Use of extracorporeal membrane oxygenation in patients with acute high-risk pulmonary embolism: a case series with literature review

Integration of Extracorporeal Membrane Oxygenation into the Management of High-Risk Pulmonary Embolism: An Overview of Current Evidence

High-risk pulmonary embolism (PE) refers to a large embolic burden causing right ventricular failure and hemodynamic instability. It accounts for approximately 5% of all cases of PE but contributes significantly to overall PE mortality. Systemic thrombolysis is the first-line revascularization therapy in high-risk PE. Surgical embolectomy or catheter-directed therapy is recommended in patients with an absolute contraindication to systemic thrombolysis. Extracorporeal membrane oxygenation (ECMO) provides respiratory and hemodynamic support for the most critically ill PE patients with refractory cardiogenic shock or cardiac arrest. The complex management of these individuals requires urgent yet coordinated multidisciplinary care. In light of existing evidence regarding the utility of ECMO in the management of high-risk PE patients, a number of possible indications for ECMO utilization have been suggested in the literature. Specifically, in patients with refractory cardiac arrest, resuscitated cardiac arrest, or refractory shock, including in cases of failed thrombolysis, venoarterial ECMO (VA-ECMO) should be considered, either as a bridge to percutaneous or surgical embolectomy or as a bridge to recovery after surgical embolectomy. We review here the current evidence on the use of ECMO as part of the management strategy for the highest-risk presentations of PE and summarize the latest data in this indication.

Mechanical Support in High-Risk Pulmonary Embolism: Review Article

Acute pulmonary embolism (PE) may manifest with mild nonspecific symptoms or progress to a more severe hemodynamic collapse and sudden cardiac arrest. A substantial thrombotic burden can precipitate sudden right ventricular strain and failure. Traditionally, systemic thrombolytics have been employed in such scenarios; however, patients often present with contraindications, or these interventions may prove ineffective. Outcomes for this medically complex patient population are unfavorable, necessitating a compelling argument for advanced therapeutic modalities or alternative approaches. Moreover, patients frequently experience complications beyond hemodynamic instability, such as profound hypoxia and multiorgan failure, necessitating assertive early interventions to avert catastrophic consequences. The existing data on the utilization of mechanical circulatory support (MCS) devices are not exhaustive. Various options for percutaneous MCS devices exist, each possessing distinct advantages and disadvantages. There is an imminent imperative to develop a tailored approach for this high-risk patient cohort to enhance their overall outcomes.

Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest: an overview of current practice and evidence

Cardiac arrest (CA) is a common and potentially avoidable cause of death, while constituting a substantial public health burden. Although survival rates for out-of-hospital cardiac arrest (OHCA) have improved in recent decades, the prognosis for refractory OHCA remains poor. The use of veno-arterial extracorporeal membrane oxygenation during cardiopulmonary resuscitation (ECPR) is increasingly being considered to support rescue measures when conventional cardiopulmonary resuscitation (CPR) fails. ECPR enables immediate haemodynamic and respiratory stabilisation of patients with CA who are refractory to conventional CPR and thereby reduces the low-flow time, promoting favourable neurological outcomes. In the case of refractory OHCA, multiple studies have shown beneficial effects in specific patient categories. However, ECPR might be more effective if it is implemented in the pre-hospital setting to reduce the low-flow time, thereby limiting permanent brain damage. The ongoing ON-SCENE trial might provide a definitive answer regarding the effectiveness of ECPR. The aim of this narrative review is to present the most recent literature available on ECPR and its current developments.

Extracorporeal Membrane Oxygenation for Pulmonary Embolism: A Systematic Review and Meta-Analysis

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) for high-risk pulmonary embolism (HRPE) with haemodynamic instability or profound cardiogenic shock has been reported. Guidelines currently support the use of ECMO only in patients with cardiac arrest or circulatory collapse and in conjunction with other curative therapies. We aimed to characterise the mortality of adults with HRPE treated with ECMO, identify factors associated with mortality, and compare different adjunct curative therapies.

METHODS

We conducted a systematic review and meta-analysis, searching four international databases from their inception until 25 June 2023 for studies reporting on more than five patients receiving ECMO for HRPE. Random-effects meta-analyses were conducted. The primary outcome was in-hospital mortality. A subgroup analysis investigating the outcomes with curative treatment for HRPE was also performed. The intra-study risk of bias and the certainty of evidence were also assessed. This study was registered with PROSPERO (CRD42022297518).

RESULTS

A total of 39 observational studies involving 6409 patients receiving ECMO for HRPE were included in the meta-analysis. The pooled mortality was 42.8% (95% confidence interval [CI]: 37.2% to 48.7%, moderate certainty). Patients treated with ECMO and catheter-directed therapy (28.6%) had significantly lower mortality (p < 0.0001) compared to those treated with ECMO and systemic thrombolysis (57.0%). Cardiac arrest prior to ECMO initiation (regression coefficient [B]: 1.77, 95%-CI: 0.29 to 3.25, p = 0.018) and pre-ECMO heart rate (B: -0.076, 95%-CI: -0.12 to 0.035, p = 0.0003) were significantly associated with mortality. The pooled risk ratio when comparing mortality between patients on ECMO and those not on ECMO was 1.51 (95%-CI: 1.07 to 2.14, p < 0.01) in favour of ECMO. The pooled mortality was 55.2% (95%-CI: 47.7% to 62.6%), using trim-and-fill analysis to account for the significant publication bias.

CONCLUSIONS

More than 50% of patients receiving ECMO for HRPE survive. While outcomes may vary based on the curative therapy used, early ECMO should be considered as a stabilising measure when treating patients with HRPE. Patients treated concurrently with systemic thrombolysis have higher mortality than those receiving ECMO alone or with other curative therapies, particularly catheter-directed therapies. Further studies are required to explore ECMO vs. non-ECMO therapies in view of currently heterogenous datasets.

Surgical Management and Mechanical Circulatory Support in High-Risk Pulmonary Embolisms: Historical Context, Current Status, and Future Directions: A Scientific Statement From the American Heart Association

Acute pulmonary embolism is the third leading cause of cardiovascular death, with most pulmonary embolism-related mortality associated with acute right ventricular failure. Although there has recently been increased clinical attention to acute pulmonary embolism with the adoption of multidisciplinary pulmonary embolism response teams, mortality of patients with pulmonary embolism who present with hemodynamic compromise remains high when current guideline-directed therapy is followed. Because historical data and practice patterns affect current consensus treatment recommendations, surgical embolectomy has largely been relegated to patients who have contraindications to other treatments or when other treatment modalities fail. Despite a selection bias toward patients with greater illness, a growing body of literature describes the safety and efficacy of the surgical management of acute pulmonary embolism, especially in the hemodynamically compromised population. The purpose of this document is to describe modern techniques, strategies, and outcomes of surgical embolectomy and venoarterial extracorporeal membrane oxygenation and to suggest strategies to better understand the role of surgery in the management of pulmonary embolisms.

Extracorporeal membrane oxygenation for large pulmonary emboli

Massive and submassive pulmonary emboli (PE) are increasingly being treated with percutaneous lytic and embolectomy procedures. While these procedures are overwhelmingly safe, patients with significant right ventricular strain are at risk for hemodynamic compromise requiring extracorporeal membrane oxygenation (ECMO). We conducted a retrospective study of all patients requiring ECMO support for PE from 2014 through 2022. The primary outcome was survival. Secondary outcomes included commonly encountered ECMO complications. From 2014 to 2022, 10 patients with submassive or massive PE required ECMO support. All 10 patients (100%) had right ventricular strain on echocardiography, 7 (70%) had a saddle PE, and 3 (30%) had extensive bilateral PE. Six (60%) patients required cardiopulmonary resuscitation prior to ECMO cannulation, and 4 (40%) were undergoing cardiopulmonary resuscitation while being cannulated. Nine (90%) patients were placed on venoarterial ECMO through the femoral vessels, while 1 (10%) was cannulated with right atrial to pulmonary artery ECMO. The median duration of support was 4 [3-8] days. During their course, 5 patients underwent percutaneous embolectomy, 1 underwent surgical embolectomy, and 4 underwent percutaneous lytic therapy. All patients (100%) survived to ECMO decannulation, and 6 (60%) survived to discharge. With a mean follow-up of 496 days, there were no postdischarge mortalities. In conclusion, although therapy for large PE is well tolerated, a small number of patients will experience periprocedural hemodynamic collapse requiring ECMO support. ECMO for PE patients is associated with acceptable morbidity and mortality. Further investigation is warranted to better characterize which patients are likely to require ECMO support.

Management of High-Risk Pulmonary Embolism: What Is the Place of Extracorporeal Membrane Oxygenation?

Pulmonary embolism (PE) is a common disease with an annual incidence rate ranging from 39–115 per 100,000 inhabitants. It is one of the leading causes of cardiovascular mortality in the USA and Europe. While the clinical presentation and severity may vary, it is a life-threatening condition in its most severe form, defined as high-risk or massive PE. Therapeutic options in high-risk PE are limited. Current guidelines recommend the use of systemic thrombolytic therapy as first-line therapy (Level Ib). However, this treatment has important drawbacks including bleeding complications, limited efficacy in patients with recurrent PE or cardiac arrest, and formal contraindications. In this context, the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in the management of high-risk PE has increased worldwide in the last decade. Strategies, including VA-ECMO as a stand-alone therapy or as a bridge to alternative reperfusion therapies, are associated with acceptable outcomes, especially if implemented before cardiac arrest. Nonetheless, the level of evidence supporting ECMO and alternative reperfusion therapies is low. The optimal management of high-risk PE patients will remain controversial until the realization of a prospective randomized trial comparing those cited strategies to systemic thrombolysis.

Percutaneous mechanical thrombectomy and extracorporeal membranous oxygenation: A case series

BACKGROUND

Massive or high-risk pulmonary embolism (PE) is a potentially life-threatening diagnosis with significant morbidity and mortality if treatment is delayed. Extracorporeal membrane oxygenation (ECMO) and large bore thrombectomy (LBT) in isolation have been used to stabilize and treat patients with massive PE, however, literature describing the combination of both modalities is lacking. We present a case series involving 9 patients who underwent combined ECMO and LBT and their outcomes.

METHODS

This was a retrospective chart review of patients with confirmed PE, who underwent LBT and ECMO. We retrospectively captured clinical, therapeutic, and outcome data at the time of pulmonary embolism response team (PERT) activation and during the follow-up period for up to 90 days.

RESULTS

Nine patients who had PERT activation with confirmed PE diagnosis have undergone combined LBT and ECMO initiation since the advent of our PERT program. The median age was 57 (range 28-68) years. Six patients out of 9 (55%) had cardiac arrest before therapy. All patients exhibited right heart strain on computed tomography and echocardiogram. The median ECMO duration was 5 days (range 2.3-11.6 days), with mean hospitalization of 16.1 days (range 1.5-30.9). Mortality was 22% at 90-day follow-up period.

CONCLUSION

Patients with massive pulmonary embolism who suffer cardiac arrest have significant morbidity and mortality. ECMO in combination with LBT is a viable treatment option for patients with significant hemodynamic compromise.

Venoarterial Extracorporeal Membrane Oxygenation in High-Risk Pulmonary Embolism: A Case Series and Literature Review

Background

High-risk Pulmonary Embolism (PE) has an ominous prognosis and requires emergent reperfusion therapy, primarily systemic thrombolysis (ST). In deteriorating patients or with contraindications to ST, Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) may be life-saving, as supported by several retrospective studies. However, due to the heterogeneous clinical presentation (refractory shock, resuscitated cardiac arrest (CA) or refractory CA), the real impact of VA-ECMO in high-risk PE remains to be fully determined. In this study, we present our centre experience with VA-ECMO for high-risk PE.

Method

From 2008 to 2020, we analyzed all consecutive patients treated with VA-ECMO for high-risk PE in our tertiary 35-bed intensive care unit (ICU). Demographic variables, types of reperfusion therapies, indications for VA-ECMO (refractory shock or refractory CA requiring extra-corporeal cardiopulmonary resuscitation, ECPR), hemodynamic variables, initial arterial blood lactate and ICU complications were recorded. The primary outcome was ICU survival, and secondary outcome was hospital survival.

Results

Our cohort included 18 patients (9F/9M, median age 57 years old). VA-ECMO was indicated for refractory shock in 7 patients (2 primary and 5 following resuscitated CA) and for refractory CA in 11 patients. Eight patients received anticoagulation only, 9 received ST, and 4 underwent surgical embolectomy. ICU survival was 1/11 (9%) for ECPR vs 3/7 (42%) in patients with refractory shock (p = 0.03, log-rank test). Hospital survival was 0/11 (0%) for ECPR vs 3/7 for refractory shock (p = 0.01, log-rank test). Survivors and Non-survivors had comparable demographic and hemodynamic variables, pulmonary obstruction index, and amounts of administered vasoactive drugs. Pre-ECMO lactate was significantly higher in non-survivors. Massive bleeding was the most frequent complication in survivors and non-survivors, and was the direct cause of death in 3 patients, all treated with ST.

Conclusions

VA-ECMO for high-risk PE has very different outcomes depending on the clinical context. Furthermore, VA-ECMO was associated with significant bleeding complications, with more severe consequences following systemic thrombolysis. Future studies on VA-ECMO for high-risk PE should therefore take into account the distinct clinical presentations and should determine the best strategy for reperfusion in such circumstances.

Clinical experiences of high-risk pulmonary thromboembolism receiving extracorporeal membrane oxygenation in single institution

Background

The main cause of death in pulmonary embolism (PE) is right-heart failure due to acute pressure overload. In this sense, extracorporeal membrane oxygenation (ECMO) might be useful in maintaining hemodynamic stability and improving organ perfusion. Some previous studies have reported ECMO as a bridge to reperfusion therapy of PE. However, little is known about the patients that benefit from ECMO.

Methods

Patients who underwent ECMO due to pulmonary thromboembolism at a single university-affiliated hospital between January 2010 and December 2018 were retrospectively reviewed.

Results

During the study period, nine patients received ECMO in high-risk PE. The median age of the patients was 60 years (range, 22–76 years), and six (66.7%) were male. All nine patients had cardiac arrests, of which three occurred outside the hospital. All the patients received mechanical support with veno-arterial ECMO, and the median ECMO duration was 1.1 days (range, 0.2–14.0 days). ECMO with anticoagulation alone was performed in six (66.7%), and ECMO with reperfusion therapy was done in three (33.3%). The 30-day mortality rate was 77.8%. The median time taken from the first cardiac arrest to initiation of ECMO was 31 minutes (range, 30–32 minutes) in survivors (n=2) and 65 minutes (range, 33–482 minutes) in non-survivors (n=7).

Conclusion

High-risk PE with cardiac arrest has a high mortality rate despite aggressive management with ECMO and reperfusion therapy. Early decision to start ECMO and its rapid initiation might help save those with cardiac arrest in high-risk PE.

Anesthetic management for intraoperative acute pulmonary embolism during inferior vena cava tumor thrombus surgery: A case report

BACKGROUND

Acute pulmonary embolism (APE) is a rare and potentially life-threatening condition, even with early detection and prompt management. Intraoperative APE required specific ways for detecting since classic symptoms of APE in the awake patient could not be observed or self-reported by the patient under general anesthesia.

CASE SUMMARY

A 44-year-old man with a history of hepatic cell carcinoma was admitted for radical nephrectomy and tumor thrombectomy due to a newly found kidney tumor with inferior vena cava (IVC) tumor thrombus. APE that occurred during tumor thrombectomy with hypercapnia and desaturation. The capnography combined with the transesophageal echocardiography (TEE) provided a crucial differential diagnosis during the operation. The patient was continuously managed with aggressive intravenous fluid resuscitation and blood transfusion under continuous cardiac output monitoring to maintain hemodynamic stability. He completed the surgery under stable hemodynamics and was extubated after percutaneous mechanical thrombectomy by a certified cardiologist. There were no significant symptoms and signs or obvious discomfort in the patient’s self-report during visits to the general ward.

CONCLUSION

Under general anesthesia for IVC tumor thrombus surgery, a sudden decrease in end-tidal carbon dioxide is the initial indicator of APE, which occurs before hemodynamic changes. When intraoperative APE is suspected, TEE is useful in the diagnosis and monitoring before computer tomography pulmonary angiogram. Timely clinical impression and supportive treatment and intervention should be conducted to obtain a better prognosis.

Pulmonary Embolism Complicated With Cardiopulmonary Arrest Treated With Combination of Thrombolytics and Aspiration Thrombectomy

Systemic thrombolytic therapy is frequently used in the treatment of massive pulmonary embolism. We describe a case of pulseless electrical activity arrest, refractory obstructive shock in the setting of massive pulmonary embolism despite tissue plasminogen activator that was successfully treated with catheter-directed aspiration thrombectomy. (Level of Difficulty: Intermediate.)

Combined use of extracorporeal membrane oxygenation with interventional surgery for acute pancreatitis with pulmonary embolism: A case report

BACKGROUND

Acute pancreatitis (AP) is an acute inflammatory process of the pancreas characterized by self-digestion of pancreatic tissue, which can trigger a systemic inflammatory response. Venous thrombosis, resulting from a hypercoagulable state, is a vascular complication of AP. AP complicated by pulmonary embolism (PE) is very rare, and the combined use of extracorporeal membrane oxygenation (ECMO) with a vascular interventional procedure for AP complicated by PE is even rarer.

CASE SUMMARY

A 32-year-old man with a history of obesity developed rapidly worsening AP secondary to hypertriglyceridemia. During treatment, the patient developed chest tightness, shortness of breath, and cardiac arrest. Computed tomography (CT) scans of his upper abdomen were consistent with pancreatitis. PE was identified by chest CT angiography involving the right main pulmonary artery and multiple lobar pulmonary arteries. The patient’s D-dimer level was significantly elevated (> 20 mg/L). The patient received high-frequency oxygen inhalation, continuous renal replacement therapies, anti-infective therapy, inhibition of pancreatic secretion, emergent endotracheal intubation, and advanced cardiac life support with cardiopulmonary resuscitation. Following both ECMO and a vascular interventional procedure, the patient recovered and was discharged.

CONCLUSION

PE is a rare but potentially lethal complication of AP. The early diagnosis of PE is important because an accurate diagnosis and timely interventional procedures can reduce mortality. The combined use of ECMO with a vascular interventional procedure for AP complicated by PE can be considered a feasible treatment method. A collaborative effort between multiple teams is also vital.

Venoarterial Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism-Related Cardiac Arrest: A Systematic Review

OBJECTIVE

Management of patients experiencing massive pulmonary embolism-related cardiac arrest is controversial. Venoarterial extracorporeal membranous oxygenation has emerged as a potential therapeutic option for these patients. We performed a systematic review assessing survival and predictors of mortality in patients with massive PE-related cardiac arrest with venoarterial extracorporeal membranous oxygenation use.

DATA SOURCES

A literature search was started on February 16, 2020, and completed on March 16, 2020, using PubMed, Embase, Cochrane Central, Cinahl, and Web of Science.

STUDY SELECTION

We included all available literature that reported survival to discharge in patients managed with venoarterial extracorporeal membranous oxygenation for massive PE-related cardiac arrest.

DATA EXTRACTION

We extracted patient characteristics, treatment details, and outcomes.

DATA SYNTHESIS

About 301 patients were included in our systemic review from 77 selected articles (total screened, n = 1,115). About 183 out of 301 patients (61%) survived to discharge. Patients (n = 51) who received systemic thrombolysis prior to cannulation had similar survival compared with patients who did not (67% vs 61%, respectively; p = 0.48). There was no significant difference in risk of death if PE was the primary reason for admission or not (odds ratio, 1.62; p = 0.35) and if extracorporeal membranous oxygenation cannulation occurred in the emergency department versus other hospital locations (odds ratio, 2.52; p = 0.16). About 53 of 60 patients (88%) were neurologically intact at discharge or follow-up. Multivariate analysis demonstrated three-fold increase in the risk of death for patients greater than 65 years old (adjusted odds ratio, 3.08; p = 0.03) and six-fold increase if cannulation occurred during cardiopulmonary resuscitation (adjusted odds ratio, 5.67; p = 0.03).

CONCLUSIONS

Venoarterial extracorporeal membranous oxygenation has an emerging role in the management of massive PE-related cardiac arrest with 61% survival. Systemic thrombolysis preceding venoarterial extracorporeal membranous oxygenation did not confer a statistically significant increase in risk of death, yet age greater than 65 and cannulation during cardiopulmonary resuscitation were associated with a three- and six-fold risks of death, respectively.

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.

Institutional Experience With Venoarterial Extracorporeal Membrane Oxygenation for Massive Pulmonary Embolism: A Retrospective Case Series

OBJECTIVE

Despite advances in treatment, massive pulmonary embolism (PE) remains associated with significant morbidity and mortality. The role of venoarterial extracorporeal membrane oxygenation (VA ECMO) in the setting of massive PE is evolving and includes potential roles both in initial management and as a rescue strategy.

DESIGN

Single-center case series that reported demographics and outcomes for patients with massive PE who underwent VA ECMO.

SETTING

This investigation was performed at a quaternary referral center with several hospitals throughout the greater Atlanta, GA, area.

PARTICIPANTS

The study comprised adult patients (age ≥18 y) admitted to the authors' hospital system. Patients were identified using an internal registry of ECMO patients that contains basic demographic information (age, weight, treatment dates and times, ECMO configuration) and primary diagnosis.

INTERVENTIONS

No interventions were performed.

MEASUREMENTS AND MAIN RESULTS

Seventeen patients who met the inclusion criteria were identified, with 16 patients cannulated peripherally and one patient cannulated centrally for VA ECMO. Survival to hospital discharge was 80% for patients who underwent VA ECMO as an initial approach versus 42% for those in whom it was used as a rescue modality.

CONCLUSIONS

The results suggested that patients placed on VA ECMO earlier during their course of massive PE may have improved mortality. Additional investigation is needed to clarify the optimal sequence and timing of therapies surrounding the initiation of VA ECMO in patients with massive PE.

Efficacy and safety of extracorporeal membrane oxygenation for high-risk pulmonary embolism: A systematic review and meta-analysis

High-risk pulmonary embolism (PE) requires hemodynamic and respiratory support along with reperfusion strategies. Recently updated European guidelines assign a low class of recommendation to extracorporeal membrane oxygenation (ECMO) for high-risk PE. This systematic review assessed clinical outcomes after ECMO in high-risk PE. We searched electronic databases including PubMed, Embase and Web of Science from January 2000 to April 2020. Efficacy outcomes included in-hospital survival with good neurological outcome and survival at follow-up. Safety outcomes included lower limb ischemia and hemorrhagic and ischemic stroke. Where possible (absence of high heterogeneity), meta-analyses of outcomes were undertaken using a random-effects model. We included 16 uncontrolled case-series (533 participants). In-hospital survival with good neurological outcome ranged between 50% and 95% while overall survival at follow-up ranged from 35% to 95%, both with a major degree of heterogeneity (I² > 70%). The prevalence of lower limb ischemia was 8% (95% CI 3% to 15%). The prevalence of stroke (either hemorrhagic or ischemic) was 11% (95% CI 3% to 23%), with notable heterogeneity (I² = 63.35%). Based on currently available literature, it is not possible to draw definite conclusions on the usefulness of ECMO for high-risk PE. Prospective, multicenter, large-scale studies or nationwide registries are needed to best define the role of ECMO for high-risk PE. PROSPERO registration ID: CRD42019136282.

A successful surgical treatment of pulmonary thromboembolism after endovenous radiofrequency ablation with extracorporeal membrane oxygenation bridging

Pulmonary embolism after endovenous radiofrequency ablation is very rare, but a clinically severe complication. Herein, we report a case of pulmonary embolism after endovenous radiofrequency ablation. Early after radiofrequency ablation pulmonary embolism developed and extracorporeal membrane oxygenation implantation was performed. Under extracorporeal membrane oxygenation support, surgical pulmonary embolectomy was performed successfully using the same cannulas and the patient was discharged without any neurological sequelae. In conclusion, although rare after radiofrequency ablation, early recognition of pulmonary embolism and prompt treatment can be life-saving.