OasisLMS

This review examines why autologous fat graft retention is so variable, focusing on both adipose tissue biology and technical factors. It outlines how aging adipose tissue shows reduced volume, vascularity, and preadipocyte/ASC proliferative capacity, along with increased fibrosis, which may compromise both skin regeneration and fat graft survival. The authors detail the central role of adipose-derived stem/stromal cells (ASCs) in modulating extracellular matrix remodeling, immune responses (notably shifting macrophages toward a pro-regenerative M2 phenotype), and angiogenesis through differentiation and a rich paracrine secretome. They also summarize evidence that graft survival depends on small parcel size and limited injection volume (to preserve oxygen diffusion and avoid high interstitial pressures), ASC and CD34⁺ progenitor content, rapid revascularization, donor factors such as age, sex, BMI, and the embryologic match between donor and recipient fat depots. The article concludes that although ASCs are key to regenerative outcomes, the impact of aging on their number, function, and secretome—and on their interaction with macrophages and vasculature—remains incompletely understood, highlighting the need for further research to optimize clinical fat grafting. 

Intended Audience
This educational activity is intended for all CME-related persons including plastic surgery practitioners, residents, and other healthcare professionals.

Learning Objectives

After viewing this course, the participant should be able to:

1. explain the three-zone model of fat graft survival (surviving, regenerating, and necrotic zones) and the primary role of adipose-derived stem/stromal cells (ASCs) in the regenerating zone.
2. compare the effects of donor age on ASC proliferation, secretome profile (e.g., VEGF, HGF), and immunomodulatory capacity, and predict the likely clinical impact on fat graft retention in older versus younger patients.
3. analyze how parcel size, grafted volume, and interstitial pressure influence graft ischemia and necrosis
4. evaluate the advantages and potential limitations of site-matched (embryologically similar) donor fat versus mismatched donor sites in terms of adipogenic potential, HOX gene expression, and long-term graft retention.

Editor-in-Chief: Kevin C. Chung, MD

Co-editor: Amy S. Colwell, MD

Josef Hadeed, MD, FACS

Samuel Lin, MD, FACS

• Systems-based Practice
• Medical Knowledge
• Practice-based Learning and Improvement

The American Society of Plastic Surgeons (ASPS) is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

Designation
The American Society of Plastic Surgeons designates this enduring material for a maximum of 1.0 AMA PRA Category 1 Credit. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

AMA PRA Category 1 Credit^TM: 1.0
Media:Journal Article
Release Date: 11/29/2025
Expiration Date: 11/29/2028*
Estimated time to complete this course: 1 hour
*Course access ends on course expiration date

Disclosure Policy
The American Society of Plastic Surgeons (ASPS) requires all faculty, authors, planners, reviewers, managers, staff and other individuals in a position to control or influence the content of an activity to disclose all relevant financial relationships or affiliations. All identified conflicts of interest must be resolved and the educational content thoroughly vetted by ASPS for fair balance, scientific objectivity and appropriateness of patient care recommendations. The ASPS also requires faculty/authors to disclose when off-label/unapproved uses of a product are discussed in a CME activity or included in related materials.

Disclaimer: All relevant financial relationships for planners, faculty, and others in control of content (either individually or as a group) are reviewed by the ASPS Continuing Education Committee and have been mitigated, if applicable. 

The following planners/faculty members/reviewers have no relevant financial relationships or affiliations to disclose:

Chloe Trotzier, MScEng

Ines Sequeira, PhD

Celine Auxenfans, PharmD, PhD

Ali A. Mojallal, MD, MSc, PhD

Josef Hadeed, MD, FACS

Samuel Lin, MD, FACS

Recognition Statement

The Continuing Medical Education (CME) credits offered by this activity are enhanced by ASPS Learner Credit Reporting for learners who have opted into this reporting. Successful completion of this CME activity enables active American Board of Surgery (ABS) members the opportunity to earn credit toward the CME requirement of the ABS's Continuous Certification program when claimed within 30 days of completion of the activity.

Participants in ASPS-accredited education who want their CME credits reported to certifying and state licensing boards must opt-in to reporting and add their NPI as well as state license ID and/or collaborating board ID(s) before claiming credit.

Directly provided by the American Society of Plastic Surgeons® (ASPS®)