Critical limb ischemia classification and therapeutic angiogenesis

[Efficacy of treatment of lower-limb critical ischaemia by methods of indirect revascularization]

AIM

The study was aimed at comparing the efficacy of implantation of autologous bone marrow cells with that of revascularizing osteotrephination in treatment of lower limb chronic critical ischaemia in patients with a poor distal vascular bed.

PATIENTS AND METHOD

We analysed the results of comprehensive examination and treatment of a total of 60 patients presenting with lower limb chronic critical ischaemia due to atherosclerotic lesions of the femoropopliteal-tibial segment. According to the technology of treatment, the patients were divided into two statistically homogenous groups of 30 people each. Group One patients underwent standard revascularizing osteotrephination and Group Two patients in accordance with the original technique received intramuscular implantation of 40 ml of autologous bone marrow cells, with this volume distributed in 2-ml injections to 20 points of the muscles of the crus and femur along the internal and external surface.

RESULTS

The use of the original technique of treatment made it possible to achieve the clinical status in the form of moderate or minimal improvement 6 months after bone marrow cells implantation in 29 (96.7%) patients and after 12 months in 28 (93.3%) patients, whereas after revascularizing osteotrephination in 25 (83.3%) and 20 (66.7%) patients, respectively. In the remote period after 12 months, the limb was saved in 28 (93.3%) and 26 (86.7%) patients in Group Two and Group One, respectively. The patients of the second group as compared with those of the first group after 12 months demonstrated a statistically significant increase in the physical health component by 19.8% and the mental health component by 9.8%.

CONCLUSION

Implantation of autologous bone-marrow cells in chronic critical limb ischaemia is pathogenetically substantiated and makes it possible to optimize the results of treatment of patients.

Stromal-Cell-Derived Factor-1 (SDF-1)/CXCL12 as Potential Target of Therapeutic Angiogenesis in Critical Leg Ischaemia

In the Western world, peripheral vascular disease (PVD) has a high prevalence with high morbidity and mortality. In a large percentage of these patients, lower limb amputation is still required. Studies of ischaemic skeletal muscle disclosed evidence of endogenous angiogenesis and adaptive skeletal muscle metabolic changes in response to hypoxia. Chemokines are potent chemoattractant cytokines that regulate leukocyte trafficking in homeostatic and inflammatory processes. More than 50 different chemokines and 20 different chemokine receptors have been cloned. The chemokine stromal-cell-derived factor-1 (SDF-1 aka CXCL12) is a constitutively expressed and inducible chemokine that regulates multiple physiological processes, including embryonic development and organ homeostasis. The biologic effects of SDF-1 are mediated by chemokine receptor CXCR4, a 352 amino acid rhodopsin-like transmembrane-specific G protein-coupled receptor (GPCR). There is evidence that the administration of SDF-1 increases blood flow and perfusion via recruitment of endothelial progenitor cells (EPCs). This review will focus on the role of the SDF-1/CXCR4 system in the pathophysiology of PVD and discuss their potential as therapeutic targets for PVD.

Angiogenic targets for potential disorders

This review shall familiarize the readers with various fundamental aspects of angiogenesis. Angiogenesis is a feature of a limited number of physiological processes like wound healing, ovulation, development of the corpus luteum, embryogenesis, lactating breast, during immune response, and during Inflammation. It is driven by a cocktail of growth factors and pro-angiogenic cytokines and is tempered by an equally diverse group of inhibitors of neovascularization. The properties and biological functions of angiogenic growth factors such as VEGF, FGF-2, nitric oxide, MMP, angiopoietin, TGF-β as well as various inhibitors such as angiostatin, endostatin, thrombospondin, canstatin, DII4, PEDF are discussed in this review with respect to their impact on angiogenic process. In recent years, it has become increasingly evident that excessive, insufficient, or abnormal angiogenesis contributes to the pathogenesis of many more disorders. A long list of disorders is characterized or caused by excessive or insufficient angiogenesis whereas several congenital or inherited diseases are also caused by abnormal vascular remodeling. It may be possible in the future to develop specific anti-angiogenic agents that offer a potential therapy for cancer and angiogenic diseases.