Ann. Thorac. Surg., 2015 vol. 99(4) pp. 1373-7 Tissue reaction...

Ann. Thorac. Surg., 2015 vol. 99(4) pp. 1373-7
Tissue reaction to porcine intestinal Submucosa (CorMatrix) implants in pediatric cardiac patients: a single-center experience
Rosario-Quinones, F; Magid, MS; Yau, J; Pawale, A; Nguyen, K
BACKGROUND: Decellularized porcine small intestine submucosa (CorMatrix, Atlanta, GA) patches have been used in the repair of congenital heart malformations. Tissue reaction to the material may create hemodynamic dysfunction and necessitate explantation. We reviewed our series of congenital cardiac patients who had a reoperation after the implantation of CorMatrix patches.
METHODS: Medical records of pediatric cardiac patient who received CorMatrix patches and those of patients who underwent reoperation were reviewed. Routine histologic sections of explanted CorMatrix specimens were examined.
RESULTS: Of 25 patients who had received CorMatrix patches during cardiac operations at our institution, 6 patients had undergone reoperations. All patients had hemodynamically significant lesions at the site of the CorMatrix implantation. Explanted specimens were associated with an intense inflammatory reaction consisting of numerous eosinophils, histiocytes, and plasma cells, with accompanying granulation tissue and fibrosis.
CONCLUSIONS: Reaction to implanted CorMatrix patches may cause hemodynamic dysfunction and produce an intense, predominantly eosinophilic inflammatory response with developing fibrosis. Although our report is limited to a small sample of congenital cardiac patients, one should take precautions in its use in pediatric cardiac patients, and long-term follow-up is warranted.
Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
Type: Journal article

Cardiovasc. Pathol., 2015
Histologic examination of decellularized porcine intestinal submucosa extracellular matrix (CorMatrix) in pediatric congenital heart surgery
Woo, JS; Fishbein, MC; Reemtsen, B
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 giant cell reaction and fibrosis of the surrounding native tissue. Degenerative changes of CorMatrix material are also seen in a majority of explanted specimens. No histologic differences were seen between patients with clinical evidence of graft failure versus patients requiring graft removal due to other factors. Additionally, no cases showed evidence of tissue integration or recellularization of patch material. Our overall clinical experience with CorMatrix demonstrates a favorable outcome for pediatric patients undergoing cardiac reconstructive surgery. However, there is no histologic evidence that CorMatrix acts as a scaffold for reconstitution of the native cardiovascular structures.
Copyright © 2015. Published by Elsevier Inc.