title: Impact of Watchman and Amplatzer devices on left atrial appendage adjacent structures and healing response in a canine model.
abstract: OBJECTIVE
  This study was designed for conducting a comparative evaluation of the healing response after Watchman (WM) (Boston Scientific, Plymouth, Minnesota) and Amplatzer Cardiac Plug (ACP) (St. Jude Medical, Minneapolis, Minnesota) in a canine left atrial appendage (LAA) model.
  
  
  BACKGROUND
  There is no direct comparison of the WM and ACP device in pre-clinical or clinical settings.
  
  
  METHODS
  The LAA from canine (n = 6) and human (n = 19) hearts were compared to determine the feasibility of the canine model and its relevance to clinical applications. Subsequently, implantation of WM and ACP in the canine LAA was performed (n = 3 per device) to evaluate the device conformation to the LA anatomy as well as the healing response at 28 days.
  
  
  RESULTS
  The LAA is a variable tubular structure in both canine and human hearts. Gross examination showed that the WM was properly seated inside the LAA ostium, in comparison to the ACP where the disk was outside of the LAA orifice and extended to the edge of the left superior pulmonary vein and mitral valve. At 28 days, complete neo-endocardial coverage of the WM was observed; however, the ACP showed an incomplete covering on the disk surface especially at the lower edge and end-screw hub regions.
  
  
  CONCLUSIONS
  There are differences in conformation of LAA surrounding structures with variable healing response between WM and ACP after LAA closure in the canine model. WM does not obstruct or impact the LAA adjacent structures, resulting in a favorable surface recovery. In comparison, the disk of ACP could potentially jeopardize LAA neighboring structures and leads to delayed healing.
authors: Heart Institute, Cedars Sinai Medical Center, Los Angeles, California.
authors: Saibal
authors: S
authors: Kar
authors: Boston Scientific Corporation, Natick, Massachusetts.
authors: Dongming
authors: D
authors: Hou
authors: CVPath, Gaithersburg, Maryland.
authors: Russell
authors: R
authors: Jones
authors: Boston Scientific Corporation, Natick, Massachusetts.
authors: Dennis
authors: D
authors: Werner
authors: Boston Scientific Corporation, Natick, Massachusetts.
authors: Lynne
authors: L
authors: Swanson
authors: Boston Scientific Corporation, Natick, Massachusetts.
authors: Brian
authors: B
authors: Tischler
authors: Boston Scientific Corporation, Natick, Massachusetts.
authors: Kenneth
authors: K
authors: Stein
authors: Boston Scientific Corporation, Natick, Massachusetts.
authors: Barbara
authors: B
authors: Huibregtse
authors: CVPath, Gaithersburg, Maryland.
authors: Elena
authors: E
authors: Ladich
authors: CVPath, Gaithersburg, Maryland.
authors: Robert
authors: R
authors: Kutys
authors: CVPath, Gaithersburg, Maryland. Electronic address: rvirmani@cvpath.org.
authors: Renu
authors: R
authors: Virmani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000473:pathology; D006328:Cardiac Catheterization / Q000009:adverse effects / Q000295:instrumentation*; D017023:Coronary Angiography; D004285:Dogs; D018618:Echocardiography, Doppler, Color; D017548:Echocardiography, Transesophageal; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D023421:Models, Animal; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D055989:Septal Occluder Device; D013997:Time Factors; D014945:Wound Healing; D055815:Young Adult
keywords: Amplatzer Cardiac Plug; Watchman; left atrial appendage; percutaneous occluson device