Ann Thorac Surg 2008;85:2110-2112. doi:10.1016/j.athoracsur.2007.12.011
© 2008 The Society of Thoracic Surgeons
Case Reports
Ex Vivo Bilateral Pulmonary Embolectomy for Donor Lungs Prior to Transplantation
Mohammad Shihata, MD*,
Nitin Ghorpade, MD,
Dale Lien, MD,
Dennis Modry, MD
Division of Cardiac Surgery, University of Alberta Hospital, Edmonton, Alberta, Canada
Accepted for publication December 5, 2007.
* Address correspondence to Dr Shihata, Division of Cardiac Surgery, University of Alberta, 303, 10904 - 102 Ave, NW, Edmonton, Alberta, T5K2Y3, Canada (Email: mshihata{at}gmail.com).
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Abstract
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Pulmonary arterial embolic disease of donor lungs is a known entity. Its implications on the technicality, the perioperative management, and the outcome of lung transplantation depend on the extent of the embolic disease and the indicators of lung function at the time of procurement. We report a case of lung transplantation from a donor who was known to have significant acute pulmonary embolic disease and the perioperative management used to optimize the outcome.
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Introduction
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Liberalization of donor criteria has been increasingly practiced in an attempt to overcome the shortage in donor organs. In the current era, many donor organs with indicators showing good lung function would not fulfill all the classic prerequisites. In this case report we describe the use of lungs from a donor who had significant pulmonary embolic disease that was underestimated during the pretransplantation workup.
The patient is a 55-year-old man with end-stage emphysema. He was on home oxygen therapy and had severe physical disability due to shortness of breath at rest and minimal exertion, and hence was listed for lung transplantation.
The donor was a previously healthy 46-year-old truck driver who had a sudden collapse at home and was resuscitated and transferred to a tertiary care center. Further investigations found that he had a large hemispherical cerebral infarction and severe cerebral edema. The cerebral infarction was believed to be secondary to a paradoxic embolic phenomenon. A transesophageal echocardiogram confirmed the presence of a patent foramen ovale and demonstrated severe right ventricular dysfunction. The diagnosis of deep venous thrombosis and pulmonary embolization was confirmed.
After 7 days of anticoagulation, the need for supplemental oxygen therapy was significantly reduced and there was no evidence of a residual central or subsegmental pulmonary embolus on a repeat computed tomography scan of the chest. A repeat echocardiogram showed marked improvement of the right ventricular dimensions and contractility. There was no central nervous system recovery, however, and cerebral perfusion studies showed no cerebral flow.
Once the brain death criteria were established, the lungs were assessed for possible organ donation. The result of the chest roentgenogram was normal, and a lung perfusion scan on day 8 after the initial presentation showed a small perfusion defect in the right lung. The donor had a partial pressure of oxygen of 378 on 100% oxygen, a positive end-expiratory pressure of 5 cm H2O, and a tidal volume of 6 mL/kg. On the basis of the last imaging studies and the pulmonary functional indicators, the lungs were accepted for transplantation. At the time of procurement, the donor lungs were grossly normal, and there was no evidence of any particulate embolic washout when retrograde pneumoplegia was administered.
The transplantation was performed on cardiopulmonary bypass. Before implantation, it was apparent on direct inspection, once the pulmonary artery was divided, that both main pulmonary arteries had a substantial embolic burden extending to the segmental and subsegmental branches.
At that time, the recipient was committed to receive the lungs after having bilateral pneumonectomies and mediastinal dissection. The decision was made to perform bilateral pulmonary embolectomy and proceed with the implantation, bearing in mind the need to institute anticoagulation therapy afterwards. Extraction of the central part of the clot was relatively easy, but there was a fair degree of clot organization in the more distal portions. We had to resort to a special type of suction catheters that we usually use for pulmonary endarterectomy, the Jamieson dissecting aspirator (MMA-7; Fehling Surgical Instruments Inc, Acworth, GA), to make sure that all visible clots were removed (Fig 1). The bilateral embolectomy added 30 minutes of ischemic time to the operation. The total ischemic time was 155 minutes for the right lung and 228 minutes for the left lung.
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Fig 1. The left and right sides of the photograph show clots removed, respectively, from the left and right donor lungs before implantation.
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The patient had an uneventful immediate postoperative course in the intensive care unit and was transferred to the ward on the second postoperative day. On day 6, the patient's recovery was complicated by the development of ischemic colitis and perforation, mandating an exploratory laparotomy, hemicolectomy, and formation of an ileostomy. Despite the additional septic and surgical stresses, prolonged intubation was not needed and he remained stable from the cardiopulmonary standpoint. He continued to recover in a timely fashion and was discharged home on oral anticoagulation therapy. Before discharge, the result of his chest roentgenogram was within normal limits (Fig 2), and a lung perfusion scan showed minor residual defects in the right lung (Fig 3).
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Comment
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Lung transplantation has become the treatment of choice for end-stage lung disease caused by different underlying pathologic entities. The main limitation, however, remains the lack of enough donor organs. The exponential increase in the number of patients awaiting lung transplantation has not been met by an equivalent increase in the donor pool. Patients on the waiting lists for lung transplantation have an annual mortality rate of 20% according to some recent reports [1]. Other study groups reported a mortality rate of 50% for patients found suitable for lung transplantation from their underlying lung disease before an organ becomes available [2].
The concept of accepting marginal or extended donors has become a common practice in many of the busy transplant centers around the world [3]. Advocates of using lungs from living donors, older donors, donors with history of smoking, non-heart-beating donors, or donors with reversible underlying lung pathologies have been increasingly reporting successful outcomes [4] that are comparable with outcomes expected when more rigid donor selection criteria are implemented [5].
The use of donor lungs from patients suspected or diagnosed to have variable degrees of pulmonary embolic disease at the time of brain death has been previously reported in a few anecdotal cases [6]. Unexpected macroscopic donor-related pulmonary emboli were reported in as many as 38% of lung transplantations, and this was found to be associated with worse outcomes in terms of primary graft failure [7].
The use of pulmonary embolectomy at the time of lung transplantation has been previously reported in two separate case reports [8, 9]. The patient reported in this article is unique due to the substantial clot burden that was removed from as distal as the subsegmental pulmonary arteries and the amount of organization in portions of the clots, indicating a subacute process. That this problem was not fully appreciated at the time of the pretransplant workup is probably the reason the lungs were accepted for the transplantation.
The excellent early outcome we had with this case has led us to a number of conclusions. First, the diagnosis of pulmonary embolism whenever suspected in a transplant workup should be based on contrast imaging techniques. Second, the combination of antegrade and retrograde pneumoplegia is very useful in providing uniform lung protection. Furthermore, the absence of particulate or visible debris with retrograde flushing of the pulmonary veins is not completely reliable in ruling out pulmonary emboli, especially if any degree of clot organization is present. Careful inspection of the pulmonary arterial tree should always be performed before implantation. Finally, this result enforces the concept of liberalization of organ donor criteria in an attempt to overcome the confounding shortage of organs. This liberalization, however, should not be in violation of any of the functional or gas exchange indicators.
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References
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- Fischer S, Gohrbandt B, Meyer A, Simon AR, Haverich A, Struber M. Should lungs from donors with severe acute pulmonary embolism be accepted for transplantation?. The Hannover experience. J Thorac Cardiovasc Surg 2003;126:1641-1643.[Free Full Text]
- Thabut G, Mal H, Cerrina J, et al. Influence of donor characteristics on outcome after lung transplantation: a multicenter study J Heart Lung Transplant 2005;24:1347-1353.[Medline]
- Filosso PL, Turello D, Cavallo A, Ruffini E, Mancuso M, Oliaro A. Lung donors selection criteria: a review J Cardiovasc Surg (Torino) 2006;47:361-366.[Medline]
- Pierre AF, Sekine Y, Hutcheon MA, Waddell TK, Keshavjee SH. Marginal donor lungs: a reassessment J Thorac Cardiovasc Surg 2002;123:421-427.[Abstract/Free Full Text]
- Aigner C, Winkler G, Jaksch P, et al. Extended donor criteria for lung transplantation–a clinical reality Eur J Cardiothorac Surg 2005;27:757-761.[Abstract/Free Full Text]
- Frenia D, Nathan SD, Ahmad S, et al. Successful lung transplantation from a donor with a saddle pulmonary embolus J Heart Lung Transplant 2005;24:1137-1139.[Medline]
- Oto T, Rabinov M, Griffiths AP, et al. Unexpected donor pulmonary embolism affects early outcomes after lung transplantation: a major mechanism of primary graft failure? J Thorac Cardiovasc Surg 2005;130:1446.[Abstract/Free Full Text]
- Nguyen DQ, Salerno CT, Bolman 3rd M, Park SJ. Pulmonary thromboembolectomy of donor lungs prior to lung transplantation Ann Thorac Surg 1999;67:1787-1789.[Abstract/Free Full Text]
- Smith JA, Mohajeri M, Rabinov M, Esmore DS. Maldistribution of pneumoplegia in pulmonary allografts secondary to post-traumatic pulmonary thromboembolism J Heart Lung Transplant 1996;15:324-325.[Medline]
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Abstract
Introduction
