Background: Treatment of critical limb ischemia (CLI) by bypass operation or percutaneous vascular intervention is occasionally difficult. The safety and efficacy of multiple intramuscular adipose tissue-derived mesenchymal stem cells (ATMSC) injections in CLI patients was determined in the study.
Methods and results: The study included 15 male CLI patients with ischemic resting pain in 1 limb with/without non-healing ulcers and necrotic foot. ATMSC were isolated from adipose tissue of thromboangiitis obliterans (TAO) patients (B-ATMSC), diabetes patients (D-ATMSC), and healthy donors (control ATMSC). In a colony-forming unit assay, the stromal vascular fraction of TAO and diabetic patients yielded lesser colonies than that of healthy donors. D-ATMSC showed lower proliferation abilitythan B-ATMSC and control ATMSC, but they showed similar angiogenic factor expression with control ATMSC and B-ATMSC. Multiple intramuscular ATMSC injections cause no complications during the follow-up period (mean follow-up time: 6 months). Clinical improvement occurred in 66.7% of patients. Five patients required minor amputation during follow-up, and all amputation sites healed completely. At 6 months, significant improvement was noted on pain rating scales and in claudication walking distance. Digital subtraction angiography before and 6 months after ATMSC implantation showed formation of numerous vascular collateral networks across affected arteries.
Conclusions: Multiple intramuscular ATMSC injections might be a safe alternative to achieve therapeutic angiogenesis in patients with CLI who are refractory to other treatment modalities.