Outcomes of Extracorporeal Membrane Oxygenation for Primary Graft Dysfunction After Lung Transplantation.

BACKGROUND: Primary graft dysfunction (PGD) is the leading cause of death in the first 30 days after lung transplantation and is also associated with worse long-term outcomes. Outcomes of patients with PGD grade 3 requiring extracorporeal membrane oxygenation (ECMO) support after lung transplantation have yet to be well described. We sought to describe short- and long-term outcomes for patients with PGD grade 3 who required ECMO support. METHODS: This is a single-center retrospective cohort study of patients undergoing lung transplantation. We stratified patients with PGD grade 3 into non-ECMO, venoarterial (VA) ECMO, and venovenous (VV) ECMO groups after transplantation. We then compared the outcomes between the groups. RESULTS: Of 773 lung transplant recipients, PGD grade 3 developed in 204 (26%) at any time in the first 72 hours after lung transplantation. Of these, 13 (5%) required VA ECMO and 25 (10%) required VV ECMO support. The 30-day, 1-year, and 5-year survival in the VA ECMO group was 62%, 54%, and 43% compared with 96%, 84%, and 65% in the VV ECMO group and 99%, 94%, and 71% in the non-ECMO group. Multivariable Cox regression analysis showed that VA ECMO was associated with increased mortality (hazard ratio, 2.37; 95% CI, 1.06-5.28; P = .04). CONCLUSIONS: Patients who required VA ECMO support for PGD grade 3 have significantly worse survival compared with those who did not require ECMO and those who required VV ECMO support. This suggests that VA ECMO treatment of patients with PGD grade 3 after lung transplantation can be a predictable risk factor for mortality.

Post-Transplant Extracorporeal Membrane Oxygenation for Severe Primary Graft Dysfunction to Support the Use of Marginal Donor Hearts.

Severe primary graft dysfunction (PGD) is the leading cause of early postoperative mortality following orthotopic heart transplantation (OHT). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as salvage therapy. This study aimed to evaluate the outcomes in adult OHT recipients who underwent VA-ECMO for severe PGD. We retrospectively reviewed 899 adult (≥18 years) patients who underwent primary OHT at our institution between 1997 and 2017. Recipients treated with VA-ECMO (19, 2.1%) exhibited a higher incidence of previous cardiac surgery (p = .0220), chronic obstructive pulmonary disease (p = .0352), and treatment with a calcium channel blocker (p = .0018) and amiodarone (p = .0148). Cardiopulmonary bypass (p = .0410) and aortic cross-clamp times (p = .0477) were longer in the VA-ECMO cohort and they were more likely to have received postoperative transfusion (p = .0013); intra-aortic balloon pump (IABP, p < .0001), and reoperation for bleeding or tamponade (p < .0001). The 30-day, 1-year, and overall survival after transplantation of non-ECMO patients were 95.9, 88.8, and 67.4%, respectively, compared to 73.7, 57.9, and 47.4%, respectively in the ECMO cohort. Fourteen (73.7%) of the ECMO patients were weaned after a median of 7 days following OHT (range: 1-12 days). Following OHT, VA-ECMO may be a useful salvage therapy for severe PGD and can potentially support the usage of marginal donor hearts.

Effect of mode of intraoperative support on primary graft dysfunction after lung transplant.

OBJECTIVE: To clarify the relationship between the use of extracorporeal life support during lung transplantation and severe primary graft dysfunction (PGD), we developed and analyzed a novel multicenter international registry. METHODS: The Extracorporeal Life Support in Lung Transplantation Registry includes double-lung transplants performed at 8 high-volume centers (>40/year). Multiorgan transplants were excluded. We defined severe PGD as grade 3 PGD (PGD3) observed 48 or 72 hours after reperfusion. Modes of support were no extracorporeal life support (off-pump), extracorporeal membrane oxygenation (ECMO), and cardiopulmonary bypass (CPB). To assess the association between mode of support and PGD3, we adjusted for demographic and intraoperative factors with a stepwise, mixed selection, multivariable regression model, ending with 10 covariates in the final model. RESULTS: We analyzed 852 transplants performed between January 2016 and March 2020: 422 (50%) off-pump, 273 (32%) ECMO, and 157 (18%) CPB cases. PGD3 rates at time point 48-72 were 12.1% (51 out of 422) for off-pump, 28.9% for ECMO (79 out of 273), and 42.7% (67 out of 157) for CPB. The adjusted model resulted in the following risk profile for PGD3: CPB versus ECMO odds ratio, 1.89 (95% CI, 1.05-3.41; P = .033), CPB versus off-pump odds ratio, 4.24 (95% CI, 2.24-8.04; P < .001), and ECMO versus off-pump odds ratio, 2.24 (95% CI, 1.38-3.65; P = .001). CONCLUSIONS: Venoarterial ECMO is increasingly used at high-volume centers to support complex transplant recipients during double-lung transplantation. This practice is associated with more risk of PGD3 than off-pump transplantation but less risk than CPB. When extracorporeal life support is required during lung transplantation, ECMO may be the preferable approach when feasible.

Use of extracorporeal membrane oxygenation for heart graft dysfunction in adults: incidence, risk factors and outcomes in a multicentric study.

BACKGROUND: The decision about whether to use venoarterial extracorporeal membrane oxygenation (VA-ECMO) in patients with cardiac graft dysfunction (GD) is usually made on a case-by-case basis and is guided by the team's experience. We aimed to determine the incidence of VA-ECMO use after heart transplantation (HT), to assess early- and long-term outcomes and to assess risk factors for the need for VA-ECMO and early mortality in these patients. METHODS: We included adults who underwent heart transplantation at 3 cardiac centres who met the most recent International Society for Heart and Lung Transplantation definition of graft dysfunction (GD) over a 10-year period. Pre-transplant, intraoperative and posttransplant characteristics of the heart recipients as well as donor characteristics were analyzed and compared among recipients with GD treated with and without VA-ECMO. RESULTS: There were 135 patients with GD in this study, of whom 66 were treated with VA-ECMO and 69 were not. The mean follow-up averaged 81.2 months (standard deviation 36 mo, range 0-184 mo); follow-up was complete in 100% of patients. The overall incidence of GD (30%) and of VA-ECMO use increased over the study period. We did not identify any predictive pre-transplantation factors for VA-ECMO use, but patients who required VA-ECMO had higher serum lactate levels and higher inotropes doses after HT. The overall survival rates were 83% and 42% at 1 year and 78% and 40% at 5 years among patients who received only medical treatment and those who received VA-ECMO, respectively. Delayed initiation of VA-ECMO and postoperative bleeding were strongly associated with increased in-hospital mortality. CONCLUSION: The incidence of GD increased over the study period, and the need for VA-ECMO among patients with GD remains difficult to predict. In-hospital mortality decreased over time but remained high among patients who required VA-ECMO, especially among patients with delayed initiation of VA-ECMO.

New Insights in Mechanisms and Therapeutics for Short- and Long-Term Impacts of Hepatic Ischemia Reperfusion Injury Post Liver Transplantation.

Liver transplantation has been identified as the most effective treatment for patients with end-stage liver diseases. However, hepatic ischemia reperfusion injury (IRI) is associated with poor graft function and poses a risk of adverse clinical outcomes post transplantation. Cell death, including apoptosis, necrosis, ferroptosis and pyroptosis, is induced during the acute phase of liver IRI. The release of danger-associated molecular patterns (DAPMs) and mitochondrial dysfunction resulting from the disturbance of metabolic homeostasis initiates graft inflammation. The inflammation in the short term exacerbates hepatic damage, leading to graft dysfunction and a higher incidence of acute rejection. The subsequent changes in the graft immune environment due to hepatic IRI may result in chronic rejection, cancer recurrence and fibrogenesis in the long term. In this review, we mainly focus on new mechanisms of inflammation initiated by immune activation related to metabolic alteration in the short term during liver IRI. The latest mechanisms of cancer recurrence and fibrogenesis due to the long-term impact of inflammation in hepatic IRI is also discussed. Furthermore, the development of therapeutic strategies, including ischemia preconditioning, pharmacological inhibitors and machine perfusion, for both attenuating acute inflammatory injury and preventing late-phase disease recurrence, will be summarized in the context of clinical, translational and basic research.

Methods of Attenuating Ischemia-Reperfusion Injury in Liver Transplantation for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most frequent indications for liver transplantation. However, the transplantation is ultimately associated with the occurrence of ischemia-reperfusion injury (IRI). It affects not only the function of the graft but also significantly worsens the oncological results. Various methods have been used so far to manage IRI. These include the non-invasive approach (pharmacotherapy) and more advanced options encompassing various types of liver conditioning and machine perfusion. Strategies aimed at shortening ischemic times and better organ allocation pathways are still under development as well. This article presents the mechanisms responsible for IRI, its impact on treatment outcomes, and strategies to mitigate it. An extensive review of the relevant literature using MEDLINE (PubMed) and Scopus databases until September 2020 was conducted. Only full-text articles written in English were included. The following search terms were used: "ischemia reperfusion injury", "liver transplantation", "hepatocellular carcinoma", "preconditioning", "machine perfusion".

Successful management of donor-acquired fat embolism after lung transplantation.

Fat embolism is a serious complication in patients with multiple traumatic injuries. It is often asymptomatic during the first hours of resuscitation, thus remains underdiagnosed in patients who progress to brain death. Lung transplantation issued from such grafts can lead to severe lung primary graft dysfunction, the management of which is deemed difficult. Herein, we report a successful management of donor-acquired fat embolism syndrome after lung transplant in a 22 years old woman for cystic fibrosis. Fat embolism was suspected because of the donor's traumatic injuries and confirmed by histopathological analysis. An immediate postoperative primary graft dysfunction was successfully managed with veno-arterial extracorporeal membrane oxygenation. The patient is alive 31 months after surgery.

Mechanically Supported Early Graft Failure After Heart Transplantation.

BACKGROUND: The occurrence of early graft failure (EGF) after heart transplantation (Htx) often requires a mechanical circulatory support (MCS) therapy. The aims of our study were to identify risk factors of mechanically supported severe EGF and evaluate their impact on both early and late outcomes. METHODS: Between January 2000 and December 2019, 499 consecutive adult patients underwent Htx at our institution. Severe EGF was defined as the need for extracorporeal life support (ECLS) within 24 hours after surgery. All available recipient and donor variables were retrospectively analyzed. RESULTS: Overall, EGF occurred in 58 (11.6%) patients. Post-Htx peripheral or central ECLS was necessary in 32 (6.4%) cases. Independent predictors of severe EGF were, in the recipient group, preoperative transpulmonary gradient (TPG) >12 mm Hg (odds ratio [OR] 4.1, P = .013), preoperative inotropic score >10 (OR 7.3, P = .0001), and pre-Htx ECLS support (OR 5.2, P = .015), while in the donors, a Eurotransplant donor score ≥17 (OR 8.5, P = .005). The absence of EGF was related with a better survival at 1 year and 5 years (94% and 85%, respectively) compared with EGF requiring ECLS population (36% and 28% at 1 year and 5 years, respectively; P < .001). A five-year conditional survival rate did not differ significantly (85% no EGF vs 83% EGF requiring ECLS). CONCLUSION: Both donor and recipient factors may influence EGF occurrence. Post-Htx ECLS may impact negatively early; however, patients weaned from ECLS eventually benefit from such a rescue treatment with outcomes comparable with Htx patients who did not suffer EGF.

Ex vivo lung perfusion for donor lung assessment and repair: a review of translational interspecies models.

For patients with end-stage lung disease, lung transplantation is a lifesaving therapy. Currently however, the number of patients who require a transplant exceeds the number of donor lungs available. One of the contributing factors to this is the conservative mindset of physicians who are concerned about transplanting marginal lungs due to the potential risk of primary graft dysfunction. Ex vivo lung perfusion (EVLP) technology has allowed for the expansion of donor pool of organs by enabling assessment and reconditioning of these marginal grafts before transplant. Ongoing efforts to optimize the therapeutic potential of EVLP are underway. Researchers have adopted the use of different large and small animal models to generate translational preclinical data. This includes the use of rejected human lungs, pig lungs, and rat lungs. In this review, we summarize some of the key current literature studies relevant to each of the major EVLP model platforms and identify the advantages and disadvantages of each platform. The review aims to guide investigators in choosing an appropriate species model to suit their specific goals of study, and ultimately aid in translation of therapy to meet the growing needs of the patient population.

Saphenous vein graft disease, pathophysiology, prevention, and treatment. A review of the literature.

BACKGROUND: The saphenous vein remains the most frequently used conduit for coronary artery bypass grafting, despite reported unsatisfactory long-term patency rates. Understanding the pathophysiology of vein graft failure and attempting to improve its longevity has been a significant area of research for more than three decades. This article aims to review the current understanding of the pathophysiology and potential new intervention strategies. METHODS: A search of three databases: MEDLINE, Web of Science, and Cochrane Library, was undertaken for the terms "pathophysiology," "prevention," and "treatment" plus the term "vein graft failure." RESULTS: Saphenous graft failure is commonly the consequence of four different pathophysiological mechanisms, early acute thrombosis, vascular inflammation, intimal hyperplasia, and late accelerated atherosclerosis. Different methods have been proposed to inhibit or attenuate these pathological processes including modified surgical technique, topical pretreatment, external graft support, and postoperative pharmacological interventions. Once graft failure occurs, the available treatments are either surgical reintervention, angioplasty, or conservative medical management reserved for patients not eligible for either procedure. CONCLUSION: Despite the extensive amount of research performed, the pathophysiology of saphenous vein graft is still not completely understood. Surgical and pharmacological interventions have improved early patency and different strategies for prevention seem to offer some hope in improving long-term patency.

A successful heart and liver transplantation requiring intraoperative extracorporeal membrane oxygenation for primary cardiac allograft dysfunction in a patient with Fontan failure.

We report a case of successful heart and liver transplantation requiring intraoperative extracorporeal membrane oxygenation (ECMO) for primary cardiac allograft dysfunction in a patient with Fontan failure. A successful outcome for both the heart and the liver can be achieved with the timely management of ECMO support. In describing our experiences treating a Fontan patient requiring multiorgan transplantation, we have shown that challenging cases such as this one can have successful outcomes if multidisciplinary collaborations and proper treatment strategies are utilized at the optimal timing, along with family support and patient cooperation.

Kidney transplantation on extracorporeal life support for primary cardiac allograft dysfunction.

Patients undergoing heart-kidney transplants who have primary graft dysfunction (PGD) of the heart are at risk of losing both organs, which may cause reluctance on the part of the transplant team to proceed with transplanting the kidney while the transplanted heart is being supported by mechanical device. We describe a case series in which 2 patients received kidney transplants while on veno-arterial ECMO support for PGD after heart transplant. Both patients are alive more than 1 year following transplant, with good cardiac and renal function and no signs of cardiac rejection. Kidney transplant surgery is safe for patients on veno-arterial ECMO support for cardiac PGD. It allows the heart recipient to receive a kidney from the same donor with both immunologic and survival advantages.

Rare crystalline nephropathy leading to acute graft dysfunction: a case report.

BACKGROUND: Adenine phosphoribosyl transferase (APRT) deficiency is a rare genetic form of kidney stones and/or kidney failure characterized by intratubular precipitation of 2,8 dihydroxyadenine crystals. Early diagnosis and prompt management can completely reverse the kidney injury. CASE PRESENTATION: 44 year old Indian male, renal transplant recipient got admitted with acute graft dysfunction. Graft biopsy showed light brown refractile intratubular crystals with surrounding giant cell reaction, consistent with APRT deficiency. Patient improved after receiving allopurinol and hydration. CONCLUSION: APRT forms a reversible cause of crystalline nephropathy. High index of suspicion is required for the correct diagnosis as timely diagnosis has therapeutic implications.

Primary graft dysfunction after heart transplantation: Outcomes and resource utilization.

BACKGROUND: A unified definition of primary graft dysfunction (PGD) after heart transplantation was adopted in 2014, with moderate and severe PGD defined as a need for mechanical circulatory support. While risk factors for PGD are well identified, outcomes and resource utilization have not been well-studied. We examined the resource utilization and associated costs with PGD. METHODS: All adult heart transplantations (2001-2016) from a statewide Society of Thoracic Surgery database were analyzed by dividing them into two groups-with PGD (requiring mechanical circulatory support) and without PGD. RESULTS: Of the 718 heart transplants, 110 (15.3%) patients developed PGD. Prevalence of PGD for the study duration ranged from 3.7% to 22.7% with no significant trend. The most frequently used mechanical circulatory support device was intra-aortic balloon pump (88%), followed by extracorporeal membrane oxygenation (17%), and catheter-based circulatory support devices (3%). There were no significant differences in demographics or preoperative variables between the two groups. Resource utilization such as total intensive care unit hours, ventilation hours, reoperation for bleeding, blood product transfusions, and length of stay were significantly higher in the PGD group. Postoperative complications were also higher in PGD group including operative mortality (31.8% vs 3.8%, P < .0001). The median cost of heart transplantation was significantly higher in the PGD group $229 482 ($126 044-$388 889) vs $101 788 ($72 638-$181 180) P < .0001. CONCLUSION: Primary graft dysfunction following heart transplantation developed in 15% of patients. Patients with PGD had significantly higher complications, resource utilization, and mortality. Preventive measures to address the development of PGD would reduce resource utilization and improve outcomes.

Extracorporeal membrane oxygenation for primary graft dysfunction after heart transplant.

OBJECTIVE: Venoarterial extracorporeal membrane oxygenation is a useful treatment for severe primary graft dysfunction after heart transplant. The ideal timing of initiation is unknown. METHODS: We retrospectively reviewed 362 adult heart transplant recipients at our center between January 2011 and December 2017. Thirty-eight patients (10.5%) experienced severe primary graft dysfunction treated with venoarterial extracorporeal membrane oxygenation. As our institution adopted a prompt venoarterial extracorporeal membrane oxygenation policy in 2015, patients were stratified into pre-2015 (conservative extracorporeal membrane oxygenation: n = 18) and post-2015 (prompt extracorporeal membrane oxygenation: n = 20) cohorts. Clinical outcomes were compared. RESULTS: Baseline characteristics were similar (conservative vs prompt) except for age (51.82 vs 59.96 years, P = .036), aspartate transaminase (32 vs 21.5 U/L, P = .038), male donor (44.4 vs 80%, P = .042), and donor ejection fraction (60 vs 65%, P = .047). Median ischemic time was significantly longer in the conservative extracorporeal membrane oxygenation cohort (210 vs 148 minutes, P = .005). Median time to initiation of extracorporeal membrane oxygenation was significantly shorter in the prompt extracorporeal membrane oxygenation cohort (7.26 vs 1.95 hours, P < .0001). There was no difference in intensive care unit stay or major complications. In-hospital mortality improved from 28% (conservative) to 5% (prompt, P = .083). Post-transplant survival at 1 year was 67% in the conservative extracorporeal membrane oxygenation cohort and 90% in the prompt extracorporeal membrane oxygenation cohort (P = .117). There was no difference in the Kaplan-Meier survival curves (P = .071), although Cox regression suggested, but certainly did not prove, a 74.6% lower risk of mortality in the prompt extracorporeal membrane oxygenation group (P = .094). CONCLUSIONS: Prompt venoarterial extracorporeal membrane oxygenation use for primary graft dysfunction after heart transplant results in excellent myocardial recovery and a possible decrease in mortality without increased risk of complications.

Extracorporeal life support for primary graft dysfunction after heart transplantation.

OBJECTIVES: Survival after heart transplantation is steadily improving but primary graft dysfunction (PGD) is still a leading cause of death. Medical management seems useful in mild or moderate PGD, whereas extracorporeal life support (ECLS) could be suggested for severe PGD refractory to conventional treatment. Our aim is to present the results of ECLS for PGD after heart transplantation at a single-centre experience. METHODS: We performed an observational analysis of our local database. According to the International Society for Heart and Lung Transplantation classification, patients were divided into a left and biventricular failure (PGD-LV) or isolated right ventricular failure (PGD-RV) group. The primary end point was survival to hospital discharge. RESULTS: Between January 2010 and December 2016, 38 patients presented with PGD (PGD-LV n = 22, 58%; PGD-RV n = 16, 42%) requiring ECLS support. The mean age was 50.8 ± 12.4 years and 79% were males. Baseline characteristics were comparable between the 2 groups. PGD-LV patients displayed a significantly higher mortality rate on ECLS support as opposed to PGD-RV patients (46% vs 13%, P = 0.033). The rate of complications during ECLS support was comparable between the 2 groups. Twenty-three (61%) patients were successfully weaned from ECLS (PGD-LV = 50% vs PGD-RV = 75%, P = 0.111) after a mean support of 9.0 ± 6.4 days. Seventeen (45%) patients survived to hospital discharge (PGD-LV = 41% vs PGD-RV = 50%, P = 0.410). CONCLUSIONS: In case of severe PGD with various manifestations of ventricular failure refractory to conventional treatment, ECLS can be considered as a feasible option with satisfactory survival in this critically ill population.

Use of durable mechanical circulatory support on outcomes of heart-kidney transplantation.

OBJECTIVES: Previous studies have demonstrated that preheart transplant mechanical circulatory support (MCS) can lead to a small but significant increase in mortality. However, data on outcomes of patients with MCS who require simultaneous heart-kidney transplant are limited. METHODS: A retrospective review of simultaneous heart-kidney transplantations (HKTxs) performed at a single institution over a 5-year period was performed. Patients were divided based on the preoperative use of durable MCS. Renal graft-related end points were evaluated, including glomerular filtration rate following transplantation, prevalence of delayed renal graft function and freedom from antibody and cellular-mediated graft rejection. Patient-specific outcomes, including survival and frequency of non-fatal major adverse cardiac events at 1 year, were additionally assessed. RESULTS: During the study period, 50 HKTxs were performed, 14 of which had preoperative MCS. HKTx patients with and without MCS implantations had a similar prevalence of delayed graft function (57.1% vs 50.0%; P = 0.757). A numerical trend was observed towards a reduced glomerular filtration rate 1-month post-transplant in patients without an MCS device (81.2 ± 32.8 vs 64.4 ± 27.5; P = 0.072), but no significant difference was observed at 6 and 12 months. No significant difference was observed on the need for post-transplant renal replacement therapy, non-fatal major adverse cardiac events, freedom from graft rejection and overall survival at 1 year. CONCLUSIONS: The use of preoperative MCS in patients undergoing combined HKTx was not found to affect renal graft function post-transplantation and does not seem to be associated with increase in morbidity or mortality.

Novel Management of Atrial Septal Defect at Time of Lung Transplantation.

We present a case of a young female patient with end-stage lung failure because of pulmonary arterial hypertension who was failing maximal medical therapy and was listed for a single sequential lung transplantation. The challenge of the case was a concomitant presence of a large atrial septal defect. The novelty of our approach was a device closure of atrial septal defect before performing transplantation with the use of intraoperative venoarterial extracorporeal membrane oxygenation.

Short-term mechanical circulatory support for severe primary graft dysfunction following orthotopic heart transplant.

OBJECTIVES: Primary graft dysfunction (PGD) is a devastating complication and the most common cause of early death following a heart transplant. The goal of this study was to report our experience of using mechanical circulatory support to manage severe PGD. METHODS: Following 208 heart transplants performed between January 2007 and May 2017, 14 (6.7%) patients presented with severe PGD. We provided haemodynamic support using the following approaches: a venoarterial extracorporeal membrane oxygenation device, left ventricular assist device, right ventricular assist device and biventricular assist device. Primary complications included severe PGD, which resulted in hospital deaths and late survival. The mean follow-up was 3.7 ± 2.7 years. RESULTS: Fourteen (6.7%) heart transplant recipients presented with severe PGD. Seven patients received a venoarterial extracorporeal membrane oxygenation device; 1 patient received a left ventricular assist device; 4 patients received a right ventricular assist device; and 2 patients received a biventricular assist device. Mean device support and explantation times were 4.7 ± 2 and 6.3 ± 2 days, respectively. Weaning with cardiac recovery was successful in 57.1% of the patients. The hospital mortality rate was 50%. Postoperative causes of morbidity included renal failure that necessitated dialysis in 28.5%, surgical re-exploration due to postoperative bleeding in 57.1%, pneumonia in 28.5%, sepsis in 14.2%, sternal wound infection in 14.2% and mediastinitis in 7.1% of the patients, respectively. There were no deaths following hospital discharge or later follow-up appointments. CONCLUSIONS: Mechanical support devices such as venoarterial extracorporeal membrane oxygenation specifically offer a reliable therapeutic approach. Recognizing the relatively high number of deaths in-hospital, patients who have cardiac recovery and a successful hospital discharge can expect a favourable late outcome.