Histologic examination of decellularized porcine intestinal submucosa extracellular matrix (CorMatrix) in pediatric congenital heart surgery

• Published in: Cardiovascular pathology 2016-01, Vol.25 (1), p.12-17
• Main Authors: Woo, Jennifer S, Fishbein, Michael C, Reemtsen, Brian
• Format: Article
• Language: English
• Subjects: Adolescent; Calcinosis - etiology; Calcinosis - pathology; Cardiac Surgical Procedures - adverse effects; Child; Child, Preschool; Congenital heart disease; CorMatrix; Databases, Factual; Extracellular Matrix - pathology; Extracellular Matrix - transplantation; Female; Fibrosis; Foreign-Body Reaction - etiology; Foreign-Body Reaction - pathology; Heart Defects, Congenital - pathology; Heart Defects, Congenital - surgery; Heart Septum - pathology; Heart Septum - surgery; Heart Valves - pathology; Heart Valves - surgery; Heterografts; Humans; Infant; Inflammation - etiology; Inflammation - pathology; Intestinal Mucosa - pathology; Intestinal Mucosa - transplantation; Los Angeles; Male; Necrosis; Pathology; Small intestinal submucosa extracellular matrix; Treatment Outcome
• ISSN: 1054-8807; 1879-1336
• DOI: 10.1016/j.carpath.2015.08.007

Abstract Background CorMatrix is a decellularized porcine small intestinal submucosa extracellular matrix that has gained attention as a promising alternative to current materials used in cardiac repair. While animal models demonstrate integration of CorMatrix material with host tissue, the histologic characteristics of CorMatrix used in humans are less well-characterized. In this retrospective study, we report our experience with CorMatrix material used in pediatric congenital heart surgery and describe the histology of CorMatrix material and of surrounding native tissue in explanted specimens. Methods Records were reviewed of all pediatric patients implanted with CorMatrix from a single institution (2011–2014). Histologic examinations were performed on CorMatrix and other tissues removed. Explanted samples of CorMatrix and adherent tissues were evaluated for inflammation (acute and chronic), fibrosis, necrosis, degenerative changes, eosinophil response, foreign-body giant cell reaction, neovascularization, and calcification of tissues on a semiquantitative basis (0, none; 1, mild; 2, moderate; 3, marked). Presence of degeneration within CorMatrix and necrosis of surrounding tissue were noted. Results CorMatrix was utilized in 532 pediatric heart reconstruction procedures since 2011. Twelve explanted CorMatrix specimens from 11 pediatric patients including 4 valves (2 mitral and 2 aortic) and 8 outflow/septal/conduit patches were identified and evaluated. Six cases (5 patients) demonstrated clinical evidence of graft failure prior to surgery ( n = 6, 1%). Chronic inflammation was seen in adjacent native tissue in 11/12 cases and consisted predominantly of a mixed population of lymphocytes, macrophages, and plasma cells. Acute inflammation was seen in three cases (3/12). Fibrosis of the surrounding native tissue was seen in all CorMatrix specimens. Eosinophils were present in 6/12 cases. Calcification in surrounding tissue was present in 3/12 cases. Giant cell reaction in adjacent native tissue was seen in 8/12 cases. Neovascularization was seen in surrounding native tissue in 5/12 cases. Degeneration of CorMatrix material was seen in 9/12 cases. Necrosis of surrounding tissue was also identified in 5/12 cases. CorMatrix was not resorbed and no cases demonstrated any remodeling of CorMatrix material by integration of native mesenchymal cells or myocytes. Conclusion CorMatrix may be associated with a marked inflammatory response, including a foreign-body gi