Design and rationale of the eLym™ System for Decompensation of Excess Lymphatic Fluid via the Thoracic Duct in Acute Heart Failure (DELTA-HF)

Abstract

Aims: The interstitial space is the major compartment in which the excess fluid is located, forming peripheral congestion in acute decompensated heart failure (ADHF). The lymphatic system is responsible for the constant drainage of the compartment. In ADHF, the inefficiency of this system causes extravascular fluid accumulation, underscoring the crucial role of lymphatic system failure in ADHF's pathophysiology. The eLym™ System is a transcutaneous device designed to facilitate lymph drainage by creating a low-pressure zone in the thoracic duct area, theoretically allowing more efficient decompression of the lymphatic system.

Methods and results: The safety and feasibility of the eLym™ System for the Decongestion of Excess Lymphatic Fluid via the Thoracic Duct in Acute Decompensated Heart Failure: DELTA-HF Study is a prospective, multicentre, single-arm study designed to evaluate the safety and feasibility of the WhiteSwell eLym™ System in the treatment of fluid overload in ADHF. A maximum of 50 subjects may be enrolled and undergo the treatment. Inclusion criteria include the presence of congestion, a home diuretic dose ≥80 mg furosemide (or equivalent) and elevated natriuretic peptides. The key exclusion criteria include anatomical abnormalities and the inability to undergo systemic anticoagulation. The study endpoints include the safety (short- and long-term) and feasibility of the procedure. Several congestion indexes will be prospectively assessed. Descriptive statistics will summarize the study results. The study was registered in clinicaltrial.gov (NCT05747196).

Conclusions: The results of the DELTA-HF study will provide information about the safety and feasibility of the eLym™ System and will provide first-in-human clinical signals of its use in ADHF patients.

Keywords: acute heart failure; decongestion; lymphatic system.

Figure 1

The flow chart of study execution.

Figure 2

(A,B) The eLym™ System. In Figure 2, the eLym catheter is placed through the eLym sheath, and the manifolds are connected. Cables extend from the manifold and are attached to the console.

Figure 3

(A,B) Reduced pressure at the venous angle with the eLym™ System. In Figure 3, the eLym sheath is introduced into the left internal jugular vein. A pressure monitor above the flow restricting balloon measures pressure in the jugular vein zone (JZ). The eLym catheter is introduced through the sheath, with the pump and distal balloon placed in the innominate vein. A pressure monitor on the catheter measures the pressure in the thoracic duct zone (TD). The pump may be controlled by setting a specific speed or by setting a target pressure for the reduced pressure zone and an automated algorithm adjusts the speed as needed to maintain that target pressure.