Objective: Peripheral arterial disease (PAD) is a chronic arterial occlusive disease which mostly affects the arteries of the lower extremities. PAD morbidity generally ranges from 3% to 10%, although it increases with advancing age and can be greater than 15% in subjects over 60 years of age. In small trials, autologous bone marrow aspirate stem cell concentrate (BMAC) has proven to be safe and effective in promoting angiogenesis in patients with PAD. In this small pilot, open-label, non-randomized, non-controlled study, we assessed the safety and feasibility of intramuscular BMAC injection and implantation for treatment of patients with PAD who are not susceptible to conventional endovascular or open revascularization.

Patients and Methods: A total of 27 patients with non-revascularizable CLI (Fontaine stages III and IV) were enrolled between 2015 and 2019. Comorbidities and risk factors for PAD such as diabetes, hypertension, dyslipidemia and cigarette smoking were also evaluated.

Results: A total of 27 patients (M/F: 25/2) with non-revascularizable critical limb ischemia (stages III and IV according to Fontaine classification) were enrolled between 2015 and 2019. Comorbidities and risk factors for PAD such as type 2 diabetes, hypertension, cigarette smoking and dyslipidemia were also evaluated. The prevalence of cigarette smoking was high (74%; 20 patients). During the follow-up, only 4 patients underwent amputation of the limb affected by critical ischemia. In such subgroup, all patients had a Fontaine stage IV PAD. The remaining 23 patients showed a remarkable improvement in clinical features and ankle-brachial index (ABI) values, without undergoing lower-limb amputation. Computed tomography angiography (CTA) performed 3 months after the intramuscular BMAC injection confirmed the presence of neovascularization in 24 out of 27 patients. The procedure was well-tolerated by all patients.

Conclusions: Our study showed that intramuscular BMAC injection is a safe and feasible approach for obtaining clinical improvement and short-term induction of neovascularization in patients with severe PAD.