Peripheral lung volume reduction improved early graft function in severe size mismatched living donor lobar lung transplantation

Background. Lung transplantation from adults to infants or small children is still challenging because of concerns related to size disparity. Peripheral lung volume reduction for size disparity in cadaveric donor lung transplantation has been widely performed; however, little is known about the efficacy and the functional outcomes of downsizing the implanted lobes for severe size disparity in living donor lobar lung transplantation. Methods. Thirteen size-mismatched (donor/recipient lung volume ratio >2.82) bilateral living donor lobar lung transplants were performed with (reduction group, n = 6) or without (no-reduction group, n = 7) peripheral lung volume reduction. Results. On spontaneous respiration, PaO₂ in the reduction group was significantly higher than that in the no-reduction group (P < .01) and PaCO₂ in the reduction group was significantly lower than that in the no-reduction group (P < .001). Pulmonary vascular resistance in the reduction group remained significantly lower than that in the no-reduction group throughout the assessment periods after chest closure (P < .05). Peak airway pressure in the no-reduction group increased significantly at the time of chest closure (P < .001) and remained significantly higher than that in the reduction group throughout the assessment period on mechanical ventilation (P < .01). The percentage of weight reduced from implanted grafts significantly correlated with donor/recipient lung volume ratio (r = 0.82, P < .05). Conclusions. Peripheral lung volume reduction is useful to improve early graft function in severe size mismatched experimental living donor lobar lung transplantation. The technique might allow for further flexibility in donor size and for increasing the donor pool for small recipients.