Vacuum-Assisted Catheter-Based Inversion of the Left Atrial Appendage: First- in-Animal Feasibility in a Swine Model

Background The left atrial appendage (LAA) is the primary source of thrombus formation in atrial fibrillation. Mechanical exclusion of the LAA using occlusion devices can prevent embolic stroke but requires permanent implants and may lead to device-related complications. Mechanical inversion of the LAA represents a potential non-implant alternative, but whether this can be achieved using a fully percutaneous, catheter-based approach is unknown. Objectives To evaluate the feasibility of catheter-based, vacuum-assisted LAA inversion using a transseptal aspiration system in a large-animal model. Methods A 59-kg domestic swine underwent transseptal access via the right femoral vein under fluoroscopy, transesophageal echocardiography (TEE), and intracardiac echocardiography (ICE). A 22-F aspiration catheter was advanced into the left atrium and positioned at the LAA apex. Negative pressure was generated manually with a 60-mL syringe attached to the aspiration port, and sequential suction–traction maneuvers were performed to induce LAA inversion. Procedural feasibility, hemodynamic stability, imaging changes, and gross pathology were assessed. Results Transseptal access, catheter positioning, and suction delivery were feasible. Complete LAA inversion into the left atrium was achieved after four suction attempts and confirmed by TEE. A mild pericardial effusion developed, likely related to contact between the stiff catheter tip and the thin appendage wall, but it was not hemodynamically significant. Necropsy demonstrated a discolored ring consistent with localized tissue injury and a small perforation at the LAA apex. Conclusions This first-in-animal feasibility study demonstrates that vacuum-assisted catheter-based inversion of the LAA is technically achievable using current-generation aspiration systems. Although preliminary safety limitations were identified, the findings support further refinement of dedicated, atraumatic aspiration catheters and justify chronic survival and design-optimization studies. A catheter-based, non-implant LAA inversion strategy may represent a future alternative for stroke prevention in patients with atrial fibrillation.