Acute pulmonary embolism: endovascular therapy

The many roles of urgent catheter interventions: from myocardial infarction to acute stroke and pulmonary embolism

INTRODUCTION

Cardiovascular diseases (CVDs) are the leading cause of cardiovascular mortality and a major contributor to disability worldwide. The prevalence of CVDs is continuously increasing, and from 1990 to 2019, it has doubled. Global cardiovascular mortality has increased from 12.1 million in 1990 to 18.6 million cases in 2019. The development of therapeutic options for these diseases is at the forefront of interest concerning the extensive socio-economic consequences. Modern endovascular transcatheter therapeutic options contribute to the reduction of cardiovascular morbidity and mortality.

AREAS COVERED

The article concentrates on the triad of the most common causes of acute cardiovascular mortality and morbidity - myocardial infarction, ischemic stroke, and pulmonary embolism. Current evidence-based indications, specific interventional techniques, and remaining unsolved issues are reviewed and compared. A personal perspective on the possible implications for the future is provided.

EXPERT OPINION

Primary angioplasty for ST-segment elevation myocardial infarction is a well-established therapeutic option with proven mortality benefits. We suppose that catheter-based interventions for acute stroke will spread quickly from centers of excellence to routine clinical practice. We believe that ongoing research will provide a basis for the expansion of interventional treatment of pulmonary embolism soon.

Current trends in image-guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

FlowTriever System for mechanical thromboembolectomy

The systemic or catheter-directed infusion of thrombolytics benefits patients with massive and probably submassive pulmonary embolism. However, the risk of bleeding may offset benefits in a substantial number of patients. Percutaneous mechanical thromboembolectomy is an alternative to thrombolysis in those patients with contraindications to the lytic therapy, also potentially a way to avoid systemic or catheter-directed infusion of the thrombolytic all together. The Inari FlowTriever System (Inari Medical Inc, CA, USA) is the first US FDA-cleared large-bore aspiration thrombectomy device with pulmonary embolism thrombectomy indication. This article is a review of the FlowTriever System, its clinical use, current supportive literates and future research directions.

Analysis of pulmonary embolism patients treated with EkoSonic™ endovascular system

Background

The aim of this study was to evaluate the efficacy and the safety of the EkoSonic™ endovascular system applications in patients hospitalized with the diagnosis of intermediate-high-risk pulmonary embolism.

Methods

Between January 2018 and March 2019, a total of 15 patients (7 males, 8 females; mean age 64.7±17.8 years, range, 35 to 90 years) who underwent ultrasound-accelerated thrombolysis using the EkoSonic™ endovascular system for pulmonary embolism were retrospectively analyzed. The diagnosis of pulmonary embolism was made based on pulmonary computed tomography angiography. All patients were evaluated by echocardiography for right ventricular dysfunction and serum levels of troponin I and brain natriuretic peptide were recorded.

Results

The mean arterial blood gas oxygen saturation values of the patients before and after the procedure were 86.3±3.5% and 94.2±2.5%, respectively, indicating a statistically significant difference (p=0.001). The mean partial oxygen pressure values before and after the procedure were 73.3±7.7 mmHg and 90.7±5.0 mmHg, respectively, indicating a statistically significant difference (p=0.001). There was also a statistically significant difference in the mean right ventricular diameter before and after the procedure (p=0.001). The mean pre- and post-procedural pulmonary arterial pressure was 44±7.1 mmHg and 36.3±4.5 mmHg, respectively, indicating a statistically significant difference (p=0.001). Of the patients, 93.7% were free from post-procedural complications.

Conclusion

The EkoSonic™ endovascular system improved right ventricular dysfunction, decreased pulmonary arterial pressure, and improved oxygenation in patients with intermediate-high-risk pulmonary embolism without increasing the risk for bleeding.

Right Atrial and Massive Pulmonary Artery Mechanical Thrombectomy Under Echocardiography Guidance Using the FlowTriever System

Introduction

Management of clot in transit in patients with pulmonary embolism, who are candidates for percutaneous intervention, can be challenging. This is a case report of simultaneous right atrial mechanical thrombectomy under echocardiography guidance and pulmonary artery embolectomy under fluoroscopy guidance, using the recently introduced FlowTriever system (Inari Medical Inc., Irvine, CA, USA).

Report

An 88 year old female, resuscitated from cardiopulmonary arrest near the end of a total right hip arthroplasty, presented for management of suspected massive pulmonary embolism. Her right atrial thrombus was removed under transthoracic echocardiography guidance, and her pulmonary arterial thrombus was subsequently successfully treated under fluoroscopy.

Discussion

The FlowTriever system can be safely and effectively used under real time transthoracic echocardiography guidance to retrieve clot in transit from the cardiac chambers, in addition to its standard application for the pulmonary artery under fluoroscopy guidance.

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FlowTriever system is recently cleared by FDA for mechanical thrombectomy of pulmonary embolism.

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This is the first case of mechanical thrombectomy in the right atrium or ventricle under echocardiography guidance.

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The mechanical thrombectomy in the right atrium/ventricle was safe and resolved the patient's symptoms.

Ultrasound-assisted versus conventional catheter-directed thrombolysis for acute pulmonary embolism: A multicenter comparison of patient-centered outcomes

Both catheter-directed thrombolysis (CDT) and ultrasound-assisted thrombolysis (USAT) are novel treatment modalities for patients presenting with acute pulmonary embolism (PE). The objective of this study was to compare clinical and quality-of-life (QOL) outcomes for patients undergoing either treatment modality. We retrospectively studied 70 consecutive patients treated with either CDT or USAT over 3 years at a multicenter health system. The primary clinical efficacy endpoint was right ventricular systolic pressure (RVSP) reduction post-procedurally. Safety endpoints were mortality and bleeding incidents based on Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries (GUSTO) criteria. Long-term QOL was assessed using the 36-Item Short-Form Health Survey (SF-36) via phone interview. Thirty-seven patients (53%) in our study underwent USAT and 33 (47%) patients were treated with conventional CDT. Among all patients studied, 96% had echocardiographic evidence for right ventricular strain on admission. Mean RVSP decreased by 18 ± 13 mmHg in the USAT group post-procedurally as compared to 14 ± 16 mmHg in the CDT group, without significant difference between groups ( p = 0.31). Rates of moderate and severe bleeding were largely identical between USAT and CDT groups (USAT: 3%; CDT: 0%; p = 0.09). There was no death in either group during admission. At long-term follow-up, there was no significant difference in QOL between both treatment modalities in all eight functional domains of SF-36. Our retrospective study demonstrated using USAT over conventional CDT for acute submassive or massive PE did not yield additional clinical, safety, or long-term QOL benefit.