Adoption of a Semi-elective Lung Transplantation Practice by Safely Extending Cold Ischemic Times.

OBJECTIVE: Lung transplantation is a complex surgical procedure performed by specialized teams. Practice changes to eliminate overnight lung transplants were implemented at our center and patient outcomes were evaluated. METHODS: Patient and donor organ selection were performed in the standard fashion. All donors with a cross clamp after 6 PM matched to any of our listed recipients-independent of their surgical complexity or risk-were kept in a temperature-controlled iceless cooler from procurement to recipient implant. All recipients had a 7 AM in-room start. Data were prospectively collected and compared to a cohort of recipients from the previous fifteen months. RESULTS: 82 transplants were performed at a single academic institution between 7/1/22 and 1/7/24, 21% of which included allografts with extended ischemic times utilizing the iceless cooler (n=18) with a median average temperature of 6.81 degrees Celsius. Median ischemic times were 13.9 (12.5 - 15.6) hours, more than twice the length of ischemic times in the standard group (n=64, 6.8 (6.1 - 7.4) hours). Post-operative outcomes were similar between groups, including post-operative ICU duration (12 vs 9 days in the standard group), length of stay (24 vs 20 days), PGD3 (17% vs 20%), post-operative ECMO (22% vs 20%), and six-month survival (94% vs 91%). CONCLUSIONS: Donor lungs preserved in an iceless cooler were successfully transplanted after extended cold ischemic times. Adoption of a semi-elective transplant strategy can be successfully implemented without compromising patient outcomes. Additional advantages may be gleaned through daytime transplantation with standard transplant surgical teams rather than overnight, on call-teams.

Case Report: Optimal utilization of marginal lung allografts by considering donor-recipient PGD risk compatibility and by mitigating allograft and recipient inflammatory risk.

Reducing the risk of high-grade primary graft dysfunction (PGD) is vital to achieve acceptable short- and long-term outcomes for recipients following lung transplantation. However, the utilization of injured lung allografts, which may confer a higher risk of PGD, must be considered due to the disparity between the increasing number of patients requiring lung transplantation and the limited donor pool. We describe a case in which highly marginal lung allografts were utilized with a good post-transplant outcome. Donor-recipient PGD risk compatibility was taken into consideration. Normothermic ex vivo lung perfusion (EVLP) was utilized to functionally assess the allografts. A second cold ischemia time following EVLP was avoided by converting the EVLP mode to a hypothermic oxygenated perfusion setup from which the lungs were transplanted directly. We attempted to mitigate lung ischemia-reperfusion injury in the recipient by employing cytokine adsorption both during the EVLP and intraoperatively during the implant procedure. In this case report, we describe our hypothermic oxygenated perfusion setup on EVLP for the first time. Furthermore, we describe the utilization of cytokine adsorption in two phases of the same transplant process.

Severe early graft dysfunction post-heart transplantation: Two clinical trajectories and diastolic perfusion pressure as a predictor of mechanical circulatory support.

BACKGROUND: Severe early graft dysfunction (EGD) is defined by mechanical circulatory support (MCS) <24 hours of heart transplantation (HT). We classified severe EGD based on timing of post-HT MCS: ''Immediate'' intra-operative vs ''Delayed'' post-operative MCS (after admission into intensive care unit (ICU) from operating theater). We hypothesized that (1) risk factors and clinical course differ between ''Immediate'' and ''Delayed'' MCS; and (2) diastolic perfusion pressure (DPP=diastolic blood pressure-central venous pressure) and Norepinephrine equivalents (NE=sum of vasopressor doses), as measures of vasoplegia are related to ''Delayed'' MCS. METHODS: Two-center study of 216 consecutive patients who underwent HT. Recipient, donor, vasopressor doses and hemodynamic data at T0 and T6 (on admission and 6 hours after admission into ICU) were collected. RESULTS: Of the 216 patients, 67 patients had severe EGD (''Immediate'' MCS: n = 43, ''Delayed'' MCS: n = 24). The likelihood of ''immediate'' MCS but not ''delayed'' MCS increased with increasing warm ischemic and cardiopulmonary bypass times on multinomial regression analysis with ''no MCS'' as the referent group. One-year mortality was highest in ''Immediate'' MCS vs ''no MCS'' and ''delayed'' MCS (34.9% vs 3.4% and 8% respectively, p < 0.001). Of the patients who had no immediate post-transplant MCS, DPP and NE at T6 were independently associated with subsequent ''delayed'' MCS. Sensitivity and specificity of NE≥ 0.2 mcg/kg/min for ''Delayed'' MCS were 71% and 81%. Sensitivity and specificity of DPP of ≥40 mmHg for No MCS were 83% and 74%. The discriminatory value of systemic vascular resistance for ''Delayed'' MCS was poor. CONCLUSION: Risk factors and 1-year survival differed significantly between ''Immediate'' and ''Delayed'' post-HT MCS. The latter is related to lower DPP and higher NE, which is consistent with vasoplegia as the dominant pathophysiology.

Contrasting predictors of severe primary graft dysfunction following transplant for chronic and acute respiratory failure.

Background: Lung transplantation represents a pivotal intervention for individuals grappling with end-stage lung diseases, and the role of lung transplantation in acute respiratory distress syndrome (ARDS) patients has garnered increased attention especially after the coronavirus disease 2019 (COVID-19) pandemic. Multiple studies have demonstrated a high incidence of primary graft dysfunction (PGD) in patients with ARDS compared to contemporaneous controls undergoing transplantation for chronic end-stage lung diseases although underlying mechanisms or risk factors remain unknown. This retrospective study investigates the contrasting risk factors for PGD grade 3 in patients with ARDS and chronic respiratory failure undergoing lung transplantation. Methods: The study included 293 patients who underwent lung transplantation from January 2018 through June 2023. We performed a multivariate logistic regression analysis using variables from the univariate logistic regression analyses to predict PGD grade 3. Results: Our findings reveal distinct predictors for PGD grade 3 in the two cohorts. ARDS patients had higher incidence of PGD grade 3 than non-ARDS patients (30.2% vs. 9.6%, P<0.001). Multivariate logistic regression analysis showed ischemic time [odds ratio (OR) =0.60; 95% confidence interval (CI): 0.40-0.90; P=0.01] as predictor of PGD grade 3 for non-ARDS patients, and age (OR =0.72; 95% CI: 0.52-0.99; P=0.048), pre-operative albumin (OR <0.01; 95% CI: <0.01-0.74; P=0.042) for ARDS patients. Interestingly, there was no notable difference in post-transplant survival between the two groups. Conclusions: This study highlights differing risk profiles for severe PGD in ARDS and non-ARDS lung transplant recipients, underscoring the need for tailored approaches in managing these patients. It paves the way for further research to refine strategies aimed at reducing PGD incidence and enhancing transplant outcomes in these distinct populations.

Comparing right- versus left-first implantation in off-pump sequential double-lung transplantation: an observational cohort study.

OBJECTIVES: Historically, the perfusion-guided sequence suggests to first transplant the side with lowest lung perfusion. This sequence is thought to limit right ventricular afterload and prevent acute heart failure after first pneumonectomy. As a paradigm shift, we adopted the right-first implantation sequence, irrespective of lung perfusion. The right donor lung generally accommodates a larger proportion of the cardiac output. We hypothesized that the right-first sequence reduces the likelihood of oedema formation in the firstly transplanted graft during second-lung implantation. Our objective was to compare the perfusion-guided and right-first sequence for intraoperative extracorporeal membrane oxygenation (ECMO) need and primary graft dysfunction (PGD). METHODS: A retrospective single-centre cohort study (2008-2021) including double-lung transplant cases (N = 696) started without ECMO was performed. Primary end-points were intraoperative ECMO cannulation and PGD grade 3 (PGD3) at 72 h. Secondary end-points were patient and chronic lung allograft dysfunction-free survival. In cases with native left lung perfusion ≤50% propensity score adjusted comparison of the perfusion-guided and right-first sequence was performed. RESULTS: When left lung perfusion was ≤50%, right-first implantation was done in 219 and left-first in 189 cases. Intraoperative escalation to ECMO support was observed in 10.96% of right-first versus 19.05% of left-first cases (odds ratio 0.448; 95% confidence interval 0.229-0.0.878; P = 0.0193). PGD3 at 72 h was observed in 8.02% of right-first versus 15.64% of left-first cases (0.566; 0.263-1.217; P = 0.1452). Right-first implantation did not affect patient or chronic lung allograft dysfunction-free survival. CONCLUSIONS: The right-first implantation sequence in off-pump double-lung transplantation reduces need for intraoperative ECMO cannulation with a trend towards less PGD grade 3.

Mitigating the risk of inflammatory type primary graft dysfunction by applying an integrated approach to assess, modify and match risk factors in lung transplantation.

Long-term outcome following lung transplantation remains one of the poorest of all solid organ transplants with a 1- and 5-year survival of 85% and 59% respectively for adult lung transplant recipients and with 50% of patients developing chronic lung allograft dysfunction (CLAD) in the first 5 years following transplant. Reducing the risk of inflammatory type primary graft dysfunction (PGD) is vital for improving both short-term survival following lung transplantation and long-term outcome due to the association of early inflammatory-mediated damage to the allograft and the risk of CLAD. PGD has a multifactorial aetiology and high-grade inflammatory-type PGD is the result of cumulative insults that may be incurred in one or more of the three variables of the transplantation continuum: the donor lungs, the recipient and intraoperative process. We set out a conceptual framework which uses a fully integrated approach to this transplant continuum to attempt to identify and, where possible, modify specific donor, recipient and intraoperative PGD risk with the goal of reducing inflammatory-type PGD risk for an individual recipient. We also consider the concept and risk-benefit of matching lung allografts and recipients on the basis of donor and recipient PGD-risk compatibility. The use of ex vivo lung perfusion (EVLP) and the extended preservation of lung allografts on EVLP will be explored as safe, non-injurious EVLP may enable extensive inflammatory testing of specific donor lungs and has the potential to provide a platform for targeted therapeutic interventions on lung allografts.

Ex Vivo Lung Perfusion and Primary Graft Dysfunction Following Lung Transplantation: A Contemporary United Network for Organ Sharing Database Analysis.

Background: Primary graft dysfunction (PGD) has detrimental effects on recipients following lung transplantation. Here, we determined the contemporary trends of PGD in a national database, factors associated with the development of PGD grade 3 (PGD3) and ex vivo lung perfusion's (EVLP) effect on this harmful postoperative complication. Methods: The United Network for Organ Sharing database was queried from 2015 to 2023, and recipients were stratified into No-PGD, PGD1/2, or PGD3. The groups were analyzed with comparative statistics, and survival was determined with Kaplan-Meier methods. Multivariable Cox regression was used to determine factors associated with increased mortality. PGD3 recipients were then stratified based on EVLP use prior to transplantation, and a 3:1 propensity match was performed to determine outcomes following transplantation. Finally, logistic regression models based on select criteria were used to determine risk factors associated with the development of PGD3 and mortality within 1 year. Results: A total of 21.4% of patients were identified as having PGD3 following lung transplant. Those with PGD3 suffered significantly worse perioperative morbidity, mortality, and had worse long-term survival. PGD3 was also independently associated with increased mortality. Matched EVLP PGD3 recipients had significantly higher use of ECMO postoperatively; however, they did not suffer other significant morbidity or mortality as compared to PGD3 recipients without EVLP use. Importantly, EVLP use prior to transplantation was significantly associated with decreased likelihood of PGD3 development, while having no significant association with early mortality. Conclusions: EVLP is associated with decreased PGD3 development, and further optimization of this technology is necessary to expand the donor pool.

COVID-19 seropositive donors yield comparable post-lung transplant outcomes.

Background: Recent reports have suggested that coronavirus disease 2019 (COVID-19) infection can cause pneumonitis even in the absence of clinical symptoms and COVID-19 associated pulmonary inflammation can persist resulting in long-term fibrosis. This single-center study utilized standardized immunological testing to determine whether lungs from COVID-19 seropositive donors, indicative of past COVID-19 infection, can be safely used for clinical transplantation. Methods: The study included 90 consecutive lung transplant procedures incorporating donor serological testing for past COVID-19 infection. Donors were negative for active COVID-19 infection and met institutional criteria to be used for lung transplantation. The outcomes of lung transplant recipients were compared between donors with and without serological evidence of past COVID-19 infection. Results: No significant difference was found in post-transplant survival rates between recipients of lungs obtained from donors with serological evidence compared to those without. Additionally, there were no significant differences in primary graft dysfunction grade 3 rates or other post-transplant clinical parameters, such as operative time, ischemic time, extracorporeal membrane oxygenation use, intensive care unit stay, and hospital stay. Conclusions: Our findings suggest that lungs from COVID-19 seropositive donors, but not active COVID-19 infection are safe and feasible for transplantation, yielding comparable post-transplant outcomes to donors who are negative COVID-19 antibodies. This study supports the utilization of lungs from donors with historic COVID-19 infection as long as they meet current transplant criteria, potentially addressing the concerns related to the use of such organs.

Amniotic fluid-derived mesenchymal stem cells reduce inflammation and improve lung function following transplantation in a porcine model.

BACKGROUND: Lung transplantation is hindered by low donor lung utilization rates. Infectious complications are reasons to decline donor grafts due to fear of post-transplant primary graft dysfunction. Mesenchymal stem cells are a promising therapy currently investigated in treating lung injury. Full-term amniotic fluid-derived lung-specific mesenchymal stem cell treatment may regenerate damaged lungs. These cells have previously demonstrated inflammatory mediation in other respiratory diseases, and we hypothesized that treatment would improve donor lung quality and postoperative outcomes. METHODS: In a transplantation model, donor pigs were stratified to either the treated or the nontreated group. Acute respiratory distress syndrome was induced in donor pigs and harvested lungs were placed on ex vivo lung perfusion (EVLP) before transplantation. Treatment consisted of 3 doses of 2 × 106 cells/kg: one during EVLP and 2 after transplantation. Donors and recipients were assessed on clinically relevant parameters and recipients were followed for 3 days before evaluation for primary graft dysfunction (PGD). RESULTS: Repeated injection of the cell treatment showed reductions in inflammation seen through lowered immune cell counts, reduced histology signs of inflammation, and decreased cytokines in the plasma and bronchoalveolar lavage fluid. Treated recipients showed improved pulmonary function, including increased PaO2/FiO2 ratios and reduced incidence of PGD. CONCLUSIONS: Repeated injection of lung-specific cell treatment during EVLP and post transplant was associated with improved function of previously damaged lungs. Cell treatment may be considered as a potential therapy to increase the number of lungs available for transplantation and the improvement of postoperative outcomes.

Impact of Pre-Transplant Left Ventricular Diastolic Pressure on Primary Graft Dysfunction after Lung Transplantation: A Narrative Review.

Lung transplantation (LT) constitutes the last therapeutic option for selected patients with end-stage respiratory disease. Primary graft dysfunction (PGD) is a form of severe lung injury, occurring in the first 72 h following LT and constitutes the most common cause of early death after LT. The presence of pulmonary hypertension (PH) has been reported to favor PGD development, with a negative impact on patients' outcomes while complicating medical management. Although several studies have suggested a potential association between pre-LT left ventricular diastolic dysfunction (LVDD) and PGD occurrence, the underlying mechanisms of such an association remain elusive. Importantly, the heterogeneity of the study protocols and the various inclusion criteria used to define the diastolic dysfunction in those patients prevents solid conclusions from being drawn. In this review, we aim at summarizing PGD mechanisms, risk factors, and diagnostic criteria, with a further focus on the interplay between LVDD and PGD development. Finally, we explore the predictive value of several diastolic dysfunction diagnostic parameters to predict PGD occurrence and severity.

The impact of bleeding on outcomes following lung transplantation: a retrospective analysis using the universal definition of perioperative bleeding.

BACKGROUND: Lung transplantation (LT) represents a high-risk procedure for end-stage lung diseases. This study describes the outcomes of patients undergoing LT that require massive transfusions as defined by the universal definition of perioperative bleeding (UDPB). METHODS: Adult patients who underwent bilateral LT at a single academic center were surveyed retrospectively. Patients were grouped by insignificant, mild, or moderate perioperative bleeding (insignificant-to-moderate bleeders) and severe or massive perioperative bleeding (severe-to-massive bleeders) based on the UDPB classification. Outcomes included 1-year survival and primary graft dysfunction (PGD) of grade 3 at 72 h postoperatively. Multivariable models were adjusted for recipient age, sex, body mass index (BMI), Lung allocation score (LAS), preoperative hemoglobin (Hb), preoperative extracorporeal membrane oxygenation (ECMO) status, transplant number, and donor status. An additional multivariable model was created to find preoperative and intraoperative predictors of severe-to-massive bleeding. A p-value less than 0.05 was selected for significance. RESULTS: A total of 528 patients were included, with 357 insignificant-to-moderate bleeders and 171 severe-to-massive bleeders. Postoperatively, severe-to-massive bleeders had higher rates of PGD grade 3 at 72 h, longer hospital stays, higher mortality rates at 30 days and one year, and were less likely to achieve textbook outcomes for LT. They also required postoperative ECMO, reintubation for over 48 h, tracheostomy, reintervention, and dialysis at higher rates. In the multivariate analysis, severe-to-massive bleeding was significantly associated with adverse outcomes after adjusting for recipient and donor factors, with an odds ratio of 7.73 (95% CI: 4.27-14.4, p < 0.001) for PGD3 at 72 h, 4.30 (95% CI: 2.30-8.12, p < 0.001) for 1-year mortality, and 1.75 (95% CI: 1.52-2.01, p < 0.001) for longer hospital stays. Additionally, severe-to-massive bleeders were less likely to achieve textbook outcomes, with an odds ratio of 0.07 (95% CI: 0.02-0.16, p < 0.001). Preoperative and intraoperative predictors of severe/massive bleeding were identified, with White patients having lower odds compared to Black patients (OR: 041, 95% CI: 0.22-0.80, p = 0.008). Each 1-unit increase in BMI decreased the odds of bleeding (OR: 0.89, 95% CI: 0.83-0.95, p < 0.001), while each 1-unit increase in MPAP increased the odds of bleeding (OR: 1.04, 95% CI: 1.02-1.06, p < 0.001). First-time transplant recipients had lower risk (OR: 0.16, 95% CI: 0.06-0.36, p < 0.001), whereas those with DCD donors had a higher risk of severe-to-massive bleeding (OR: 3.09, 95% CI: 1.63-5.87, p = 0.001). CONCLUSION: These results suggest that patients at high risk of massive bleeding require higher utilization of hospital resources. Understanding their outcomes is important, as it may inform future decisions to transplant comparable patients.

IRF1 and IL1A associated with PANoptosis serve as potential immune signatures for lung ischemia reperfusion injury following lung transplantation.

BACKGROUND: Lung ischemia reperfusion injury (IRI) is the principal cause of primary graft dysfunction (PGD) after lung transplantation, affecting short-term and long-term mortality post-transplantation. PANoptosis, a newly identified form of regulated cell death involving apoptosis, necroptosis, and pyroptosis, is now considered a possible cause of organ damage and IRI. However, the specific role of PANoptosis to the development of lung IRI following lung transplantation is still not fully understood. METHODS: In this study, we identified differentially expressed genes (DEGs) by analyzing the gene expression data from the GEO database related to lung IRI following lung transplantation. PANoptosis-IRI DEGs were determined based on the intersection of PANoptosis-related genes and screened DEGs. Hub genes associated with lung IRI were further screened using Lasso regression and the SVM-RFE algorithm. Additionally, the Cibersort algorithm was employed to assess immune cell infiltration and investigate the interaction between immune cells and hub genes. The upstream miRNAs that may regulate hub genes and compounds that may interact with hub genes were also analyzed. Moreover, an external dataset was utilized to validate the differential expression analysis of hub genes. Finally, the expressions of hub genes were ultimately confirmed using quantitative real-time PCR, western blotting, and immunohistochemistry in both animal models of lung IRI and lung transplant patients. RESULTS: PANoptosis-related genes, specifically interferon regulatory factor 1 (IRF1) and interleukin 1 alpha (IL1A), have been identified as potential biomarkers for lung IRI following lung transplantation. In mouse models of lung IRI, both the mRNA and protein expression levels of IRF1 and IL1A were significantly elevated in lung tissues of the IRI group compared to the control group. Moreover, lung transplant recipients exhibited significantly higher protein levels of IRF1 and IL1A in PBMCs when compared to healthy controls. Patients who experienced PGD showed elevated levels of IRF1 and IL1A proteins in their blood samples. Furthermore, in patients undergoing lung transplantation, the protein levels of IRF1 and IL1A were notably increased in peripheral blood mononuclear cells (PBMCs) compared to healthy controls. In addition, patients who developed primary graft dysfunction (PGD) exhibited even higher protein levels of IRF1 and IL1A than those without PGD. Furthermore, PANoptosis was observed in the lung tissues of mouse models of lung IRI and in the PBMCs of patients who underwent lung transplantation. CONCLUSIONS: Our research identified IRF1 and IL1A as biomarkers associated with PANoptosis in lung IRI, suggesting their potential utility as targets for diagnosing and therapeutically intervening in lung IRI and PGD following lung transplantation.

Alterations in circulating measures of Th2 immune responses pre-lung transplant associates with reduced primary graft dysfunction.

Primary graft dysfunction (PGD) is a complication of lung transplantation that continues to cause significant morbidity. The Th2 immune response has been shown to counteract tissue-damaging inflammation. We hypothesized that Th2 cytokines/chemokines in blood would be associated with protection from PGD. Utilizing pretransplant sera from the multicenter clinical trials in organ transplantation study, we evaluated Th2 cytokines/chemokines in 211 patients. Increased concentrations of Th2 cytokines were associated with freedom from PGD, namely IL-4 (odds ratio [OR] 0.66 [95% confidence interval {CI} 0.45-0.99], p = 0.043), IL-9 (OR 0.68 [95% CI 0.49-0.94], p = 0.019), IL-13 (OR 0.73 [95% CI 0.55-0.96], p = 0.023), and IL-6 (OR 0.74 [95% CI 0.56-0.98], p = 0.036). Multivariable regression performed for each cytokine, including clinically relevant covariables, confirmed these associations and additionally demonstrated association with IL-5 (OR 0.57 [95% CI 0.36-0.89], p = 0.014) and IL-10 (OR 0.55 [95% CI 0.32-0.96], p = 0.035). Higher levels of Th2 immune response before lung transplant appear to have a protective effect against PGD, which parallels the Th2 role in resolving inflammation and tissue injury. Pretransplant cytokine assessments could be utilized for recipient risk stratification.

Association of Amiodarone Use Prior to Orthotopic Heart Transplant with Post-Transplant Graft Dysfunction and All-Cause Mortality: A Systematic Review and Meta-Analysis.

BACKGROUND: There is conflicting data on the association between pre-orthotopic heart transplant (OHT) amiodarone use and post-OHT graft dysfunction (GD) leading to heterogeneity in clinical practice. METHODS: We performed a meta-analysis to evaluate whether pre-OHT amiodarone use was associated with meaningful increases in the incidence of GD, 30-day mortality, and 1-year mortality. Studies were identified by searching PubMed and the Cochrane Register of Clinical Trials. The Mantel-Haenszel method was used to calculate odds ratios (OR) and 95% confidence intervals (CI95) for each endpoint. RESULTS: 17 retrospective studies were identified that included 48,782 patients. 14 studies (n = 48,018) reported GD as an outcome. Pre-OHT amiodarone use was associated with increased odds of GD (OR 1.3, CI95 1.2-1.5, p < 0.001). 10 studies (n = 45,875) reported 30-day mortality based on amiodarone use. Pre-OHT amiodarone use was associated with increased odds of 30-day mortality (OR 1.4, CI95 1.2-1.5, p < 0.001). 5 studies (n = 41,404) reported 1-year mortality based on amiodarone use. Pre-OHT amiodarone use was associated with increased odds of 1-year mortality (OR 1.2, CI95 1.1-1.4, p < 0.001). The increase in absolute risk of GD, 30-day mortality, and 1-year mortality for patients with pre-OHT amiodarone use was 1.3%, 1.2%, and 1.4%, respectively. CONCLUSION: Pre-OHT amiodarone exposure was associated with increased odds of GD, 30-day mortality, and 1-year mortality. The increase in absolute risk for each endpoint was modest, and it is unclear to what extent, if any, pre-OHT amiodarone use should influence assessment of OHT candidacy.

Portal vein arterialization in 25 liver transplant recipients: A Latin American single-center experience.

BACKGROUND: Portal vein arterialization (PVA) has been used in liver transplantation (LT) to maximize oxygen delivery when arterial circulation is compromised or has been used as an alternative reperfusion technique for complex portal vein thrombosis (PVT). The effect of PVA on portal perfusion and primary graft dysfunction (PGD) has not been assessed. AIM: To examine the outcomes of patients who required PVA in correlation with their LT procedure. METHODS: All patients receiving PVA and LT at the Fundacion Santa Fe de Bogota between 2011 and 2022 were analyzed. To account for the time-sensitive effects of graft perfusion, patients were classified into two groups: prereperfusion (pre-PVA), if the arterioportal anastomosis was performed before graft revascularization, and postreperfusion (post-PVA), if PVA was performed afterward. The pre-PVA rationale contemplated poor portal hemodynamics, severe vascular steal, or PVT. Post-PVA was considered if graft hypoperfusion became evident. Conservative interventions were attempted before PVA. RESULTS: A total of 25 cases were identified: 15 before and 10 after graft reperfusion. Pre-PVA patients were more affected by diabetes, decompensated cirrhosis, impaired portal vein (PV) hemodynamics, and PVT. PGD was less common after pre-PVA (20.0% vs 60.0%) (P = 0.041). Those who developed PGD had a smaller increase in PV velocity (25.00 cm/s vs 73.42 cm/s) (P = 0.036) and flow (1.31 L/min vs 3.34 L/min) (P = 0.136) after arterialization. Nine patients required PVA closure (median time: 62 d). Pre-PVA and non-PGD cases had better survival rates than their counterparts (56.09 months vs 22.77 months and 54.15 months vs 31.91 months, respectively). CONCLUSION: This is the largest report presenting PVA in LT. Results suggest that pre-PVA provides better graft perfusion than post-PVA. Graft hyperperfusion could play a protective role against PGD.

Long-term air pollution exposure and the risk of primary graft dysfunction after lung transplantation.

BACKGROUND: Primary graft dysfunction (PGD) contributes substantially to both short- and long-term mortality after lung transplantation, but the mechanisms that lead to PGD are not well understood. Exposure to ambient air pollutants is associated with adverse events during waitlisting for lung transplantation and chronic lung allograft dysfunction, but its association with PGD has not been studied. We hypothesized that long-term exposure of the lung donor and recipient to high levels of ambient air pollutants would increase the risk of PGD in lung transplant recipients. METHODS: Using data from 1428 lung transplant recipients and their donors enrolled in the Lung Transplant Outcomes Group observational cohort study, we evaluated the association between the development of PGD and zip-code-based estimates of long-term exposure to 6 major air pollutants (ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, particulate matter 2.5, and particulate matter 10) in both the lung donor and the lung recipient. Exposure estimates used daily EPA air pollutant monitoring data and were based on the geographic centroid of each subject's residential zip code. Associations were tested in both univariable and multivariable models controlling for known PGD risk factors. RESULTS: We did not find strong associations between air pollutant exposures in either the donor or the recipient and PGD. CONCLUSIONS: Exposure to ambient air pollutants, at the levels observed in this study, may not be sufficiently harmful to prime the donor lung or the recipient to develop PGD, particularly when considering the robust associations with other established PGD risk factors.

Necropsy findings in heart transplant recipients with or without primary graft dysfunction.

BACKGROUND: Primary graft dysfunction (PGD) is the leading cause of death in the first year after heart transplant (HT), but pathophysiology and histology are not completely understood. This study describes and compares morphological findings of hearts of patients with and without PGD. METHODS: We included adult patients submitted to HT in a single center who died within the first 14 days after HT and were submitted to necropsy. Clinical and histological data were recorded retrospectively. All heart slides were reviewed by a blinded pathologist. We categorized patients in two groups (PGD and non-PGD) and compared findings between them. RESULTS: Among 322 HTs, 26 patients were included. Median age was 51.5 years, 57.7% were male, 46.1% had non-ischemic cardiomyopathy, 30.8% Chagas cardiomyopathy and 23% ischemic cardiomyopathy. Eleven patients presented PGD, while 15 patients did not. PGD was severe in 72.7% of cases and moderate in 27.3%. PGD group had longer ischemic time (p=0.08), higher incidence of mechanical circulatory support (p=0.004), lower post-transplant biventricular ejection fraction (p=0.005). However, necropsy findings were similar between groups. Necrosis was detected in 80.7% of all cases (p=0.907 comparing groups), taking ≥ 10% of myocardial area in 46.1% of them, and 4 types of necrosis were found either in patients with and without PGD. CONCLUSION: Cardiac pathological findings were similar in HT patients with or without PGD who died within 14 days after the transplant and necrosis was frequent in both groups, raising the hypothesis necrosis is not the cause of cardiac dysfunction in PGD.