Outcomes of intraoperative venoarterial extracorporeal membrane oxygenation versus cardiopulmonary bypass during lung transplantation

Comparison of mechanical cardiopulmonary support strategies during lung transplantation

INTRODUCTION

Lung transplantation outcomes are influenced by the intraoperative mechanical cardiopulmonary support strategy used. This surgery was historically done either on cardiopulmonary bypass (CPB) or off pump. Recently, there has been increased interest in intraoperative support with veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). However, there is a lack of consensus on the relative risks, benefits and indications for each intraoperative support strategy.

AREAS COVERED

This review includes information from cohort studies, case-control studies, and case series that compare morbidity and/or mortality of two or more intraoperative cardiopulmonary support strategies during lung transplantation.

EXPERT OPINION

The optimal strategy for intraoperative cardiopulmonary support during lung transplantation remains an area of debate. Current data suggest that off pump is associated with better outcomes and could be considered whenever feasible. ECMO is generally associated with preferable outcomes to CPB, but the data supporting this association is not robust. Interestingly, whether CPB is unplanned or prolonged might influence outcomes more than the use of CPB itself. These observations can help guide surgical teams in their approach for intraoperative mechanical support strategy during lung transplantation and should serve as the basis for further investigations.

Utilization of extracorporeal membrane oxygenation in DCD and DBD lung transplants: a 2-year single-center experience

Donation after circulatory death (DCD) has the potential to expand the lung donor pool. We aimed to assess whether DCD affected the need for perioperative extracorporeal membrane oxygenation (ECMO) and perioperative outcomes in lung transplantation (LTx) as compared to donation after brain death (DBD). All consecutive LTxs performed between April 2017 and March 2019 at our tertiary center were analyzed. Donor and recipient preoperative characteristics, utilization of ECMO, and perioperative clinical outcomes were compared between DCD and DBD LTx. Multivariate models (frequentist and Bayes) were fitted to evaluate an independent effect of DCD on the intra- and postoperative need for ECMO. Out of 105 enrolled patients, 25 (23.8%) were DCD LTx. Donors' and preoperative recipients' characteristics were comparable between the groups. Intraoperatively, mechanical circulatory support (MCS) was more common in DCD LTx (56.0% vs. 36.2%), but the adjusted difference was minor (RR = 1.16, 95% CI 0.64-2.12; P = 0.613). MCS duration, and first and second lung ischemia time were longer in the DCD group. Postoperatively, DCD recipients more commonly required ECMO (32.0% vs. 7.5%) and the difference remained considerable after adjustment for the pre- and intraoperative covariates: RR = 4.11 (95% CI 0.95-17.7), P = 0.058, Bayes RR = 4.15 (95% CrI 1.28-13.0). Sensitivity analyses (two DCD-DBD matching procedures) supported a higher risk of postoperative ECMO need in DCD patients. Incidence of delayed chest closure, postoperative chest drainage, and renal replacement therapy was higher in the DCD group. Early postoperative outcomes after DCD LTx appeared generally comparable to those after DBD LTx. DCD was associated with a higher need for postoperative ECMO which could influence clinical outcomes. However, as the DCD group had a significantly higher use of EVLP with more common ECMO preoperatively, this might have contributed to worse outcomes in the DCD group.

Intraoperative Extracorporeal Circulatory Support in Lung Transplantation for Pulmonary Fibrosis

BACKGROUND

Venous-arterial extracorporeal membrane oxygenation (ECMO) is an established technique for intraoperative cardiopulmonary support in patients undergoing lung transplantation. Patients with pulmonary fibrosis have a higher risk to require it. The aim of this study was to identify risk factors for the need of intraoperative ECMO use.

METHODS

Records of patients undergoing lung transplantation for pulmonary fibrosis at our institution between January 2010 and May 2018 were retrospectively reviewed. Univariate logistic regression analysis was used for statistical identification of risk factors.

RESULTS

There were 105 patients (34%) who required intraoperative ECMO support (ECMO+ group), and 203 (66%) did not (ECMO- group). Preoperative proof of pulmonary hypertension was identified as a risk factor for intraoperative ECMO support (odds ratio [OR], 3.8; 95% confidence interval [CI], 2.2-6.5; P < .01). Revealed mean pulmonary arterial pressure values exceeding 50 mm Hg and pulmonary vascular resistance values exceeding 9.4 Wood units were identified as risk factors for the need of intraoperative ECMO use with a prediction probability of 70%. Increased recipient body surface area (OR, 0.2; 95% CI, 0.1-0.5; P < .01) emerged as a protective factor against intraoperative ECMO (Hosmer-Lemeshow statistic, P = .71) as well as higher cardiac output (OR, 0.7; 95% CI, 0.6-0.9; P < .01). The postoperative course was more complicated in the ECMO+ group, whereas survival at 5 years did not differ among groups (70% vs 69%, P = .79).

CONCLUSIONS

Pulmonary hypertension with elevated pulmonary vascular resistance values predicts the need of intraoperative ECMO in patients receiving lung transplantation for pulmonary fibrosis. Although the postoperative course was more complicated in the ECMO+ group, long-term survival did not differ significantly.

Anesthetic management of lung transplantation: Results from a multicenter, cross-sectional survey by the society for advancement of transplant anesthesia

BACKGROUND

Current protocols for the perioperative care of lung transplant (LTX) recipients lack rigorous evidence and are often empiric, based upon institutional preferences. We surveyed LTX anesthesiologists to determine the most common practices.

METHODS

We developed a survey of 40 questions regarding perioperative care of LTX recipients using Qualtrics software. The survey was sent out to members of the Society of Cardiovascular Anesthesiologists performing LTX at geographically diverse sites to facilitate data collection for as many practices as possible.

RESULTS

The responses were center-weighed (127 responses, 85% from academic settings). The clamshell approach was commonly used (70%). Cardiopulmonary bypass was preferred by 56%, ex vivo lung perfusion utilized by 43%, and 49.4% indicated they use lungs from donation after circulatory determination of death. Most (69%) used oximetric pulmonary artery catheters, 60% used tissue oximetry, and 89.3% utilized transesophageal echocardiography. Inhaled nitric oxide was preferred by 48%, restrictive fluid management by 48%, and systemic analgesia advocated by 49% of participants. Inspired oxygen concentration <30% was applied to the new lung on reperfusion by 28% of the respondents.

CONCLUSION

Variations in healthcare delivery and utilization for LTX recipients indicate gaps in knowledge and potential opportunities to improve the quality of care.

Axillary Approach for Venoarterial Extracorporeal Membrane Oxygenation Cannulation

Extracorporeal membrane oxygenation support (ECMO) is a form of mechanical circulatory support that is used in patients with severe dysfunction of heart or lung or both. Depending on whether it is venovenous or venoarterial support, it can temporarily substitute for circulation and ventilation while the underlying cause is addressed. Traditional approach for cannulation usually involves the femoral vessels. This is due to the easy accessibility, larger lumen of vessels, and physician expertise and training in femoral approach. However, in certain circumstances like critical lower extremity ischemia, crush injury or trauma to lower extremity, and lower extremity infections (like necrotizing fasciitis), this approach is not practical. In these situations, axillary vasculature provides a good substitute for ECMO cannulation. 

Factors associated with intraoperative extracorporeal membrane oxygenation support during lung transplantation

BACKGROUND

Intraoperative Extracorporeal membrane oxygenation (ECMO) is increasingly being applied as life-support for lung transplantation patients. However, factors associated with this procedure in lung transplantation patients have not yet been characterized. The aim of this study was to identify preoperative factors of intraoperative ECMO support during lung transplantation and to evaluated the outcome of lung transplantation patients supported with ECMO.

METHODS

Patients underwent lung transplantation treated with and without ECMO in Guangzhou Institute of Respiratory Diseases between January 2015 to August 2018 were retrospectively reviewed. Patient demographics and clinical variables were collected and analyzed. Multivariate logistic regression was performed to identify factors independently associated with intraoperative extracorporeal membrane oxygenation support during lung transplantation.

RESULTS

During the study period, 138 patients underwent lung transplantation at our institution, the mean LAS was (56.63 ± 18.39) (range, 32.79 to 88.70). Fourty four patients were treated with veno-venous/veno-arterial ECMO. Among the patients, 32 patients wean successfully ECMO after operation, 12 patients remain ECMO after operation, and 32 patients (62.74%) survived to hospital discharge. In multiple analysis, the following factors were associated with intraoperative ECMO support: advanced age, high PAP before operation, duration of mechanical ventilation before operation, a higher APACHE II and primary diagnosis for transplantation. The overall survival rates at 1, 3, and 12 months were 90.91, 72.73, and 56.81% in the ECMO group, and 95.40, 82.76, and 73.56% in the non-ECMO group, respectively (log-rank P = 0.081). Patients who underwent single lung transplant had a lower survival rates in ECMO group as compared with non-ECMO group at 1, 3, and 12 months (90.47% vs 98.25, 71.43% vs 84.21, and 52.38% vs 75.44%) (log-rank P = 0.048).

CONCLUSIONS

The preoperative factors of intraoperative ECMO support during lung transplantation included age, high PAP before operation, preoperative mechanical ventilation, a higher APACHE II and primary diagnosis for transplantation based on multivariate analysis.

Extracorporeal life support during and after bilateral sequential lung transplantation in patients with pulmonary artery hypertension

The use of extracorporeal membrane oxygenator instead of standard cardiopulmonary bypass during lung transplantation is debatable. Moreover, recently, the concept of prolonged postoperative extracorporeal membrane oxygenator (ECMO) support has been introduced in many transplant centers to prevent primary graft dysfunction (PGD) and improve early and long-term results. The objective of this study was to review the results of our extracorporeal life support strategy during and after bilateral sequential lung transplantation (BSLT) for pulmonary artery hypertension. We review retrospectively our experience in BSLT for pulmonary artery hypertension between January 2010 and August 2018. A total of 38 patients were identified. Nine patients were transplanted using cardiopulmonary bypass (CPB), in eight cases CPB was followed by a prolonged ECMO (pECMO) support, 14 patients were transplanted on central ECMO support, and seven patients were transplanted with central ECMO support followed by a pECMO assistance. The effects of different support strategies were evaluated, in particular in-hospital morbidity, mortality, incidence of PGD, and long-term follow-up. The use of CPB was associated with poor postoperative results and worse long-term survival compared with ECMO-supported patients. Predictive preoperative factors for the need of intraoperative CPB instead of ECMO were identified. The pECMO strategy had a favorable effect to mitigate postoperative morbidity and mortality, not only in intraoperative ECMO-supported patients, but even in CPB-supported cases. In our experience, ECMO may be considered as the first choice circulatory support for lung transplantation. Sometimes, in very complex cases, CBP is still necessary. The pECMO strategy is very effective to reduce incidence of PGD even in CPB-supported patients.

Extracorporeal Membrane Oxygenation During Adult Noncardiac Surgery and Perioperative Emergencies: A Narrative Review

Over the last decade, the use of extracorporeal membrane oxygenation (ECMO) has increased significantly. In some centers, ECMO has been deployed to manage perioperative emergencies and plays a role in facilitating high-risk thoracic, airway, and trauma surgery, which may not be feasible without ECMO support. General anesthesiologists who usually manage these cases may not be familiar with the initiation and management of patients on ECMO. This review discusses the use of ECMO in the operating room for thoracic, airway, and trauma surgery, as well as obstetric and perioperative emergencies.

Extracorporeal Membrane Oxygenation in the Perioperative Care of the Lung Transplant Patient

Lung transplantation (LT) is definitive therapy for end-stage lung disease. Donor allocation based on medical urgency has led to an increased trend in the transplantation of sicker and older patients. Mechanical ventilation (MV) formerly was the only method of bridging high-acuity patients to LT. When the physiological demands of ventilatory support exceeds the capability of MV, extracorporeal membrane oxygenation (ECMO) may become necessary. Recent improvements in ECMO technology and component design have led to a resurgence of interest in its use before, during, and after LT. Survival with ECMO as a bridge to LT has improved over time, now with many centers reporting little or no difference in outcomes, and some even reporting better outcomes, as compared with MV. Extracorporeal life support may also be used intraoperatively. In many studies to date, ECMO or cardiopulmonary bypass (CPB) has been reserved for patients who became hemodynamically unstable during the procedure or patients who could not tolerate single-lung ventilation. Both methods of support are fraught with potential complications. However, multiple studies comparing ECMO with CPB have shown that intraoperative use of ECMO resulted in improved outcomes and overall survival as well as lower rates of bleeding complications. In order to further reduce complications associated with ECMO, planned intraoperative ECMO use is occasionally reserved for high-risk patients who might otherwise require CPB. Future studies will need to improve patient selection to fully take advantage of the use of ECMO in LT while minimizing its costs.

Effect of left ventricular diastolic dysfunction on development of primary graft dysfunction after lung transplant

PURPOSE OF REVIEW

Primary graft dysfunction (PGD) is one of the most common complications after lung transplant and is associated with significant early and late morbidity and mortality. The cause of primary graft dysfunction is often multifactorial involving patient, donor, and operational factors. Diastolic dysfunction is increasingly recognized as an important risk factor for development of PGD after lung transplant and here we examine recent evidence on the topic.

RECENT FINDINGS

Patients with end-stage lung disease are more likely to suffer from cardiovascular disease including diastolic dysfunction. PGD as result of ischemia-reperfusion injury after lung transplant is exacerbated by increased left atrial pressure and pulmonary venous congestion impacted by diastolic dysfunction. Recent studies on relationship between diastolic dysfunction and PGD after lung transplant show that patients with diastolic dysfunction are more likely to develop PGD with worse survival outcome and complicated hospital course.

SUMMARY

Patients with diastolic dysfunction is more likely to suffer from PGD after lung transplant. From the lung transplant candidate selection to perioperative and posttransplant care, thorough evaluation and documentation diastolic dysfunction to guide patient care are imperative.

Bilateral lung transplantation on intraoperative extracorporeal membrane oxygenator: An observational study

OBJECTIVE

Intraoperative extracorporeal membrane oxygenation (ECMO) is usually reserved to support patients during complex lung transplantation. We hypothesized that a routine application of intraoperative ECMO in all patients improves primary graft function.

METHODS

Patients receiving a bilateral lung transplantation between November 2016 and July 2018 at the Medical University of Vienna were included in this prospective, single-center observational study. All transplantations were uniformly performed on central venoarterial ECMO support, with the possibility to extend ECMO into the early postoperative period whenever graft function did not meet established quality criteria at the end of implantation. Primary graft dysfunction (PGD) grades were evaluated at 24, 48, and 72 hours after transplantation. Perioperative complications and survival outcome were assessed.

RESULTS

A total of 159 patients were included in the study. At 24 hours post-transplantation, 38.4% (n = 61) of patients were already extubated, 48.4% (n = 77) were classified as PGD0, 4.4% (n = 7) as PGD1, 3.1% (n = 5) as PGD2, 2.5% (n = 4) as PGD3, and 3.1% (n = 5) were "ungradable" due to prophylactic postoperative prolongation of ECMO. At 72 hours after transplantation, 76.7% (n = 122) of the patients were extubated, as opposed to only 1.3% (n = 2) of patients classified as PGD3. The median time of mechanical ventilation was 29 hours (interquartile range, 17-58). The 90-day-mortality was 3.1%, and 2-year survival was 86%.

CONCLUSIONS

Routine use of intraoperative ECMO resulted in excellent primary graft function and mid-term outcome in patients undergoing lung transplantation. To the best of our knowledge, the herein measured PGD rates are the lowest reported in the literature to date. Our results advocate a routine intraoperative use of ECMO in bilateral lung transplantation.

Predictors of blood loss in lung transplant surgery-a single center retrospective cohort analysis

Background

This retrospective study aims to identify clinical predictors of intraoperative blood loss during lung transplantation. While for other surgical specialties predictors of blood loss have been identified such as previous likewise located surgery, poor preoperative health status of patients, blood coagulation status, and use of extra corporeal circulation, predictors of blood loss during lung transplantation are not yet established.

Methods

A total of 326 lung transplants were performed between January 2000 and February 2014 at a tertiary hospital. The primary aim was to associate blood loss with the following potential predictors: pulmonary arterial hypertension, pre- or intraoperative extracorporeal life support (ECLS), previous thoracic surgery, previous lung transplant, and Charlson Comorbidity Index (CCI). Postoperative complications and 30-day mortality were secondary endpoints of the study.

Results

Median estimated blood loss during lung transplant was 1,500 mL (IQR, 1,000-2,875 mL). Pre- and intraoperative ECLS (P=0.02, P<0.001) independently increased blood loss by 59% and 107%, respectively. The higher blood loss during re-transplant marginally missed the significance level (P=0.05). Pulmonary arterial hypertension, previous thoracic surgery and high CCI were not associated with increased blood loss. As secondary outcomes, postoperative complications were more common in patients with a higher blood loss (P=0.04) but was not associated with higher 30-day mortality (P=0.18).

Conclusions

Pre- and intraoperative ECLS were significant risk factors for higher blood loss during lung transplantation. Higher blood loss was associated with higher incidence of postoperative complications but not with a higher 30-day mortality.

Mitigation of Primary Graft Dysfunction in Lung Transplantation: Current Understanding and Hopes for the Future

Primary graft dysfunction (PGD) is a form of acute lung injury that develops within the first 72 hours after lung transplantation. The overall incidence of PGD is estimated to be around 30%, and the 30-day mortality for grade 3 PGD around 36%. PGD is also associated with the development of bronchiolitis obliterans syndrome, a specific form of chronic lung allograft dysfunction. In this article, we will discuss perioperative strategies for PGD prevention as well as possible future avenues for prevention and treatment.

Perioperative Management of Bleeding and Transfusion for Lung Transplantation

Perioperative allogeneic blood product transfusion is common in lung transplantation and has various implications on the short- and long-term outcomes of lung recipients. This review summarizes the effect of transfusion on outcomes including primary graft dysfunction, chronic lung allograft dysfunction, and all-cause mortality. We outline known risk factors for increased transfusion requirement in lung transplantation and present current evidence regarding the effect of hemostatic agents including antifibrinolytics, recombinant factor VII, and prothrombin complex concentrates. Finally, we highlight the roles of point-of-care coagulation testing and goal-directed transfusion strategies in reducing transfusion requirements in lung transplantation.

The technique of intraoperative axillary artery cannulation for extracorporeal membrane oxygenation in lung transplantation

Background

To show our experiences of using the axillary artery with a side graft as a cannulation technique for the inflow of veno-arterial extracorporeal membrane oxygenation (ECMO) in lung transplantation (LTx). This method can avoid complications associated with central and femoral vessel cannulation techniques, and be convenient for the use of intraoperative ECMO into the early postoperative period.

Methods

Between November 2016 and July 2017, we established intraoperative V/A-ECMO in 32 patients. Among these patients, 5 patients were performed on via axillary artery-percutaneous femoral vein cannulation (15.6%), 2 patients were performed on with veno-venous ECMO (V/V-ECMO) as a bridge to transplantation with hemodynamic instability during transplantation, and additional axillary artery cannulations were performed to establish veno-veno-arterial (V/V/A) ECMO. Mean age was 45.2±10.1 years (range, 26-71 years).

Results

In 7 patients undergoing ECMO support during operation, the ECMO was removed in 4 patients immediately after the procedure, 3 patients with "prolonged ECMO" were transferred to the ICU. There were no ECMO-related complications and no patients died.

Conclusions

Our protocol for V/A-ECMO cannulation that uses the axillary artery for arterial cannulation provides a safe and improved means for delivering V/A-ECMO support during LTx. Also, it is helpful for prolonging the intraoperative ECMO in the early postoperative period.

Intensive care, right ventricular support and lung transplantation in patients with pulmonary hypertension

Intensive care of patients with pulmonary hypertension (PH) and right-sided heart failure includes treatment of factors causing or contributing to heart failure, careful fluid management, and strategies to reduce ventricular afterload and improve cardiac function. Extracorporeal membrane oxygenation (ECMO) should be considered in distinct situations, especially in candidates for lung transplantation (bridge to transplant) or, occasionally, in patients with a reversible cause of right-sided heart failure (bridge to recovery). ECMO should not be used in patients with end-stage disease without a realistic chance for recovery or for transplantation. For patients with refractory disease, lung transplantation remains an important treatment option. Patients should be referred to a transplant centre when they remain in an intermediate- or high-risk category despite receiving optimised pulmonary arterial hypertension therapy. Meticulous peri-operative management including the intra-operative and post-operative use of ECMO effectively prevents graft failure. In experienced centres, the 1-year survival rates after lung transplantation for PH now exceed 90%.

Lung transplantation via cardiopulmonary bypass: excellent survival outcomes from extended criteria donors

OBJECTIVES

The role of intraoperative cardiopulmonary bypass (CPB) in lung transplant (LTx) surgery is controversial. CPB enables slow pulmonary reperfusion and initial ventilation with low oxygen concentrations, both theoretically protective of transplanted lungs. In this study, we explored clinical outcomes following extended criteria donor LTx surgery implementing a thoroughly protective allograft reperfusion strategy using CPB.

METHODS

Thirty-nine consecutive adult patients who underwent bilateral LTx with elective CPB and protective allograft reperfusion were reviewed. Bilaterally implanted lungs were reperfused simultaneously, via slow CPB flow reduction and initial ventilation with 21% oxygen and nitric oxide, followed by a brief modified ultrafiltration. During weaning from CPB, mean pulmonary arterial pressure was strictly maintained at 10-15 mmHg by controlling CPB and pulmonary flow. The clinical outcomes in 23 patients who received lungs from extended criteria donors (ECD group) were elucidated and compared to 16 patients undergoing LTx from standard criteria donors (SCD group).

RESULTS

No life-threatening deterioration was observed to graft functionality during the first 72 h after LTx in the ECD group; however, only one patient required post-transplant extracorporeal membrane oxygenation. In three of 23 ECD LTx patients (12%), surgical revision for bleeding was required. Survival outcomes for the ECD group were favorable, with 100% survival at 6-months, 87.0% at 1-year, and 80.7% at 5-years. Outcomes in the ECD group were comparable to those in the SCD group.

CONCLUSIONS

Despite a certain extent of risk associated with full-dose heparinization, use of CPB does not undermine survival outcomes after ECD LTx surgery if protective allograft reperfusion is securely performed.

Early Graft Dysfunction after Lung Transplantation

PURPOSE OF REVIEW

Primary graft dysfunction is an acute lung injury syndrome occurring immediately following lung transplantation. This review aims to provide an overview of the current understanding of PGD, including epidemiology, immunology, clinical outcomes and management.

RECENT FINDINGS

Identification of donor and recipient factors allowing accurate prediction of PGD has been actively pursued. Improved understanding of the immunology underlying PGD has spurred interest in identifying relevant biomarkers. Work in PGD prediction, severity stratification and targeted therapies continue to make progress. Donor expansion strategies continue to be pursued with ex vivo lung perfusion playing a prominent role. While care of PGD remains supportive, ECMO has established a prominent role in the early aggressive management of severe PGD.

SUMMARY

A consensus definition of PGD has allowed marked advances in research and clinical care of affected patients. Future research will lead to reliable predictive tools, and targeted therapeutics of this important syndrome.

Technique and Outcomes of Less Invasive Lung Retransplantation

BACKGROUND

Lung retransplantation is a demanding procedure with outcomes lagging primary transplantation. We implemented less invasive surgical techniques aiming at improving early outcomes. Here, we wish to describe these techniques and analyze the clinical outcomes.

METHODS

Since April 2010, a protocol of less invasive techniques was applied to all lung retransplantations. This protocol comprises bilateral lung retransplantation via sternum-sparing anterolateral thoracotomies, off-pump surgery, and empiric administration of 2 g fibrinogen and 2 platelet concentrates. Patient charts were retrospectively reviewed starting in April 2010 until May 2016 for this study and compared with a cohort of patients undergoing lung retransplantation between January 2005 and March 2010.

RESULTS

From April 2010 through March 2016, 774 total lung transplantations were performed at our center, 49 were retransplantations. In the era January 2005 to March 2010, a total of 480 lung transplantations were performed, 38 of those being retransplantations. Mean operation time in the era April 2010 to May 2016 was significantly longer as compared with the era January 2005 to March 2010, median time until extubation was significantly shorter in the era April 2010 to May 2016 (1 [1-2] days vs 11.5 [1-24] days; P = 0.0009). Similarly, median intensive care unit stay time was shorter in the era April 2010 to May 2016 (4 [2-5.5] days vs 12.5 [3-30.5] days; P = 0.003). Patient survival was significantly better in the era starting in April 2010 at 30 days (98% vs 76.3%, P = 0.002) as well as at 1 year (80.6% vs 63.2%; P = 0.01).

CONCLUSIONS

Less invasive retransplantation of the lung via sternum-sparing anterolateral thoracotomies and off-pump is a safe procedure with low associated morbidity and favorable midterm survival.

Perioperative Management of the Lung Graft Following Lung Transplantation

Perioperative management of patients undergoing lung transplantation is one of the most complex in cardiothoracic surgery. Certain perioperative interventions, such as mechanical ventilation, fluid management and blood transfusions, use of extracorporeal mechanical support, and pain management, may have significant impact on the lung graft function and clinical outcome. This article provides a review of perioperative interventions that have been shown to impact the perioperative course after lung transplantation.

Lung volume reduction followed by lung transplantation-considerations on selection criteria and outcome

Lung transplantation (LuTX) and lung volume reduction (LVR), either surgical (LVRS: lung volume reduction surgery) or endoscopic (ELVR: endoscopic lung volume reduction), are established therapies in the treatment of end-stage chronic obstructive pulmonary disease (COPD) patients. Careful patient selection is crucial for each intervention. If these techniques are sequentially applied there is a paucity of available data and individual center experiences vary depending on details in selection criteria and operative technique. This review aims to summarize the published data with a focus on LuTX after LVRS. This review covers patient selection for LuTX and LVR, technical considerations, limitations and outcomes. Published literature was identified by systematic search on Medline and appropriate papers were reviewed. Seven case reports/series, 7 comparative observational studies and one multicenter database analysis incorporating a total of 284 patients with LuTX and LVR were evaluated. Prior LVR can significantly affect intraoperative and postoperative risks after subsequent LuTX. Careful patient selection and timing and the choice of appropriate techniques such as minimal invasive LVRS and using ECMO as extracorporeal support during LuTX if required can minimize those risks, ultimately leading to very good postoperative outcomes in terms of lung function and survival. LVRS has the potential to delay listing and to bridge patients to LuTX by improving their physical condition while on the waiting list. After single lung transplantation (SLuTX) contralateral LVRS can counteract the deleterious effects of native lung hyperinflation (NLH). LVR and LuTX are adjunct therapies in the treatment of end-stage COPD. The combination of both can safely be considered in selected patients.

Extracorporeal lung support

PURPOSE OF REVIEW

The applications for extracorporeal membrane oxygenation for lung support are constantly evolving. This review highlights fundamental concepts in extracorporeal lung support and describes directions for future research.

RECENT FINDINGS

Since the 1950s, extracorporeal lung support has experienced continuous advancements in circuit design and safety in acute respiratory distress syndrome, chronic obstructive pulmonary disease exacerbations, as a bridge to transplantation, intraoperative cardiopulmonary support, and for transportation to referral centers. Patients on extracorporeal membrane oxygenation are now capable of being awake, extubated, and ambulatory for accelerated recovery or optimization for transplantation.

SUMMARY

Extracorporeal lung support is a safe and an easily implemented intervention for refractory respiratory failure. Recent advances have extended its use beyond acute illnesses and the developments for chronic support will facilitate the development of durable devices and possible artificial lung development.

Lung transplantation for idiopathic pulmonary arterial hypertension on intraoperative and postoperatively prolonged extracorporeal membrane oxygenation provides optimally controlled reperfusion and excellent outcome

OBJECTIVES

Lung transplantation for idiopathic pulmonary arterial hypertension has the highest reported postoperative mortality of all indications. Reasons lie in the complexity of treatment of these patients and the frequent occurrence of postoperative left ventricular failure. Transplantation on intraoperative extracorporeal membrane oxygenation support instead of cardiopulmonary bypass and even more the prolongation of extracorporeal membrane oxygenation into the postoperative period helps to overcome these problems. We reviewed our experience with this concept.

METHODS

All patients undergoing bilateral lung transplantation for idiopathic pulmonary arterial hypertension on intraoperative extracorporeal membrane oxygenation with or without prophylactic extracorporeal membrane oxygenation prolongation into the postoperative period between January 2000 and December 2014 were retrospectively analysed.

RESULTS

Forty-one patients entered the study. Venoarterial extracorporeal membrane oxygenation support was prolonged into the postoperative period for a median of 2.5 days (range 1–40). Ninety-day, 1-, 3- and 5-year survival rates for the patient collective were 92.7%, 90.2%, 87.4% and 87.4%, respectively. When compared with 31 patients with idiopathic pulmonary arterial hypertension transplanted in the same period of time without prolongation of extracorporeal membrane oxygenation into the postoperative period, the results compared favourably (83.9%, 77.4%, 77.4%, and 77.4%; P = 0.189). Furthermore, these results are among the best results ever reported for this particularly difficult patient population.

CONCLUSIONS

Bilateral lung transplantation for idiopathic pulmonary arterial hypertension with intraoperative venoarterial extracorporeal membrane oxygenation support seems to provide superior outcome compared with the results reported about the use of cardiopulmonary bypass. Prophylactic prolongation of venoarterial extracorporeal membrane oxygenation into the early postoperative period provides stable postoperative conditions and seems to further improve the results.

Extracorporeal support, during and after lung transplantation: the history of an idea

During recent years, continuous technological innovation has provoked an increase of extracorporeal life support (ECLS) use for perioperative cardiopulmonary support in lung transplantation. Initial results were disappointing, due to ECLS-specific complications and high surgical risk of the supported patients. However, the combination of improved patient management, multidisciplinary team work and standardization of ECLS protocols has recently yielded excellent results in several case series from high-volume transplant centres. Therein, it was demonstrated that, although the prevalence of complications remains higher in supported patients, there may be no difference in long-term graft function between supported and non-supported patients. These results are important, because most of the patients who require ECLS support in lung transplantation are young and have no other chance to survive, but to be transplanted. Moreover, there is no device for "bridging to destination" therapy in lung transplantation. Of note, the evidence in favour of ECLS support in lung transplantation was never validated by randomized controlled trials, but by everyday experience at the patient bed-side. Here, we review the state-of-the-art ECLS evidence for intraoperative and postoperative cardiopulmonary support in lung transplantation.

Blood Products Transfusion and Mid-Term Outcomes of Lung Transplanted Patients Under Extracorporeal Membrane Oxygenation Support

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is considered a reliable technique in lung transplantation requiring cardiorespiratory support. However, the impact of this technology on blood product transfusion rate and outcomes compared to off-pump lung transplantation has been rarely investigated.

METHODS

Between January 2012 and June 2015, 52 elective adult lung transplants were performed at our institution. Of these, 15 recipients required intraoperative venoarterial extracorporeal support and 37 did not. We compared blood product consumption and other outcome variables between the 2 groups.

RESULTS

We found comparable in-hospital (86.7% vs 97.3%, P = .14) and 6-month (86.7% vs 91.9%, P = .56) survival between patients with and without extracorporeal support, respectively. Survival at 30 days was lower in the ECMO group (86.7% vs 100%, P = .02). Although patients who underwent ECMO received more intraoperative transfusions, postoperative transfusion rate was similar between the 2 groups. The ECMO group experienced longer mechanical ventilation (median 3 vs 2 days, P = .02) and intensive care unit stay (median 7 vs 5 days, P = .02), besides more cardiogenic shock and deep vein thrombosis. However, we observed no difference in other major and minor in-hospital complications and 6-month complications.

CONCLUSIONS

In our experience, despite the higher need for intraoperative transfusions, lung transplantation performed with ECMO support is comparable to the off-pump procedure as to short-term survival and outcomes.

Established and potential predictors of blood loss during lung transplant surgery

Lung transplantation is an established therapeutic procedure for end stage lung diseases. Its success may be impaired by perioperative complications. Intraoperative blood loss and the resulting blood transfusion are among the most common complications. The various factors contributing to increased blood loss during lung transplantation are only scarcely investigated and not yet completely understood. This is in sharp contrast to other surgical fields, as in orthopedic surgery, liver transplantation and cardiac surgery the contributors to blood loss are well identified. This narrative review article aims to highlight the acknowledged factors influencing blood loss in lung transplantation (such as double vs. single lung transplant) and to discuss potential factors that may be of interest for further research or helpful to develop strategies targeting risk factors in order to minimize blood loss during lung transplantation and finally improve patient outcome.

Extracorporeal Circulation During Lung Transplantation Procedures: A Meta-Analysis

Extracorporeal circulation (ECC) is an invaluable tool in lung transplantation (lutx). More than the past years, an increasing number of centers changed their standard for intraoperative ECC from cardiopulmonary bypass (CPB) to extracorporeal membrane oxygenation (ECMO) - with differing results. This meta-analysis reviews the existing evidence. An online literature research on Medline, Embase, and PubMed has been performed. Two persons independently judged the papers using the ACROBAT-NRSI tool of the Cochrane collaboration. Meta-analyses and meta-regressions were used to determine whether veno-arterial ECMO (VA-ECMO) resulted in better outcomes compared with CPB. Six papers - all observational studies without randomization - were included in the analysis. All were considered to have serious bias caused by heparinization as co-intervention. Forest plots showed a beneficial trend of ECMO regarding blood transfusions (packed red blood cells (RBCs) with an average mean difference of -0.46 units [95% CI = -3.72, 2.80], fresh-frozen plasma with an average mean difference of -0.65 units [95% CI = -1.56, 0.25], platelets with an average mean difference of -1.72 units [95% CI = -3.67, 0.23]). Duration of ventilator support with an average mean difference of -2.86 days [95% CI = -11.43, 5.71] and intensive care unit (ICU) length of stay with an average mean difference of -4.79 days [95% CI = -8.17, -1.41] were shorter in ECMO patients. Extracorporeal membrane oxygenation treatment tended to be superior regarding 3 month mortality (odds ratio = 0.46, 95% CI = 0.21-1.02) and 1 year mortality (odds ratio = 0.65, 95% CI = 0.37-1.13). However, only the ICU length of stay reached statistical significance. Meta-regression analyses showed that heterogeneity across studies (sex, year of ECMO implementation, and underlying disease) influenced differences. These data indicate a benefit of the intraoperative use of ECMO as compared with CPB during lung transplant procedures regarding short-term outcome (ICU stay). There was no statistically significant effect regarding blood transfusion needs or long-term outcome. The superiority of ECMO in lutx patients remains to be determined in larger multi-center randomized trials.

Care of the Postoperative Pulmonary Resection Patient

Patients undergoing pulmonary resection all exhibit, to some degree, a level of pulmonary dysfunction. This is due to the physiologic stress of the procedure performed, the patient’s comorbidities, and preexisting cardiopulmonary reserve. Although prognostic factors for intensive care requirement exist, to date, there is no consensus for postoperative admission. Institutional practices vary across the country, with patients often admitted to intensive care for surveillance. Guidelines published from the American Thoracic Society in 1999 emphasize that admission to the ICU be reserved for those patients requiring care and monitoring for severe physiologic instability. Admissions following pulmonary resection are typically due to respiratory complications and are an independent predictor of mortality. The following chapter will review the indications for admission to the ICU and common issues encountered following pulmonary resection and conclude with a discussion of the management of patients undergoing pulmonary transplantation.

Advanced pulmonary arterial hypertension: mechanical support and lung transplantation

The development of targeted therapies has transformed the outlook for patients with pulmonary arterial hypertension (PAH); however, some patients fail to achieve an adequate clinical response despite receiving maximal treatment. For these patients, lung transplantation remains an important therapeutic option, and recommendations for transplantation are included in the current European Society of Cardiology/European Respiratory Society guidelines for the diagnosis and treatment of pulmonary hypertension. Although lung transplantation is not without risk, overall long-term survival rates are good and substantial improvements in quality of life have been reported for lung transplant recipients. In this review, we describe the important considerations prior to, during and after transplantation, including the role of mechanical support, in patients with advanced PAH.

Lung transplantation and mechanical support play key therapeutic roles in patients with advanced PAHhttp://ow.ly/mqfG30gMcMd

Intraoperative extracorporeal membrane oxygenation and the possibility of postoperative prolongation improve survival in bilateral lung transplantation

OBJECTIVES

The value of intraoperative extracorporeal membrane oxygenation (ECMO) in lung transplantation remains controversial. In our department, ECMO has been used routinely for intraoperatively unstable patients for more than 15 years. Recently, we have extended its indication to a preemptive application in almost all cases. In addition, we prolong ECMO into the early postoperative period whenever graft function does not meet certain quality criteria or in patients with primary pulmonary hypertension. The objective of this study was to review the results of this strategy.

METHODS

All standard bilateral lung transplantations performed between January 2010 and June 2016 were included in this single-center, retrospective analysis. Patients were divided into 3 groups: group I-no ECMO (n = 116), group II-intraoperative ECMO (n = 343), and group III-intraoperative and prolonged postoperative ECMO (n = 123). The impact of different ECMO strategies on primary graft function, short-term outcomes, and patient survival were analyzed.

RESULTS

The use of intraoperative ECMO was associated with improved 1-, 3-, and 5-year survival compared with non-ECMO patients (91% vs 82%, 85% vs 76%, and 80% vs 74%; log-rank P = .041). This effect was still evident after propensity score matching of both cohorts. Despite the high number of complex patients in group III, outcome was excellent with higher survival rates than in the non-ECMO group at all time points.

CONCLUSIONS

Intraoperative ECMO results in superior survival when compared with transplantation without any extracorporeal support. The concept of prophylactic postoperative ECMO prolongation is associated with excellent outcomes in recipients with pulmonary hypertension and in patients with questionable graft function at the end of implantation.

History of lung transplantation

Lung transplantation nowadays is a well-accepted and routine treatment for well selected patients with terminal respiratory disease. However, it took several decades of experimental studies and clinical attempts to reach this success. In this paper, we describe the early experimental activity from the mid-forties until the early sixties. The first clinical attempt in humans was reported by Hardy and Webb in 1963 followed by others with short survival only except for one case by Derom et al. who lived for 10 months. Long-term successes were not reported until after the discovery of cyclosporine as a new immunosuppressive agent. Successful heart-lung transplantation (HLTx) for pulmonary vascular disease was performed by the Stanford group starting in 1981 while the Toronto group described good outcome after single-lung transplantation (SLTx) for pulmonary fibrosis in 1983 and after double-lung transplantation for emphysema in 1986. Further evolution in surgical techniques and in transplant type for the various forms of end-stage lung diseases are reviewed. The evolution in lung transplantation still continues nowadays with the use of pulmonary allografts coming from living-related donors, from donors after circulatory death, or after prior assessment and reconditioning during ex vivo lung perfusion (EVLP) in an attempt to overcome the critical shortage of suitable organs. Early outcome has significantly improved over the last three decades. Better treatment and prevention of chronic lung allograft dysfunction will hopefully result in further improvement of long-term survival after lung transplantation.

Outcomes of perioperative extracorporeal membrane oxygenation use in patients undergoing lung transplantation

Background

The aim of this single-center study is to review the transplant outcomes of patients receiving lung transplantation (LTx) using intraoperative extracorporeal membrane oxygenation (ECMO) according to the perioperative use of ECMO.

Methods

We retrospectively reviewed the transplant outcomes of 107 consecutive patients who underwent LTx using intraoperative ECMO between March 2013 and August 2016 at Severance Hospital of Yonsei University (Seoul, Korea).

Results

Patients were divided into the following three groups according to the use of perioperative ECMO: only intraoperative ECMO (n=47) or extended post-operative ECMO but no bridging and no postoperative ECMO re-implantation (secondary ECMO; n=28) as Group A (n=75); bridging ECMO without secondary ECMO (n=14) as Group B; and secondary ECMO with (n=7) or without (n=11) bridging as Group C. Baseline demographics were comparable among the three groups. The mean duration of preoperative ECMO bridging was 16.4±15.6 (n=21). After a median of 17.7 months (range, 3.1-40.9 months) for survivors, the one year overall survival (OS) rates after LTx for the three groups were 76.3%±5.2% for Group A, 59.9%±14.3% for Group B, and 14.0%±9.0% for Group C (P<0.0001). The secondary ECMO (Group C) was established a mean of 7.9±5.3 days after LTx. The main cause of secondary ECMO was acute respiratory failure from pneumonia, and the main cause of death was infection-related events.

Conclusions

Our data suggests that the use of perioperative ECMO, including its extended postoperative use during LTx, is feasible and has favorable outcomes. However, as shown by the poor survival outcome after secondary ECMO, the development of solid strategy to reduce the need for secondary ECMO implantation after LTx seems important.

Risk Factor Analysis for Intraoperative Extracorporeal Membrane Oxygenation Weaning Failure After Lung Transplantation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been widely used for hemodynamic support during lung transplantation (LTx). We evaluated the risk factors associated with failure of weaning from ECMO in the operating room during LTx.

METHODS

We retrospectively reviewed 74 consecutive patients who had undergone LTx from March 2013 to February 2016. Patients who underwent single LTx, multiorgan transplantation, and LTx for pulmonary hypertension were excluded. All operations were performed under ECMO support. Clinical data of donor, recipient, and intraoperative parameters were reviewed.

RESULTS

Younger donors (40 ± 11 versus 45 ± 10 years, p = 0.047), donors with shorter mechanical ventilation (125 ± 74 versus 160 ± 80 minutes, p = 0.066) and donors with higher Pao₂ at 100% oxygen (455 ± 87 mm Hg versus 399 ± 88 mm Hg, p = 0.008) were significantly different in the ECMO weaning group than in the weaning failure group. Of the recipients, the number of patients who had preoperative ECMO support were significantly fewer in the successful weaning group than in the weaning failure group (11.9% versus 34.4%, p = 0.061). The operation time was significantly shorter in the weaning group than in the weaning failure group (392 ± 66 versus 435 ± 82 minutes, p = 0.014). In multivariate logistic regression analysis, the independent risk factors for ECMO weaning were donor age (odds ratio 1.101, 95% confidence interval: 1.030 to 1.177, p = 0.005), donor Pao₂ (odds ratio 0.992, 95% confidence interval: 0.984 to 0.999, p = 0.034), and operation time (odds ratio 1.010, 95% confidence interval: 1.000 to 1.019, p = 0.043).

CONCLUSIONS

Our results showed that younger donor age, high Pao₂, and shorter operation time were factors related to successful ECMO weaning in the operating room after LTx.

Anesthetic management of the patient with extracorporeal membrane oxygenator support

The use of short-term mechanical circulatory support in the form of extracorporeal membrane oxygenation (ECMO) in adult patients has increased over the last decade. Cardiothoracic anesthesiologists may care for these patients during ECMO placement and for procedures while ECMO support is in place. An understanding of ECMO capabilities, indications, and complications is essential to the anesthesiologist caring for these patients. Below we review the anesthetic considerations for the implantation of ECMO and concerns when caring for patients on ECMO.