The use of acellular dermal matrix to prevent capsule formation around implants in a primate model.
BACKGROUND
Implant-based breast reconstruction is a popular option after mastectomy, but capsular contracture may detract from long-term outcomes. The authors have observed that breast implants covered with acellular dermal matrix (AlloDerm) are less likely to develop a capsule in the area where the implant is in direct contact with the acellular matrix. The authors tested this observation experimentally by comparing capsular formation around implants in the presence and absence of AlloDerm in primates.


METHODS
Eight smooth-surfaced tissue expanders were implanted into eight African green monkeys. In four experimental animals, a sheet of AlloDerm was draped over the tissue expander so as to cover the implant. Four control animals underwent placement of a tissue expander only. Animals were killed after 10 weeks and specimens underwent histologic and immunohistochemical analysis.


RESULTS
Hematoxylin and eosin staining of control specimens revealed the presence of a distinct layer of wavy, parallel arrays of collagen fibers consistent with capsule formation. Immunostaining identified abundant myofibroblasts, a profibrotic cell found in breast capsules. In the AlloDerm-covered specimens, no capsule layer was visible, and specimens stained weakly for myofibroblasts. The difference in myofibroblast staining intensity was statistically significant.


CONCLUSIONS
The use of AlloDerm to partially enclose implants effectively prevented formation of a capsule in areas where AlloDerm contacted the implant at 10 weeks. Long-term studies will be required to determine whether this is a durable result that can be reproduced in humans.
Stump
Amy
A
Baltimore, Md.; and Branchburg, N.J. From the Division of Plastic Surgery, University of Maryland Medical Center, and LifeCell Corporation.
Holton
Luther H
LH
Connor
Jerome
J
Harper
John R
JR
Slezak
Sheri
S
Silverman
Ronald P
RP
D000818:Animals; D018427:Breast Implants / Q000009:adverse effects*; D002522:Chlorocebus aethiops; D003094:Collagen; D011183:Postoperative Complications / Q000517:prevention & control; D017768:Skin, Artificial
C440568:Alloderm; D003094:Collagen