Pre-arrest heparinization and ventilation during warm ischemia preserves lung function in non-heart-beating donors

To solve the problem of donor scarcity, many attempts have been made including improved community education, relaxed organ acceptance criteria, increased reliance on single lung transplantation, and the use of partial organ donation. Unfortunately, these efforts have produced only modest increases in lung allograft availability; therefore, the so-called non-heart-beating organ donation must be considered. The aim of this study is to assess the viability of the non-heart-beating donor (NHBD) lung transplant rat model and determine the best strategy to manage the donor before and after cardiac arrest.

Fifty-five inbred Fischer rats were used as donors and recipients in an isogenic model of left lung transplantation. The rats were divided into 6 groups (n = 5): group I, normal controls without transplant; group II, heart-beating donor controls (HBD); group III, NHBD, no heparin, no ventilation during warm ischemia; group IV, NHBD, heparin, no ventilation; group V, NHBD, no heparin, ventilation; group VI, NHBD, heparin, ventilation. All lungs were stored at 4 degrees C for 4 hours. Animals were killed 24 hours after implantation. Gas exchange, pulmonary artery pressure, compliance, chest x-ray score, and histological score were assessed.

Heparinized and ventilated animals during warm ischemia (group VI) had similar performance than those transplanted without warm ischemia time in a scenario of heart-beating donor (group II). Groups III, IV, and V transplanted lungs showed severe damage.

The authors conclude that the rat lung transplantation model is useful to study the phenomena that occur in a setting of transplantation using NHBD and that heparinization and ventilation before cardiac arrest is the best strategy to manage non-heart-beating donors in this model.