Pathologic findings in explanted clinical bioprosthetic valves fabricated from photooxidized bovine pericardium.
OBJECTIVE
The study aim was to assess tissue quality and host-biomaterial interactions in clinical bioprostheses fabricated from bovine pericardium preserved by dye-mediated photooxidation, but not glutaraldehyde-pretreated.


METHODS
Ten aortic valves explanted for regurgitation after 8-23 months' function from 10 patients aged 67-83 years were analyzed by gross and dissecting microscope examination, radiography and light microscopy.


RESULTS
Each valve had one to several commissural-basal tears (5 mm) to complete leaflet detachment (four valves). The pattern of tearing was consistent among valves and suggested that a mechanism of design-related proximal inflow surface cuspal abrasion against Dacron cloth was contributory. Mild cuspal sagging/stretching was noted in five valves, pannus overgrowth was mild, and there was no evidence of infection or macroscopic thrombus. Microscopically, tissue distant from tears in all valves had an essentially intact but acellular collagenous matrix, was devoid of residual connective tissue cells and host inflammatory cells, with mild fragmentation of the inflow collagen bundles, and showed no evidence of endothelialization. Despite radiographs uniformly negative for mineralization, focal intrinsic cuspal microcalcification was noted histologically in four valves.


CONCLUSIONS
Design-related and largely abrasion-induced tearing caused failures of this cohort of photooxidized pericardial valves. Nevertheless, this nonglutaraldehyde-preserved photofixed pericardial tissue from valves suffering design-related cuspal tears to two years postoperatively remained without significant degradation, inflammation, infection, thrombus, pannus or calcification.
Schoen
F J
FJ
Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001021:Aortic Valve / Q000473:pathology* / Q000601:surgery; D001022:Aortic Valve Insufficiency / Q000601:surgery; D001705:Bioprosthesis / Q000009:adverse effects*; D002114:Calcinosis / Q000209:etiology / Q000473:pathology*; D002417:Cattle; D004396:Coloring Agents; D005069:Evaluation Studies as Topic; D005260:Female; D005976:Glutaral; D006349:Heart Valve Diseases / Q000209:etiology / Q000473:pathology*; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008422:Materials Testing / Q000379:methods; D010496:Pericardium / Q000473:pathology*; D011093:Polyethylene Terephthalates / Q000009:adverse effects*; D011474:Prosthesis Design / Q000379:methods; D011475:Prosthesis Failure; D013499:Surface Properties; D013529:Surgical Wound Dehiscence / Q000209:etiology / Q000473:pathology; D014021:Tissue Preservation / Q000379:methods
D004396:Coloring Agents; D011093:Polyethylene Terephthalates; D005976:Glutaral