Recipient candidates for LDLLT should meet the criteria for cadaveric lung transplantation , and in the US should be listed on the Organ Procurement and Transplantation Network lung transplantation waiting list [5, 6]. Given that cadaveric whole lungs are preferable to lobes from living donors , most candidates for living donor lung transplantation should be expected to die or become too ill for transplantation while waiting to receive cadaveric lungs from the waiting list. Approximately 80 % of our recipients of living donor lungs, both adult and pediatric, have been transplanted for end-stage pulmonary failure secondary to cystic fibrosis. Other diagnoses include pulmonary hypertension, idiopathic pulmonary fibrosis, bronchopulmonary dysplasia, and obliterative bronchiolitis [7]. Seventy-five percent of adults and 50 % of children were hospitalized, and 18 % of patients were ventilator dependent at the time of transplantation. In Japan, where cystic fibrosis is rare, interstitial pneumonia is the most common diagnosis, followed by bronchiolitis obliterans, pulmonary artery hypertension, bronchiectasis, and lymphangioleiomyomatosis [3].

Though living donor kidney and liver transplantation had been performed for some time prior to the first living donor lung transplant, the potential risks associated with pulmonary lobectomy, as well as the need for two healthy donors for each recipient, raised potential ethical issues not previously seen in organ transplantation. In their discussion of the ethics of living donor lung transplantation, Wells and Barr pointed out that donation of a pulmonary lobe by a living volunteer was incompatible with the pillar of medical ethics as established by the Hippocratic maxim “primum non nocere” (first do no harm) [8]. The absence of physical benefit to the donors, coupled with the potential for pain, surgical complications, and long-term pulmonary compromise, required a more complex set of moral theories. These were provided by Beauchamp and Childress [9], who put these issues into the perspective of four basic principles of biomedical ethics:

Using this framework, it becomes ethically possible to identify healthy donors with adequate pulmonary reserve, appropriate motivation, and an understanding and willingness to accept the risks of donation. Our criteria for donation are as follows:

Whereas we originally considered only parents as appropriate potential donors , we have expanded our criteria to include siblings, extended family members, and occasionally unrelated individuals who can demonstrate an appropriate nonfinancial relationship to the recipient. Potential donors are carefully interviewed and analyzed from a psychological and social standpoint to determine their relationship with the recipient, motivation for donation, ability to withstand the pain and recovery from the operation, and their understanding and ability to withstand a potentially poor recipient outcome. They are also interviewed independently in order to identify potential evidence of coercion or other emotional issues that might exclude them from participating.

After determination of ABO blood group compatibility with the potential recipient, potential donors undergo an anatomic and physiologic evaluation to determine their suitability for donation, and to choose one donor to donate the right lower lobe, and another for the left lower lobe. The evaluation includes a room air arterial blood gas, spirometry, echocardiography, ventilation-perfusion (VQ) scan, and computed tomography (CT) scan of the chest to exclude pulmonary pathology and to allow volumetric assessment of the lobes being considered [10]. Considerable attention must be paid to matching a given recipient with donor lobes that provide adequate function and fit. Undersized lobes run the risk of providing inadequate pulmonary reserve, as well as pleural space problems such as persistent air leaks, pleural effusions, and empyema. Oversized lungs run the risk of atelectasis with subsequent pneumonia, decreased diaphragmatic excursion with poor ventilation, or compression of the contralateral side. Some centers use three-dimensional CT to determine size compatibility of donor lobes and to predictpost-transplant graft forced vital capacity [11, 12]. The chest CT scan can also be used to identify anatomic features that can be used to assist in choosing a donor for one side over another. These features might include variations in pulmonary arterial or venous anatomy, or the degree of completeness of the pulmonary fissures. Unilateral pathology, such as small granulomas or blebs, or a history of previous thoracic surgery on one side does not necessarily exclude individuals from donating a lower lobe from the contralateral side.

The technical aspects of donor lobectomies are significantly different from lobectomies performed for cancer or other pathology. The donor surgeons must provide the recipient surgeon with grafts containing bronchial and vascular cuffs that are sufficient for surgical implantation using standard surgical anastomotic techniques. At the same time, an adequate margin must be left on each donor side in order to close the lobar bronchus, pulmonary artery, and pulmonary vein without compromising the remaining lungs. Variations in pulmonary vascular and bronchial anatomy, combined with varying degrees of completeness of the pulmonary fissures, can make these procedures challenging. Great care is taken to handle and manipulate the donor lobes as little as possible in order to avoid parenchymal injury that might translate into pulmonary damage or dysfunction in the recipient.

After placement of an epidural catheter for postoperative analgesia, general anesthesia is induced and fiber-optic bronchoscopy performed to exclude bronchial pathology or identify variations in bronchial anatomy. After placement of a double-lumen endotracheal tube, donors are placed in the lateral decubitus position with the operative side up. An intravenous drip of prostaglandin E₁ is initiated and titrated to a systolic blood pressure of 90–100 mmHg in order to dilate the pulmonary vascular bed. A lateral thoracotomy incision is made and the pleural space entered through the fifth interspace. Though we usually start with a relatively small muscle-sparing incision, it is sometimes necessary to enlarge the incision in order to minimize handling of the lobe, as well as maximize safety when dissecting, transecting, and repairing the pulmonary artery and vein. After deflating the lung with the double-lumen endotracheal tube, the lung and pleural space are examined, and a time estimate forwarded to the recipient operating room. Using an atraumatic clamp on the lung for retraction, the inferior pulmonary ligament is incised up to the inferior pulmonary vein. The posterior mediastinal pleura is then incised from the inferior hilum to just below the takeoff of the upper lobe bronchus. After making sure that there are no branches draining either the middle or upper lobes into the inferior pulmonary vein, the inferior vein is circumferentially dissected. Care is taken not to manipulate or injure the phrenic nerve. The pericardium is then opened over the anterior aspect of the inferior pulmonary vein, and then incised circumferentially around the vein in order to maximize the amount of pulmonary venous cuff on the donor lobe. In fact, providing a donor graft with a small amount of left atrial cuff facilitates the venous anastomosis for the implanting surgeon. The pericardium will frequently be adherent to the inferior aspect of the inferior pulmonary vein, making dissection slightly more hazardous in that area. After this point, the dissections of the donor right and left lower lobes differ enough as to require that they be described separately.