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CLTI- Chronic Limb Threatening Ischemia
Definition and Clinical Presentation
✔️Chronic Limb Threatening Ischemia is a clinical diagnosis defined by severe peripheral arterial disease causing ischemic rest pain or tissue loss such as non healing ulcers and gangrene that has persisted for more than two weeks. ✔️The hallmark symptom is nocturnal rest pain which is severe forefoot or toe pain that is worse when lying flat and is uniquely relieved by dangling the foot over the side of the bed. This position of dependency uses gravity to increase hydrostatic pressure and meet basic metabolic demands of the tissues. ✔️Physical examination signs include cool and shiny hairless skin with thick nails plus the presence of punched out distal ulcers or black dry gangrene.
Classification and Risk ✔️Assessment Clinical severity is traditionally measured by the Rutherford system where category four indicates rest pain and categories five or six involve varying degrees of tissue loss.
✔️The modern gold standard for predicting amputation risk is the WIfI system which stands for Wound Ischemia and foot Infection. Each category in this system is graded from zero to three to determine the urgency of intervention. Patients with high WIfI scores are at a significantly increased risk of major limb loss within six months and require urgent evaluation.
Diagnostic Evaluation
✔️The Ankle Brachial Index is the initial first line test but it is often falsely elevated above one point three zero in patients with diabetes or chronic kidney disease because of calcified and noncompressible vessels.
✔️In these instances a Toe Brachial Index of less than zero point seven zero or a toe pressure below thirty to forty millimeters of mercury is required to confirm the diagnosis. ✔️Computed Tomography Angiography is considered the gold standard imaging study to map the arterial anatomy and provide the necessary information for planning revascularization.
Treatment and Revascularization Strategies
✔️Management of this condition requires urgent revascularization typically within days to weeks. ✔️Treatment options include endovascular techniques like balloon angioplasty and stenting which are less invasive and preferred for focal lesions or frail patients with high surgical risk.
✔️Open surgical bypass is indicated for fit patients with long segment arterial occlusions. The great saphenous vein is the gold standard conduit for bypass and must be preserved for leg salvage rather than being used for other procedures. After surgery a multidisciplinary team is essential for wound healing which can take three to six months.
Medical Therapy and Long Term Prognosis
✔️Aggressive medical management is necessary to save the life of the patient even after the limb has been successfully salvaged.
✔️This includes high intensity statins and antiplatelet medications plus strict smoking cessation and diabetes optimization. Without this intensive therapy approximately fifty percent of patients will die from cardiovascular causes such as heart attack or stroke within five years. Additionally up to thirty percent of patients may still require a major amputation within five years highlighting the severe nature of the underlying systemic disease.
