The effect of pressure and shear on autologous fat grafting.
Plast Reconstr Surg
; 131(5): 1125-1136, 2013 May.
Article
em En
| MEDLINE
| ID: mdl-23385989
ABSTRACT
BACKGROUND:
Fat grafting has become routine in plastic surgery because of low donor-site morbidity, a low complication rate, and fast recovery time. The optimal technique, however, has yet to be defined. Two critical variables are pressure and shear, both defined as force divided by area. In this study, the authors examined the effect of pressure and shear on human fat grafts in a nude mouse model.METHODS:
For negative pressure, tumescent liposuction was performed on fresh panniculectomy specimens. Suction pressure was either -15 inHg or -25 inHg. Lipoaspirate was centrifuged at 1200 g and injected into the flanks of nude mice. For positive pressure, positive pressure was applied to lipoaspirate up to 6 atm for up to 3 minutes and then injected into nude mice. For shear stress, lipoaspirate was centrifuged at 1200 g for 3 minutes and then injected with a fast flow rate (3 to 5 cc/second) or slow flow rate (0.5 to 1 cc/second). After 4 weeks, the fat grafts were analyzed for weight and histology.RESULTS:
For negative pressure, there were no differences in weight or histology with high versus low suction pressures. For positive pressure, application of positive pressures up to 6 atm for up to 3 minutes did not create a significant difference in graft weight or histology at 4 weeks. For shear stress, in vivo, a slow injection pressure yielded a 38 percent increase in weight (p < 0.001) compared with fast injection. Histology was similarly affected.CONCLUSIONS:
Higher aspiration pressures up to -0.83 atm did not affect fat graft viability in vivo. Positive pressure up to 6 atm also did not affect fat graft viability. The degree of shear stress, which is a function of flow rate, did significantly affect fat graft viability. Fat grafts injected slowly with low shear stress significantly outperformed fat injected with high shear stress. These data suggest that shear stress is a more important variable regarding fat graft viability than pressure.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pressão
/
Cirurgia Plástica
/
Lipectomia
/
Tecido Adiposo
/
Sobrevivência de Enxerto
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Plast Reconstr Surg
Ano de publicação:
2013
Tipo de documento:
Article