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Background: Bronchial anastomotic complications develop in 31% of lung transplant recipients, leading to additional operative procedures and increased morbidity. Advances in surgical technique have thus far resulted in only modestly improved outcomes. We hypothesized that creating the bronchial anastomosis at the secondary carina using a combination of running and figure-of-eight sutures would minimize donor bronchial ischemia and airway complications., Methods: This retrospective review of a single surgeon's operative experience from 2000 to 2007 compares a new bronchial anastomotic technique with the conventional technique. The primary outcome was the occurrence of bronchial anastomotic complications requiring invasive intervention. The secondary outcome was distal airway complications. Patients were monitored for 1 year after transplant. Recipient and donor demographic data as well as relevant variables from their preoperative, perioperative, and postoperative courses were collected for analysis. These data were compared using t tests for normally distributed continuous variables, Mann-Whitney tests for nonnormally distributed continuous variables, and χ2 tests or Fisher exact test for categoric variables. Logistic regression was used to control for covariates while comparing the primary outcome between the new and conventional bronchial anastomotic techniques., Results: The analysis included 230 patients, representing 407 anastomoses. The occurrence of anastomotic complications requiring intervention and distal airway complications decreased from 18.1% to 2.3% of anastomoses and 12.2% to 4.4% of patients, respectively. After controlling for available risk factors, the new technique significantly reduced both anastomotic (p<0.001) and distal (p=0.03) airway complications., Conclusions: This new anastomotic technique dramatically reduces anastomotic and distal airway complications after lung transplantation., (Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Ischemia-reperfusion injury impairs lung transplant outcomes. The transcription factors, activator protein-1, and nuclear factor kappa B, are activated early in reperfusion and drive the development of injury. Thrombin inhibition with hirudin, and calcineurin inhibition with tacrolimus have independently been shown to ameliorate lung ischemia-reperfusion injury by reducing activator protein-1 and nuclear factor kappa B activation, respectively. However, high doses were required to achieve protection using individual agents, raising concerns about potential toxicities. We sought to determine if low-dose combination therapy reduced injury through synergistic inhibition of pretranscriptional signaling events., Methods: Rats were pretreated with either intravenous hirudin or tacrolimus at low doses or high doses, or both at low doses, prior to undergoing left lung ischemia and reperfusion. Lungs were assessed for markers of lung injury, including bronchoalveolar lavage cytokine-chemokine content and transcription factor transactivation of activator protein-1 and nuclear factor kappa B., Results: High-dose monotherapy with hirudin or tacrolimus reduced lung injury and transactivation of activator protein-1 and nuclear factor kappa B activation, respectively, whereas low-dose monotherapy with either agent did not alter transcription factor activation or lung injury compared with positive controls. Low-dose combination therapy was more protective than high-dose monotherapy with either drug, and correlated with a reduction in activation of both transcription factors and their associated cytokines., Conclusions: The significant decrease in lung injury severity and transcription factor activation with combined pathway inhibition suggests pretranscriptional signaling redundancy between the calcineurin and thrombin dependent pathways in lung reperfusion injury., (2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The availability of suitable lung donors has remained a significant barrier to lung transplantation. The clinical relevance of an isolated positive Gram stain in potential donor lungs, which occurs in >80%, is unclear. Low doses of lipopolysaccharide (LPS) have been protective in several models of ischemia-reperfusion injury through a pre-conditioning response. We sought to demonstrate that low-dose LPS is protective against subsequent lung ischemia-reperfusion injury., Methods: Pathogen-free Long-Evans rats were pre-treated with vehicle or LPS 24 hours before 90 minutes of ischemia and up to 4 hours of reperfusion. Lungs were assessed for vascular permeability, myeloperoxidase content, bronchoalveolar lavage inflammatory cell and cytokine/chemokine content, as well as nuclear translocation of nuclear factor kappaB (NFkappaB) and activator protein-1 (AP-1), and interleukin-1 receptor-associated kinase-1 (IRAK-1) and stress-activated protein kinase (SAPK) activation., Results: Compared with positive controls, LPS pre-treatment resulted in reductions in vascular permeability (70%, p < 0.001), myeloperoxidase content (93%, p < 0.001), bronchoalveolar lavage inflammatory cells (91%, p < 0.001), and inflammatory cytokine/chemokine content (cytokine-induced neutrophil chemoattractant, 99%, p = 0.003; interleukin-1beta, 72%, p < 0.0001; tumor necrosis factor-alpha, 76%, p < 0.0001), NFkappaB (86%, p < 0.001) and AP-1 (97%, p < 0.001) nuclear translocation, and IRAK-1 (87%, p < 0.001) and SAPK (80%, p < 0.001) phosphorylation., Conclusions: Lipopolysaccharide pre-treatment reduced lung injury and inflammatory mediator production after subsequent exposure to ischemia-reperfusion. Understanding the clinical significance of lipopolysaccharide in donor lungs has the potential to expand and clarify donor inclusion criteria.

Background: Activation of the alveolar macrophage is centrally important to the development of lung ischemia reperfusion injury. Alveolar macrophages and type 2 pneumocytes secrete a variety of proinflammatory mediators in response to oxidative stress. The manner in which they interact and how the macrophage may influence pneumocyte responses in lung ischemia reperfusion injury is unknown. Utilizing an in vitro model of hypoxia and reoxygenation, we sought to determine if the proinflammatory response of type 2 pneumocytes to oxidative stress would be amplified by alveolar macrophage secretory products., Methods: Cultured pneumocytes were exposed to control media or media from cultured macrophages exposed to hypoxia and reoxygenation. Pneumocytes were subsequently subjected to hypoxia and reoxygenation and assessed for both nuclear translocation of nuclear factor kappa B and inflammatory cytokine and chemokine secretion. To examine for any reciprocal interactions, we reversed the experiment, exposing macrophages to conditioned pneumocyte media., Results: In the presence of media from stimulated macrophages, production of proinflammatory mediators by type 2 pneumocytes was dramatically enhanced. In contrast, exposure of the macrophage to conditioned pneumocyte media had an inhibitory effect on macrophage responses subsequently exposed to hypoxia and reoxygenation., Conclusions: The alveolar macrophage drives the development of lung reperfusion injury in part through amplification of the inflammatory response of type 2 pneumocytes subjected to hypoxia and reoxygenation.