The composition and behavior of capsules around smooth and textured breast implants in pigs.
BACKGROUND
The surface of the implant is one of the many factors often associated with the occurrence of capsular contracture, the etiopathogeny of which remains unclear. The purpose of this study was to analyze the behavior of capsular contracture by means of applanation tonometry and histology using a midsized animal model.


METHODS
Silicone breast implants were implanted into 33 pigs and observed at 30, 60, 180, and 270 postoperative days.


RESULTS
Capsular contracture in smooth implants showed significantly greater pressure values of tonometry, and the smooth implant capsule was significantly thicker than the textured implant capsule. Both pressure and thickness of the capsules increased at each period. The collagenous layer did not show any difference considering the periods of time in which the total thickness was analyzed; on the other hand, the increase in total capsular thickness occurred by thickening of the noncollagenous layer in both smooth and textured implants. Taking into consideration both kinds of implants, histomorphometric analysis showed that thin fibers were replaced by thick fibers in later postoperatives periods (180 and 270 days).


CONCLUSIONS
The greater incidence of capsular contracture in smooth implants was correlated with the progressive increase in total capsule thickness, due to a higher concentration of collagenous fibers, when compared with textured implants (p = 0.011; mean difference, 6.61), and a higher concentration of thick fibers (p = 0.034; average, >5.51 percentage points per field of thick fibers than the textured implants in all periods). Pigs are good animal models for studying the healing process after breast augmentation with implants.
Minami
Eliza
E
São Paulo, Brazil From the Departments of Surgery and Pathology, Federal University of São Paulo, and Department of Pathology, University of São Paulo.
Koh
Ivan Hong Jun
IHJ
Ferreira
José Carlos Ronche
JCR
Waitzberg
Angela Flávia Logullo
AFL
Chifferi
Valcir
V
Rosewick
Tomás Fortoul
TF
Pereira
Max Domingues
MD
Saldiva
Paulo Hilário Nascimento
PHN
de Figueiredo
Luiz Francisco Poli
LFP
D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000009:adverse effects*; D019928:Breast Implantation / Q000009:adverse effects*; D018427:Breast Implants / Q000009:adverse effects*; D004195:Disease Models, Animal; D005355:Fibrosis / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008365:Manometry; D020034:Silicone Gels / Q000008:administration & dosage / Q000009:adverse effects*; D013552:Swine
D001672:Biocompatible Materials; D020034:Silicone Gels