title: Effects of coagulase-negative staphylococci and fibrin on breast capsule formation in a rabbit model.
abstract: BACKGROUND
  The etiology and ideal clinical treatment of capsular contracture (CC) remain unresolved. Bacteria, especially coagulase-negative staphylococci, have been previously shown to accelerate the onset of CC. The role of fibrin in capsule formation has also been controversial.
  
  
  OBJECTIVE
  The authors investigate whether fibrin and coagulase-negative staphylococci (CoNS) modulate the histological, microbiological, and clinical outcomes of breast implant capsule formation in a rabbit model and evaluate contamination during the surgical procedure.
  
  
  METHODS
  Thirty-one New Zealand white female rabbits were each implanted with one tissue expander and two breast implants. The rabbits received (1) untreated implants and expanders (control; n = 10), (2) two implants sprayed with 2 mL of fibrin and one expander sprayed with 0.5 mL of fibrin (fibrin; n = 11), or (3) two implants inoculated with 100 µL of a CoNS suspension (10(8)CFU/mL-0.5 density on the McFarland scale) and one expander inoculated with a CoNS suspension of 2.5 × 10(7) CFU/mL (CoNS; n = 10). Pressure/volume curves and histological and microbiological evaluations were performed. Operating room air samples and contact skin samples were collected for microbiological evaluation. The rabbits were euthanized at four weeks.
  
  
  RESULTS
  In the fibrin group, significantly decreased intracapsular pressures, thinner capsules, loose/dense (<25%) connective tissue, and negative/mild angiogenesis were observed. In the CoNS group, increased capsular thicknesses and polymorph-type inflammatory cells were the most common findings. Similar bacteria in capsules, implants, and skin were cultured from all the study groups. One Baker grade IV contracture was observed in an implant infected with Micrococcus spp.
  
  
  CONCLUSIONS
  Fibrin was associated with reduced capsule formation in this preclinical animal model, which makes fibrin an attractive potential therapeutic agent in women undergoing breast augmentation procedures. Clinical strategies for preventing bacterial contamination during surgery are crucial, as low pathogenic agents may promote CC.
authors.affiliation: Hospital de Sao Joao, Servico de Cirurgia Plastica, Porto, Portugal. marisamarquesmd@gmail.com
authors.forename: Marisa
authors.initials: M
authors.lastname: Marques
authors.forename: Spencer A
authors.initials: SA
authors.lastname: Brown
authors.forename: Natália D S
authors.initials: ND
authors.lastname: Cordeiro
authors.forename: Pedro
authors.initials: P
authors.lastname: Rodrigues-Pereira
authors.forename: M Luís
authors.initials: ML
authors.lastname: Cobrado
authors.forename: Aliuska
authors.initials: A
authors.lastname: Morales-Helguera
authors.forename: Lara
authors.initials: L
authors.lastname: Queirós
authors.forename: André
authors.initials: A
authors.lastname: Luís
authors.forename: Rui
authors.initials: R
authors.lastname: Freitas
authors.forename: Acácio
authors.initials: A
authors.lastname: Gonçalves-Rodrigues
authors.forename: José
authors.initials: J
authors.lastname: Amarante
mesh_terms: D000818:Animals; D018427:Breast Implants / Q000009:adverse effects*; D004195:Disease Models, Animal; D005260:Female; D005337:Fibrin / Q000008:administration & dosage / Q000494:pharmacology*; D057910:Implant Capsular Contracture / Q000209:etiology* / Q000382:microbiology; D011817:Rabbits; D013203:Staphylococcal Infections / Q000150:complications* / Q000382:microbiology; D013210:Staphylococcus / Q000201:enzymology / Q000302:isolation & purification; D015625:Tissue Expansion Devices
chemical_list: D005337:Fibrin