Thrombectomy System, Blood Return System Get FDA Approval

Oct. 12, 2026 — Endovascular Engineering (E2) has announced that the U.S. Food and Drug Administration (FDA) has granted 510(k) clearance for both the Hēlo Thrombectomy System and Hēlo Return (Blood Return System).

Hēlo, which is a physician-inspired, purpose-built thrombectomy platform for treating pulmonary embolism, leverages a unique design that consistently led to efficient single-pass procedures in the Engulf IDE study. The platform showcased the highest reported clot reduction and the lowest estimated blood loss across all PE Thrombectomy IDE studies.¹ While Engulf provided important clinical validation of the platform’s capabilities, the FDA clearances represent a significant step forward as E2 brings its innovative platform to a broad range of physicians and patients. PE remains aleading cause of cardiovascular death and disability, and there is growing demand for mechanical solutions that support clot removal while reducing procedural complexity and right heart strain.

"The treatment of PE with mechanical thrombectomy is rapidly evolving as emerging data and new technologies continue to shape the field. These clearances mark an important milestone in that evolution," said Eric Secemsky, MD, Director of Vascular Intervention, Beth Israel Deaconess Medical Center in Boston. "The platform addresses real practical challenges we face in these procedures, and I believe it has the potential to meaningfully expand access to mechanical thrombectomy for a broad range of patients."

Hēlo Thrombectomy System and Blood Return System

The Hēlo Thrombectomy System is a lower profile platform designed to navigate small and act big. Its 15F crossing profile and steerable navigation enables physician-controlled movement within the pulmonary vasculature. A 24F clot ingestion funnel on the distal end of the catheter helps pull in clots that are then remodeled through a dual-action approach combining continuous aspiration and mechanical clot disruption.

Hēlo Return completes the platform by providing workflow-integrated blood return when used with the Hēlo Thrombectomy System, leading to near-zero blood loss as observed during the ENGULF trial. Supported by testing conducted in accordance with FDA guidance to evaluate blood quality under continuous vacuum conditions, Hēlo Return is the first blood return system cleared for use with continuous vacuum aspiration. Data from the testing was presented at the Society of Interventional Radiology (SIR) Annual Scientific Meeting in April 2026.

“This milestone is the culmination of years of focused innovation to create a unique and complete platform that addresses the procedural limitations physicians currently experience when treating PE,” said Dan Rose, CEO of E2. “Physicians have communicated their needs clearly: large-bore clot removal performance in a low-profile catheter, with a single pass procedure and integrated blood return capability. The Hēlo System offers all these features and more. With dual FDA clearances in hand, we are accelerating our plans to deliver this complete solution to a broad range of physicians and patients.”

The FDA's decision to grant 510(k) clearance follows its review of clinical data from the ENGULF IDE study, which demonstrated safety and efficacy of the Helo Thrombectomy System.

1. Reported across all published pulmonary embolism pivotal studies. ENGULF results shown for patients treated with blood return (N=40). Cross-study comparisons are descriptive only and limited by differences in study design, patient populations, and endpoints. Not derived from head-to-head trials. ENGULF data on file.