A Novel-Design Poly-L-Lactic Acid Biodegradable Device for Closure of Atrial Septal Defect: Long-Term Results in Swine

Abstract

Objectives: The aim of this study is to evaluate the long-term effectiveness and safety of a self-expandable, double-disk biodegradable device made of poly-<smlcap>L</smlcap>-lactic acid (PLLA) for closure of atrial septal defects (ASDs) in swine. Methods: ASDs were created by transseptal needle puncture followed by balloon dilatation in 20 piglets. The experimental group comprised 18 animals, while the remaining 2 animals were used as controls. Effectiveness and safety were evaluated by rectal temperature, leukocyte count, chest radiography, electrocardiogram, transthoracic echocardiography (TTE), intracardiac echocardiography (ICE), and histologic studies. Animals were followed up at 1, 3, 6, and 12 months. Results: An ASD model was successfully created in 19 animals; 1 piglet died during the procedure. The ASD diameters that were created ranged from 5 to 6.4 mm. Devices were successfully implanted in 17 animals. No animal died during the follow-up studies. Rectal temperatures and electrocardiograms were normal at follow-up, while leukocyte counts transiently increased from 1 to 6 months. Radiography, TTE, ICE, and macroscopic studies demonstrated that PLLA occluders were positioned well, with no shifting, mural thrombus formation, or atrioventricular valve insufficiency. Histologic evaluations showed that PLLA devices were partially degraded in the follow-up study. Conclusions: ASD closure with the novel PLLA biodegradable device is safe and effective. Longer-term studies are needed to evaluate long-term biodegradability.