Angiogenic growth factors in the treatment of peripheral arterial disease

Peripheral arterial disease (PAD) remains a major cause of morbidity. Despite advances in revascularisation procedures and medical treatment, limb salvage and relief of pain are still not satisfactory in patients with severe disease. This has prompted the exploration of alternative modes of treatment including enhancement of new vessel formation (angiogenesis). Angiogenic Growth Factors (AGF), mainly Vascular Endothelial Growth Factor (VEGF), basic Fibroblast Growth Factor (bFGF) and Hepatocyte Growth Factor (HGF) have emerged as exciting therapeutic modalities. Both experimental and clinical studies have demonstrated that topical (mainly intramuscular) AGF gene therapy results in improved peripheral vasculature and alleviation of symptoms. However, most clinical work is limited to small patient series and the long-term safety and efficacy are still unclear. Clinical benefit must be balanced against potential untoward effects, such as tumour growth and atherosclerotic plaque angiogenesis leading to plaque instability. VEGF is important in the pathogenesis of diabetic microvascular disease. Further studies are required before implementation of AGF therapy in clinical practice.