Design characteristics and analysis of a biodegradable polymeric heart plug device

• Main Author: Khoo, Yong Keong.
• Other Authors: Subramanian Venkatraman
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/15384
• Institution: Nanyang Technological University

Patent foramen ovale (PFO) is a congenital cardiac abnormality found in about one-fourth of the general population which is highly associated with many medical complications such as embolic ischemic stroke, migraine with aura, neurological decompression sickness. Different treatments have been recommended for patients with PFO such as anticoagulant therapy, surgical closure and percutaneous closure. In recent decades, percutaneous closure has been the preferred mode of treatment for complete closure of PFO. However, non-biodegradable materials in the body from these devices such as nitinol have caused long term complications such as thrombus formation, device arm fracture and nickel allergy. As such, fully biodegradable approach would be the next generation of PFO closure devices. In this project, two fully biodegradable designs are being analyzed and optimized. The Double Umbrella (DU) design adopting an ANSYS simulation approach have optimized the design to a 4x4 configuration with 30% BaSO4 PCL as the front umbrella and 30% BaSO4 Copolymer (PLA-PCL) as the back umbrella attached together by a 30% BaSO4 Copolymer (PLA-PCL) stem. The Chinese Lantern (CL) design which adopted a more practical approach of fabrication, design modification and in-vitro studies, has eventually developed into a design with 3 radio-opaque markers made of 40% BaSO4 Copolymer (PLA-PCL) welded between two 4% BaSO4 Copolymer (PLA-PCL) film that works on a straightening and collapsing mechanism. Both optimized designs are fabricated for in-vivo studies. Six swine were used and two died during the creation of the PFO/ASD model. The remaining four continued with the closure procedure with good radio-opacity of the device observed through angiography. All four recovered well after implantation of device. After 30 days of implantation, echocardiography and angiography images have shown no leakages, indicating complete sealing. In conclusion, both the fully biodegradable polymeric designs (DU and CL) are successful in the complete closure of PFO.