Mechanical Thrombectomy With the FlowTriever Device in Acute Pulmonary Embolism - a Retrospective Analysis

Outcomes of Mechanical Thrombectomy With the FlowTriever Device in Acute Pulmonary Embolism, Results of a Swedish Retrospective Analysis

International guidelines recommend intravenous thrombolysis (IVT) for high-risk pulmonary embolism (PE). In high-risk PE where IVT is contraindicated or has failed, surgical embolectomy or catheter-directed intervention (CDI) is recommended. CDI is also recommended as an alternative in patients with intermediate-risk PE with haemodynamic deterioration during anticoagulation treatment.

Although there is a lack of randomized studies comparing CDI to anticoagulation or systemic thrombolysis in PE, several studies and recent meta-analyses have shown that CDI is an effective treatment that is associated with fewer complications than IVT, especially bleeding.

Study Overview

• Status: Completed
• Conditions: Pulmonary Embolism
• Intervention / Treatment: Device: Mechanical thrombectomy; Drug: Intravenous thrombolysis

Detailed Description

The FlowTriever® retrieval/aspiration system is the first mechanical thrombectomy device to receive PE as an indication from the United States Food and Drug administration agency. It combines large-bore aspiration with expanding mesh disks designed to trap and subsequently retract the blood clots from the pulmonary arteries. While Inari Medical, the medical device company that produces the FlowTriever® system, has initiated and published a few prospective trials on FlowTriever® in PE, non-industry sponsored studies are small and mostly retrospective.

In 2021 FlowTriever® became the primary device for CDI in PE at Sahlgrenska University Hospital in Gothenburg, Sweden. Concurrently, several hospitals in Sweden have started using FlowTriever® in high-risk PE. As such, the method needs evaluation and validation on a local and national level.

This retrospective observational study aims to evaluate the outcomes of patients with acute PE treated with the FlowTriever® device in Sweden. A control group consisting of PE patients treated with IVT will be used for comparison.

• Study Type: Observational
• Enrollment (Actual): 132

Contacts and Locations

Study Locations

• Sweden
  • Gothenburg, Sweden
    • Sahlgrenska University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients with acute PE

Description

Inclusion Criteria:

• Age ≥18 years
• Acute PE verified by computed tomography (CT) or angiography
• PE treated with thrombolysis or FlowTriever® during the time period from January 1st of the year when FlowTriever was introduced at each respective participating center to the end of 2023.

Exclusion Criteria:

• None

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
FlowTriever; Acute PE patients treated with the FlowTriever device	Device: Mechanical thrombectomy; Aspirational mechanical thrombectomy; Other Names: FlowTriever
Intravenous Thrombolysis; Acute PE patients treated with intravenous thrombolysis	Drug: Intravenous thrombolysis; Intravenous thrombolysis with tissue-type plasminogen activator (tPA); Other Names: Alteplase

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite endpoint of survival and major bleeding	Composite endpoint of survival at 30 days and major bleeding within 7 days, after intervention.	up to 7 days and up to 30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Survival	Survival at 30 days.	up to 30 days
Right Ventricle/Left Ventricle (RV/LV) ratio	Change in RV/LV-ratio with the intervention.	from 48 hours before intervention up to 48 hours after intervention
Total Length of stay in hospital	Length of stay in hospital	From diagnosis of PE until discharge from hospital, up to 30 days
Major Bleeding	Major bleeding within 7 days after intervention.	up to 7 days
Total Length of stay in the ICU or IMCU	Length of stay in the ICU/IMCU	From administration until discharge from ICU/IMCU, up to 30 days

Collaborators and Investigators

• Sponsor: Kristina Svennerholm
• Collaborators: Karolinska University Hospital; Sunderby Hospital; University Hospital, Linkoeping; Danderyd Hospital; Stockholm South General Hospital
• Investigators: Principal Investigator: Kristina Svennerholm, MD, PhD, Sahlgrenska University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2023
• Primary Completion (Actual): January 31, 2025
• Study Completion (Actual): March 31, 2025

Study Registration Dates

• First Submitted: December 12, 2023
• First Submitted That Met QC Criteria: January 1, 2024
• First Posted (Actual): January 3, 2024

Study Record Updates

• Last Update Posted (Estimated): May 20, 2025
• Last Update Submitted That Met QC Criteria: May 16, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: FlowTriever; Catheter-Directed Intervention; Aspirational thrombectomy
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Respiratory Tract Diseases; Lung Diseases; Embolism and Thrombosis; Pulmonary Embolism; Embolism; Molecular Mechanisms of Pharmacological Action; Fibrin Modulating Agents; Fibrinolytic Agents; Tissue Plasminogen Activator
• Other Study ID Numbers: Flow-PE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes