhe M.D., Philippe Pouard M.D. et al. Primary repair of tetralogy of Failot in infancy. Congress of the American Association of Thoracic Surgery, BOSTON, May 1989. 4- Harold L. Lazar M.D., G. Arnaud Painvin M.D.. Arthur J.
MYOCARDlAL PRESERVATION FOR HEART TRANSPLANTATION IN CHILDREN Ph. Pouard’ MD, Ph. Mauriat’ MD, P. Jayais’ MD, P. R. Vouhe** M.D, D. Journois’ MD, F. Leca” MD Department of ANAESTHESIOLOGY, LAENNEC, NECKER-ENFANTS MAtiDES ** Department of Cardiothoracic Surgery LAENNEC Hospital, Paris, FRANCE. ??
INTRODUCTION. Most children undergoing heart transplantation have end stage heart disease with pulmonary hypertension (PHT). This PHT may lead to acute right ventricular graft failure. Right ventricular failure or biventricular failure may be exacerbated by an inadequate myocardial preservation resulting in ischaemla and a decrease of the myocardial function. Due to distant procurement ischaemic time is usually prolonged. (mean ischaemic time was 166f 50 min in our serie). This finding enables us to enhance myocardial preservation by using diluted cold oxygenated dilute blood cardioplegic solution (COBC) alone or COBC associated with warm blood reperfusion as we do for prolonged operative ischaemic times. To evaluate the differences between these two methods of myocardial protection we reviewed the 32 heart, and heart and lung transplantations performed in children In our lnsitution since 1987 (divided into 3 groups below). METHODS. The patients ranged in age from three weeks to 13 years (mean age f SD, 5.7 years f 4.7). Recipients and donnors were only matched for weight and ABO compatibility. Before graft excision all donnor hearts were perfused with a cold hyperkaliemic crystalloid solution (CC). After excision they were placed in an iced saline solution for transport. In the operating room, the first four patients had nothing except the initial cardioplegia (groupe I), 20 received a COBC (group II) and in the 8 final cases (goupe Ill) the COBC was associated with warm reperfusion (WR) before aortic unclamping. The following data were analysed: rate of spontaneous rhythm rs covery, duration of assistance in cardiopulmonary bypass (CPB), need for inotropic support and early mortality. Occurences of spontaneous rhythm recovery, rhythm troubles, and need of an inotropic support were compared in the 3 groups using a contingency Khi square test. Anova test was used to compare inotropic doses. A p value of 0.05 was considered as significant to reject the null hypothesis. RESULTS. Spontaneous rhythm recovery: In group I, 50% of the patients had a spontaneous rhythm recovery (25% sinus rhythm, 25% heart block). This was increased to 95% in group II (65% sinus rhythm, 30% nodal rhythm) and 100% in group Ill (75% sinus rhythm, 13% nodal rhythm and 12% heart block) (p < 0.05). Duration of CPB assistance: time between aortic unclamping and discontinua-
tion of CPB was 66 f 2 minutes In group I, 57 f 29 minutes In group II, and 52 f 10 in group Ill. Need for inotropic support: In group I. 75% of the patients received double inotropic support, 25% had none. In group II, 10% had double inotropic support, 70% single inotropic support and 20% received nothing (p c 0.05). In group Ill, 70% had single inotropic support and 30% had no inotropic support. The mean doses of dobutamine were 2M5 pg/kg.min in group I, 126 pg/kg.min in group II and Qf2 pglkg.min in group Ill. Early mortality: there were six (19%) premature deaths, one acute graft rejection, two cases of inadequate graft preservation, and three cases of irreversible pulmonary hypertension. DISCUSSION. Paediatric heart transplantation remains controversial. Both for ethical (long term survival time in children is unknown) and technical reasons : (high rate of pulmonary hypertension leading to graft failure). However heart transplantation is often the only effective therapy for end stage cardiac failure in children and Is now accepted. Prolonged myocardial preservation remains also controversial. As It has been demonstrated, crystalloid cardioplegic solution may be inappropriate in children [l]. The benefits of cold oxygenated dilute blood cardioplegia have been established In adults by Dagett and al [2] and in children during routine use in our Institution [3]. Furthermore, it has been reported that using an infusion of cardioplegic solution when the donnor heart has just been implanted may decrease the need for inotropic support [4]. In addition, blood reperfusion is known to enhance recovery of preservated associating diluted blood cardioplegic hearts [5]. By solution and warm blood reperfusion our preliminary results suggest a better myocardial recovery of grafts. REFERENCE: l- Pedro J. del Nido, Donald A.G. Mickle, M.D., Gregory J. Wilson M.D. et al. Inadequate myocardial protection with cold cardioplegic arrest during repair of tretralogy of Fallot. J Thorac Cardiovasc Surg, 1988, 95: 223-g. 2- Will&d M. Daggett, Jr., M.D., John D. Randolph, M.D., et al. The superiority of cold oxygenated dilute blood cardioplegia. Ann Thorac Surg 43: 397-402, Apr 1887. 3- Gilles D. Touati M.D., Pascal R. Vouhe M.D., Philippe Pouard M.D. et al. Primary repair of tetralogy of Failot in infancy. Congress of the American Association of Thoracic Surgery, BOSTON, May 1989. 4- Harold L. Lazar M.D., G. Arnaud Painvin M.D.. Arthur J.