Cell-assisted lipotransfer (CAL), which means the enrichment of adipose tissue with
adipose-derived stromal cells (ASCs), is suggested to enhance the stability of fat
grafts. In former studies to evaluate the use of CAL for injection laryngoplasty no
evidence for advantage of CAL regarding the long-term volume stability of the fat
grafts was found. This might have been the result of an extensive processing of the
injected adipose tissue. Thus, in this study processing of the fat tissue was modified.
Small pieces of fat were enriched with cells, implanted and evaluated over 3 months
in a rabbit model.
ASCs were isolated from the adipose tissue of the neck of 12 New Zealand White Rabbits
and cultivated in vitro. After four weeks, adipose tissue was harvested and cut into
small pieces. 200 µl of these lipografts were implanted subcutaneously into the rabbits'
pinna and enriched with labelled ASCs. Lipografts without cells served as control.
After 1, 3 and 12 weeks the implants were harvested. Viability and volume of the implants
were determined and the tissue was analyzed using histological and immunhistochemical
techniques.
During 3 months after implantation there was a distinct reduction of the fat volume
in all groups, while cell-enriched fat implants were more stable than the controls.
The fat implants were viable over time course and showed an intact tissue structure
with viable adipocytes.
In this study, we found viable and stable implanted adipose tissue, which was processed
as small lipografts, over 3 months. Thus, small lipografts, enriched with ASCs may
be a suitable autologous injection material with improved long-term volume stability
for injection laryngoplasty.
