Adipose Stem Cell Therapy for Amputation Site Soft Tissue Restoration: A Prospective Randomized Controlled Clinical Trial
Francesco M. Egro, MBChB, MSc, MRCS, Debra A. Bourne, MD, Danielle Minteer, PhD, M. Asher Schusterman, MD, Aaron Wyse, Albert Donnenberg, PhD, Vera Donnenberg, PhD, Gretchen Haas, MD, Rory Cooper, Kacey Marra, PhD, Lauren Kokai, PhD, Sydney Coleman, MD, Paul Pasquina, MD, J. Peter Rubin, MD, FACS.
University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
BACKGROUND: Nearly 2 million people in America suffer from limb loss. Challenges precluding successful long-term prosthesis use include skin break down, pain, and poor fit. The aim of this study, which funded through the United States Department of Defense, is to assess the efficacy of standard autologous fat transfer compared to fat graft enriched with adipose derived stem cells to improve lower extremity amputation site soft tissue quality and pain.
METHODS: Ten patients suffering from pain and limited function at amputation sites were randomized to either the Standard Group treated with autologous fat grafting to the amputation site; or the Enriched Group which was enriched with stromal vascular fraction, which is a concentrated source of adipose derived stem cells (ASC). Outcome measures included: 1) Pain score (visual analog scale), 2) Graft cell composition (flow cytometry), 3) Volume retention assessed by CT scan, and 4) Quality of life questionnaires.
RESULTS: Study subjects were randomized (Enriched, n=3, mean age 46.4±18.1; Standard, n=7, mean age 56.3±13.0). All participants received treatment with no significant adverse events. Follow-up was two years. No significant differences (p=0.06) were detected in graft cell viability (82.7±3.6% in the Enriched Group and 69.9±31.8% in the Standard Group). The composition of the harvested fat was similar between groups (Enriched: 36.0% ASC, 5.9% endothelial, 1.5% pericyte, 54.8% non-hematopoietic; Standard: 28.8% ASC, 4.3% endothelial, 1.3% pericyte, 42.3% non-hematopoietic). Subjects in the Enriched Group experienced significant improvement in pain, and earlier than the Standard Group (p=0.02). Together, there was an improvement in hypersensitivity, prosthetic fit, and pain at 1-month post-treatment, lasting through two years. Importantly, six of the ten subjects discontinued pain and/or anti-anxiety medication after fat grafting.There was no significant difference between groups in graft volume retention (p>0.05). There was significant improvement in self-rated satisfaction with physical appearance (p=0.007) and a trend for improvement in self-rated freedom from pain.
CONCLUSIONS: Fat grafting improves pain, hypersensitivity, prosthesis fitting, and quality of life for patients suffering from lower limb amputation pain. Fat grafts enriched with adipose stromal cells may enhance pain relief.
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