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Precise comprehensive imaging of arterial circulation is the cornerstone of successful revascularization of the ischemic extremity in patients with diabetes mellitus. Arterial imaging is challenging in these patients because the disease is often multisegmental, with a predilection for the distal tibial and peroneal arteries. Occlusive lesions and the arterial wall itself are often calcified, and patients with ischemic complications frequently have underlying renal insufficiency. Intra-arterial digital subtraction angiography, contrast-enhanced magnetic resonance angiography, and, more recently, computed tomographic angiography have been used as imaging modalities in lower-extremity ischemia. Each modality has specific advantages and shortcomings in this patient population, which are summarized and contrasted in this review. (J Am Podiatr Med Assoc 100(5): 412–423, 2010)
Challenges of Distal Bypass Surgery in Patients with Diabetes
Patient Selection, Techniques, and Outcomes
Surgical revascularization of the lower extremity using bypass grafts to distal target arteries is an established, effective therapy for advanced ischemia. Recent multicenter data confirm the primacy of autogenous vein bypass grafting, yet there remains significant heterogeneity in the utilization, techniques, and outcomes associated with these procedures in current practice. Experienced clinical judgment, creativity, technical precision, and fastidious postoperative care are required to optimize long-term results. The diabetic patient with a critically ischemic limb offers some specific challenges; however, numerous studies demonstrate that the outcomes of vein bypass surgery in this population are excellent and define the standard of care. Technical factors, such as conduit and inflow/outflow artery selection, play a dominant role in determining clinical success. An adequate-caliber, good-quality great saphenous vein is the optimal graft for distal bypass in the leg. Alternative veins perform acceptably in the absence of the great saphenous vein, whereas prosthetic and other nonautogenous conduits have markedly inferior outcomes. Graft configuration (reversed, nonreversed, or in situ) seems to have little effect on outcome. Shorter grafts have improved patency. Inflow can be improved by surgical or endovascular means if necessary, and distal-origin grafts (eg, those arising from the superficial femoral or popliteal arteries) can perform as well as those originating from the common femoral artery. The selected outflow vessel should supply unimpeded runoff to the foot, conserve conduit length, and allow for adequate soft-tissue coverage of the graft and simplified surgical exposure. This review summarizes the available data linking patient selection and technical factors to outcomes and highlights the importance of surgical judgment and operative planning in the current practice of infrainguinal bypass surgery. (J Am Podiatr Med Assoc 100(5): 429–438, 2010)
The Costs of Diabetic Foot
The Economic Case for the Limb Salvage Team
In 2007, the treatment of diabetes and its complications in the United States generated at least $116 billion in direct costs; at least 33% of these costs were linked to the treatment of foot ulcers. Although the team approach to diabetic foot problems is effective in preventing lower-extremity amputations, the costs associated with implementing a diabetic-foot–care team are not well understood. An analysis of these costs provides the basis for this report.
Diabetic foot problems impose a major economic burden, and costs increase disproportionately to the severity of the condition. Compared with diabetic patients without foot ulcers, the cost of care for those with foot ulcers is 5.4 times higher in the year after the first ulcer episode and 2.8 times higher in the second year. Costs for treating the highest-grade ulcers are 8 times higher than are those for treating low-grade ulcers. Patients with diabetic foot ulcers require more frequent emergency department visits and are more commonly admitted to the hospital, requiring longer lengths of stay. Implementation of the team approach to manage diabetic foot ulcers in a given region or health-care system has been reported to reduce long-term amputation rates 62% to 82%. Limb salvage efforts may include aggressive therapy such as revascularization procedures and advanced wound-healing modalities. Although these procedures are costly, the team approach gradually leads to improved screening and prevention programs and earlier interventions and, thus, seems to reduce long-term costs.
To date, aggressive limb preservation management for patients with diabetic foot ulcers has not usually been paired with adequate reimbursement. It is essential to direct efforts in patient-caregiver education to allow early recognition and management of all diabetic foot problems and to build integrated pathways of care that facilitate timely access to limb salvage procedures. Increasing evidence suggests that the costs of implementing diabetic foot teams can be offset in the long term by improved access to care and reductions in foot complications and amputation rates. (J Am Podiatr Med Assoc 100(5): 335–341, 2010)
Endovascular therapy has increasingly become the initial clinical option for the treatment of lower-extremity peripheral arterial occlusive disease not only for patients with claudication but also for those with critical limb ischemia. Despite this major clinical practice paradigm shift, the outcomes of endovascular therapy for peripheral arterial disease are difficult to evaluate and compare with established surgical benchmarks because of the lack of prospective randomized trials, incomplete characterization of indications for intervention, mixing of arterial segments and extent of disease treated, the multiplicity of endovascular therapy techniques used, the exclusion of early treatment failures, crossover to open bypass during follow-up, and the frequent lack of intermediate and long-term patency and limb salvage rates in life-table format. These data limitations are especially problematic when one tries to assess the outcomes of endovascular therapy in patients with diabetes. The purpose of the present article is to succinctly review and objectively analyze available data regarding the results of endovascular therapy in patients with diabetes. (J Am Podiatr Med Assoc 100(5): 424–428, 2010)
The utility of wound debridement has expanded to include the management of all chronic wounds, even in the absence of infection and gross necrosis. Biofilms, metalloproteases on the wound base, and senescent cells at the wound edge irreversibly change the physiologic features of wound healing and contribute to a pathologic, chronic inflammatory environment. The objective of this review is to provide surgeons with a basic understanding of the processes of debridement in the noninfected wound. (J Am Podiatr Med Assoc 100(5): 353–359, 2010)
History of the Team Approach to Amputation Prevention
Pioneers and Milestones
This historical perspective highlights some of the pioneers, milestones, teams, and system changes that have had a major impact on management of the diabetic foot during the past 100 years. In 1934, American diabetologist Elliott P. Joslin noted that mortality from diabetic coma had fallen from 60% to 5% after the introduction of insulin, yet deaths from diabetic gangrene of the lower extremity had risen significantly. He believed that diabetic gangrene was preventable. His remedy was a team approach that included foot care, diet, exercise, prompt treatment of foot infections, and specialized surgical care.
The history of the team approach to management of the diabetic foot chronicles the rise of a new health profession—podiatric medicine and surgery—and emergence of the specialty of vascular surgery. The partnership among the diabetologist, vascular surgeon, and podiatric surgeon is a natural one. The complementary skills and knowledge of each can improve limb salvage and functional outcomes. Comprehensive multidisciplinary foot-care programs have been shown to increase quality of care and reduce amputation rates by 36% to 86%. Development of distal revascularization techniques to restore pulsatile blood flow to the foot has also been a major advancement.
Patients with diabetic foot complications are among the most complex and vulnerable of all patient populations. Specialized diabetic foot clinics of the 21st century should be multidisciplinary and equipped to coordinate diagnosis, off-loading, and preventive care; to perform revascularization procedures; to aggressively treat infections; and to manage medical comorbidities. (J Am Podiatr Med Assoc 100(5): 317–334, 2010)
Diabetic foot infections are a common and often serious problem, accounting for more hospital bed days than any other complication of diabetes. Despite advances in antibiotic drug therapy and surgical management, these infections continue to be a major risk factor for amputations of the lower extremity. Although a variety of wound size and depth classification systems have been adapted for use in codifying diabetic foot ulcerations, none are specific to infection. In 2003, the International Working Group on the Diabetic Foot developed guidelines for managing diabetic foot infections, including the first severity scale specific to these infections. The following year, the Infectious Diseases Society of America published their diabetic foot infection guidelines. Herein, we review some of the critical points from the Executive Summary of the Infectious Diseases Society of America document and provide a commentary following each issue to update the reader on any pertinent changes that have occurred since publication of the original document in 2004.
The importance of a multidisciplinary limb salvage team, apropos of this special issue jointly published by the American Podiatric Medical Association and the Society for Vascular Surgery, cannot be overstated. (J Am Podiatr Med Assoc 100(5): 395–400, 2010)
The timely and accurate noninvasive assessment of peripheral arterial disease is a critical component of a limb preservation initiative in patients with diabetes mellitus. Noninvasive vascular studies can be useful in screening patients with diabetes for peripheral arterial disease. In patients with clinical signs or symptoms, noninvasive vascular studies provide crucial information on the presence, location, and severity of peripheral arterial disease and an objective assessment of the potential for primary healing of an index wound or a surgical incision. Appropriately selected noninvasive vascular studies are important in the decision-making process to determine whether and what type of intervention might be most appropriate given the clinical circumstances. Hemodynamic monitoring is likewise important after either an endovascular procedure or a surgical bypass. Surveillance studies, usually with a combination of physiologic testing and imaging with duplex ultrasound, accurately identify recurrent disease before the occurrence of thrombosis, allowing targeted reintervention. Noninvasive vascular studies can be broadly grouped into three general categories: physiologic or hemodynamic measurements, anatomical imaging, and measurements of tissue perfusion. These types of tests and suggestions for their appropriate application in patients with diabetes are reviewed. (J Am Podiatr Med Assoc 100(5): 406–411, 2010)
Retrospective and prospective studies have shown that elevated plantar pressure is a causative factor in the development of many plantar ulcers in diabetic patients and that ulceration is often a precursor of lower-extremity amputation. Herein, we review the evidence that relieving areas of elevated plantar pressure (off-loading) can prevent and heal plantar ulceration.
There is no consensus in the literature concerning the role of off-loading through footwear in the primary or secondary prevention of ulcers. This is likely due to the diversity of intervention and control conditions tested, the lack of information about off-loading efficacy of the footwear used, and the absence of a target pressure threshold for off-loading. Uncomplicated plantar ulcers should heal in 6 to 8 weeks with adequate off-loading. Total-contact casts and other nonremovable devices are most effective because they eliminate the problem of nonadherence to recommendations for using a removable device. Conventional or standard therapeutic footwear is not effective in ulcer healing. Recent US and European surveys show that there is a large discrepancy between guidelines and clinical practice in off-loading diabetic foot ulcers. Many clinics continue to use methods that are known to be ineffective or that have not been proved to be effective while ignoring methods that have demonstrated efficacy.
A variety of strategies are proposed to address this situation, notably the adoption and implementation of recently established international guidelines, which are evidence based and specific, by professional societies in the United States and Europe. Such an approach would improve the often poor current expectations for healing diabetic plantar ulcers. (J Am Podiatr Med Assoc 100(5): 360–368, 2010)
Diabetic foot disease frequently leads to substantial long-term complications, imposing a huge socioeconomic burden on available resources and health-care systems. Peripheral neuropathy, repetitive trauma, and peripheral vascular disease are common underlying pathways that lead to skin breakdown, often setting the stage for limb-threatening infection. Individuals with diabetes presenting with foot infection warrant optimal surgical management to affect limb salvage and prevent amputation; aggressive short-term and meticulous long-term care plans are required. In addition, the initial surgical intervention or series of interventions must be coupled with appropriate systemic metabolic management as part of an integrated, multidisciplinary team. Such teams typically include multiple medical, surgical, and nursing specialties across a variety of public and private health-care systems. This article presents a stepwise approach to the diagnosis and treatment of diabetic foot infections with emphasis on the appropriate use of surgical interventions and includes the following key elements: incision, wound investigation, debridement, wound irrigation and lavage, and definitive wound closure. (J Am Podiatr Med Assoc 100(5): 401–405, 2010)
