Atherosclerosis of the lower extremity arteries causes arterial luminal narrowing. Lower extremity arteries are affected much more commonly than upper extremity arteries. Peripheral arterial disease (PAD) risk is equivalent to that of coronary heart disease. About 20% of adults over age 55 years have lower extremity peripheral arterial disease. (chung , 2015)
The ankle-brachial index (ABI) is widely used for the assessment of the degree of peripheral ischemia. The use of the ankle‑brachial pressure measurement is limited by the fact that a significant proportion of diabetic patients suffer some degree of arterial wall calcification, tissue necrosis , ulceration or gangrene which may render ankle pressure impossible to measure or falsely elevated. (Hosny et al , 2016)
Ankle peak systolic velocity is an attractive arterial flow measure. This fast and simple functional measurement can be a valuable addition to the duplex examination to objectively quantify the vascular status and to monitor the progress of ischemia over time, especially in patients in whom the ABI cannot be reliably determined. ( Hosny et al , 2016)
The aim of the work is to assess the validity of peak systolic velocity of distal anterior and posterior tibial arteries to evaluate chronic lower limb ischemia replacing ankle brachial index. For this purpose 58 limbs from 50 cases patients were studied. All these patients were subjected to:
• Full history taking and clinical examination including (Age, Sex, Smoking, History of Hypertension, History of D.M, History of ischaemic pain (claudication, rest pain), Cardiac troubles, Trophic changes, Color changes and gangrene, Leg temperature and Peripheral pulses).
• Multi-detector CT angiography.
• Color Doppler sonography with measurement of mean peak systolic velocity of the anterior and posterior tibial arteries at the ankle level and correlation with mean ankle brachial index pressure measurement .
Our study reveals the following:
• Males are affected more than females with mean age 60 years.
• (40%) of patients were smokers, (48%) were diabetics , (72%) were hypertensive and ( 26 %) had ischemic heart disease .
• Intermittent claudication is the most common symptom ( 39.7% ) followed by rest pain ( 24.1 %) .
• The average mean APSV of the 58 limbs was 40.67 ±21.14 cm/sec while the median APSV was 36.78 cm/sec & the average mean ABI was 0.73 ±0.28 while the median ABI was 0.71.
• The average mean APSV in limbs with severe ischemia was 20.87 ±7.5 cm/sec , the average mean APSV in limbs with moderate ischemia was 32.54±2.35 cm/sec and the average mean APSV in limbs with minimal or no ischemia was 64.3±12.58 cm/sec.
• The sensitivity and specificity of cutoff value of 45.7 cm/sec to differentiate between ischemic and non ischemic limbs was 96.7% & 100% respectively. The sensitivity and specificity of cutoff value of 27.45 cm/sec to differentiate between severe ischemia and moderate ischemia was 81.8% & 88.9 % respectively.
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