Hypothesis: Alloderm is resistant to the fibroblastic response typically observed with foreign body implantation.

Introduction: Clinical observations show decreased scarring and capsule formation with implanted Alloderm.

Methods: 20 female patients who underwent post mastectomy breast reconstruction with tissue expanders and Alloderm were evaluated for clinical and histologic evidence of capsule fibroplasia. The tissue expanders were explanted and the implant pocket was examined for capsular bands. The pockets were divided into medial, superior, lateral and inferior quadrants. Photo documentation of contracture bands and Alloderm - capsule interface were obtained. The number of bands /quadrant was compared. Two groups of biopsy specimens were obtained for histologic analysis. Group 1 – biopsy of capsular bands ; Group 2 biopsy of the Alloderm – capsule interface. Histologic measures included nucleated cells and myofibroblasts / cross sectional area expressed as cells /mm.

Results/Conclusion: The number of contracture bands was significantly greater in superior, medial, and lateral quadrants as compared to the inferior quadrants (p < .001). The concentration of myofibroblasts and nucleated cells is decreased in Alloderm specimen of capsule as compared to capsular band specimen. Alloderm is resistant to the fibroblastic foreign body response. Capsular contracture may be decreased with the use of Alloderm.