A novel animal model for studying silicone gel-related capsular contracture.
BACKGROUND
Capsular contracture remains one of the major problems following prosthetic implantation of the breast, especially in postmastectomy breast reconstruction patients receiving radiation therapy. Advances in this area have been hampered by the absence of an acceptable animal model. This study evaluates a new murine model with which to facilitate research into the cellular and molecular pathways underlying capsular contracture and provides a surrogate for evaluating potential therapies.


METHODS
On day 0, mice were implanted with silicone gel implants. Postoperatively, animals were imaged using live-scan micro-computed tomography. Animals in the irradiation group then received a 10-Gy directed radiation dose from a slit-beam cesium source. On days 21, 28, 35, and 42, both irradiated and nonirradiated animals were imaged again and histologic evaluation was performed.


RESULTS
Nonirradiated implants demonstrated little change in contour from day 0 through day 42 on micro-computed tomography, whereas irradiated implants demonstrated consistent shape deformation and irregularities in contour at these time points. Histologic evaluation showed that irradiated specimens developed thicker capsules and more disorganized capsules than nonirradiated specimens at each time point.


CONCLUSIONS
In this article, the authors introduce a novel animal model with which to study capsular contracture. This model is the first of its kind to use radiation to induce, and live-scan micro-computed tomography to evaluate, capsular contracture. Radiation was shown to cause reproducible changes that can be consistently evaluated with micro-computed tomography and histology. Future studies with this model will study the cellular and molecular mechanisms underlying capsular contracture using knockout and transgenic mouse strains.
Rochester, N.Y. From the Division of Plastic and Reconstructive Surgery, Department of General Surgery, the Center for Musculoskeletal Research, Department of Orthopedics, and the Departments of Radiation Oncology and Biomedical Engineering, University of Rochester Medical Center.
Evan B
EB
Katzel
Peter F
PF
Koltz
Ryan
R
Tierney
Jacqueline P
JP
Williams
Hani A
HA
Awad
Regis J
RJ
O'Keefe
Howard N
HN
Langstein
D000818:Animals; D018427:Breast Implants / Q000009:adverse effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D008852:Microradiography; D023421:Models, Animal; D011829:Radiation Dosage; D020034:Silicone Gels; D014057:Tomography, X-Ray Computed
D020034:Silicone Gels