L dure for patients with end-stage pulmonary disease.

HOW TO DO IT Donor Lung Procurement: Assessment and Operative Technique Sudhir Sundaresan, MD, Gregory D. Trachiotis, MD, Motoi Aoe, MD, G. Alexander Patterson, MD, and Joel D. Cooper, MD Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes Hospital, St. Louis, Missouri Given the relative scarcity of suitable donors and the widespread application of cardiac and pulmonary transplantation, it is imperative that a heart and two lungs be extracted from each donor. From increasing clinical experience and laboratory investigation in lung preservation, more flexible criteria for the assessment of potential lung donors are emerging. In this communication, we present our current criteria of donor lung suitability, and a simple and reliable technique of combined cardiopulmonary extraction that has provided suitable heart and lung grafts with excellent preservation, used in our last 150 donor organ procurements. (Ann Thorac Surg ) ung transplantation has become an established proce- L dure for patients with end-stage pulmonary disease. Since the first successful long-term single lung transplantation in 1983 [l], there have been more than 1,500 lung transplantations performed worldwide [2]. Over the past 2 years, both the number of centers performing lung transplantation and the corresponding number of recipients have dramatically increased [2]. Nonetheless, the main limitation to widespread application of lung transplantation remains the scarcity of suitable donors. At present, only about 5% to 10% of multiple-organ donors have lungs that are suitable for transplantation. Given this donor shortage, it is imperative that, whenever possible, each donor provide a heart and two lungs, thereby potentially benefiting three recipients [3]. In the 5 years since our discussion of donor lung selection and technique of operative extraction [4], a number of changes have occurred. Greater clinical experience has shown that the relatively rigid criteria formerly applied to potential lung donors, although still useful as general guidelines, may be relaxed somewhat in certain circumstances. Differences in our current methods of clinical lung preservation reflect advances achieved from experimental investigation in this area. The operative technique described in this report has been employed with success in our program during the past 150 transplantations. The purpose of this communication is to provide an update on our criteria of donor lung suitability, and on our technique of combined cardiopulmonary extraction, as performed in the setting of multiple teams from different institutions procuring organs from a single donor. Accepted for publication July 16, 1993. Address reprint requests to Dr Sundaresan, Division of Cardiothoracic Surgery, Washington University School of Medicine, One Barnes Hospital Plaza, Suite 3107 Queeny Tower, St. Louis, MO 63110. Criteria of Donor Lung Suitability Information regarding the potential suitability of donor lungs comes in two stages. First, a set of preliminary criteria must be satisfied, after which our retrieval team is sent to the donor hospital. There a second and final evaluation is carried out. These criteria are somewhat overlapping, and can be listed as follows: Preliminary Age < 55 years ABO compatibility Chest roentgenogram Clear Allows estimate of size match History Smoking 5 20 pack-years No significant trauma (blunt, penetrating) No aspiratiodsepsis Gram stain and culture data if prolonged intubation No prior cardiac/pulmonary operation Oxygenation Arterial oxygen tension 2 300 mm Hg, on inspired oxygen fraction of 1.0, 5 cm H,O positive endexpiratory pressure Adequate size match Final assessment Chest roentgenogram shows no unfavorable changes Oxygenation has not deteriorated Bronchoscopy shows no aspiration or mass VisuaUmanual assessment Parenchyma satisfactory No adhesions or masses Further evaluation of trauma The basic criteria that must be met initially are ABO compatibility; a clear chest radiograph; a history that is negative for significant tobacco use, chest trauma, aspira- 0 1993 by The Society of Thoracic Surgeons 0003-4975/93/$6.00

1410 HOW TO DO IT SUNDARESAN ET AL DONOR LUNG ASSESSMENT/EXTRACTlON Ann Thorac Surg tion, infection, and prior chest operation; satisfactory oxygenation (arterial oxygen tension 2 300 mm Hg on 100% oxygen and 5 cm H,O positive end-expiratory pressure); and an appropriate size match [5-71. We have become increasingly flexible in that we now accept lungs under certain circumstances from donors up to age 55 years and with up to 20 pack-years of tobacco use. Also, in practical terms, some degree of chest trauma is common in multiple organ donors, making judgment important in evaluating its severity in the context of the recipient (see below). Size match can be estimated from a standard chest radiograph of donor and recipient. The vertical dimension is measured at the midclavicular line, and the transverse dimension at the level of the domes of the diaphragm. Predicted lung volumes of donor and recipient are also reliable means by which to judge size match. We attempt to provide a prospective recipient with donor lungs that would be an appropriate size for the patient if the thoracic configuration were not altered by his or her lung disease. For single-lung recipients, we attempt to oversize the donor lung. This is, of course, not difficult for small recipients but will cause a prolonged waiting time for recipients of larger body size. For double-lung recipients, we make an effort not to oversize so as to facilitate recipient chest closure. In general, patients with pulmonary fibrosis will receive a lung larger than the native one, and patients with emphysema will have a lung smaller than the native one(s) implanted. This rationale is based on observations of mediastinal shift, diaphragm realignment, and chest cavity changes subsequent to lung transplantation. It remains to be determined whether a right or left-sided implant provides a functional difference in single-lung transplantation, but to date no difference in outcome or in function has been observed. For patients with pulmonary hypertension, a single lung that closely matches the size of the native lung is preferable. The data gathered on-site by the retrieval surgeon constitutes the final assessment. The most recent chest radiograph is examined, and serial radiographs are viewed to rule out any unfavorable progression. There should be no significant deterioration in the oxygenation. Flexible bronchoscopy is performed to rule out aspiration. Bronchial washings are always obtained for Gram stain and culture, as these results are useful in guiding initial antibiotic selection in the recipient. Finally, at sternotomy, the pleural spaces are opened and the lungs visualized and palpated to verify the presence of satisfactory lung parenchyma and the absence of adhesions, contusion, or masses, and to provide further evaluation of any antecedent trauma. General guidelines for managing the multiple organ donor are as follows: Blood pressure (mean) > 70 mm Hg Pulmonary capillary wedge pressure 5 12 mm Hg Judicious fluid replacement Replace electrolyte losses Maintain urine output at 1 to 2 ml - kg-' * h-' Use DDAVP for treatment of documented diabetes insipidus Treat hypotension with a combination of fluid replacement and dopamine infusion up to 10 pg * kg-' * min-' Maintain normothermia (35 C to 37 C) Maintain positive end-expiratory pressure at 5 cm H,O, arterial oxygen tension > 100 mm Hg on lowest inspired oxygen fraction Strict pulmonary toilet Measure arterial blood gases every 2 hours Elevate head of bed if possible Increasing clinical experience, superimposed on the acute donor lung shortage, has led to an appreciation of the degree to which a lung can fail to meet the "perfect" standard and still provide a satisfactory result. Bronchoscopy ideally should be clear, but this is often not the case. The absolute contraindications to accepting a donor lung (based on bronchoscopy) are grossly purulent secretions (especially if voluminous) and the finding of aspirated foreign material or evidence thereof (ie, severe erythema and tracheobronchitis). Blood entering the airway is obviously common after head trauma. With the passage of time, the blood imparts a distinctly brown coloration to the bronchial secretions, which can be distinguished from pus. If this can be cleared by suctioning, and the bronchial mucosa appears normal, then the lung is suitable for use. Not uncommonly, open evaluation of the lungs shows the extent of pulmonary trauma to be more severe than initially judged. The presence of a chest tube (usually placed to treat a pneumothorax inadvertently sustained during placement of a central venous line) is not a contraindication to use of the lung, in the absence of air leak. Lungs with contusions of mild severity have also been used with satisfactory results. On one occasion, we successfully used a lung from a donor who sustained a gunshot wound to the head, despite finding a bullet free in the pleural space with some associated contusion of the posterior aspect of the lower lobe. Overall, the tolerance of donor lung abnormality depends on the recipient. For example, in single-lung transplantation for primary pulmonary hypertension, the graft will receive virtually all of the postoperative blood flow, and therefore must display excellent oxygenation and hemodynamic characteristics immediately [S]. Conversely, in single-lung transplantation for emphysema, the contralateral native lung will provide satisfactory oxygenation after transplantation, and some degree of reversible donor lung dysfunction may be tolerable [9]. Technique of Operative Extraction In our previous report [4], certain technical aspects were stressed. (1) Because the predominant clinical experience at that time was with left single-lung transplantation, a technique was described for isolated procurement of the left lung, which entailed cutting the right pulmonary veins and discarding the right lung. We now routinely extract both lungs en bloc by using the method described below. In the rare event that one of the lungs is unsuitable for implantation, this lung is trimmed off the double-lung

Ann Thorac Surg 1993;56: 1409-13 HOW TO DO IT SUNDARESAN ET AL 1411 DONOR LUNG ASSESSMENTiEXTRACTION block after extraction, either in the donor operating room itself or upon arrival at our own institution. (2) The basic approach to lung preservation at the time of our original report was that of hypothermic atelectatic immersion, facilitated by the use of a left bronchial blocker. Only incidental note was made of flush perfusion of the pulmonary artery with crystalloid solution. Based on sound experimental evidence for the beneficial effects of prostaglandin El pretreatment [lo, 111, as well as the use of a variety of flush perfusates [12, 131, we now routinely use this method clinically, as do the majority of lung transplant programs. The operation is accomplished through a median sternotomy, extended inferiorly to the pubis to permit extraction of the abdominal organs. The determination of suitability of the heart and lungs (bronchoscopy, open assessment) is made early on, after which the abdominal team(s) continue their dissection. Advanced request is made to the abdominal surgeons to place a cannula in the inferior vena cava (just before cross-clamp) to allow drainage of their effluent flush off the table, as opposed to venting into the right pleural space (which is commonly practiced when the lungs are not being procured). Upon completion of the abdominal dissection, pericardial stay sutures are placed and the thoracic dissection is performed. There are three basic components to this dissection: (1) Venous inflow: The intrapericardial superior vena cava is isolated and encircled with two heavy silk ligatures, and the inferior vena cava is encircled with an umbilical tape. (2) Arterial: The ascending aorta and main pulmonary artery are separated from one another, and each encircled with an umbilical tape. (Passage of the tape around the main pulmonary artery is best done using the technique of exclusion through the transverse sinus of the pericardium.) (3) Airway: The posterior pericardium (between the aorta and superior vena cava) is incised, exposing the distal trachea. We prefer to develop the groove on either side of the airway, but do not encircle it, to avoid potential damage to the airway at this point; this step permits easy digital encirclement of the airway later. The completed dissection is depicted in Figure 1. On completion of these steps, the patient is heparinized before insertion of the various cannulas. All teams (abdominal, cardiac, and pulmonary) can cannulate simultaneously; alternately, sequential cannulation (with either the abdominal or thoracic teams proceeding first) is technically more convenient, and may be employed as long as the donor remains in stable condition. A standard cardioplegia cannula is inserted in the ascending aorta. The main pulmonary artery is cannulated with a Sarns (Ann Arbor, MI) 6.5-mm curved, metal-tipped perfusion cannula, and secured with a Prolene (Ethicon, Somerville, NJ) suture and tourniquet. The cannula is placed at the bifurcation of the main pulmonary artery (see Fig 1). After cannulation and just before inflow occlusion, the distance between the right pulmonary veins and interatrial groove is examined. Usually there is sufficient distance to allow ample left atrial cuffs for both the donor lung and heart grafts. However, when there is any doubt, the interatrial groove should be opened so as to increase Fig 1. Appearance of completed dissection. the length of available left atrial cuff. This step is deferred until now in case the degree of cardiac manipulation required causes hypotension or arrhythmias. Finally, the steps at the time of cross-clamp, which are depicted in Figure 2, are as follows: (1) bolus administration of prostaglandin E, (500 pg of prostaglandin El, drawn up in 10 ml of saline solution, is administered using a 25-gauge needle into the main pulmonary artery alongside the cannula); (2) inflow occlusion (achieved by doubly ligating the superior vena cava and clamping the inferior vena cava inside the pericardium); (3) venting the right heart (by transecting the inferior vena cava above the clamp); (4) cross-clamping the aorta and administration of cardioplegia solution; and (5) venting the left heart (by amputating the tip of the left atrial appendage), after which the lung flush is commenced. We currently employ the technique of a high-volume, low-pressure flush, using 3 L of cold (4 C) modified Euro-Collins solution. The perfusate bag is hung such that its top is about 40 cm above the level of the operating table. The chest is then flooded with ice-cold saline solution. We prefer to maintain gentle manual ventilation of the lungs during the flush, using 100% oxygen and small tidal volumes. Avoidance of atelectasis enhances the distribution of the flush. After completion of cardioplegia administration and the lung flush (which generally takes a couple of minutes longer than the cardioplegia), the heart is extracted (Fig 3). The superior vena cava is divided between the ligatures, the aorta is transected proximal to the cross-clamp,

1412 HOW TO DO IT SUNDARESAN ET AL DONOR LUNG ASSESSMENT/EXTRACTION Ann Thorac Surg Fig 4. Completion of division of left atrium. Fig 2. Steps taken to achieve safe myocardial and pulmonary preservation at the time of inflow occlusionlcross-clamp. Open arrows show route of cardioplegia solution, whereas closed arrows show route of lung push. and the pulmonary flush cannula is removed. The distal main pulmonary artery is then transected, starting at the cannulation site. Care must be taken to identify both pulmonary artery branches, as these must be preserved intact on the lung graft side (see Fig 3). Occasionally, a length of left or right pulmonary artery is required for a congenital heart defect requiring cardiac transplantation. Fig 3. Preliminary steps in cardiac extraction. In this circumstance, the pulmonary artery can be transected at the pericardial reflection without sacrificing the quality of the lung graft. The left atrial incision, performed last, is accomplished by having the surgeon on the right side of the table retract the cardiac apex toward the donor's right shoulder. The left atrial incision, which is best made by the surgeon on the left side of the table, is begun by incising the atrium midway between the confluence of the left pulmonary veins and the coronary sinus. This incision is then continued both superiorly and inferiorly. The roof of the left atrium is then divided toward the interatrial groove. The inferior incision should be well away from the mitral valve and the coronary sinus. Finally, the right half of the incision is completed by visualizing the ostia of the right pulmonary veins from within the left atrium, and simply leaving a small rim of atrial muscle around them as the cut is finished (Fig 4). With cooperation of the lung and heart extraction teams, this technique of in situ cardiac extraction can be performed in less than 5 minutes. The remaining steps in extraction of the double-lung block are as follows: (1) The trachea is encircled digitally one or two rings above the carina. With the lungs moderately inflated (10 to 20 cm H,O pressure), the trachea is doubly stapled using a TA-30 stapling device, and divided between the staple lines (Fig 5). (2) The esophagus is encircled digitally at this level and divided with one application of the GIA stapler. (3) All superior mediastinal tissue on either side is then manually grasped and incised back to the thoracic spine. The esophagus and aorta are extracted with the specimen to minimize risk of extraction injury to the airway or pulmonary artery. (4) The pericardium near the diaphragm is incised from one side to the other (taking care to stay superior to the open inferior vena cava), the pulmonary ligaments are divided, and the distal esophagus is divided with a final application of the GIA stapler (see insert, Fig 5). (6) The lung block is removed by dividing the descending thoracic aorta, then

Ann Thorac Surg HOW TO DO IT SUNDARESAN ET AL 1413 DONOR LUNG ASSESSMENT/EXTRACTlON upper insert). Figure 6 also depicts the dissection used in preparing the two lungs for implantation. The main bronchi are neatly transected between cartilaginous rings, leaving two intact rings proximal to the right upper lobe bronchus and the left-sided carina (see Fig 6, lower insert). Fig 5. Division of aimay and esophagus before extraction of doublelung block. freeing the block from the thoracic spine, using either knife, scissors, or some degree of "blunt" manual dissection. The lung block is then triple-bagged, placed on ice, and made ready for transport. On several occasions, we have retrieved lungs in conjunction with another lung transplant program. If necessary, the right and left lungs can be rapidly separated at this point by dividing the posterior pericardium, left atrium, pulmonary artery, and residual mediastinal tissue, and by doubly stapling the proximal left main bronchus, allowing the airway to be divided at this site between the staple lines (Fig 6 and Fig 6. Method of separation of the double-lung block. Posterior pericardium, left atrium, pulmona y artey and residual mediastinal tissue are divided in the midline. (Upper insert) Division of proximal left main bronchus between staple lines allows lung separation without deflation (eg, for use in different centers). (Lower insert) Preparation of the right and left main bronchi for implantation. Summary Despite the nationwide increase in use of lung transplantation as a lifesaving therapeutic modality, we still frequently encounter retrieval teams from other centers who are somewhat unfamiliar with the technique of sequential heart and lung allograft extraction. This article has provided a detailed description of our criteria for appraisal of the donor lungs, as well as the technique of combined cardiac and pulmonary extraction for single or bilateral sequential single-lung transplantation. In the 4 years that have elapsed since our last report, our experience has expanded to include a further 150 cases of isolated lung transplantation. The heightened need for donor organs, along with this greater clinical experience, has allowed us to modify and update our criteria and technique as put forth in this article. It is hoped that this will facilitate the maximum utilization of donor organs for cardiac and pulmonary transplantation. References 1. Toronto Lung Transplant Group. Unilateral lung transplantation for pulmonary fibrosis. N Engl J Med 1986;314:114Cb5. 2. St. Louis International Lung Transplant Registry, August 1992 (permission by Dr Joel Cooper). 3. Cooper JD. The evolution of techniques and indications for lung transplantation. Ann Surg 1990;212:249-55. 4. Todd TR, Goldberg M, Koshal A, et al. Separate extraction of cardiac and pulmonary grafts from a single organ donor. Ann Thorac Surg 1988;46:356-9. 5. Cooper JD. The lung donor: special considerations. Transplant Proc 1988;20:17-8. 6. Patterson GA, Cooper JD. Status of lung transplantation. Surg Clin North Am 1988;68:545-58. 7. Egan TM, Kaiser LR, Cooper JD. Lung transplantation. Curr Probl Surg 1989;26:673-751. 8. Pasque MK, Kaiser LR, Dresler CM, Trulock E, Triantafillou AN, Cooper JD. Single lung transplantation for pulmonary hypertension. J Thorac Cardiovasc Surg 1992;103:47%32. 9. Cooper JD. Lung transplantation for chronic obstructive lung disease. Ann N Y Acad Sci 1991;624:209-11. 10. Mayer E, Puskas JD, Cardoso PFG, Shi S, Slutsky AS, Patterson GA. Reliable IS-hour lung preservation at 4 C and 10 C by pulmonary artery flush after high dose prostaglandin E-1 administration. J Thorac Cardiovasc Surg 1992;103: 1136-42. 11. Puskas JD, Cardoso PFG, Mayer E, Shi S, Slutsky AS, Patterson GA. Equivalent 18-hour lung preservation with low potassium dextran or Euro-Collins solution after prostaglandin E-1 infusion. J Thorac Cardiovasc Surg 1992;104: 8%9. 12. Keshavjee SH, Yamazaki F, Cardoso PF, McRitchie DI, Patterson GA, Cooper JD. A method for safe twelve-hour pulmonary preservation. J Thorac Cardiovasc Surg 1989;98: 529-34. 13. Date H, Matsumura A, Manchester JK, et al. Successful 24 hour lung preservation with low potassium dextran glucose solution and evaluation of lung metabolism. J Thorac Cardiovasc Surg 1993;105:480-91.