HISTOLOGIC AND IMMUNOHISTOCHEMICAL FEATURES IN BIOPSY SITES IN WHICH BOVINE COLLAGEN MATRIX WAS USED FOR HEMOSTASIS

Background: Bovine collagen matrix (Helistat and Helatene), which is u sed primarily for hemostasis, decreases wound contracture in skin biop sy sites and promotes wound granulation. Objective: Our purpose was to evaluate excision specimens of previous biopsy sites to determine whe ther there are histologic differences between cases in which bovine co llagen matrix was used for hemostasis and those in which it was not us ed. Methods: Thirty-two diagnostic punch biopsies were done with hemos tasis obtained with bovine collagen matrix in 24 biopsies and by press ure alone in eight, The biopsy sites were reexcised at various time in tervals, and the histologic and immunohistochemical features were eval uated and compared. Results: In specimens in which collagen matrix was used, migration of stromal and epithelial cells along the bovine coll agen matrix was evident by 2 days and had progressed rapidly by 4 days . Around and within the matrix hyaluronic acid increased during the fi rst 8 to 10 days. Initially stromal cells stained with CD34 and reticu lum fibers were present at 8 to 10 days. At 12 to 15 days, factor XIII a(+) stromal cells were present within the matrix, and host collagen f ibers were present and well-oriented within the degenerating matrix. B iopsy specimens allowed to heal without the matrix showed a delayed an d an uneven increase in hyaluronic acid. Furthermore, the granulation tissue within the dermis showed no organization with a persistent acut e inflammatory infiltrate and increased muscle actin-positive stromal cells as scar formation proceeded. Conclusion: Bovine collagen product s appear to provide a matrix that promotes thrombosis, The collagen ma trix also promotes migration and attachment of stromal and epithelial cells, thereby organizing and accelerating wound healing.