Modalities to Deliver Cell Therapy for Treatment of Chronic Limb Threatening Ischemia

Abstract

Significance: Chronic limb threatening ischemia (CLTI) is a severe form of peripheral arterial disease (PAD) that is associated with high rates of morbidity and mortality, and especially limb loss. In patients with no options for revascularization, stem cell therapy is a promising treatment option. Recent Advances: Cell therapy directly delivered to the affected ischemic limb has been shown to be a safe, effective, and feasible therapeutic alternative for patients with severe PAD. Multiple methods for cell delivery, including local, regional, and combination approaches, have been examined in both pre-clinical studies and clinical trials. This review focuses on delivery modalities used in clinical trials that deliver cell therapy to patients with severe PAD. Critical Issues: Patients with CLTI are at high risk for complications of the disease, such as amputations, leading to a poor quality of life. Many of these patients do not have viable options for revascularization using traditional interventional or surgical methods. Clinical trials have shown therapeutic benefit for cell therapy in these patients, but methods of cell treatment are not standardized, including the method of cell delivery to the ischemic limb. Future Directions: The ideal delivery approach for stem cell therapy in PAD patients remains unclear. Further studies are needed to determine the best modality of cell delivery to maximize clinical benefits.

Keywords: PAD; peripheral artery disease; peripheral vascular disease; stem cells.

Alan Dardik, MD, PhD

Figure 1.

Process of study selection and screening.

Figure 2.

Illustration depicting intramuscular injection plan for the RESTORE-CLI clinical trial. RESTORE-CLI, Use of Tissue Repair Cells (TRCs-Autologous Bone Marrow Cells) in Patients with Peripheral Arterial Disease to Treat Critical Limb Ischemia.