Menlo Park – October 12, 2026 -- Endovascular Engineering, Inc. (E2) has received U.S. FDA 510(k) clearance for both the Hēlo Thrombectomy System and Hēlo Return, a blood return system the company describes as the first cleared for use with continuous vacuum aspiration.
FDA clears two devices for pulmonary embolism treatment
The Hēlo platform is built for treating pulmonary embolism (PE). The FDA's decision followed its review of clinical data from the ENGULF IDE study, which demonstrated safety and efficacy of the Hēlo Thrombectomy System. E2 says it is now accelerating plans to bring the platform to a broad range of physicians and patients.
ENGULF data show single-pass procedures and low blood loss
E2 says the platform consistently led to efficient single-pass procedures in ENGULF. It reports the highest clot reduction and the lowest estimated blood loss across all published PE thrombectomy IDE studies. ENGULF results cited are for patients treated with blood return (N=40). E2 notes that cross-study comparisons are descriptive only. They are limited by differences in study design, patient populations and endpoints, and are not derived from head-to-head trials.
Thrombectomy catheter pairs 15F profile with 24F clot funnel
The Hēlo Thrombectomy System has a 15F crossing profile and steerable navigation, allowing physician-controlled movement within the pulmonary vasculature. A 24F clot ingestion funnel on the distal end of the catheter pulls in clots. The clots are then remodeled through a dual-action approach combining continuous aspiration and mechanical clot disruption.
Hēlo Return targets near-zero blood loss under continuous vacuum
Hēlo Return is designed to collect and filter aspirated whole blood before returning it to the patient. It is used with the Hēlo Thrombectomy System. E2 reports near-zero blood loss was observed during ENGULF. Testing to evaluate blood quality under continuous vacuum conditions was conducted in accordance with FDA guidance. The data were presented at the Society of Interventional Radiology (SIR) Annual Scientific Meeting in April 2026.
Clinicians and management frame clearances as access expansion
Eric Secemsky, MD, Director of Vascular Intervention at Beth Israel Deaconess Medical Center in Boston, said the platform addresses practical procedural challenges and could meaningfully expand access to mechanical thrombectomy.
E2 CEO Dan Rose said physicians have asked for large-bore clot removal performance in a low-profile catheter, a single-pass procedure and integrated blood return. According to the release, PE remains a leading cause of cardiovascular death and disability, with growing demand for mechanical solutions that reduce procedural complexity and right heart strain.
The Hēlo Thrombectomy System is indicated for non-surgical removal of emboli and thrombi from pulmonary arteries and venous vasculature, and for use in the peripheral veins and in treating PE.