title: A novel design biodegradable stent for use in congenital heart disease: mid-term results in rabbit descending aorta.
abstract: OBJECTIVE
  This study evaluates the feasibility of delivery and deployment of low and medium molecular weight (LMW and MMW, respectively) double-opposing helical (DH) poly-l-lactic acid biodegradable stent (BDS) in rabbit descending aorta (DAO). Secondary objectives were to assess patency and inflammation of stented vessels at 9 months and to investigate safety following intentional embolization of stent fragments in DAO.
  
  
  BACKGROUND
  A BDS that will relieve aortic obstruction and disappears as the child grows older allowing for preservation of aortic wall elasticity and natural growth of aorta will be ideal to treat Coarctation (CoA). BDS have never been evaluated in the DAO.
  
  
  METHODS
  Seven New Zealand white rabbits underwent implantation of DH-LMW (n = 7), DH-MMW (n = 3), and metal stents (n = 7) in DAO. BDS fragments were intentionally embolized into DAO in two rabbits.
  
  
  RESULTS
  All stents were deployed via a 6-French sheath. Five BDS covered the origin of major DAO side branches. Angiography and intravascular ultrasound showed good stent apposition to the wall of DAO with minimal luminal loss at 9 months follow-up. All stents had minimal neointimal hyperplasia on histopathology. Adverse events included 1 death, 1 aortic aneurysm, and lower extremity ulceration due to self-mutilation in an embolization rabbit.
  
  
  CONCLUSIONS
  Pilot study confirms the feasibility of delivery and deployment of up to 6-millimeter diameter DH BDS in rabbit DAO. Stent integrity with DH design was maintained at 9 months with minimal vessel inflammation. Potential morbidity due to embolized BD fragments cannot be ruled out and needs further evaluation.
authors.affiliation: Departments of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Surendranath R
authors.initials: SR
authors.lastname: Veeram Reddy
authors.forename: Tré R
authors.initials: TR
authors.lastname: Welch
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: James A
authors.initials: JA
authors.lastname: Richardson
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Forbess
authors.forename: Matthew
authors.initials: M
authors.lastname: Riegel
authors.forename: Alan W
authors.initials: AW
authors.lastname: Nugent
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology; D001018:Aortic Diseases / Q000628:therapy*; D001027:Aortography; D001157:Arterial Occlusive Diseases / Q000175:diagnosis / Q000628:therapy*; D003251:Constriction, Pathologic; D004195:Disease Models, Animal; D004617:Embolism / Q000209:etiology; D057510:Endovascular Procedures / Q000295:instrumentation*; D005240:Feasibility Studies; D005260:Female; D005548:Foreign-Body Migration / Q000209:etiology; D006330:Heart Defects, Congenital / Q000628:therapy*; D019344:Lactic Acid / Q000737:chemistry; D008970:Molecular Weight; D010865:Pilot Projects; D011091:Polyesters; D011108:Polymers / Q000737:chemistry; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011817:Rabbits; D015607:Stents; D013997:Time Factors; D018084:Ultrasonography, Interventional
chemical_list: D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)
keywords: aortic stent; biodegradable stents; congenital heart disease; poly-l-lactic acid (PLLA)