Preservation with a retrograde second flushing of Eurocollins in clinical lung transplantation

Airway Complications after Lung Transplantation-A Contemporary Series of 400 Bronchial Anastomoses from a Single Center

(1) Objective: To determine whether recent advances in lung transplantation (LT) have reduced the incidence and changed the risk factors for airway complications (AC). (2) Methods: Retrospective analysis of patients receiving a lung transplant between January 2007 and January 2019. An AC was defined as a bronchoscopic abnormality in the airway, either requiring or not requiring an endoscopic or surgical intervention. Both univariable and multivariable analyses were performed to identify risk factors for AC. (3) Results: 285 lung transplants (170 single and 115 bilateral lung transplants) were analysed, comprising 400 anastomoses at risk. A total of 50 anastomoses resulted in AC (12%). There were 14 anastomotic and 11 non-anastomotic stenoses, 4 dehiscences, and 3 malacias. Independent predictors for AC were: gender male (OR: 4.18; p = 0.002), cardiac comorbidities (OR: 2.74; p = 0.009), prolonged postoperative mechanical ventilation (OR: 2.5; p = 0.02), P_aO₂/F_iO₂ < 300 mmHg at 24 h post-LT (OR: 2.48; p = 0.01), graft infection (OR: 2.16; p = 0.05), and post-LT isolation of Aspergillus spp. (OR: 2.63; p = 0.03). (4) Conclusions: In spite of advances in lung transplantation practice, the risk factors, incidence, and lethality of AC after LT remains unchanged. Graft dysfunction, an infected environment, and the need of prolonged mechanical ventilation remain an Achilles heel for AC.

Antibodies against Apoptotic Cells Present in End-stage Lung Disease Patients Do Not Correlate with Clinical Outcome after Lung Transplantation

Antibodies against HLA and non-HLA are associated with transplantation outcome. Recently, pretransplant serum IgG antibody levels against apoptotic cells were found to correlate with kidney allograft loss. We investigated the presence of these antibodies in lung transplantation (LTx) patients and evaluated the correlation of pre-LTx serum levels of IgG antibodies against apoptotic cells with LTx outcome. These cells included donor lung endothelial cells (ECs) obtained from lung perfusion fluid collected during LTx procedure. Cells were isolated, expanded in vitro, and analyzed as targets for antiapoptotic cell reactivity. Cultured cells exhibited EC morphology and were CD31+, CD13+, and vWF+. End-stage lung disease patients showed elevated serum IgG levels against apoptotic lung EC (p = 0.0018) compared to healthy controls. Interestingly, the levels of circulating antibodies directed against either apoptotic Jurkat cells or apoptotic lung ECs did not correlate, suggesting a target cell specificity. We observed no correlation between chronic or acute rejection and pre-LTx serum levels of antiapoptotic antibodies. Also, these levels did not differ between matched patients developing chronic rejection or not during follow-up or at the time of diagnosis, as they remained as high as prior to transplantation. Thus, circulating levels of antiapoptotic cell antibodies are elevated in end-stage lung disease patients, but our data do not correlate with outcome after LTx.

Oxidative Stress and Lung Ischemia-Reperfusion Injury

Ischemia-reperfusion (IR) injury is directly related to the formation of reactive oxygen species (ROS), endothelial cell injury, increased vascular permeability, and the activation of neutrophils and platelets, cytokines, and the complement system. Several studies have confirmed the destructiveness of the toxic oxygen metabolites produced and their role in the pathophysiology of different processes, such as oxygen poisoning, inflammation, and ischemic injury. Due to the different degrees of tissue damage resulting from the process of ischemia and subsequent reperfusion, several studies in animal models have focused on the prevention of IR injury and methods of lung protection. Lung IR injury has clinical relevance in the setting of lung transplantation and cardiopulmonary bypass, for which the consequences of IR injury may be devastating in critically ill patients.

Extended recipients but not extended donors are associated with poor outcomes following lung transplantation

OBJECTIVES

Extended donors (EDs) are safely used to increase the donor pool in lung transplantation (LT), but their influence in critically ill patients (extended recipients [ERs]) remains controversial. We compared LT outcomes matching optimal donors (ODs) or EDs with optimal recipients (ORs) or ERs.

METHODS

Three hundred and sixty-five LTs were reviewed. ED criteria: age >55, PaO2/FiO2 < 350 mmHg, pulmonary infiltrates/purulent secretions and ischaemic times >6 h (single LT [SLT]) and >9 h (double LT [DLT]). ER criteria: pulmonary fibrosis or pulmonary hypertension, pretransplant intubation, age >60 years and bypass >2 h. Four groups were created: Group 1 (OD/OR), Group 2 (OD/ER), Group 3 (ED/OR) and Group 4 (ED/ER). Thirty-day mortality, primary graft dysfunction (PGD), onset of bronchiolitis obliterans syndrome (BOS), long-term survival and other transplant outcomes were compared between OD and ED, OR and ER and among the four groups of study.

RESULTS

There were 151 SLTs and 214 DLTs. Donors: OD (n = 229) vs ED (n = 136); PGD 8 vs 10% (P = 0.43); 30-day mortality 19 vs 20% (P = 0.53) and survival (1, 5, 10 and 15 years) 67, 47, 34, 26 vs 69, 53, 46 and 29% (P = 0.33). Recipients: OR (n = 182) vs ER (n = 183); PGD 7 vs 10% (P = 0.10); 30-day mortality 15 vs 23% (P = 0.04) and survival (1, 5, 10 and 15 years): 73, 57, 46, 30 vs 61, 42, 29 and 23% (P = 0.002). Four donor/recipient (D/R) groups: Group 1 (n = 122), Group 2 (n = 106), Group 3 (n = 61), Group 4 (n = 76); PGD 10, 6, 3 and 16% (P = 0.05); 30-day mortality 13, 26, 19 and 20%, respectively (P = 0.13); survival (1, 5, 10 and 15 years) 74, 55, 44 and 35% (Group 1), 55, 39, 22 and 16% (Group 2), 70, 59, 48 and 26% (Group 3) and 68, 47, 37 and 22% (Group 4) (P = 0.004). No differences in the onset of BOS were observed among the four study groups.

CONCLUSIONS

LT in critically ill recipients is associated with poor early and long-term outcomes, irrespective of the quality of the donor and length of ischaemic times.

Lung volume reduction surgery after lung transplantation for emphysema-chronic obstructive pulmonary disease

Lung Volume Reduction Surgery (LVRS) has become a palliative treatment for patients with advanced emphysema and disabling dyspnea. After single lung transplantation in chronic obstructive pulmonary disease, LVRS may be indicated to improve graft dysfunction caused by native lung hyperinflation compressing the grafted lung. This common complication is the subject of our study, which showed LVRS to be helpful to manage this situation. We performed an observational retrospective and descriptive study using the data of 293 patients transplanted in our center between January 1996 and October 2011. Some of the patients who underwent a single lung transplantation developed native lung hyperinflation years after the transplantation, interfering with respiratory function due to graft compression.

Influence of donor-recipient gender mismatch on graft function and survival following lung transplantation

OBJECTIVES

In current practice, donors and recipients are not matched for gender in lung transplantation. However, some data have suggested a possible effect of gender combinations on lung transplant outcomes. We examined whether donor-recipient (D/R) gender mismatch is related to adverse outcomes after lung transplantation in terms of early and long-term graft function and survival.

METHODS

We reviewed 256 donors and lung transplant recipients over a 14-year period. Patients were distributed into four groups: Group A (D/R: female/female), Group B (D/R: male/male), Group C (D/R: female/male), Group D (D/R: male/female). Donor and recipient variables were compared among groups, including early graft function, 30-day mortality, freedom from bronchiolitis obliterans syndrome (BOS), and long-term survival.

RESULTS

Group A: 57 (22%), Group B: 99 (39%), Group C: 62 (24%), Group D: 38 (15%) transplants (P = 0.001). Donor age was 29 ± 14, 27 ± 12, 33 ± 13 and 23 ± 12 years for Groups A, B, C and D, respectively (P = 0.004). Recipient age was 31 ± 15, 44 ± 17, 42 ± 16 and 30 ± 16 years for Groups A, B, C and D, respectively (P = 0.000). PaO2/FiO2 (mmHg) 24 h post-transplant was: Group A: 276 ± 144, Group B: 297 ± 131, Group C: 344 ± 133 and Group D: 238 ± 138 (P = 0.015). Primary graft dysfunction developed in 23, 14, 17 and 21% of recipients from Groups A, B, C and D, respectively (P = 0.45). Operative mortality was 4.4, 6.5, 5.2 and 2%, for recipients from Groups A, B, C and D, respectively (P = 0.66). Freedom from BOS was 73, 59 and 36% for gender-matched transplants vs 76, 67 and 40% for gender-mismatched transplants at 3, 5 and 10 years, respectively (P = 0.618), without differences among groups. A non-significant survival benefit was observed for female recipients, irrespective of the donor gender.

CONCLUSIONS

Donor-recipient gender mismatch does not have a negative impact on early graft function and mortality following lung transplantation. There is a trend towards a survival benefit for female recipients, irrespective of the donor gender.

Experience of the Reina Sofia hospital in lobar lung transplantation

The number of patients awaiting lung transplantation has steadily increased over the past decade, but the number of donors has remained relatively stable. Owing to the increasing scarcity of donor lungs, especially for pediatric and small adult recipients, advanced operative strategies for the use of larger grafts for smaller recipients have been developed. Size matching between donors and recipients represents one of the organ distribution criteria widely accepted by lung transplantation teams. However, in some cases it is not possible to allocate a donor to the corresponding size-compatible recipient. To avoid possible complications derived from the implantation of oversized lungs into smaller recipients, various methods of downsizing are applied for cadaveric donor lungs, such as lobar transplantation. We review our experience in 6 patients undergoing volume reduction of the lung graft by lobar resection at the time of transplantation. Graft volume reduction by anatomic resection (lobar transplantation) is a reliable and safe procedure to overcome size disparities between the donor and the recipient of a lung transplant, and thus to maximize the number of donors.

Results of lung transplantation in idiopathic pulmonary fibrosis patients

Lung transplantation (OLT) remains the only available therapy for patients with end-stage idiopathic pulmonary fibrosis (IPF). The objective of this study was to review our experience of OLT for end-stage IPF (IPFLT) patients, seeking to identify variables associated with survival for comparison with outcomes of other indications for LT (OILT). From October 1993 to December 2009, we performed 310 consecutive OLT in 301 patients for treatment of various end-stage pulmonary conditions. The indications for OLT were: IPF (n=89, 30.5%) chronic obstructive pulmonary disease (n=82), cystic fibrosis (n=80), bronchiectasis (n=12), alfa-1-antitrypsin deficit (n=6), primary pulmonary hypertension (n=4), bronchiolitis obliterans (n=4), other conditions (n=15). We observed significant differences in the actuarial survival between the IPFLT and the OILT groups particularly at the expense of worse perioperative 30-day and early 1-year mortality in the IPFLT group. Upon univariate and multivariate analyses, the need for cardiopulmonary bypass, previous recipient ventilator dependence, and donor age>50 years were all associated with poorer survival rates among IPF patients. In our experience, survival did not differ between patients who underwent a single versus a bilateral sequential lung transplant (BSLT); however, BSLT cases were associated with short-term damage but long-term survival. The functional results in the IPFLT group were excellent. We observed significant improvements in the values of arterial oxygen pressure (PaO2), arterial carbon dioxide pressure (PaCO2), forced vital capacity (FVC%) and forced expiratory volume in 1 second (FEV1%) at 6, 12, and 36 months compared to their pretransplant baseline results.

Airway complications after lung transplantation can be avoided without bronchial artery revascularization

PURPOSE OF REVIEW

The major cause of death following lung transplantation in the beginning after the first human lung transplantation in 1963 was airway dehiscence, representing a major obstacle to widespread use of this treatment option. Lung transplantation is unique among all solid organ transplantations, since systemic arterial blood supply is not restored during engraftment. In the eighties and thereafter the problem of airway healing after lung transplantation was the main focus of research. This review focuses on the incidence of airway anastomotic complications after lung transplantation and delineates potential risk factors.

RECENT FINDINGS

Refinements in lung preservation and surgical technique have reduced the incidence of airway complications. Reflecting these changes, the contemporary rate of anastomotic lesions following lung transplantation has dropped from 80% before 1983 to less than 3% with a range of 2.6-23.8%. Small clinical series of lung transplantation with direct bronchial artery revascularization have reported promising early results. However, direct bronchial artery revascularization has been considered a difficult and unreliable method to be used clinically, as it prolongs the operation and ischemic time, increases risk of bleeding, and because of the good results reported from transplants without bronchial artery revascularization. At the present time (nearly) all transplant centers perform the airway anastomosis without bronchial artery revascularization.

SUMMARY

Bronchial anastomotic complications can be avoided by use of a standardized surgical technique which respects the fact that the donor bronchus is poorly vascularized. Prevention of fungal infections with aggressive antifungal treatment may play an important additive role.

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.

Lung preservation: pulmonary flush route affects bronchial mucosal temperature and expression of IFN-gamma and Gro in regional lymph nodes

Optimal lung preservation via flush of the pulmonary vasculature minimizes early graft failure post-lung transplantation. We hypothesized that the route of pulmonary flush has differential effects on thermal gradients in the lung and expression of inflammatory mediators. Swine underwent antegrade flush (AG) via pulmonary artery; AG/RG: antegrade + retrograde flush via pulmonary veins or AG/BA: antegrade + bronchial artery flush via bronchial artery. Temperatures were recorded in bronchial mucosa and peribronchial lymph nodes. RT-PCR was utilized to detect cytokine gene expression in the nodes. AG/BA flush resulted in greatest cooling of bronchial mucosa and lymph nodes (p < 0.001). The route of flush did not affect expression of RANTES, MCP-1, IL-8, IL-1beta, TNF-alpha or IL-6. However, expression of Gro was reduced 4-h post-preservation in all groups. Only AG/BA resulted in decreased IFN-gamma transcripts. These data show that, compared to AG or AG/RG, AG/BA flush results in the greatest cooling of lung compartments and down regulates lymph node expression of a cytokine and chemokine that have key roles in inflammation and immunity. These data suggest that pulmonary flush via AG/BA during donor harvest may be optimal to decrease the risk of early graft failure.

Analysis of Lung Transplant Recipients Surviving Beyond 5 Years

INTRODUCTION

We started lung transplantation (LT) in October 1993 and review the status of recipients who have survived beyond 5 years.

METHODS

A retrospective review of patients undergoing LT from October 1993 to October 1998 included pulmonary function data, incidence of bronchiolitis obliterans syndrome (BOS), functional status, and survival.

RESULTS

Of 73 transplantations 41 (56%) patients have survived beyond 5 years (study group), including 23 men and 18 women of age 33.2 +/- 15.6 years. Indications for LT were as follows: cystic fibrosis (n = 16), emphysema (n = 13), pulmonary fibrosis (n = 8), and other (n = 4). Actuarial survival at 5, 7, and 9 years was 56%, 53%, and 43%, respectively. Freedom from BOS was 63%, 56%, and 50% at 5, 7, and 9 years, respectively. The median percent predicted FEV1 was 67%, 56%, and 56%, respectively. Also, 79% of recipients had no limitations in their daily activities; 65% were active and working. Only 5% of patients showed some degree of limitation at 5 years posttransplantation. When survivors beyond 5 years were compared with nonsurvivors beyond 5 years, differences were observed: nonsurvivors more frequently required bypass (P = .01), experienced longer postoperative intubation times (P = .01), and exhibited lower PaO2 at 12 months posttransplantation (P < .01).

CONCLUSION

Our data show good survival rates among patients surviving beyond 5 years after LT, with a moderate incidence of BOS at 9 years posttransplantation. Despite the incidence of BOS, these patients have good pulmonary function and activity status.

Pediatric Lung Transplantation

INTRODUCTION

Pediatric lung transplantation (LT) was started in Spain in 1996 at our institution. We compare the results of pediatric LT with those in adult patients.

METHODS

A retrospective review of LT patients from 1993 to 2003 included demographic donor and recipient data, pulmonary function, gas exchange parameters, complications, episodes of rejection and pneumonia, as well as survival. Patients were divided into 2 groups: pediatric (<16 years) and adult (>16 years) LT patients.

RESULTS

Of 165 LTs performed, 23 recipients were pediatric patients (10 boys, 13 girls; mean age, 11.9 +/- 2.9 years [range, 5-16 years]). The indications were cystic fibrosis (n = 21), pulmonary fibrosis (n = 1), and Kartagener syndrome (n = 1). The actuarial survival rate was 73%, 67%, and 62% at 1, 3, and 8 years post-LT in children, versus 67%, 56%, and 41% at 1, 3, and 8 years post-LT in adult patients (P = NS). Of the pediatric patients, 35% required mechanical ventilation preoperatively (P < .001). Pediatric patients showed a higher incidence of pneumonia (P < .01) and acute rejection episodes (P = .02) during the first month post-LT, and longer stays in the intensive care unit (P = .02). Pediatric patients displayed more immunosuppression-related adverse effects: diabetes (P = .04), neuropathy (P < .01), and hirsutism (P < .001). In children, arterial oxygen tension improved, from 51 mm Hg pre-LT to 93 mm Hg at 5 years post-LT. Forced expiratory volume in 1 second improved from 28% pre-LT to 84% at 5 years post-LT.

CONCLUSION

In children, LT is a high-risk procedure because of the critical status of these patients. However, the results of pediatric LT are similar to those in adults, but with better long-term survival.

Pulmonary Tailoring and Lobar Transplantation to Overcome Size Disparities in Lung Transplantation

Size matching between donors and recipients represents one of the organ distribution criteria widely accepted by lung transplant teams. However, in some cases it is not possible to allocate a donor to the corresponding size-compatible recipient. To avoid possible complications derived from the implantation of oversized lungs into smaller recipients, surgical procedures such as pulmonary tailoring and lobar transplantation have been advocated. We review our experience in 13 patients undergoing volume reduction of the lung graft at the time of transplantation, either by nonanatomical lung volume reduction or by lobar transplantation. There were no significant differences between lung-downsized patients and standard lung transplantation patients in terms of donor characteristics, surgical and postoperative complications, functional outcome, and survival. We conclude that downsizing the lung graft either by nonanatomical resection or lobar transplantation is safe and reliable to overcome size disparities between donor and recipients, with no additional morbidity and with similar early and midterm outcomes to those in standard lung transplants.

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.

Long-Term Results of Lung Transplantation for Emphysema

INTRODUCTION

We sought to assess the differences between lung transplantation (LT) to treat emphysema, versus other pulmonary diseases.

METHODS

This retrospective review of lung transplantations (LTs) performed from October 1993 to September 2003, included donor and recipient demographic data, pulmonary function, oxygenation, postoperative complications, incidence of rejection and pneumonia, and survival.

RESULTS

Of 159 LTs performed the 39 transplanted to treat emphysema (24.4%), were in 33 men and 6 women of age 50.9 +/- 8.7 years (men, 25 to 65 years). There were differences between the emphysema vs other groups in terms of age (P < .001), gender (P = .001), need for bypass (P = .004), and immediate posttransplantation oxygenation index (P = .001). Perioperative mortality tended to be lower among patients with emphysema (2.7% vs 10.8%; P = .131). The incidences of complications and acute rejections was similar. Forced vital capacity, forced expiratory volume in 1 second, arterial oxygen tension, and arterial carbon dioxide tension improved significantly post-Tx. Actuarial survivals were 82%, 68%, and 63%, respectively, at 1, 3, and 7 years posttransplantation for emphysema patients vs 60%, 53%, and 42%, respectively, at 1, 3, and 7 years posttransplantation for non-emphysema patients (P = .049).

CONCLUSION

Lung transplantation in patients with emphysema offers good long-term survival, with significant improvement in functional status and low morbidity. The older age of emphysema patients was not associated with a higher incidence of postoperative complications.

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.

Lung Retrieval from Non-Heart-Beating Donors: First Experience with an Innovative Preservation Strategy in a Pig Lung Transplantation Model

OBJECTIVE

Lung transplantation is limited by the scarcity of donor organs. Lung retrieval from non-heart-beating donors (NHBD) might extend the donor pool and has been reported recently. However, no studies in NHBD exist using the novel approach of retrograde preservation with Perfadex solution.

METHODS

Heparinized asystolic pigs (n = 5, 30-35 kg) were ventilated for 90 min. The lungs were retrogradely preserved with Perfadex solution and stored inflated at 4 degrees C for 3 h. Left lung transplantation in the recipient was followed by exclusion of the right lung. Results were compared to sham-operated animals. Oxygenation, hemodynamics and dynamic compliance were monitored for 4 h. Infiltration of polymorphonuclear cells (PMNs) and stereological quantification of alveolar edema was performed. Statistical analysis comprised Kruskal-Wallis and Mann-Whitney tests and ANOVA analysis with repeated measures.

RESULTS

No mortality was observed. During preservation, continuous elimination of blood clots via the pulmonary artery venting site was observed. Oxygenation and compliance were similar between groups, but sham controls showed significantly lower pulmonary vascular resistance. Stereological quantification revealed higher volume fractions of intra-alveolar edema in NHBD grafts, while PMN infiltration was comparable to sham controls.

CONCLUSIONS

Use of NHBD lungs results in excellent outcome after 90 min of warm ischemia followed by retrograde preservation with Perfadex solution. This novel approach can optimize lung preservation by eliminating clots from the pulmonary circulation and might clinically be considered in brain-dead organ donors who become hemodynamically unstable prior to organ harvest. Further trials with longer warm and cold ischemic periods are necessary to further elucidate this promising approach to donor pool expansion.

[Single-lung transplant and primary graft failure]

OBJECTIVE

To quantify primary graft failure (PGF) and its impact on perioperative and early mortality in single-lung transplant (SLT).

METHOD

We analyzed 35 SLT procedures performed using similar techniques. PGF was defined as a PaO2/FiO2 coefficient lower than 200 mmHg during the first 72 hours or ventilation assistance lasting longer than 5 days attributable to primary lung dysfunction. We defined perioperative mortality as occurring within 30 days of surgery and early mortality within 90 days.

RESULTS

Twenty-five men and 10 women received lungs, 22 for pulmonary fibrosis and 13 for emphysema; the mean age was 53.26 10.77 years. Twenty right SLTs were performed and 15 left SLTs. Twenty-nine donors were men and 6 were women, with a mean age of 29.31 12.33 years. Twenty-six died from cranial trauma, 8 from stroke and 1 from a brain tumor. The mean time of intubation was 1.69 1.35 days. The mean PaO2 was 470.71 70.82 mmHg. The mean time of ischemia was 201.77 62.64 minutes. Four patients (11.42%) developed PGF and 3 died during the perioperative period. Two additional patients died within the early postoperative period. Survival was 91.4% at one month and 85.5% at three months. The cause of donor death was the only variable that influenced the development of PGF.

CONCLUSION

We observed a low incidence of PGF and of perioperative and early mortality, with one and three month survival rates similar to those reported internationally.

Airway complications after lung transplantation: a review of 151 anastomoses

OBJECTIVE

To analyze the incidence, treatment and follow up of airway complications after lung transplantation.

METHODS

From October 1993 to April 2000, 104 lung transplants were performed in 101 patients. One hundred and fifty one bronchial anastomoses at risk were included in the study (29 single lung and 61 sequential double lung). Donor lungs were flushed both antegradely and retrogradely with Eurocollins. In the recipients, either a single or a sequential bilateral lung transplantation was performed when indicated. The bronchial anastomosis was telescoped and covered with peribronchial tissue in all cases. Postoperative fiberoptic bronchoscopic examinations were dictated by clinical grounds. Recipient variables were recorded and analyzed to assess possible differences between both complicated and non-complicated groups.

RESULTS

Eight bronchial anastomotic complications (5.3%) occurred in six patients (6.8%). All complicated cases developed in sequential bilateral lung recipients (P=0.08): stenosis (n=5), granulation tissue (n=2), and bronchial dehiscence (n=1). Treatment consisted of lobectomy and subsequent completion pneumonectomy in one patient, rigid bronchoscopy dilation in two, balloon bronchodilation in two, laser debridement and stenting in one, and conservative therapy in two cases. One patient with severe sepsis and bronchial dehiscence died on day +30. The rest of the patients remain well so far. Airway complications were related to longer intubation periods (P<0.01). Other perioperative donor and recipient factors including the incidence of infections and acute rejection episodes, and actuarial survival, did not differ between groups.

CONCLUSION

In our experience, the incidence of airway complications after lung transplantation is 5.3%. The careful surgical technique and organ preservation, the close surveillance of rejection and infection, and early postoperative extubation might play a role in reducing this incidence. Either surgical therapy or bronchoscopic dilation and stenting methods may contribute to resolve these complications.