title: Cuspal dehiscence at a post and along the stent cloth in a bovine pericardium heart valve implanted for seven years.
abstract: A failing mitral valve prosthesis made from bovine pericardium was explanted from a 50-year-old patient. Preoperative transthoracic-echocardiography had confirmed severe mitral regurgitation due to structural failure of this HP Bio bovine pericardium heart valve prosthesis. The explanted device was examined macroscopically, by scanning electron microscopy (SEM), by light microscopy, and by transmission electron microscopy (TEM). Samples of unassembled patches of bovine pericardium were used as a pre-implantation control to better understand the changes that occurred in the structure of the pericardium following the 7 years of implantation. Examination confirmed complete dehiscence of a cusp along a valve post and the stent: This detached cusp was observed floating in the bloodstream at echocardiography. The fibrous pannus overgrowth was well developed along the stent and extended to the bottom of the cusps both on the inflow and the outflow sides. The fibrous panni were found to be poorly adhesive to the pericardium cusps and had become stiff, thus impairing the opening and closure of the valve. The structure of the pericardium cusps was severely deteriorated compared to the control bovine pericardium tissue samples. The collagen bundles were frequently broken and more stretched in the explanted device, lacking the wavy histological pattern of normal collagen fibers. However, the tissues were devoid of any calcification. In conclusion, the failure mode of this valve was the dehiscence of a cusp from a valve post and along the stent cloth in the absence calcification.
authors: Department of Surgery and Radiology, Laval University, Quebec, Canada. robertguidoin@hotmail.com
authors: Robert
authors: R
authors: Guidoin
authors: Taniela Marli
authors: TM
authors: Bes
authors: Tomas Francisco
authors: TF
authors: Cianciulli
authors: Julianne
authors: J
authors: Klein
authors: Bin
authors: B
authors: Li
authors: Robert
authors: R
authors: Gauvin
authors: Randolph
authors: R
authors: Guzman
authors: Olivier
authors: O
authors: Rochette-Drouin
authors: Lucie
authors: L
authors: Germain
authors: Ze
authors: Z
authors: Zhang
mesh_terms: D000818:Animals; D001705:Bioprosthesis / Q000009:adverse effects*; D002417:Cattle; D020878:Device Removal; D019544:Equipment Failure Analysis; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D010496:Pericardium; D011475:Prosthesis Failure; D013529:Surgical Wound Dehiscence / Q000473:pathology*