Preclinical evaluation of a new left atrial appendage occluder (Lifetech LAmbre™ device) in a canine model

The study evaluated the feasibility and safety of a novel left atrial appendage (LAA) occluder (LAmbre™, Lifetech Scientific Corp., China) in canines.

Transcatheter LAA occlusion is comparable to warfarin in preventing atrial fibrillation-related strokes.

Twenty-two healthy dogs (28 ± 3 kg) received LAmbre implants. The device is delivered by an 8-10 French sheath and has full recapture and repositioning capabilities. All dogs received 1-week antibiotics and 4-week aspirin (80 mg daily) after implants and they were sacrificed in groups at Days 1-3 (n = 5), 1- (n = 7), 3- (n = 4) and 6-months (n = 6) for pathological examinations. Transthoracic echocardiography (TTE) was performed immediately after implant, at Day 3 and before sacrifice.

The LAmbre was successfully implanted, retrieved, repositioned and re-implanted in all dogs. The mean implant size was 24 ± 3 mm and the device chosen was 36 ± 7% larger than the measured landing zone diameter. Improper device selection (only 21% oversizing) resulted in dislodgement and death of 1 dog on Day 3. Post-implant angiography and TTE showed well-positioned device without pericardial effusion or impingement on surrounding structures. Late complications included device-related thrombus at 1 month (n = 1) and clinically insignificant pericardial effusion at Day 3 (n = 1). Complete healing on the atrial facing surface with optimal LAA obliteration was confirmed by gross and microscopic examinations in dogs that have been followed up ≥3 months (n = 10). No infarct was detected in major organs.

Our preliminary data suggested the LAmbre™ device is feasible with high success rate in canines. Further studies are needed to evaluate its safety and efficacy.