Author + information
- Sanlin Robinson1,
- Seyedhamidreza Alaie2,
- Jordyn Auge2,
- Lohendran Baskaran1,
- James Min1,
- Simon Dunham1 and
- Bobak Mosadegh2
The left atrial appendage (LAA) is the source for more than 90% of thrombi in patients with non-rheumatic atrial fibrillation (AF). Closure of the LAA offers a non-pharmacological alternative to anticoagulation for the prevention of stroke in patients with AF. This procedure, however, often results in incomplete closures due to the high variability in LAA morphology amongst patients. Currently devices are made with a circular shape and from nitinol frames that don't accomodate the irregular shape of the LAA ostium. LAA occlusion would benefit from a highly conformable device with a patient-specific design, such that full occlusion could be achieved in vitrually any LAA morphology.
A CT image of a large animal model was segmented to produce a 3D rendering of the blood volume for the LAA. Based upon this segmented computer-aided drafting (CAD) model, 3D printed molds were used to fabricate an inflatable balloon, which was made from a highly extensible silicone rubber and a hemocompatible polycarbonate urethane. The patient-specific balloon was implanted through the distal tip of the LAA using a 18 Fr introducer and secured in place using suture. Efficacy of closure was evaluated by CT, transesophageal echocardiogram (TEE) and necropsy.
As proof of principle demonstrations, we show: i) how patient-specific occluders using this fabrication scheme are highly conformable using 3D printed models of various LAA morphologies, ii) patient-specific design occludes at lower strains and with a smoother interface to the atrial wall (i.e., lower risk of thrombus formation) than a spherical design in an in vitro flow loop, and iii) the full procedure (CT scan, image segmentation, device fabrication, and in vivo deployment) can be conducted in vivo using a large animal model.
Implantation of a patient-specific LAA occluder was able to fully occlude the LAA in a large animal model. This work provides the basis for a new class of cardiac occluders that are designed from patient images and fabricated from elastomeric materials.
STRUCTURAL: Left Atrial Appendage Exclusion