الفهرس 
EPIDEMIOLOGY AND ETIOLOGY OF DIABETIC FOOTOnly 14 pages are availabe for public view
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Abstract
Diabetic foot disease is already a major cause of admissions for diabetic patients, and comprises a disproportionately high number of hospital days because of increased surgical procedures and prolonged length of stay.
Diabetes is an important risk factor for peripheral arterial disease (PAD), foot ulcers and infections. Hypertension, smoking, and hyperlipidemia, which are frequently present in patients with diabetes contribute additional risk for vascular disease.
The incidence and prevalence of PAD increase with age in both diabetic and non-diabetic persons and, in those with diabetes, increase with duration of diabetes. Many elderly diabetic persons have PAD at the time of diabetes diagnosis.
Diabetes accounts for about 50% of all non-traumatic amputations in the United States. Mortality is increased in patients with PAD, particularly: if foot ulcerations, infection, or gangrene occur.
PAD in diabetes is compounded by the presence of peripheral neuropathy and by susceptibility to infection. These confounding factors in diabetic patients contribute to progression of PAD to foot ulcerations, gangrene, and ultimately to amputation of part of the affected extremity.
In the patient with a confirmed diagnosis of PAD in whom an assessment of the location and severity is desired, the next step would be a vascular laboratory evaluation for segmental pressures and pulse volume recordings (PVRs). Segmental pressures help with lesion localization, while PVRs provide segmental waveform analysis, a qualitative assessment of blood flow.
For patients with atypical symptoms or a normal ABI with typical symptoms of claudication, functional testing with a graded treadmill may help with diagnosis. Patients with claudication will typically exhibit 20 mmHg DROP in ankle pressure after exercise.
For those patients in whom revascularization is considered and anatomical localization of stenosis or occlusions is important, an evaluation with a duplex ultrasound or a magnetic resonance angiogram (MRA) may be valuable. Duplex ultrasound can directly visualize vessels and is also useful in the surveillance of post procedure patients for graft or stent patency.
While MRA is a safe and promising new technology and noninvasive with minimal risk of renal insult, the gold standard for vascular imaging is X-ray angiography, and it is indicated primarily for the anatomical evaluation of the patient in whom a revascularization procedure is intended.
The management of a patient that presents with an ischemic diabetic foot should be approached in a premeditated and stepwise fashion. The initial priority is the prompt and thorough drainage and/or debridement of any infected or necrotic tissue.
Once the infection is controlled, the next step is determining the level of ischemia. This step should not be delayed, and can be pursued even in the presence of active infection.
Once angiography is complete, planning for revascularization is undertaken. Once revascularization has been accomplished, attention can then again be turned to the repair of the initial foot lesion.
New treatment modalities have emerged recently in the era of management of diabetic foot disease, these include: Stem cell therapy, hyperbaric oxygen therapy, and Gene therapy.
Hyperbaric oxygen therapy has been demonstrated to have an antimicrobial effect and to increase oxygenation of the hypoxic wound tissues. This enhances the neutrophil killing ability, stimulates angiogenesis, and enhances fibroblasts activity and collagen synthesis.
The definition of successful angiogenic gene therapy may need to be reconsidered. Traditionally, therapies for treatment of vascular disorders must demonstrate improvements in morbidity or mortality, Avoiding hospitalization and other manifestations of progressive disease could also be appropriate goals for angiogenic gene therapy.
Stem cells are special cells that can turn into many different cell types in the body such as heart muscle cells, brain cells, and skin cells.
The concept of stem cell based revascularisation emerged in 1997, when Isner’s group described circulating cells in adults called endothelial progenitor cells (EPC) with the capacity to differentiate into endothelial cells (EC) and incorporate into new vessels in ischaemic tissue.
Stem cells for therapeutic use can be obtained from three potential sources: Embryonic, Certain Adult Tissues, Umbilical Cord Blood
However, stem cell therapy has shown promise, clinical and basic science studies show that these therapies can provide a comprehensive solution by addressing multiple factors during treatment of diabetic foot complication, including cell proliferation, extracellular matrix (ECM) synthesis, growth factor release, and vascularization.
Despite considerable advances in the therapy of patients with diabetic foot disease, a substantial number remain, in whom amputation has to be considered the only and final option. These are the patients that most benefit from stem cell therapy as the final and only hope of limb salvage.
The issues to be addressed about adult stem cells:-
Many important issues about adult stem cells remain to be addressed. They include:
• Types and sites of adult stem cells in tissues.
• Sources of adult stem cells in the body.
• Whether they are ”leftover” embryonic stem cells, or they arise in some other way.
• The reason why they remain in an undifferentiated state when all the cells around them have differentiated.
• Whether adult stem cells normally exhibit plasticity, or they only transdifferentiate when scientists manipulate them experimentally.
• The signals that regulate the proliferation and differentiation of stem cells that demonstrate plasticity.
• The possibility to manipulate adult stem cells to enhance their proliferation so that sufficient tissue for transplants can be produced.
• Whether a single type of stem cell exists possibly in the bone marrow or circulating in the blood that can generate the cells of any organ or tissue.
• The factors that stimulate stem cells to relocate to sites of injury or damage.