The ALSA plasma gel filler from ALSA S-1 machine showed better duration than those from the traditional
methods. In respect of durability, we injected the ALSA plasma gel filler to the rabbits to see pattern of
alteration and the histologic changes in process of time. Twenty-four rabbits were injected with the ALSA
plasma gel filler and the hyaluronic acid filler in both sides of its back. The authors assumed the injection site
an ellipsoid and evaluated the relative change in volume by measuring the major axis, minor axis, and height
after the 1st, 2nd, 4th, 8th and 16th week after the injection. A histologic section was taken on weeks 1st,
2nd, 4th, and 16th week. Four weeks after the injection, there was a significant volume decrease in the ALSA
plasma gel filler compare to the hyaluronic acid filler. On 16th week, only 2% volume left in the ALSA plasma
gel filler group compare to that in the hyaluronic acid filler group, 34%. In histology, both groups showed
neither inflammatory change nor foreign body reaction. In this study, we observed an insufficient duration of
the ALSA plasma gel filler in comparison with the hyaluronic acid filler.