Assessment of degradability and endothelialization of modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluders over time in vivo

Figures

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  Fig. 1. The PLLA device and the delivery system. (A) Schematic drawing of the PLLA occluders; (B) Schematic drawing of the delivery system; (C) The PLLA occluder device; (D) The delivery system. PLLA: poly L-lactide

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  Fig. 2. Steps of PLLA filaments implanted in rabbits’ abdominal aorta. (A) Free proximal femoral artery was conducted; (B, C) The femoral artery was incised and PLLA wire was implanted from the femoral artery into the abdominal aorta; (D, E) Femoral artery ligation was performed; (F) The wound was sutured. PLLA: poly L-lactide

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  Fig. 3. Steps of pigs implanted with PLLA occluders. (A) Pigs were given tracheal intubation under general anesthesia; the red arrow indicated the atrial septum. (B) Atrial septal puncture; the red arrow indicated the Left atrium. (C, D) The balloon dilates the atrial septum; the red arrow indicated the atrial septum. (E) Left atrial angiography; the red arrow indicated the Left atrium. (F) Ultrasonic measurement of atrial septal defect; the red arrow indicated the ASD. PLLA: poly L-lactide. ASD: atrial septal defect

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  Fig. 4. Imaging examination of pigs implanted with PLLA occluders. (A) The PLLA occluder was released through the X-ray position of seven platinum-iridium markers; (B) X-ray after release of PLLA occluder; (C) Ultrasonic morphology and position after release of PLLA occluder. Red arrows indicated the PLLA ASD occluder. PLLA: poly L-lactide. ASD: atrial septal defect

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  Fig. 5. Detection of Mechanical property of PLLA filaments after endovascular implantation. (A) Quality retention; (B) Molecular weight retention; (C) Upper yield strength retention; (D) Tensile strength retention. PLLA: poly L-lactide

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  Fig. 6. Pathological observation of PLLA filaments at 6 months after endovascular implantation. (A) PLLA filament of NO.1021; (B) PLLA filament of NO.1023; (C) PLLA filament of NO.1627. PLLA: poly L-lactide

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  Fig. 7. Postoperative examinations of PLLA occluders by X-ray and transthoracic echocardiography (TTE). (A) 3 months after implantation. (B) 6 months after implantation. (C) 2 months after implantation. (D) 24 months after implantation. Green arrows indicated the PLLA ASD occluder. PLLA: poly L-lactide.ASD: atrial septal defect

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  Fig. 8. Macroscopic examination of PLLA ASD occluder at different time points after implantation. (A) 3 months after implantation. (B) 6 months after implantation. (C) 12 months after implantation. (D) 24 months after implantation. PLLA: poly L-lactide.ASD: atrial septal defect

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  Fig. 9. Histopathological observation of PLLA ASD occluders by HE staining and IHC at different follow-up points of 3 (A), 6 (B), 12 (C), 24 (D) months. Green arrows indicated the PLLA ASD occluder. Blue arrows indicated fibroblasts, collagen fibers, inflammatory cells or multinuclear giant cells. Red arrows indicated the endothelial cells in the new endocardium. Black arrows indicated the endothelial cells in new small vessels. PLLA: poly L-lactide. ASD: atrial septal defect. HE: haematoxylin-eosin. IHC: immunohistochemistry

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  Fig. 10. The center and edge parts of PLLA ASD occluders characterized by scanning electron microscopy (SEM) at the indicated time points of 3 (A), 6 (B), 12 (C), 24 months (D) after implantation. PLLA: poly L-lactide. ASD: atrial septal defect