Emerging Vascular Interventions In The Diabetic Foot
Ensuring adequate vascularity can be critical to facilitating the healing of diabetic foot ulcerations. Accordingly, these authors discuss current mainstay approaches in vascular surgery as well as emerging techniques that could make a difference in the future for limb salvage in patients with diabetes and chronic wounds.
Despite its primary classification as an endocrine disease, diabetes mellitus manifests with wide-ranging secondary effects on multiple organ systems, including the cardiac, vascular, nervous and renal systems. With almost 18 million Americans diagnosed with diabetes mellitus in 2007 and an expected increasing prevalence, the burden of the complications of the disease on the medical system is best represented in its economic cost. The American Diabetes Association estimates $116 billion in excess medical expenditures and another $58 billion in lost productivity from the affected patients.1
The particular challenges diabetes mellitus presents to the practicing podiatrist often manifests in the architectural sequelae of the secondary effects of diabetes, mainly in the predilection toward ulcer formation and subsequent infection, as well as the contribution of long-standing diabetes toward poor wound healing and chronic limb ischemia. However, the seemingly inevitable progression of the diabetic foot toward the feared complication of amputation is no stranger to the medical practitioners who treat these patients.
Indeed, researchers have estimated that diabetes mellitus, worldwide, is associated with 25 to 90 percent of all amputations.2 Diabetes mellitus and its secondary complications, when considered as a single disease entity, are the leading cause of lower extremity amputations not due to trauma in the United States.3 A 2002 analysis of patients discharged from U.S. hospitals demonstrated that vascular disease, including diabetic complications, was the underlying pathology leading to amputations in 82 percent of cases.4
The impact of increasing numbers of revascularization procedures on the rate of amputation in patients with vascular disease remains a current source of continuing debate. In the 2007 update to the Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Artery Disease (TASC II), the authors noted that older U.S. studies had shown no reduction on amputation rates with the increase of revascularization procedures.5
Nonetheless, more recent data from Sweden, Denmark and Finland reflected a significant decrease in amputations with the increased availability and use of both endovascular interventions and surgical revascularization.5 United Kingdom data demonstrated a plateau in major amputations that may reflect increasingly successful limb salvage.5 Recent studies of Medicare B claims between 1996 to 2006 confirmed trends similar to the European studies, namely a clear decrease in total lower extremity amputations with increasing numbers of vascular interventions.6 The advent of emerging interventions in vascular surgery may hold promise in reducing amputations and increasing limb salvage for those with diabetic feet.
Understanding The Pathophysiology Of The Diabetic Foot
Before delving into the details of what vascular surgery has to offer, a brief review of diabetic foot disorders is beneficial. The diabetic foot arises from the combined effects of hyperglycemia on the vascular, immune and nervous systems of the affected patient, projecting subsequent sequelae on the musculoskeletal architecture of the foot.