Preliminary experience with porcine intestinal submucosa (CorMatrix) for valve reconstruction in congenital heart disease: histologic evaluation of explanted valves.
OBJECTIVE
We compared the histologic findings in explanted CorMatrix (9 patients) and autologous pericardium (9 patients) used for valvuloplasty of the aortic (7 patients) and/or mitral (11 patients) valve in patients with congenital heart defects.


METHODS
We used standard tissue stains and immunohistochemistry to identify the inflammatory cell type.


RESULTS
CorMatrix was associated with an intense inflammatory response in the surrounding native tissue, extending into CorMatrix in 8 of 9 cases, continuing to the longest follow-up point (9 months). The typical response included macrophages and giant cells in contact with the material, surrounded by lymphocytes, macrophages, plasma cells, and eosinophils. The thickness of the residual CorMatrix material was 280 to 300 μm, similar to the nominal thickness at implantation and unrelated to the implantation duration. Only at the longest follow-up interval was any significant resorption of CorMatrix material evident. A neointima had formed on the surface of CorMatrix, increasing in thickness with the period in situ. Mild cellular infiltration of CorMatrix was noted in all cases; however, in no case, did it appear that CorMatrix was being remodeled into tissue resembling a 3-layered native valve. In contrast, a near absence of any inflammatory reaction was seen and no eosinophilia associated with autologous pericardium was present, irrespective of the duration in situ. Furthermore, we observed more tissue infiltration, remodeling, vascularization, and neointima formation with autologous pericardium.


CONCLUSIONS
Although CorMatrix used for valve repair induced an intense inflammatory response, little or no remodeling to form tissue resembling a 3-layered native valve was seen at ≤9 months after implantation.
Department of Cardiology, Boston Children's Hospital, Boston, Mass; Department of Pediatrics, Harvard Medical School, Boston, Mass.
Abbas Haider
AH
Zaidi
Department of Cardiac Surgery, Boston Children's Hospital, Boston, Mass; Department of Surgery, Harvard Medical School, Boston, Mass.
Meena
M
Nathan
Department of Cardiac Surgery, Boston Children's Hospital, Boston, Mass; Department of Surgery, Harvard Medical School, Boston, Mass.
Sitaram
S
Emani
Department of Cardiac Surgery, Boston Children's Hospital, Boston, Mass; Department of Surgery, Harvard Medical School, Boston, Mass.
Christopher
C
Baird
Department of Cardiac Surgery, Boston Children's Hospital, Boston, Mass; Department of Surgery, Harvard Medical School, Boston, Mass.
Pedro J
PJ
del Nido
Department of Cardiology, Boston Children's Hospital, Boston, Mass; Department of Pediatrics, Harvard Medical School, Boston, Mass.
Kimberlee
K
Gauvreau
Department of Pathology, Boston Children's Hospital, Boston, Mass; Department of Pathology, Harvard Medical School, Boston, Mass.
Marian
M
Harris
Department of Cardiology, Boston Children's Hospital, Boston, Mass; Department of Cardiac Surgery, Boston Children's Hospital, Boston, Mass; Department of Pathology, Boston Children's Hospital, Boston, Mass; Department of Pediatrics, Harvard Medical School, Boston, Mass. Electronic address: stephen.sanders@childrens.harvard.edu.
Stephen P
SP
Sanders
Department of Pathology, Boston Children's Hospital, Boston, Mass; Department of Pathology, Brigham and Women's Hospital, Boston, Mass; Department of Pathology, Harvard Medical School, Boston, Mass.
Robert F
RF
Padera
D000293:Adolescent; D000328:Adult; D000818:Animals; D001021:Aortic Valve / Q000473:pathology / Q000601:surgery*; D064592:Autografts; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005109:Extracellular Matrix / Q000473:pathology / Q000637:transplantation*; D005260:Female; D005549:Foreign-Body Reaction / Q000209:etiology / Q000473:pathology; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000601:surgery*; D064593:Heterografts; D006801:Humans; D007223:Infant; D007249:Inflammation / Q000209:etiology / Q000473:pathology; D007413:Intestinal Mucosa / Q000473:pathology / Q000637:transplantation*; D008297:Male; D008943:Mitral Valve / Q000473:pathology / Q000601:surgery*; D010496:Pericardium / Q000473:pathology / Q000637:transplantation*; D019651:Plastic Surgery Procedures / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D013552:Swine; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult