Percutaneous Aspiration Thrombectomy in Treatment of Massive Pulmonary Embolism

Safety and efficacy of catheter-directed thrombectomy without thrombolysis in acute pulmonary embolism: A systematic review and meta-analysis

BACKGROUND

This meta-analysis aims to investigate the safety and efficacy of catheter-directed thrombectomy (CDT) without using adjunct thrombolysis as reperfusion therapy to manage intermediate and high-risk pulmonary embolism (PE).

METHODS

A literature search of Ovid MEDLINE, Embase, CiNAHL, Cochrane Library, and Web of Science was conducted from inception to January 2024. Eligible studies reported more than 10 patients treated for acute PE with catheter-directed thrombectomy only, who were over 18 years of age. Primary endpoints were major bleeding, in-hospital mortality, and hemodynamic changes.

RESULTS

Eighteen studies (n = 803) were included for quantitative analysis. The pooled estimate of incidences of in-hospital mortality and major bleeding was 1.8 % (95 % CI 0.009, 0.027) and 2.1 % (95 % CI 0.011, 0.031) respectively. A pooled estimate reported a post-procedural increase in oxygen saturation and systolic blood pressure by 8.96 % (95 % CI: 3.54, 14.38) and 15.02 mmHg (95 % CI 6.35, 23.69) respectively. Post-procedural mean pulmonary artery pressure, right ventricle/left ventricle (RV/LV) ratio, and Miller score were reduced by 10.30 mmHg (95 % CI -14.94, -5.66), 0.29 (95 % CI -0.50, -0.08) and 8.09 (95 % CI -10.70, -5.47) respectively.

CONCLUSION

CDT without adjunctive thrombolysis may lead to improvements in hemodynamic outcomes and exhibits favorable safety profiles. This meta-analysis provides a rationale for lowering the threshold for considering this technique, and ongoing randomized trials will further advance the field to determine optimal managment strategies for intermediate and high-risk acute PE.

A meta-analysis of outcomes of aspiration thrombectomy for high and intermediate-risk pulmonary embolism

BACKGROUND

Aspiration thrombectomy has gained popularity in patients with massive and sub-massive pulmonary embolism (PE) and having contraindications to thrombolysis.

METHODS

A meta-analysis was conducted including studies on aspiration thrombectomy in patients with high-risk and intermediate-risk PE. The pooled odds ratio for efficacy parameters, including change in heart rate, blood pressure and right ventricle/left ventricle (RV/LV) ratio, and safety parameters including major bleeding and stroke, was calculated using a random effects model.

RESULTS

The meta-analysis of 24 selected studies revealed that intermediate and high-risk pulmonary embolism (PE) patients demonstrated significant improvements: modified Miller score odds ratio of 10.60, mean pulmonary artery pressure reduction by 0.04 mm Hg, and an overall all-cause mortality odds ratio of 0.10. Considerable heterogeneity was observed in various outcomes.

CONCLUSION

Aspiration thrombectomy has success rates in both high-risk and intermediate-risk PE, however, procedural risks, including bleeding, must be anticipated.

Percutaneous thrombectomy in patients with intermediate- and high-risk pulmonary embolism and contraindications to thrombolytics: a systematic review and meta-analysis

Catheter-directed interventions have slowly been gaining ground in the treatment of pulmonary embolism (PE), especially in patients with increased risk of bleeding. The goal of this study is to summarize the evidence for the efficacy and safety of percutaneous thrombectomy (PT) in patients with contraindications to systemic and local thrombolysis. We performed a systematic review and meta-analysis using MEDLINE, Cochrane, Scopus and the Web of Science databases for studies from inception to March 2022. We included patients with intermediate- and high-risk PE with contraindications to thrombolysis; patients who received systematic or local thrombolysis were excluded. Primary endpoint was in-hospital and 30-day mortality, with secondary outcomes based on hemodynamic and radiographic changes. Major bleeding events were assessed as a safety endpoint. Seventeen studies enrolled 455 patients, with a mean age of 58.6 years and encompassing 50.4% females. In-hospital and 30-day mortality rates were 4% (95% CI 3-6%) and 5% (95% CI 3-9%) for all-comers, respectively. We found a post-procedural reduction in systolic and mean pulmonary arterial pressures by 15.4 mmHg (95% CI 7-23.7) and 10.3 mmHg (95% CI 3.1-17.5) respectively. The RV/LV ratio and Miller Index were reduced by 0.42 (95% CI 0.38-46) and 7.8 (95% CI 5.2-10.5). Major bleeding events occurred in 4% (95% CI 3-6%). This is the first meta-analysis to report pooled outcomes on PT in intermediate- and high-risk PE patients without the use of systemic or local thrombolytics. The overall mortality rate is comparable to other contemporary treatments, and is an important modality particularly in those with contraindications for adjunctive thrombolytic therapy. Further studies are needed to understand the interplay of anticoagulation with PT and catheter-directed thrombolysis.

Submassive Pulmonary Embolism in the Setting of Intracerebral Hemorrhage: A Case of Suction Thrombectomy

Pulmonary embolism (PE) in the setting of intracerebral hemorrhage (ICH) is an unfortunate, challenging, and highly morbid clinical problem. Interventional strategies have lower associated bleeding risks than the standby for PE treatment: systemic anticoagulation. Despite this benefit, there are few examples in the literature of its utilization in the management of PE in the setting of ICH. This present case provides an example of the successful utilization of suction thrombectomy to manage PE in the setting of ICH. An 80-year-old female presented to an outside hospital with complaints of dizziness, headache, nausea, and vomiting of abrupt onset one hour before arrival. Computed tomography (CT) of the head with CT Angiography (CTA) of the head and neck was performed and demonstrated hemorrhage in all ventricles; most prominently within the left lateral ventricle. Magnetic Resonance Imaging (MRI) of the brain suggested that the cause of her hemorrhage was reperfusion injury after a small acute infarction in the left internal capsule in the setting of anticoagulant use. Ten days after her diagnosis of ICH, a submassive PE was diagnosed with a class IV pulmonary embolism severity index (PESI). An interdisciplinary evaluation was conducted between hospitalist medicine, neurology, neurosurgery, and interventional radiology. A successful suction thrombectomy was performed on hospital day 11. No new neurologic deficits were appreciated post-procedure. The patient's heart rate remained elevated but improved. Blood pressure remained controlled. The patient was weaned off oxygen to room air. Neurosurgery assessed the patient to be of acceptable risk for discharge with the further deferment of anticoagulation until repeat CT head six weeks after discharge. The patient was discharged on hospital day 14. Treating PE in the setting of ICH is without clear guidelines. The appropriate treatment modality is reliant upon the clinical judgment and the individual details of each case. In this case, a high PESI with imaging demonstrating a stable hematoma without evidence of new blood resulted in the decision to use a suction thrombectomy. More research is needed to develop consistent evidence-based guidelines for this clinical challenge.

Mechanical aspiration thrombectomy for the treatment of pulmonary embolism: A systematic review and meta-analysis

INTRODUCTION

There are no randomized trials studying the outcomes of mechanical aspiration thrombectomy (MAT) for management of pulmonary embolism (PE).

METHODS

We performed a systematic review and meta-analysis of existing literature to evaluate the safety and efficacy of MAT in the setting of PE. Inclusion criteria were as follows: studies reporting more than five patients, study involved MAT, and reported clinical outcomes and pulmonary artery pressures. Studies were excluded if they failed to separate thrombectomy data from catheter-directed thrombolysis data. Databases searched include PubMed, EMBASE, Web of Science until April, 2021.

RESULTS

Fourteen case series were identified, consisting of 516 total patients (mean age 58.4 ± 13.6 years). Three studies had only high-risk PE, two studies had only intermediate-risk PE, and the remaining nine studies had a combination of both high-risk and intermediate-risk PE. Six studies used the Inari FlowTriever device, five studies used the Indigo Aspiration system, and the remaining three studies used the Rotarex or Aspirex suction thrombectomy system. Four total studies employed thrombolytics in a patient-specific manner, with seven receiving local lysis and 17 receiving systemic lysis, and 40 receiving both. A random-effects meta-analyses of proportions of in-hospital mortality, major bleeding, technical success, and clinical success were calculated, which yielded estimate pooled percentages [95% CI] of 3.6% [0.7%, 7.9%], 0.5% [0.0%, 1.8%], 97.1% [94.8%, 98.4%], and 90.7% [85.5%, 94.3%].

CONCLUSION

There is significant heterogeneity in clinical, physiologic, and angiographic data in the currently available data on MAT. RCTs with consistent parameters and outcomes measures are still needed.

Percutaneous treatment options for acute pulmonary embolism: a clinical consensus statement by the ESC Working Group on Pulmonary Circulation and Right Ventricular Function and the European Association of Percutaneous Cardiovascular Interventions

There is a growing clinical and scientific interest in catheter-directed therapy (CDT) of acute pulmonary embolism (PE). Currently, CDT should be considered for patients with high-risk PE, in whom thrombolysis is contraindicated or has failed. Also, CDT is a treatment option for initially stable patients in whom anticoagulant treatment fails, i.e., those who experience haemodynamic deterioration despite adequately dosed anticoagulation. However, the definition of treatment failure (primary reperfusion therapy or anticoagulation alone) remains an important area of uncertainty. Moreover, several techniques for CDT are available without evidence supporting one over the other, and variation in practice with regard to periprocedural anticoagulation is considerable. The aim of this position paper is to describe the currently available CDT approaches in PE patients and to standardise patient selection, the timing and technique of the procedure itself as well as anticoagulation regimens during CDT. We discuss several clinical scenarios of the clinical evaluation of the "efficacy" of thrombolysis and anticoagulation, including treatment failure with haemodynamic deterioration and treatment failure based on a lack of improvement. This clinical consensus statement serves as a practical guide for CDT, complementary to the formal guidelines.

VA-ECMO and thrombus aspiration in a pulmonary embolism patient with cardiac arrest and contraindications to thrombolytic therapy

Summary: A 57-year-old male patient with a history of proximal deep vein thrombosis on vitamin K antagonist therapy, suffered a recent hypertensive intracranial hemorrhage without significant neurological deficit. Three weeks later he presented with bilateral central pulmonary embolism. He had witnessed cardiac arrest and was put on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Endovascular thrombectomy with an Aspirex device led to a significant improvement of hemodynamics. VA-ECMO was terminated after one day, an IVC filter was inserted, and he was discharged from ICU after 15 days. In conclusion, VA-ECMO and endovascular therapy are rescue strategies in patients with contraindications for thrombolysis.

Progress in interventional radiology treatment of pulmonary embolism: A brief review

Pulmonary embolism represents a common life-threatening condition. Prompt identification and treatment of this pathological condition are mandatory. In cases of massive pulmonary embolism and hemodynamic instability or right heart failure, interventional radiology treatment for pulmonary embolism is emerging as an alternative to medical treatment (systemic thrombolysis) and surgical treatment. Interventional radiology techniques include percutaneous endovascular catheter directed therapies as selective thrombolysis and thrombus aspiration, which can prove useful in cases of failure or infeasibility of medical and surgical approaches.

COVID-19 infection complicated with acute pulmonary embolism treated with percutaneous pulmonary artery thrombectomy: a case report

Background

Coronavirus disease 2019 (COVID-19) disease is a highly prothrombotic state. Deep vein thrombosis (DVT) and pulmonary embolism (PE) are observed with increased incidence in patients infected with the severe acute respiratory syndrome coronavirus 2 virus.

Case summary

A 57-year-old male patient with a recent COVID-19 infection complained of leg swelling shortly after his COVID ward discharge. A few days later he was hospitalized with acute massive PE and DVT of his left leg was diagnosed. In another facility, as the first line of treatment, the PE was managed with catheter-directed therapy (CDT) using thrombus defragmentation via 5F (French) Pigtail catheter and supraselective application of 40 mg alteplase. Following the procedure, in addition, 50 mg alteplase was also applied as a 1 hour systemic infusion. Despite the haemodynamic stabilization of the patient, he remained persistently symptomatic and tachycardic. Three days later—in our institution, a second computed tomography pulmoangiography revealed massive thrombotic masses mainly in the left pulmonary artery. Successful percutaneous thrombus aspiration was conducted. The procedure was uneventful with an immediate drop of systolic pulmonary artery pressure from 68 to 47 mmHg and relief of the patient’s symptoms.

Discussion

In the era of the COVID-19 pandemic, physicians have to remain vigilant of its potential thrombotic complications, the most commonly observed being DVT and PE. We demonstrated the efficacy of percutaneous thrombus aspiration in a patient with acute COVID-19-associated PE, after initial CDT with thrombus defragmentation and high-dose tissue plasminogen activator was implemented with a suboptimal result.

Pulmonary Embolism and Pregnancy-Challenges in Diagnostic and Therapeutic Decisions in High-Risk Patients

Diagnosis of acute PE in pregnant women with haemodynamic instability is following the general integrated risk-adapted diagnostic algorithm and starts with bedside echocardiography to assess RV function. If RV dysfunction is identified, a prompt and immediate reperfusion without further imaging should be initiated. Although pregnancy is listed as a relative contraindication of systemic thrombolysis, in pregnant women with acute PE and haemodynamic instability thrombolysis must be considered. In those cases, other treatment strategies as surgical embolectomy or catheter-directed low-dose thromboylysis or percutaneous thrombectomy should be taken into consideration as well. A multidisciplinary team with experience of PE management in pregnancy should be consulted to reach consensus on the best treatment approach.

Comparison of Aspiration Catheters with Modified Standard Catheters for Treatment of Large Pulmonary Embolism Using an In-vitro Patho-Physiological Model

PURPOSE

The presented in-vitro study provides a comparison of various catheters for mechanical treatment of large-burden pulmonary embolism (PE) under standardized conditions, using a new test rig. Dedicated aspiration catheters (JETi®, Penumbra Indigo®, Aspirex®) were compared with standard catheters (Pigtail, Multi-Purpose, Balloon Catheter) applied for embolus fragmentation.

MATERIALS AND METHODS

Emboli prepared from porcine blood were washed into the test rig which consists of anatomical models of the pulmonary artery (PA) and of the right heart in combination with a pulsatile drive system. For all catheters, the duration of the recanalization procedure and the weight percentage (wt%) of the remaining, removed and washed-down clot fractions were evaluated. For aspiration catheters, the aspirated volume was measured.

RESULTS

All catheters achieved full or partial recanalization. The aspiration catheters showed a significantly (p < 0.05) lower procedure time (3:15 min ± 4:26 min) than the standard fragmentation catheters (7:19 min ± 4:40 min). The amount of thrombus removed by aspiration was significantly (p < 0.001) higher than that by fragmentation, averaging 86.1 wt% ± 15.6 wt% and 31.7 wt% ± 3.8 wt%, respectively. Nonetheless, most of the residue was fragmented into pieces of ≥ 1 mm and washed down. Only in 2 of 36 tests, a residual thrombus of 11.9 wt% ± 5.1 wt% remained in the central PA.

CONCLUSION

Comparison under standardized in-vitro patho-physiological conditions showed that embolus fragmentation with standard catheters is clearly inferior to aspiration with dedicated catheters in the treatment of large-burden PE, but can still achieve considerable success.

LEVEL OF EVIDENCE

No level of evidence, experimental study.

Catheter-directed therapy in pulmonary embolism

Acute pulmonary embolism (PE) is a life-threatening condition with high mortality rates and potential long-term sequelae. Systemic thrombolysis has been virtually the only therapeutic option available for patients with hemodynamic instability over decades. Recently, interventional therapy of PE has gained increasing interest. Multiple devices were developed; these include devices for local thrombolysis, thrombus fragmentation, thrombus aspiration, and combined approaches. However, the available evidence is limited to mostly small, nonrandomized studies. In these studies, safety and efficacy data from patients with intermediate or high-risk PE are promising. However, due to the lack of adequately powered randomized trials, interventional treatment of intermediate or high-risk PE cannot be recommended as standard-of-care. The decision on whether and how to perform a catheter-based intervention should therefore be left to the discretion of the local team, depending on the patients' clinical status, bleeding risk, local expertise, and available devices. The implementation of local multidisciplinary PE response teams is recommended by international guidelines to provide the best possible treatment.

Contemporary Catheter-Based Treatment Options for Management of Acute Pulmonary Embolism

Introduction

Acute pulmonary embolism (PE) remains an important cause of cardiovascular mortality and morbidity in the USA and worldwide. Catheter-based therapies are emerging as a new armamentarium for improving outcomes in these patients.

Purpose of review

The purpose of this review is to familiarize the clinicians with (1) various types of catheter-based modalities available for patients with acute PE, (2) advantages, disadvantages, and appropriate patient selection for the use of these devices, and (3) evidence base and the relevance of such therapies in the COVID-19 pandemic.

Recent findings

There are four main types of catheter-based therapies in acute PE: (1) standard catheter-directed thrombolysis (CDT), (2) ultrasound-assisted CDT, (3) pharmacomechanical CDT, and (4) mechanical thrombectomy without thrombolysis. Ultrasound-assisted thrombolysis is the most widely studied modality in this group; however, evidence base for other catheter-based technologies is rapidly emerging.

Summary

Current use of catheter-based therapies is most suitable for patients with intermediate and high-risk acute PE. The adoption of a multidisciplinary approach like the pulmonary embolism response team (PERT) is desirable for appropriate patient selection and possibly/potentially improving patient outcomes. We discuss the current status of these therapies.

Endovascular therapies for pulmonary embolism

Purpose

The aim of this article is to define the place of new endovascular methods for the management of pulmonary embolisms (PE), on the basis of a multidisciplinary consensus.

Method and results

Briefly, from the recent literature, for high-risk PE presenting with shock or cardiac arrest, systemic thrombolysis or embolectomy is recommended, while for lowrisk PE, anticoagulation alone is proposed. Normo-tense patients with PE but with biological or imaging signs of right heart dysfunction constitute a group known as “at intermediate risk” for which the therapeutic strategy remains controversial. In fact, some patients may require more aggressive treatment in addition to the anticoagulant treatment, because approximately 10% will decompensate hemodynamically with a high risk of mortality. Systemic thrombolysis may be an option, but with hemorrhagic risks, particularly intra cranial. Various hybrid pharmacomechanical approaches are proposed to maintain the benefits of thrombolysis while reducing its risks, but the overall clinical experience of these different techniques remains limited. Patients with high intermediate and high risk pulmonary embolism should be managed by a multidisciplinary team combining the skills of cardiologists, resuscitators, pneumologists, interventional radiologists and cardiac surgeons. Such a team can determine which intervention – thrombolysis alone or assisted, percutaneous mechanical fragmentation of the thrombus or surgical embolectomy – is best suited to a particular patient.

Conclusions

This consensus document define the place of endovascular thrombectomy based on an appropriate risk stratification of PE.

Successful aspiration thrombectomy in a patient with submassive, intermediate-risk pulmonary embolism following COVID-19 pneumonia

A 64-year-old female patient presented with severe dyspnea shortly after apparent recovery from COVID-19 disease. Chest computed tomography revealed central pulmonary embolism and ultrasonography showed a deep vein thrombosis of her right leg. The patient was tachycardiac with evidence of right ventricular strain on echocardiography. An interdisciplinary decision for interventional therapy was made.

Angiographic aspiration thrombectomy resulted in a significant reduction of thrombus material and improved flow in the pulmonary arteries and immediate marked clinical improvement and subsequent normalization of functional echocardiographic parameters.

This case adds to the emerging evidence for severe thromboembolic complications following COVID-19 and suggests aspiration thrombectomy can be considered in pulmonary embolism of intermediate risk.

Treatment of the acute severe pulmonary embolism using endovascular methods

Purpose

To present a single-centre experience with endovascular treatment of patients with severe symptoms secondary to acute pulmonary embolism (PE).

Material and methods

Twenty-five patients were treated due to contraindications or deficient effects of systemic thrombolytic therapy. The patients were treated with a combination of fragmentation and aspiration, only aspiration, or only fragmentation, and with catheter-directed thrombolytic therapy.

Results

The saturation was improved following treatment in all patients, except in one where the procedure could not be completed. There were no immediate or late procedure-related complications.

Conclusions

Endovascular treatment of severe PE is a safe and efficient option in patients with failing effect or contraindication to systemic thrombolysis.

Percutaneous suction thrombectomy of large tumor thrombus causing massive pulmonary embolism

We describe a patient who underwent a renal cell carcinoma resection with inferior vena cava thrombectomy complicated by tumor embolization. This resulted in massive pulmonary embolism requiring venous-arterial extracorporeal membrane oxygenation. The patient was ineligible for systemic or catheter-directed thrombolysis because of the recent surgical resection and postoperative hemorrhage. Hence, the patient underwent percutaneous suction thrombectomy with successful removal of the tumor thrombus and significant clinical improvement. This report represents a unique case of suction thrombectomy for the removal of tumor embolus from the pulmonary circulation and highlights the ability of suction thrombectomy in the management of massive pulmonary embolism.

Interventional Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is a serious and prevalent cause of vascular disease. Nevertheless, optimal treatment for many phenotypes of PE remains uncertain. Treating PE requires appropriate risk stratification as a first step. For the highest-risk PE, presenting as shock or arrest, emergent systemic thrombolysis or embolectomy is reasonable, while for low-risk PE, anticoagulation alone is often chosen. Normotensive patients with PE but with indicia of right heart dysfunction (by biomarkers or imaging) constitute an intermediate-risk group for whom there is controversy on therapeutic strategy. Some intermediate-risk patients with PE may require urgent stabilization, and ≈10% will decompensate hemodynamically and suffer high mortality, though identifying these specific patients remains challenging. Systemic thrombolysis is a consideration, but its risks of major and intracranial hemorrhages rival overall harms from intermediate PE. Multiple hybrid pharmacomechanical approaches have been devised to capture the benefits of thrombolysis while reducing its risks, but there is limited aggregate clinical experience with such novel interventional strategies. One method to counteract uncertainty and generate a consensus multidisciplinary prognostic and therapeutic plan is through a Pulmonary Embolism Response Team, which combines expertise from interventional cardiology, interventional radiology, cardiac surgery, cardiac imaging, and critical care. Such a team can help determine which intervention-catheter-directed fibrinolysis, ultrasound-assisted thrombolysis, percutaneous mechanical thrombus fragmentation, or percutaneous or surgical embolectomy-is best suited to a particular patient. This article reviews these various modalities and the background for each.