Autologous Bone Marrow Stem Cell Transfer in Patients With Chronical Critical Limb Ischemia and Diabetic Foot

1. INTRODUCTION:

The local method of autologous bone marrow stem cells transplantation consists of harvesting bone marrow from the iliac crest, its separation using cell separator to generate ABMSCs (CD 34 positive) and their subsequent multiple injections into a limb suffering from chronic and critical ischemia. The aim of this therapy is to induce angiogenesis and vasculogenesis which would correct ischemia and hypoxia, improve tissue perfusion and metabolism and thus prevent limb amputation. Due to correction of hypoxia and ischemia by improvement of blood supply regeneration of damaged tissues is initiated. Improved tissue perfusion is achieved by a large number of mediators including growth and angiogenic factors which in turn stimulate growth of primitive vessel wall within the ischemic tissue, a part of healing process. In general, such reparative process could be divided into the initial phase characterized by the release of inflammatory mediators and neurotransmitters followed by phase of formation of primitive vascular tubes composed of the endothelial cell precursors which are later on adhered to and stabilized by pericyte cells. Process of angiogenesis (by sprouting as well as nonsprouting) takes usually between 4-6 weeks depending on degree of the initial tissue ischemia and hypoxia. Development of new collateral blood flow in the ischemic/hypoxic tissue can be monitored by the Laser Doppler - Flowmetry, level of Transcutaneous TcpO2 and TcpCO2, Toe Pressure and Skin Perfusion Pressure measurements, the Index Ankle-Arm ABI using Duplex Doppler Ultrasound, angiography, MRI or alternatively by common methods used in nuclear medicine. Analysis and interpretation of all these measurements should define degree of efficacy and safety of this therapeutic modality and may suggest future directions in optimization of this therapy. 2. PROJECT OBJECTIVES:

Primary objective: To evaluate an efficacy-safety profile of autologous bone marrow stem cells (ABMSCs) transplantated into chronically and critically ischemic limb (CLI) and into diabetic foot in stage IV Fontaine classification.

Secondary objectives: To assess effect of ABMSCs on tissue perfusion of ischemic limb after transplantation by transcutaneous oximetry and the laser Doppler flowmetry using Periflux 5000 system under normal and provocation test conditions. In addition, wound healing of ulcers will be evaluated using a planimetry method from photographs of affected skin taken pre- and post-transplantation.

Relationship between CD 34 progenitor counts separated on gradient-density separation centrifuge from Harvest Technologies and overall effectiveness and safety to treat ischemic limb.