Experience with extracorporeal membrane oxygenation in massive and submassive pulmonary embolism in a tertiary care center

Extracorporeal membrane oxygenation for the treatment of massive pulmonary embolism. An analysis of the ELSO database

AIM

Extracorporeal membrane oxygenation (ECMO) may be beneficial in treatment of massive pulmonary embolus (PE), however the current evidence to guide its use is limited. We aimed to compare the incidence, characteristics, treatments, and outcomes of patients with massive PE by mode of ECMO from a large international registry.

METHODS

Retrospective observational study of the Extracorporeal Life Support Organization (ELSO) database.

RESULTS

A total of 821 patients underwent 833 ECMO episodes for PE. Mean age was 49 (±15) years, 408 (50.1%) were female, and 450 (54.7%) had a cardiac arrest prior to ECMO initiation. Venoarterial (VA) ECMO was the most common mode in 489 (58.7%), followed by extracorporeal cardiopulmonary resuscitation (ECPR) in 229 (27.4%) and venovenous (VV) ECMO in 85 (10.2%). The number of episodes per year increased over the study period, predominantly driven by an increase in ECPR. In-hospital mortality was the highest for ECPR 156/229 (68.1%), followed by VA ECMO 209/498 (42.7%) and VV ECMO 24/85 (28.2%) P < 0.001. After controlling for univariate and clinically significant variables at the time of ECMO initiation, increasing age (OR 1.02 (1.00-1.03), lower pH (OR 0.18 (0.03-0.44), lower diastolic blood pressure (OR 0.99 (0.97-1.00) and ECPR mode (OR 3.67 (1.46-9.230) were independently associated with in-hospital mortality.

CONCLUSION

ECMO use for massive PE is increasing globally, and overall mortality rates compare favorably with other indications of ECMO. The use of ECPR and worsening metabolic status at initiation were associated with higher in-hospital mortality, suggesting delays in initiating ECMO should be avoided.

The Challenge of Intermediate-Risk Pulmonary Embolism

BACKGROUND

Intermediate-risk pulmonary embolism is a common disease that is associated with significant morbidity and mortality; however, a standardized treatment protocol is not well-established.

AREAS OF UNCERTAINTY

Treatments available for intermediate-risk pulmonary embolisms include anticoagulation, systemic thrombolytics, catheter-directed therapies, surgical embolectomy, and extracorporeal membrane oxygenation. Despite these options, there is no clear consensus on the optimal indication and timing of these interventions.

THERAPEUTIC ADVANCES

Anticoagulation remains the cornerstone of treatment for pulmonary embolism; however, over the past 2 decades, there have been advances in the safety and efficacy of catheter-directed therapies. For massive pulmonary embolism, systemic thrombolytics and, sometimes, surgical thrombectomy are considered first-line treatments. Patients with intermediate-risk pulmonary embolism are at high risk of clinical deterioration; however, it is unclear whether anticoagulation alone is sufficient. The optimal treatment of intermediate-risk pulmonary embolism in the setting of hemodynamic stability with right heart strain present is not well-defined. Therapies such as catheter-directed thrombolysis and suction thrombectomy are being investigated given their potential to offload right ventricular strain. Several studies have recently evaluated catheter-directed thrombolysis and embolectomies and demonstrated the efficacy and safety of these interventions. Here, we review the literature on the management of intermediate-risk pulmonary embolisms and the evidence behind those interventions.

CONCLUSIONS

There are many treatments available in the management of intermediate-risk pulmonary embolism. Although the current literature does not favor 1 treatment as superior, multiple studies have shown growing data to support catheter-directed therapies as potential options for these patients. Multidisciplinary pulmonary embolism response teams remain a key feature in improving the selection of advanced therapies and optimization of care.

Intermediate-Risk Pulmonary Embolism: A Review of Contemporary Diagnosis, Risk Stratification and Management

Pulmonary embolism (PE) can have a wide range of hemodynamic effects, from asymptomatic to a life-threatening medical emergency. Pulmonary embolism (PE) is associated with high mortality and requires careful risk stratification for individualized management. PE is divided into three risk categories: low risk, intermediate-risk, and high risk. In terms of initial therapeutic choice and long-term management, intermediate-risk (or submassive) PE remains the most challenging subtype. The definitions, classifications, risk stratification, and management options of intermediate-risk PE are discussed in this review.

Rare pulmonary embolism in a pregnant patient: A primary diffused pulmonary artery myxofibrosarcoma case report

A 37-year-old female patient presented with shortness of breath, cough, and chest pain complaints from the 12th week of her first pregnancy. At the 28th week, labor induction had to be performed because of severe dyspnea and hyoxemia. Thereafter, a diffused pulmonary embolism was detected by echocardiography and CT angiography, without histological diagnosis. Pulmonary endarterectomy was performed, and it was found during operation that a huge, lobular mass originated in the posterior wall and extended throughout the vasculature of both lungs, and a mucinous pellicle covered the entire pulmonary endothelium. Pathology revealed a low-grade myxofibrosarcoma with positive vimentin and SMA, partially positive CD-34.

Acoustic pulse thrombolysis complemented by ECMO improved survival in patients with high-risk pulmonary embolism

BACKGROUND

The optimal treatment of high-risk pulmonary embolism (PE) with cardiac arrest is still controversial although various treatment approaches have been developed and improved. Here, we present a serie of patients with high-risk PE showing hemodynamic collapse, who were successfully treated with extracorporeal membrane oxygenation (ECMO) as an adjunct to EKOS™ acoustic pulse thrombolysis (APT).

METHODS

From April 2016 to June 2020, 29 patients with high-risk PE with cardiac arrest were retrospectively included. The mean age was 55.3 ± 9.2 years. A total of 12 (41.3%) patients were female. All patients had cardiac arrest, either as an initial presentation or in-hospital after presentation. All patients exhibited acute symptoms, computed tomography evidence of large thrombus burden, and severe right ventricular dysfunction. Primary outcome was all-cause 30-day mortality.

RESULTS

Twenty-two patients survived to hospital discharge, with a mean intensive care unit stay of 9.9 ± 1.6 days (range: 7-22 days) and mean length of hospital stay of 23.7 ± 8.5 days (range: 11-44 days). Six patients died from refractory shock. Ninety-day mortality was 24.1% (7/29). The Mean ECMO duration was 3.5 ± 1.1 days and the mean RV/LV ratio decreased from 1.31 ± 0.17 to 0.92 ± 0.11 in patients who survived to discharge. The mean tissue plasminogen activator dose for survivor patients was 20.5 ± 1.6 mg.

CONCLUSION

Patients with high-risk pulmonary embolism who suffer a cardiac arrest have high morbidity and mortality. APT complemented by ECMO could be a successful treatment option for the patients who have high-risk PE with circulatory collapse.

Clinical use and outcome of extracorporeal membrane oxygenation in patients with pulmonary embolism

AIM OF THE STUDY

Extracorporeal membrane oxygenation (ECMO) is considered a life-saving treatment option for patients in cardiogenic shock or cardiac arrest undergoing cardiopulmonary resuscitation (CPR) due to acute pulmonary embolism (PE). We sought to analyze use and outcome of ECMO with or without adjunctive treatment strategies in patients with acute PE.

METHODS

We retrospectively analyzed data on patient characteristics, treatments, and in-hospital outcomes for all PE patients (ICD-code I26) undergoing ECMO in Germany between 2005 and 2018.

RESULTS

At total of 1,172,354 patients were hospitalized with PE; of those, 2,197 (0.2%) were treated with ECMO support. Cardiac arrest requiring cardiopulmonary resuscitation was present in 77,196 (6.5%) patients. While more than one fourth of those patients were treated with systemic thrombolysis alone (n = 20,839 patients; 27.0%), a minority of patients received thrombolysis and VA-ECMO (n = 165; 0.2%), embolectomy and VA-ECMO (n = 385; 0.5%) or VA-ECMOalone (n = 588; 0.8%). A multivariable logistic regression analysis indicated the lowest risk for in-hospital death in patients who received embolectomy in combination with VA-ECMO (OR, 0.50 [95% CI, 0.41-0.61], p < 0.001), thrombolysis and VA-ECMO (0.60 [0.43-0.85], p = 0.003) or VA-ECMO alone (0.68 [0.57-0.82], p < 0.001) compared to thrombolysis alone (1.04 [0.99-1.01], p = 0.116).

CONCLUSION

Our findings suggest that the use of VA-ECMO alone or as part of a multi-pronged reperfusion approach including embolectomy or thrombolysis might offer survival advantages compared to thrombolysis alone in patients with PE deteriorating to cardiac arrest.

Survival of patients with acute pulmonary embolism treated with venoarterial extracorporeal membrane oxygenation: A systematic review and meta-analysis

BACKGROUND

To examine whether venoarterial extracorporeal membrane oxygenation (VA-ECMO) improves survival of patients with acute pulmonary embolism (PE).

METHODS

Following the PRISMA guidelines, a systematic search was conducted up to August 2019 of the databases: PubMed/MEDLINE, EMBASE and Cochrane. All studies reporting the survival of adult patients with acute PE treated with VA-ECMO and including four patients or more were included. Exclusion criteria were: correspondences, reviews and studies in absence of a full text, written in other languages than English or Dutch, or dating before 1980. Short-term (hospital or 30-day) survival data were pooled and presented with relative risks (RR) and 95% confidence intervals (95% CI). Also, the following pre-defined factors were evaluated for their association with survival in VA-ECMO treated patients: age > 60 years, male sex, pre-ECMO cardiac arrest, surgical embolectomy, catheter directed therapy, systemic thrombolysis, and VA-ECMO as single therapy.

RESULTS

A total of 29 observational studies were included (N = 1947 patients: VA-ECMO N = 1138 and control N = 809). There was no difference in short-term survival between VA-ECMO treated patients and control patients (RR 0.91, 95% CI 0.71-1.16). In acute PE patients undergoing VA-ECMO, age > 60 years was associated with lower survival (RR 0.72, 95% CI 0.52-0.99), surgical embolectomy was associated with higher survival (RR 1.96, 95% CI 1.39-2.76) and pre-ECMO cardiac arrest showed a trend toward lower survival (RR 0.88, 95% CI 0.77-1.01). The other evaluated factors were not associated with a difference in survival.

CONCLUSIONS

At present, there is insufficient evidence that VA-ECMO treatment improves short-term survival of acute PE patients. Low quality evidence suggest that VA-ECMO patients aged ≤60 years or who received SE have higher survival rates. Considering the limited evidence derived from the present data, this study emphasizes the need for prospective studies.

PROTOCOL REGISTRATION

PROSPERO CRD42019120370.

Current Endovascular Treatment Options in Acute Pulmonary Embolism

Acute pulmonary embolism (PE) is a significant cause of mortality and morbidity across the globe. Over the last few decades, there have been major therapeutic advances in acute PE management, including catheter-based therapy. However, the effectiveness of catheter-based therapy in acute PE is not supported by Level I evidence, making the use of this promising treatment rather controversial and ambiguous. In this paper, we discuss the risk stratification of acute PE and review the medical and endovascular treatment options. We also summarize and review the data supporting the use of endovascular treatment options in acute PE and describe the potential role of the PE response team.

Use of extracorporeal membrane oxygenation in high-risk acute pulmonary embolism: A systematic review and meta-analysis

Extracorporeal membrane oxygenation (ECMO) represents a therapeutic option for cardiopulmonary support in patients with high-risk pulmonary embolism (PE); however, no definite consensus exists on ECMO use in high-risk PE. Hence, we aim to provide insights into its real-world use pooling together all available published experiences. We performed a systematic review and pooled analysis of all published studies (up to April 17, 2020) investigating ECMO support in high-risk PE. All studies including at least four patients were collectively analyzed. Study outcomes were early all-cause death (primary endpoint) and relevant in-hospital adverse events. A total of 21 studies were included in the pooled analysis (n = 635 patients). In this population (mean age 47.8 ± 17.3 years, 44.5% females), ECMO was indicated for cardiac arrest in 62.3% and immediate ECMO support was pursued in 61.9% of patients. Adjunctive reperfusion therapies were implemented in 57.0% of patients. Pooled estimate rate of early all-cause mortality was 41.1% (95% CI 27.7%-54.5%). The most common in-hospital adverse event was major bleeding, with an estimated rate of 28.6% (95%CI 21.0%-36.3%). At meta-regression analyses, no significant impact of multiple covariates on the primary endpoint was found. In this systematic review of patients who received ECMO for high-risk PE, pooled all-cause mortality was 41.1%. Principal indication for ECMO was cardiac arrest, cannulation was chiefly performed at presentation, and major bleeding was the most common complication.

Bivalirudin and Alteplase for Pulmonary Embolism Requiring Veno-Arterial Extracorporeal Membrane Oxygenation in an Adolescent

Saddle pulmonary embolism (PE) remains a challenge to diagnose and manage in pediatric patients. Current literature encourages early consideration of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in high-risk PE patients with impending right ventricular failure. We present a 17-year-old patient who was admitted to a pediatric cardiac intensive care unit with saddle PE requiring emergent VA-ECMO support because of cardiovascular collapse. Despite anticoagulation with bivalirudin and receiving systemic thrombolysis with alteplase, the clot burden was persistent with minimal improvement in right ventricular function. We proceeded to catheter thrombolysis while on VA-ECMO. This ultimately led to a successful resolution of the PE and allowed for weaning off VA-ECMO. PE is rare in children compared with adults, and pediatricians may be unaware of therapies becoming increasingly used in adults such as the use of VA-ECMO, with systemic and local thrombolysis. The concurrent use of a direct thrombin inhibitor for ECMO anticoagulation alongside the thrombolysis is a novel combination in this condition and age-group.

Technical efficiency, short-term clinical results and safety of a large-bore aspiration catheter in acute pulmonary embolism - A retrospective case study

BACKGROUND

Mechanical thrombectomy plays an important role in the management of acute pulmonary embolism (PE), either when rapid clot dissolution is needed or when thrombolytics are contraindicated. We describe our clinical and technical experience with the FlowTriever mechanical thrombectomy device in patients with acute PE.

MATERIALS AND METHODS

A retrospective analysis was performed on all cases of acute PE treated with the FlowTriever device at a single tertiary care hospital system during the trial period (November 2019-January 2020). Technical and clinical results, including complications, are reported.

RESULTS

Technical success was achieved in all eight successive cases (seven cases of submassive and 1 case of massive PE). Mean pulmonary artery pressure (MPAP) improved significantly after mechanical thrombectomy (27.8 ± 6.4 mmHg preprocedure; 20.5 ± 3.8 mmHg postprocedure; 7.3 ± 5.2 mmHg decrease after the procedure; P = 0.016). Hemoglobin levels did not change significantly after mechanical thrombectomy (11.8 g/dl ± 3.4 preprocedure; 9.9 g/dl ± 2.1 postprocedure; P = 0.20). Reduction in MPAP was achieved in 88% of cases (7/8) and hypoxia improved in all the nonintubated patients (7/7). Mortality observed in one patient with a massive central PE, was not related to the procedure. No mortality or procedural complications were observed in patients with submassive PE.

CONCLUSIONS

The positive initial clinical experience and safety profile using the FlowTriever in the treatment of acute PE suggests, it has the potential to fill the unmet needs of a good mechanical thrombectomy device to treat massive and submassive high-risk PE especially when thrombolytics are contraindicated.

Invasive Strategies for the Treatment of Pulmonary Embolism. Where Are We in 2020?

Pulmonary Embolism (PE) is the third most common cause of cardiovascular mortality in the United States, with 60,000-100,000 deaths per year following myocardial infarction and stroke. During the past 5 years, there has been an introduction of novel interventions as a result of a renewed interest in optimizing PE management, particularly among those individuals with more severe disease of hemodynamic significance. The cornerstone treatment for PE is anticoagulation. More aggressive alternatives have been considered for patients with intermediate and high-risk PE. In general, these options can be grouped into 3 different categories: systemic thrombolysis, catheter-directed interventions, and surgical embolectomy. Systemic thrombolysis has shown statistical benefit in several randomized trials for intermediate- and high-risk PE, however, this benefit has been offset by an elevated risk of major bleeding and intracerebral hemorrhage, limiting their use in clinical practice. Catheter-directed thrombolysis refers to catheter-directed injection of a thrombolytic drug directly into the pulmonary artery. Three interventional devices (EKOSonic endovascular system, FlowTriever embolectomy device and the Indigo thrombectomy system) have recently been cleared by the US Food and Drug Administration for marketing, and several others are in various stages of development. As of today, catheter-based interventions are limited to small randomized trials and single arm-prospective studies focused on short-term surrogate endpoints. Although single arm studies carry some value establishing the preliminary safety and effectiveness of these devices, they are not sufficient to stratify risk and guide clinical practice. Furthermore, no trials have been performed with enough power to assess potential mortality benefit with the use of catheter-directed thrombolysis or catheter-based embolectomy devices, hence treatment decisions continue to be influenced by individual risk of bleeding, the location of thrombus and operator expertise until additional evidence becomes available.

Venoarterial extracorporeal membrane oxygenation is an effective management strategy for massive pulmonary embolism patients

OBJECTIVE

Treatment of massive pulmonary embolism (MPE) is controversial, with mortality rates ranging from 25% to 65%. Patients commonly present with profound shock or cardiac arrest. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly being used as a form of acute cardiopulmonary support in critically ill patients. We reviewed our institution's pulmonary embolism response team experience using VA-ECMO for patients presenting with advanced shock and/or cardiac arrest from MPE.

METHODS

From March 2017 to July 2019 we retrospectively reviewed 17 consecutive patients at our institution with MPE who were placed on VA-ECMO for initial hemodynamic stabilization.

RESULTS

The mean patient age and body mass index was 55.8 years and 31.8, respectively. Ten of 17 patients (59%) required cardiopulmonary resuscitation before or during VA-ECMO cannulation. All patients had evidence of profound shock with a mean initial lactate of 8.95 mmol/L, a mean pH of 7.10, and a mean serum creatinine of 1.78 mg/dL. Seventeen of 17 cannulations (100%) were performed percutaneously, with 41% (n = 7) of patients placed on VA-ECMO while awake and using local analgesia. Five of 17 patients (29%) required reperfusion cannulas, with 0% incidence of limb loss. Overall survival was 13 of 17 patients (76%), with causes of death resulting from anoxic brain injury (n = 2), septic shock (n = 1), and cardiopulmonary resuscitation-induced hemorrhage from liver laceration (n = 1). In survivors, 12 of 13 patients (92%) were discharged without evidence of neurologic insult. The median duration of the VA-ECMO run for survivors was 86 hours (range, 45-218 hours). In survivors, the median length of time from ECMO cannulation to lactate clearance (<2.0 mmol/L) was 10 hours and the median length of time from ECMO cannulation to freedom from vasopressors was 6 hours. Three of 13 patients (23%) required concomitant percutaneous thrombectomy and catheter-directed thrombolysis to address persistent right heart dysfunction, with the remaining survivors (77%) receiving VA-ECMO and anticoagulation alone as definitive therapy for their MPE. The median intensive care and hospital length of stay for survivors was 9 and 13 days, respectively.

CONCLUSIONS

VA-ECMO was effective at salvaging highly unstable patients with MPE. Survivors had rapid reversal of multiple organ failure with ECMO as their primary therapy. The majority of survivors required ECMO and anticoagulation alone for definitive therapy of their MPE.

Interventional Therapies for Acute Pulmonary Embolism: Current Status and Principles for the Development of Novel Evidence: A Scientific Statement From the American Heart Association

Pulmonary embolism (PE) represents the third leading cause of cardiovascular mortality. The technological landscape for management of acute intermediate- and high-risk PE is rapidly evolving. Two interventional devices using pharmacomechanical means to recanalize the pulmonary arteries have recently been cleared by the US Food and Drug Administration for marketing, and several others are in various stages of development. The purpose of this document is to clarify the current state of endovascular interventional therapy for acute PE and to provide considerations for evidence development for new devices that will define which patients with PE would derive the greatest net benefit from their use in various clinical settings. First, definitions and limitations of commonly used risk stratification tools for PE are reviewed. An adjudication of risks and benefits of available interventional therapies for PE follows. Next, considerations for optimal future evidence development in this field are presented in the context of the current US regulatory framework. Finally, the document concludes with a discussion of the pros and cons of the rapidly expanding PE response team model of care delivery.

Extracorporeal membrane oxygenation in acute massive pulmonary embolism: a case series and review of the literature

Background:

Extracorporeal membrane oxygenation (ECMO) has been used to stabilize patients with massive pulmonary embolism though few reports describe this approach. We describe the presentation, management and outcomes of patients who received ECMO for massive pulmonary embolism (PE) in our pulmonary embolism response team (PERT) registry.

Methods:

We enrolled a consecutive cohort of patients with confirmed PE for whom PERT was activated and selected patients treated with ECMO. We prospectively captured clinical, therapeutic and outcome data at the time of PERT activation and during the follow-up period for up to 365 days.

Results:

Thirteen patients who had PERT activation with confirmed PE diagnosis have undergone ECMO since the initiation of our PERT program in 2012. The mean age was 49 ± 19 years. Six (46%) patients were female. All the patients had cardiac arrest, either as an initial presentation or in-hospital cardiac arrest after presentation. All the patients exhibited right ventricular (RV) dilation on echocardiogram with RV hypokinesis. Eight (62%) patients received systemic thrombolysis with intravenous tissue plasminogen activator (tPA) and three (23%) patients underwent catheter-directed thrombolysis therapy using the EKOS system (EKOS Corporation, Bothell, WA, USA). Four (31%) patients underwent surgical embolectomy. Mean ECMO duration was 5.5 days, ranging from 2-18 days. Thirty-day mortality was 31% and one-year mortality was 54%.

Conclusions:

Patients with massive pulmonary embolism who suffer a cardiac arrest have high morbidity and mortality. ECMO can be used in conjunction with systemic thrombolysis, catheter-directed therapy or as a bridge to surgical embolectomy.

Extracorporeal Life Support as Salvage Therapy for Massive Pulmonary Embolus and Cardiac Arrest in Pregnancy

BACKGROUND

Massive pulmonary embolus (PE) with prolonged cardiac arrest in the setting of pregnancy has few treatment options. Selections are further restricted if there are contraindications to the standard therapies of embolectomy and thrombolysis. We report a case of extracorporeal life support (ECLS) used as salvage therapy for a critically ill pregnant patient.

CASE REPORT

A 21-year-old woman presented to a small rural hospital with chest pain, dyspnea, hypoxia, and syncope. In their emergency department, she suffered 2 episodes of cardiac arrest requiring cardiopulmonary resuscitation, and fetal demise followed. A computed tomography scan revealed a saddle PE. She was transferred to our tertiary care hospital and arrived critically ill, on multiple vasopressors, and in cardiogenic shock. Because standard treatments, namely thrombolysis and embolectomy, were contraindicated in this case, ECLS was employed for 7 days. She was discharged home after 23 days, and at follow-up 5 months after her admission, she was found to have made a near-complete recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: ECLS is a viable option as salvage therapy for pregnant patients with massive PE who have contraindications to thrombolysis and embolectomy.

Extra-corporeal membrane oxygenation and outcomes in massive pulmonary embolism: Two eras at an urban tertiary care hospital

Mortality associated with high-risk pulmonary embolism (PE) remains high. Extra-corporeal membrane oxygenation (ECMO) allows for acute hemodynamic stabilization and potentially for administration of other disease process altering therapies. We sought to compare two eras: pre-ECMO and post-ECMO in relation to high-risk PE treatment and mortality. A single-center retrospective chart review was conducted of high-risk PE patients. High-risk PE was defined as acute PE and cardiac arrest or shock. A total of 60 patients were identified, 31 in the pre-ECMO era and 29 in the post-ECMO era. Mean age was 56.1±21.1 years and 51.7% were women. More patients in the post-ECMO era were identified with computed tomography (82.8% vs 51.6%, p=0.011) and more patients in the post-ECMO era had right ventricular dysfunction on echocardiography (96.4% vs 78.3%, p=0.045). No other differences were noted in baseline characteristics or clinical, laboratory and imaging data between the two groups. In total, ECMO was used in 13 (44.8%) patients in the post-ECMO era. There was greater utilization of catheter-directed therapies in the post-ECMO era compared to the pre-ECMO era ( n = 7 (24.1%) vs n = 1 (3.2%), p=0.024). Thirty-day survival increased from 17.2% in patients who presented in the pre-ECMO era to 41.4% in the post-ECMO era ( p=0.043). While more work is necessary to better identify those PE patients who stand to benefit from mechanical circulatory support, our findings have important implications for the management of such patients.

Life-threatening massive pulmonary embolism rescued by venoarterial-extracorporeal membrane oxygenation

Background

Despite quick implementation of reperfusion therapies, a few patients with high-risk, acute, massive, pulmonary embolism (PE) remain highly hemodynamically unstable. Others have absolute contraindication to receive reperfusion therapies. Venoarterial-extracorporeal membrane oxygenation (VA-ECMO) might lower their right ventricular overload, improve hemodynamic status, and restore tissue oxygenation.

Methods

ECMO-related complications and 90-day mortality were analyzed for 17 highly unstable, ECMO-treated, massive PE patients admitted to a tertiary-care center (2006–2015). Hospital- discharge survivors were assessed for long-term health-related quality of life. A systematic review of this topic was also conducted.

Results

Seventeen high-risk PE patients [median age 51 (range 18–70) years, Simplified Acute Physiology Score II (SAPS II) 78 (45–95)] were placed on VA-ECMO for 4 (1–12) days. Among 15 (82%) patients with pre-ECMO cardiac arrest, seven (41%) were cannulated during cardiopulmonary resuscitation, and eight (47%) underwent pre-ECMO thrombolysis. Pre-ECMO median blood pressure, pH, and blood lactate were, respectively: 42 (0–106) mmHg, 6.99 (6.54–7.37) and 13 (4–19) mmol/L. Ninety-day survival was 47%. Fifteen (88%) patients suffered in-ICU severe hemorrhages with no impact on survival. Like other ECMO-treated patients, ours reported limitations of all physical domains but preserved mental health 19 (4–69) months post-ICU discharge.

Conclusions

VA-ECMO could be a lifesaving rescue therapy for patients with high-risk, acute, massive PE when thrombolytic therapy fails or the patient is too sick to benefit from surgical thrombectomy. Because heparin-induced clot dissolution and spontaneous fibrinolysis allows ECMO weaning within several days, future studies should investigate whether VA-ECMO should be the sole therapy or completed by additional mechanical clot-removal therapies in this setting.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1655-8) contains supplementary material, which is available to authorized users.

Clinical and billing review of extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a temporary technique for providing life support for cardiac dysfunction, pulmonary dysfunction, or both. The two forms of ECMO, veno-arterial (VA) and veno-venous (VV), are used to support cardiopulmonary and pulmonary dysfunction, respectively. Historically, ECMO was predominantly used in the neonatal and pediatric populations, as early adult studies failed to improve outcomes. ECMO has become far more common in the adult population because of positive results in published case series and clinical trials during the 2009 influenza A(H1N1) pandemic in 2009 to 2010. Advances in technology that make the technique much easier to implement likely fueled the renewed interest. Although exact criteria for ECMO are not available, patients who are good candidates are generally considered to be relatively young and suffering from acute illness that is believed to be reversible or organ dysfunction that is otherwise treatable. With the increase in the use in the adult population, a number of different codes have been generated to better identify the method of support with distinctly different relative value units assigned to each code from a very simple prior coding scheme. To effectively be reimbursed for use of the technique, it is imperative that the clinician understands the new coding scheme and works with payers to determine what is incorporated into each specific code.

Extracorporeal membrane oxygenation in acute massive pulmonary embolism: a systematic review

Massive pulmonary embolism (PE) can present with extreme physiological dysfunction, characterised by acute right ventricular failure, hypoxaemia unresponsive to conventional therapy and cardiac arrest. Consensus regarding the management of patients with persistent shock following thrombolysis is lacking. Our primary objective was to describe the application of extracorporeal membrane oxygenation (ECMO) in the treatment of acute massive PE. We were unable to identify any randomised controlled trials (RCTs) comparing ECMO with other support systems in the setting of massive PE. We reviewed case reports and case series published in the past 20 years to evaluate the mortality rate and any poor prognostic factors. Overall survival was 70.1% and none of the definitive treatment modalities was associated with a higher mortality (thrombolysis - OR - 0.99, P - 0.9, catheter embolectomy - OR - 1.01, P - 0.99, surgical embolectomy - OR - 0.44, P - 0.20). Patients who had ECMO instituted whilst in cardiorespiratory arrest had a higher risk of death. (OR - 16.71, P - 0.0004). When compared with other causes of cardiac arrest, patients who survived a massive PE presented a good neurological outcome (cerebral performance category 1 or 2).

[The place of extra-corporeal oxygenation in pulmonary diseases]

Extra-corporeal membrane oxygenation (ECMO) effectively replaces the lung in providing oxygenation and carbon dioxide (CO2) removal. For some years, and in parallel to the H1N1 influenza pandemic, this technique has gained interest in relation to significant technological improvements, leading to new concepts of "awake and mobile ECMO" or rehabilitation with ECMO. Finally, the publication of randomized controlled trials giving encouraging results in the adult respiratory distress syndrome (ARDS) has helped to validate this technique and further studies are warranted. This general review aims to outline the definition, classification and principles of ECMO and to give some current information about the indications and possibilities of the technique to the pulmonologist and intensivist. Further possible uses for this technique include extra-corporeal removal of CO2 during hypercapnic respiratory failure and assistance during lung transplantation from the preoperative to the early postoperative period.