title: A new biodegradable patch for closure of atrial septal defect. An experimental study.
abstract: Biodegradable patches made from polyhydroxybutyrate (PHB) were used to close experimentally induced atrial septal defect in six calves. The implants were evaluated after 3-12 months macroscopically and by light and scanning electron microscopy with regard to regeneration of tissue and degradation of the polymer. At implant degradation, complete endothelial layers facing the right and left atrium were observed, with a subendothelial layer of collagen and some smooth-muscle cells. The patch was degraded by polynucleated macrophages, and 12 months postoperatively no polymer material was identifiable at ordinary light microscopy, but in polarized light small particles of polymer with persisting foreign body reaction were still seen. Scanning electron microscopy revealed a complete layer of surface cells with morphologic signs of endothelium. There was no shunt or sign of infection. Biodegradable PHB patches implanted in atrial septal defects in this experimental model thus prompted formation of regenerated tissue that macroscopically and microscopically resembled native atrial septal wall. The total degradation time exceeded 12 months.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, University Hospital, Uppsala, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Malm
authors.forename: S
authors.initials: S
authors.lastname: Bowald
authors.forename: S
authors.initials: S
authors.lastname: Karacagil
authors.forename: A
authors.initials: A
authors.lastname: Bylock
authors.forename: C
authors.initials: C
authors.lastname: Busch
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D002417:Cattle; D006344:Heart Septal Defects, Atrial / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006346:Heart Septum / Q000033:anatomy & histology / Q000502:physiology / Q000648:ultrastructure; D006885:Hydroxybutyrates; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019736:Prostheses and Implants; D012038:Regeneration
chemical_list: D006885:Hydroxybutyrates