Living Lung Donor

Generally but not exclusively, lung donors for a specific recipient are chosen in pairs and hence put two donors at risk.^[73] This affords the recipient an adequate mass of normal lung tissue without diminishing the postoperative pulmonary reserve of either donor more than necessary. Cystic fibrosis (CF) is the most common indication for living lung donation. Frequently, the donors are parents of the recipient, although siblings, other relatives, and even nonrelatives have been used. Occasionally, living lung donation is considered for selected patients with end-stage pulmonary disease other than CF. Each donor undergoes a thorough evaluation, including pulmonary function testing, ventilation-perfusion scanning, roentgenography, computed tomography of the chest, and echocardiography. ^[74] Together, these tests are used to determine whether a potential donor has adequate pulmonary and cardiac function to safely relinquish a lobe, as well as determine the suitability of the lobes for the recipient (size matching is important). As with cadaveric donors, serologic testing is performed to establish ABO compatibility (the extent of HLA matching is not currently known to affect the outcome of this procedure). Usually, a left lower lobe is harvested from one donor and a right lower lobe from the other. Other lobes may be used, but often with greater technical challenge or suboptimal function in the recipient.

Although mortality in living lung donors is low, significant morbidity has been reported. Battafarano and associates reported postoperative complications in 61.3% (of 62 donors) of patients undergoing living lung donation. Complications included pleural effusion requiring drainage, hemorrhage, phrenic nerve injury, pericarditis, pneumonia, and ileus.^[75] Furthermore, Barr coauthors reported a 2.5% incidence of donor re-exploration during the initial hospitalization, as well as two patients with pulmonary artery thrombosis. In addition, during a 1- and 2-year follow-up, pulmonary function testing in donors demonstrated a decrease of 15% to 17% in forced expiratory volume (FEV), total lung capacity (TLC), and forced vital capacity (FVC).^[76] Postoperative quality of life was rated favorably by donors, and most stated that their health was unchanged after donation.^[77]

Retrieval of the organs is performed in much the same way as a lobectomy is performed for conventional indications. An important difference when compared with cancer surgery is the need to preserve an adequate cuff of the bronchus, pulmonary artery, and vein to allow implantation into the recipient.^[76] Accordingly, the anesthetic management is very similar. General anesthesia with or without epidural analgesia is performed with standard lung separation techniques and lateral decubitus positioning. Typically, the surgeon will announce the impending lobar artery ligation so that intravenous heparin may be given before halting the circulation within the lobe. Preservative solution is flushed through the lobe ex vivo to avoid systemic administration to the donor.