If the initial evaluation (i.e., donor history, chest radiograph, bronchoscopy, and manual inspection) reveals no contraindications, we proceed with donor lung procurement. Our technique has been described previously.7 After median sternotomy and opening of the pleural spaces, the pericardium is opened, and stay sutures are placed, permitting exposure of the great vessels. The superior vena cava (SVC) is encircled caudal to the azygos vein with silk sutures. The inferior vena cava is also encircled unless hemodynamic instability occurs on the attempt to do so. The periadventitial tissue overlying the right pulmonary artery (PA) is dissected. The plane between the artery and the SVC is cleansed. In similar fashion, the right PA is separated from the back of the ascending aorta.
The aorta-pulmonary artery window is dissected in preparation for the aortic cross-clamp. The SVC and aorta are gently retracted laterally, and the posterior pericardium is incised above the right PA, permitting access to the trachea. The plane of the trachea is developed manually, and the trachea can be encircled with an umbilical tape. After the thoracic dissection is complete, the donor is heparinized (250–300 U/kg). The ascending aorta is cannulated with a routine cardioplegia cannula for cardiac preservation. At the bifurcation of the main PA, a Sarns (Ann Arbor, MI) 6.5-mm curved metal cannula is placed and secured with a purse-string suture. After the cannulas have been placed, a bolus dose of prostaglandin E1 (500 μg) is given directly into the PA using a 16-gauge needle.
Immediately after the prostaglandin E1 infusion, the SVC is ligated, and the inferior vena cava is divided, permitting the right side of the heart to decompress. The aorta is cross-clamped, and cardioplegia is initiated. The left atrial appendage is generously incised, decompressing the left side of the heart. The pulmonary flush consisting of several liters (50–75 mL/kg) of cold (4°C) Perfadex is initiated (Fig. 95-2). The chest cavity is cooled with ice-slush normal saline. Gentle ventilation is continued throughout to prevent hyperinflation or atelectasis and to enhance distribution of the flush solution.
Donor heart prepared for explant. Note that the cross-clamp has been placed on the aorta, and two cannulas vent the right and left sides of the heart for delivery of cardioplegic solution. A plane of atria has been developed, and the trachea is encircled with umbilical tape.
After the cardioplegia and antegrade pulmonary flush are completed, the cannulas are removed. The heart then is extracted. The inferior vena cava is freed posteriorly and dissected up to the level of the right atrium. Division of the left atrium proceeds with the cooperation of the heart and lung teams. The heart is retracted to the right, and an incision is made with a no. 11 blade scalpel in the left atrium midway between the coronary sinus and the left pulmonary veins. Scissors then are used to extend the opening superiorly and inferiorly while visualizing the orifices of the left superior and inferior pulmonary veins. The remaining cuff of left atrium can be transected while internally visualizing the right pulmonary veins. The surgeon on the left side of the table can visualize the right vein orifices best and should divide the left atrial cuff over the right pulmonary veins. An appropriate residual atrial cuff should have a rim of left atrial muscle around each of the pulmonary vein orifices. An adequate cuff can be ensured if the interatrial groove is developed on the right (Fig. 95-3). The SVC is transected between ties, followed by both division of the aorta proximal to the cross-clamp and the PA at its bifurcation. The heart then is passed off the field.
The donor heart is explanted along with a sufficient cuff of the left atrium. A. The heart is retracted to the right while the cuff is trimmed on the left. B. The heart is flipped over for inspection. Developing the interatrial groove on the right ensures an adequate atrial cuff.
After extracting the heart, we use a Foley catheter to deliver a retrograde flush via the pulmonary vein orifices (approximately 300 mL of cold Perfadex in each orifice). During retrograde flushing, residual blood and small clots are often flushed out of the opened PA bifurcation. Alternatively, this retrograde flush can be done on the back table before departing from the donor site. We incorporated this retrograde flushing procedure into our donor procurements after experimental8 and clinical research9 found it to be superior to the antegrade flush, with less pulmonary edema, lower airway resistance, and better oxygenation during the first several hours after transplantation.
We then proceed with en bloc removal of the contents of the thoracic cavity. Removal of the lungs by this technique prevents injury to the membranous trachea, pulmonary arteries, and pulmonary veins. If not already completely encircled, the tracheal dissection is completed two to three rings above the carina. The endotracheal tube is opened to atmosphere, and the lungs are permitted to deflate to approximate end-tidal volume while the endotracheal tube is backed into the proximal trachea. The trachea is sealed with a linear stapler and divided at least two rings above the carina (Fig. 95-4). Immediately posteriorly, the esophagus is encircled, stapled, and divided using a linear stapler. While retracting both lungs, heavy scissors are used to divide all the mediastinal tissue down to the spine. Staying directly on the spine, the posterior mediastinal tissue is divided. At this point, the pericardium near the diaphragm is transected. The inferior pulmonary ligaments are sharply divided. The lower esophagus is encircled and divided with the linear stapler (see Fig. 95-4). Posterior mediastinal tissue is sharply divided to connect with the superior aspect of the dissection. The lungs then are removed en bloc along with the thoracic esophagus and aorta.
Appearance of chest cavity after the donor heart has been removed but before the double-lung bloc has been resected. Esophagectomy has been performed (not shown), and the trachea has been divided.
If the lungs are returning to the same institution, they are tripled-bagged together with cold preservation solution and transported on ice. Alternatively, if the lungs are to be used at separate institutions, they are divided on the back table. While the lung bloc is kept in an ice-slush bath, the donor esophagus and aorta are removed, and the pericardium is excised. The lungs are separated by dividing the posterior pericardium, the left atrium between the pulmonary veins, the main PA at the bifurcation, and the left bronchus above the takeoff of the upper lobe bronchus. The left bronchus is divided between staples to maintain the inflation of each lung.
If the lungs have been transported en bloc, they are separated as detailed earlier. The PA and left atrial cuffs are freed from any pericardial attachments because these may cause kinking after the anastomosis is completed. The right and left PAs are cleaned back to their first branches and inspected for any injuries or embolic material. The donor bronchus is divided two rings proximal to the upper lobe orifice. Care is taken to minimize dissection of the donor bronchus to preserve collateral flow through the peribronchial nodal tissue.