Early lung allograft function after retrograde and antegrade preservation

Pathophysiology and Predictors of Bronchial Complications After Lung Transplantation

Bronchial anastomotic breakdown was a major complication in the early days of lung transplantation. Their solution, achieved through an understanding of airway ischemia from the laboratory, was key to the initial clinical success. Subsequently, risk factors, such as prolonged ventilation in both donor and recipient, primary graft dysfunction, and recipient age, have emerged. Innovations, such as local tissue wrapping, telescoping the anastomosis, and bronchial artery revascularization, have not stood the test of time. The short donor bronchus, with a suture line at the level of the lobar bronchus carina, is a proven technique that should be adopted by surgeons.

A novel dual ex vivo lung perfusion technique improves immediate outcomes in an experimental model of lung transplantation

The lungs are dually perfused by the pulmonary artery and the bronchial arteries. This study aimed to test the feasibility of dual-perfusion techniques with the bronchial artery circulation and pulmonary artery circulation synchronously perfused using ex vivo lung perfusion (EVLP) and evaluate the effects of dual-perfusion on posttransplant lung graft function. Using rat heart-lung blocks, we developed a dual-perfusion EVLP circuit (dual-EVLP), and compared cellular metabolism, expression of inflammatory mediators, and posttransplant graft function in lung allografts maintained with dual-EVLP, standard-EVLP, or cold static preservation. The microvasculature in lung grafts after transplant was objectively evaluated using microcomputed tomography angiography. Lung grafts subjected to dual-EVLP exhibited significantly better lung graft function with reduced proinflammatory profiles and more mitochondrial biogenesis, leading to better posttransplant function and compliance, as compared with standard-EVLP or static cold preservation. Interestingly, lung grafts maintained on dual-EVLP exhibited remarkably increased microvasculature and perfusion as compared with lungs maintained on standard-EVLP. Our results suggest that lung grafts can be perfused and preserved using dual-perfusion EVLP techniques that contribute to better graft function by reducing proinflammatory profiles and activating mitochondrial respiration. Dual-EVLP also yields better posttransplant graft function through increased microvasculature and better perfusion of the lung grafts after transplantation.

Overview of clinical lung transplantation

Since the first successful lung transplant 30 years ago, lung transplantation has rapidly become an established standard of care to treat end-stage lung disease in selected patients. Advances in lung preservation, surgical technique, and immunosuppression regimens have resulted in the routine performance of lung transplantation around the world for an increasing number of patients, with wider indications. Despite this, donor shortages and chronic lung allograft dysfunction continue to prevent lung transplantation from reaching its full potential. With research into the underlying mechanisms of acute and chronic lung graft dysfunction and advances in personalized diagnostic and therapeutic approaches to both the donor lung and the lung transplant recipient, there is increasing confidence that we will improve short- and long-term outcomes in the near future.

Present state of nonheart-beating lung donation

PURPOSE OF REVIEW

Indications for lung transplantation have increased through the years, and currently we have to face a lack of grafts to attend this growing demand with the subsequent increase in waiting-list deaths. Several strategies have been proposed to solve this challenging problem (living-lobe donors, extended donors, size-reduced lung grafts and so on), the use of nonheart-beating donors (NHBDs) being the most promising of them.

RECENT FINDINGS

The last experimental works concerning NHBDs have focused on the improvement of graft preservation in order to minimize warm ischemic injury and the capacity of noninvasive parameters in bronchial lavage to predict good function after implantation. There have also been several reports on the clinical use of controlled and uncontrolled NHBDs with excellent results.

CONCLUSION

Several methods have been effective in protecting these grafts from ischemic damage. Functional predictors will be very useful in the near future allowing us to know in a simple and noninvasive way which grafts are suitable for transplantation. Definitely, NHBDs for lung transplantation are no more a promising source of grafts but a real one, with encouraging short-term and mid-term results.

Cytostatic lung perfusion results in heterogeneous spatial regional blood flow and drug distribution: Evaluation of different cytostatic lung perfusion techniques in a porcine model

OBJECTIVES

Comparison of doxorubicin uptake, leakage and spatial regional blood flow, and drug distribution was made for antegrade, retrograde, combined antegrade and retrograde isolated lung perfusion, and pulmonary artery infusion by endovascular inflow occlusion (blood flow occlusion), as opposed to intravenous administration in a porcine model.

METHODS

White pigs underwent single-pass lung perfusion with doxorubicin (320 mug/mL), labeled 99mTc-microspheres, and Indian ink. Visual assessment of the ink distribution and perfusion scintigraphy of the perfused lung was performed. 99mTc activity and doxorubicin levels were measured by gamma counting and high-performance liquid chromatography on 15 tissue samples from each perfused lung at predetermined localizations.

RESULTS

Overall doxorubicin uptake in the perfused lung was significantly higher (P = .001) and the plasma concentration was significantly lower (P < .0001) after all isolated lung perfusion techniques, compared with intravenous administration, without differences between them. Pulmonary artery infusion (blood flow occlusion) showed an equally high doxorubicin uptake in the perfused lung but a higher systemic leakage than surgical isolated lung perfusion (P < .0001). The geometric coefficients of variation of the doxorubicin lung tissue levels were 175%, 279%, 226%, and 151% for antegrade, retrograde, combined antegrade and retrograde isolated lung perfusion, and pulmonary artery infusion by endovascular inflow occlusion (blood flow occlusion), respectively, compared with 51% for intravenous administration (P = .09). 99mTc activity measurements of the samples paralleled the doxorubicin level measurements, indicating a trend to a more heterogeneous spatial regional blood flow and drug distribution after isolated lung perfusion and blood flow occlusion compared with intravenous administration.

CONCLUSIONS

Cytostatic lung perfusion results in a high overall doxorubicin uptake, which is, however, heterogeneously distributed within the perfused lung.

Non-heart-beating donors: an excellent choice to increase the donor pool

A specific program was adopted to obtain organs, for transplant purposes from people who die at home or in the street from sudden or unexpected death (type I non-heart-beating donors [NHBD] according to the Maastricht classification). The objective of our program was to increase the donor pool by obtaining organs from well-selected potential donors who die at home, work, or in the street and are maintained on advanced life support (ALS) until hospital arrival. The great number of people who die in a previously healthy situation constitute an excellent source of organs for transplant purposes. Our program includes pre- and in-hospital attendance. Prehospital attendance is based on application of cardiopulmonary resuscitation in situ and ALS until arrival at hospital. In hospital, specific preservation maneuvers must be performed and family assessment and judge permission obtained. In the last 15 years, we developed a kidney transplant program with better results than transplants performed with organs obtained from encephalic death donors (EDD). A specific NHBD subprogram for lung transplant was developed with excellent results as well. We are now improving the liver transplant program. NHBD are an important source of human tissues, including pancreas islets. It is clear that NHBD are a great source of organs and tissues for transplant, and that this kind of program must be established in all countries in which legal regulations allow it.

Lung transplantation from out-of-hospital non-heart-beating lung donors. one-year experience and results

There is currently no method for preservation and functional evaluation of clinical out-of-hospital non-heart-beating lung donors (NHBLD) that can be applied practically and systematically in clinical lung transplantation programs. A new method of preservation and functional evaluation of the lung has been developed in NHBLD that is based on the knowledge of various experimental studies. Initially, the viability of lungs harvested this way was proved from preliminary functional and histologic tests. In November 2002, we started using lung allografts from non-heart-beating donors. Five lung transplantations (4 bipulmonary and 1 unipulmonary) were performed successfully. The short and mid-term results have been excellent and all recipients are alive. We report our initial experience, which we hope will be of help to those involved in clinical lung transplantation programs worldwide.

Experimental Lung Transplantation: Impact of Preservation Solution and Route of Delivery

BACKGROUND

Optimal preservation of allograft integrity is essential to reduce post-ischemic organ dysfunction after lung transplantation. Retrograde organ preservation leads to homogeneous intrapulmonary distribution and eliminates intravascular thrombi. So far, no comparative studies exist with regard to preservation quality following retrograde preservation with Perfadex and Celsior after extended cold-ischemia intervals.

METHODS

In an in vivo pig model, 5 lungs each were preserved for 27 hours using antegrade or retrograde perfusion techniques with Celsior (Ce(ant)/CE(ret)) and Perfadex (PER(ant)/PER(ret)). After left lung transplantation and contralateral lung exclusion, hemodynamics, oxygenation and dynamic compliance were monitored for 6 hours and compared with sham-operated controls. Pulmonary edema was determined stereologically. Statistics consisted of analysis of variance (ANOVA) with repeated measures.

RESULTS

Mortality of all Celsior-protected lungs was 100% due to severe reperfusion injury with profound lung edema. In contrast, organ preservation with PER(ant) led to sufficient graft function without mortality. Preservation quality after retrograde administration of Perfadex resulted in optimized oxygenation capacity compared with PER(ant) (p = 0.046). Furthermore, intra-alveolar edema was reduced and generally comparable with sham controls. In general, retrograde preservation led to continuous washout of small blood and fibrin clots from the pulmonary capillary system.

CONCLUSIONS

Perfadex solution provided sufficient lung preservation for 27 hours of cold ischemia, and its retrograde application led to significant functional and histologic improvement compared with antegrade perfusion. In contrast, preservation with Celsior solution resulted in lethal post-ischemic outcome, regardless of the route of administration, and therefore must be considered unsuitable for extended lung procurement.

Donor pretreatment using the aerosolized prostacyclin analogue iloprost optimizes post-ischemic function of non-heart beating donor lungs

BACKGROUND

Ischemia-reperfusion injury accounts for one-third of early deaths after lung transplantation. To expand the limited donor pool, lung retrieval from non-heart beating donors (NHBD) has been introduced recently. However, because of potentially deleterious effects of warm ischemia on microvascular integrity, use of NHBD lungs is limited by short tolerable time periods before preservation. After intravenous prostanoids are routinely used to ameliorate reperfusion injury, the latest evidence suggests similar efficacy of inhaled prostacyclin. Therefore, the impact of donor pretreatment with the prostacyclin analogue iloprost on postischemic NHBD lung function and preservation quality was evaluated.

METHODS

Asystolic pigs (5 per group) were ventilated for 180 minutes of warm ischemia (Group 2). In Group 3, 100 microg iloprost was aerosolized during the final 30 minutes of ventilation with a novel mobile ultrasonic nebulizer. Lungs were then retrogradely preserved with Perfadex and stored for 3 hours. After left lung transplantation and contralateral lung exclusion, hemodynamics, rO2/FiO2, and dynamic compliance were monitored for 6 hours and compared with sham-operated controls (Group 1). Pulmonary edema was determined both stereologically and by wet-to-dry weight ratio (W/D). Statistics comprised analysis of variance with repeated measures and Mann-Whitney test.

RESULTS

Flush preservation pressures, dynamic compliance, inspiratory pressures, and W/D were significantly superior in iloprost-treated lungs, and oxygenation and pulmonary hemodynamics were comparable between groups. Stereology revealed a trend toward lower intraalveolar edema formation in iloprost-treated lungs compared with untreated grafts.

CONCLUSIONS

Alveolar deposition of Iloprost and NHBD lungs before preservation ameliorates postischemic edema and significantly improves lung compliance. This easily applicable innovation approach, which uses a mobile ultrasonic nebulizer, offers an important strategy for improvement of pulmonary preservation quality and might expand the pool of donor lungs.

Impact of retrograde graft preservation in perfadex-based experimental lung transplantation

OBJECTIVE

Optimal preservation of postischemic organ function is a continuing challenge in clinical lung transplantation. Retrograde instillation of preservation solutions has theoretical advantages to achieve a homogeneous distribution in the lung due to perfusion of both the pulmonary and the bronchial circulation. Thus far, no systematic screening studies followed by in vivo large animal reevaluation including stereological analysis of intrapulmonary edema exist concerning the influence of retrograde preservation on postischemic lung function after preservation with low potassium dextran (LPD) solution (Perfadex).

MATERIALS AND METHODS

For initial screening in an extracorporeal rat model eight lungs, each, were preserved for 4 h using antegrade or retrograde preservation with LPD solution (Perfadex; PER(ant)/PER(ret)). Respiratory and hemodynamic results after reperfusion were compared to low-potassium Euro-Collins (LPEC). For systematic reevaluation, five pig lungs, each, were preserved correspondingly for 27 h, and results were compared to sham-operated control lungs. In both models, edema formation was quantified stereologically. Statistics comprised different ANOVA models.

RESULTS

In both models, use of PER(ret) resulted in significantly higher oxygenation capacity, lower inspiratory pressures, and lower amounts of intraalveolar edema as compared to PER(ant). Results of PER(ret) were not different from sham controls in the in vivo model; furthermore, a continuous retrograde elimination of blood clots from pulmonary microcirculation was noticed.

CONCLUSIONS

Retrograde application of LPD solution (Perfadex) results in significant functional and histological improvement as compared to antegrade perfusion. This innovative technique can be applied very easily in clinical practice and might be an ideal adjunct to further optimize the results after lung transplantation with LPD-based graft protection.

Inhaled nitric oxide affects endogenous surfactant in experimental lung transplantation

BACKGROUND

Inhalation of nitric oxide (NO) has been proposed as a therapy to improve lung transplantation outcome. We investigated the effect that inhaled NO has on the surfactant system in the context of ischemia-reperfusion injury.

METHODS

Single left-lung transplantation was performed in weight-matched pairs of Landrace pigs. A double-lung block from the donor animal was flushed with University of Wisconsin solution at 4 degrees C followed by immersion in cold University of Wisconsin solution for 22 hr. The left donor lung was transplanted into the recipient. Recipients were divided into two groups: (1) treated with inhaled NO (40 ppm) (n=6) immediately after initiating lung reperfusion and (2) without treatment (n=6). Lung function was measured during 2 hr of reperfusion. Surfactant components in small and large aggregates, isolated from cell-free bronchoalveolar lavages, and surfactant function were measured.

RESULTS

NO inhalation significantly decreased arterial oxygenation. With respect to the surfactant system, NO inhalation worsened the surfactant adsorption rate to an air-liquid interface and affected levels of hydrophobic surfactant proteins (SPs), SP-B and SP-C, and phospholipids, which decreased in large surfactant aggregates but not in small surfactant aggregates. SP-A was reduced in large surfactant aggregates of transplanted lungs from both untreated and NO-treated groups.

CONCLUSION

A decreased level of SP-A, SP-B, and SP-C in large surfactant aggregates of transplanted lungs treated with NO is a marker of lung injury. We conclude that treatment with inhaled NO after lung transplantation is deleterious for the surfactant system and causes a parallel worsening of arterial oxygenation.

Lung transplantation. Lung preservation

Over the past decade, improvements in the technique of lung preservation have led to significant reduction in the incidence of ischemia-reperfusion-induced lung injury after lung transplantation. The challenge remains to improve the number of donor lungs available for transplantation. While the number of patients on the waiting list is constantly increasing, only 10% to 30% of donor lungs are currently being used for transplantation. Hence, the development of new strategies to assess, repair, and improve the quality of the lungs could have a tremendous impact on the number of transplants performed. In addition, an improved understanding of the mechanisms involved in lung preservation might help elucidate the potential link between acute lung injury and chronic graft dysfunction. In the future, genetic analysis using novel technologies such as microarray analysis will help researchers determine which genes control the injury seen in the transplantation process. Hopefully, this information will provide new insights into the mechanisms of injury and reveal potential new strategies and targets for therapies to improve lung preservation.

[Prognostic factors of early morbidity and mortality after lung transplantation]

OBJECTIVES

Despite years of experience with lung transplantation, the rate of perioperative mortality remains high. The objective of this study was to look at our experience in the early postoperative period following lung transplantation in an effort to identify possible pre-, intra- and postoperative risk factors associated with mortality.

PATIENTS AND METHODS

A retrospective study of 68 consecutive patients receiving lung transplants over a period of 56 months. The conditions that led to transplantation were obstructive disease (40%), interstitial disease (33%) and suppurative disease (27%). Pre-, intra- and postoperative characteristics of donors and recipients were analyzed for their relation to morbidity and mortality. Statistical studies were done using SPSS 10.0 software. A p-value less than.05 was considered significant. Univariate analysis identified variables associated with the incidence of mortality in the postoperative recovery unit, and the variables with statistically significant associations were entered into multivariate analysis, using a logistic regression model to calculate odds ratio (OR) and 95% confidence intervals (CI).

RESULTS

No donor variables correlated with mortality. Patients with suppurative lung disease had a lower mortality rate (0% vs 30%; P = 0.04). Mortality was related to ischemic time longer than 300 minutes (OR = 2) and the use of extracorporeal circulation (OR = 4). A PaO2/FiO2 ratio less than 150 during the first 24 hours following transplantation (OR = 5) and reoperation due to bleeding (OR = 12) were the variables showing the highest correlations with mortality during the early postoperative period.

CONCLUSIONS

The mortality rate during the early postoperative period in our series was 22%. The survival rate was better in patients with suppurative lung disease. Bleeding that required reoperation and early graft dysfunction (defined in part by a PaO2/FiO2 ratio less than 150 during the first 24 hours) were the variables that best predicted death in the early postoperative period following lung transplantation.

Improved lung function by means of retrograde flush in canine lung transplantation with non-heart-beating donors

OBJECTIVE

Use of lungs from non-heart-beating donors would increase the pulmonary donor pool. The aim of this study was to evaluate the effects of retrograde flush in canine lung transplantation from non-heart-beating donors.

METHODS

Left lung transplantation was performed in 12 weight-matched pairs of dogs. Donors were killed without heparinization, left at room temperature for 2 hours, and then randomized into 2 groups. In group AF (n = 6) lung retrieval was performed after flushing the lung block with low potassium dextran glucose (50 mL/kg) solution through the pulmonary artery. In group AF+RF (n = 6) additional retrograde flushing (low potassium dextran glucose, 25 mL/kg) was performed through the left atrium before retrieval. Flushed solution was sampled at intervals to measure hemoglobin concentrations. The lungs were preserved at 4 degrees C for 2 hours, and the left lung was implanted to the recipient being subjected to a total ischemic time of 5 hours. After left lung transplantation, the right pulmonary artery and main bronchus were ligated. Lung function, including arterial blood gas and pulmonary hemodynamics, was measured for 3 hours. For lung function study, statistical analyses were performed by using 1-way analysis of variance with repeated measures.

RESULTS

Group AF+RF had significantly better gas exchange and lower wet/dry weight ratio of the transplanted lung than group AF. Changes of hemoglobin concentration in the flushed solution indicated that additional retrograde flush could remove residual microthrombi after antegrade flush.

CONCLUSIONS

This study supports the theory that additional retrograde flush improves lung function after lung transplantation by removing residual pulmonary microthrombi in the lungs of non-heart-beating donors.

Ischemia-reperfusion-induced lung injury

Ischemia-reperfusion-induced lung injury is characterized by nonspecific alveolar damage, lung edema, and hypoxemia occurring within 72 hours after lung transplantation. The most severe form may lead to primary graft failure and remains a significant cause of morbidity and mortality after lung transplantation. Over the past decade, better understanding of the mechanisms of ischemia-reperfusion injury, improvements in the technique of lung preservation, and the development of a new preservation solution specifically for the lung have been associated with a reduction in the incidence of primary graft failure from approximately 30 to 15% or less. Several strategies have also been introduced into clinical practice for the prevention and treatment of ischemia-reperfusion-induced lung injury with various degrees of success. However, only three randomized, double-blinded, placebo-controlled trials on ischemia-reperfusion-induced lung injury have been reported in the literature. In the future, the development of new agents and their application in prospective clinical trials are to be expected to prevent the occurrence of this potentially devastating complication and to further improve the success of lung transplantation.

Thirteen-year experience in lung transplantation for emphysema

BACKGROUND

Emphysema is the most common indication for lung transplantation. Recipients include younger patients with genetically determined alpha-1 antitrypsin deficiency (AAD) and, more commonly, patients with chronic obstructive pulmonary disease (COPD). We analyzed the results of our single-institution series of lung transplants for emphysema to identify outcome differences and factors predicting mortality and morbidity in these two groups.

METHODS

A retrospective analysis was undertaken of the 306 consecutive lung transplants for emphysema performed at our institution between 1988 and 2000 (220 COPD, 86 AAD). Follow-up was complete and averaged 3.7 years.

RESULTS

The mean age of AAD recipients (49 +/- 6 years) was less than those with COPD (55 +/- 6 years; p < 0.001). Hospital mortality was 6.2%, with no difference between COPD and AAD, or between single-lung transplants and bilateral-lung transplants. Hospital mortality during the most recent 6 years was significantly lower (3.9% vs 9.5%, p = 0.044). Five-year survival was 58.6% +/- 3.5%, with no difference between COPD (56.8% +/- 4.4%) and AAD (60.5% +/- 5.8%). Five-year survival was better with bilateral-lung transplants (66.7% +/- 4.0%) than with single-lung transplants (44.9% +/- 6.0%, p < 0.005). Independent predictors of mortality by Cox analysis were single lung transplantation (relative hazard = 1.98, p < 0.001), and need for cardiopulmonary bypass during the transplant (relative hazard = 1.84, p = 0.038).

CONCLUSIONS

AAD recipients, despite a younger age, do not achieve significantly superior survival results than those with COPD. Bilateral lung transplantation for emphysema results in better long-term survival. Accumulated experience and modifications in perioperative care over our 13-year series may explain recently improved early and long-term survival.

Does donor cause of death affect the outcome of lung transplantation?

BACKGROUND

Accumulating evidence suggests that the donor's cause of death may influence posttransplantation allograft function. We conducted a retrospective analysis of our adult lung transplant experience to investigate the influence of donor traumatic brain injury versus nontraumatic brain injury on posttransplantation outcome.

METHODS

We retrospectively reviewed donor records and recipient medical charts for 500 consecutive lung transplants performed between July 1988 and December 1999. Recipient follow-up was complete, with a minimum follow-up of 1 year of survival.

RESULTS

There were 295 and 205 donors in the traumatic and nontraumatic brain injury groups, respectively. Young male donors predominated in the traumatic brain injury group. Recipients receiving donor lungs from the traumatic and nontraumatic brain injury groups did not differ by age, sex, diagnosis, type of transplant (single-lung versus double-lung) or requirement for pretransplantation mechanical ventilatory assistance. Recipients did not differ in immediate or 24-hour PaO (2)/inspired oxygen ratio, ventilation time, hospital stay, hospital mortality, or overall survival. Recipients of organs from donors who died of traumatic brain injury showed a higher severity and frequency of rejection episodes during the first year after transplantation. Freedoms from bronchiolitis obliterans syndrome at 5 years were 34.5% and 50.8% for recipients of organs from donors who died of traumatic and nontraumatic brain injury, respectively (P =.002).

CONCLUSIONS

The cause of donor brain death does not appear to influence early results of lung transplantation. Traumatic brain injury, or some phenomenon associated with it, may predispose a transplanted lung and its recipient toward more severe early rejection episodes and subsequent development of bronchiolitis obliterans syndrome.

Retrograde flush perfusion with low-potassium solutions for improvement of experimental pulmonary preservation

BACKGROUND

Optimal preservation of post-ischemic organ function is a continuing challenge in clinical lung transplantation. Retrograde instillation of preservation solutions has the theoretic advantage of achieving homogeneous distribution in the lung because of perfusing both the pulmonary and the bronchial circulation. So far, we have seen no experimental studies that include stereologic analysis of intrapulmonary edema concerning the influence of retrograde preservation on post-ischemic lung function after preservation with Perfadex and Celsior.

METHODS

In an extracorporeal rat model, we perfused 8 lungs, each, using either antegrade or retrograde perfusion technique with Celsior (CE(ant)/CE(ret)) and Perfadex (PER(ant)/PER(ret)). Results were compared with low-potassium Euro-Collins. Post-ischemic lungs were reventilated and reperfused mechanically. We continuously monitored relative oxygenation capacity (ROC), pulmonary artery pressure, flush time, and wet/dry ratio. Furthermore, we used stereologic means to evaluate edema formation. Statistics comprised different analysis of variance models.

RESULTS

Relative oxygen capacity of CE(ant)-protected lungs was superior to that of PER(ant) preservation (p = 0.05). Use of PER(ret) resulted in significantly higher ROC as compared with PER(ant) (p < 0.001) and was comparable to results obtained with CE-preservation, which was not further improved with retrograde application.

CONCLUSIONS

Celsior provides better lung preservation than does Perfadex when administered antegradely. Retrograde application of Perfadex results in significant functional improvement as compared with antegrade perfusion, which reaches the standard of Celsior-protected organs. Additional in vivo experiments in combination with ultrastructural analysis are warranted to further evaluate retrograde delivery of preservation solutions, which could be used in clinical lung transplantation to further optimize current results.

Preimplantation retrograde pneumoplegia in clinical lung transplantation

OBJECTIVE

Retrograde pneumoplegia seems to improve early graft function in experimental and clinical lung transplantation. We evaluated the role of retrograde flushing in addition to antegrade pneumoplegia in clinical lung transplantation.

METHODS

Fourteen patients undergoing lung transplantation were randomized into 2 groups: in group I we performed antegrade pulmonary artery flushing with alprostadil (prostaglandin E1) and modified Euro-Collins solution at the time of retrieval. In group II additional retrograde flushing through the pulmonary veins was performed at the back table, before reimplantation. Hemodynamic variables, mean airway pressure, and blood gas analysis were monitored at different time points. Postoperative volumetric monitoring was performed to assess extravascular lung water. The reimplantation response was assessed by a radiographic score; extubation time and intensive care unit stay were recorded.

RESULTS

During retrograde flushing, blood and clots coming out from the pulmonary artery were observed; 2 lungs harvested from a donor with multiple bone fractures had fat emboli in the retrograde perfusate. Hemodynamic monitoring did not demonstrate any difference between the 2 groups. The ratio of arterial oxygen tension to inspired oxygen fraction, extravascular lung water, duration of intubation, and length of stay in the intensive care unit were improved in group II, but the differences did not reach statistical significance. Intrapulmonary shunt fraction was significantly improved in group II at each time point ( P =.02), as well as indexed alveolar-arterial oxygen tension gradient (P =.04), mean airway pressure (P =.04), and chest x-ray score ( P =.03).

CONCLUSIONS

Preimplantation retrograde flushing is not detrimental and helps to improve early graft function.

Pulmonary thromboembolectomy of donor lungs prior to lung transplantation

Successful bilateral single-lung transplantation was performed after pulmonary thromboembolectomy of the donor lungs. The donor lungs were not thought to contain large amounts of pulmonary thromboemboli because they satisfied all the donor selection criteria. This case reinforces the need of not only meticulous inspection of the donor lungs prior to implantation but also the productive use of available donor organs.