REDUCED-SIZE LUNG TRANSPLANTATION FROM ADULT TO NEONATAL SWINE

Background: Lung donor shortage is a critical factor limiting the expa nsion of pediatric lung transplantation programs. This report details the surgical technical feasibility of a training model of lobar lung t ransplantation as well as the perioperative monitoring to evaluate the appropriate pulmonary graft function. Methods: Ten hybrid Large-White pigs underwent left lower lobe lung allotransplantation; Donors weigh ed 15 to 20 kg and recipients 5 to 7 kg, The first five animals were u sed to learn the surgical anatomy and to establish the surgical techni que and instrumentation's model (Group A). One hour after transplantat ion the right lung was excluded. Lung function and hemodynamic data we re collected sequentially in the following five animals (Group B). Res ults: The left inferior pulmonary lobe was found to be the most suitab le allograft for transplantation. Usually, bronchial size discrepancy allowed telescoping of the airway anastomosis. Left atrial clamping wa s well tolerated during the pulmonary vein anastomoses. Preoperative a ntiaggregation and postoperatively heparinization achieved with ACT va lues over 200 seconds, prevented left atrial thrombosis. After right l ung exclusion, hemodynamic changes consisted of a sustained increase i n pulmonary vascular resistance and a reduction in cardiac output. Lun g mechanics were also modified, with a gradual rise in airway resistan ce and a fall in compliance. Conclusions: The neonatal pig tolerates l eft lobar pulmonary transplantation satisfactorily. Although it is a u seful and promising surgical learning model, questions remain regardin g the applicability of this experience to clinical pediatric lung tran splantation.