What is cell-assisted lipotransfer (CAL)?
Cell-assisted lipotransfer is a fat grafting protocol in which the stromal vascular fraction isolated from one portion of the harvested fat is added to the remaining, unprocessed fat before injection, with the stated aim of improving graft retention. It is not a culture-expanded stem cell therapy: the stromal vascular fraction is a mixed cell population rather than a purified stem cell product.
Answer
The lipoaspirate is divided; one portion is processed, enzymatically or mechanically, to isolate the stromal vascular fraction, which is then combined with the untreated portion before grafting[1]. What is added is a heterogeneous fraction containing adipose-derived stem cells alongside endothelial and blood cells, not an isolated stem cell preparation[2].
Isolation method, cell dose and the ratio of processed to untreated fat differ between centres, so procedures sharing this name are not necessarily the same procedure[1]. Cell processing is also regulated differently across jurisdictions, which is worth establishing before comparing offers[2].
Sources
- academicCell-Assisted Lipotransfer: A Systematic Review of its Efficacy — Aesthetic Plastic Surgery (2024) · accessed Sep 20, 2026 · Evidence page
- academicSafety profile of autologous adipose-derived stromal vascular fraction in clinical use: an exhaustive literature review — Stem Cell Research & Therapy (2026) · accessed Sep 20, 2026 · Evidence page