The distribution of atherosclerosis in the lower limbs

Sixty-seven consecutive aortograms in non-diabetic patients were studied to establish the distribution of atherosclerosis in the arteries of 134 lower limbs. Prolonged filming and multiple exposures of the feet showed ankle vessels in 131 of the limbs (98%) and a pedal arch or collaterals in 126 (93%). In 51% of the limbs at least one of the calf arteries was occluded and only 24% had two patent arteries at ankle level. The pedal arch was complete in only 16%. The patency rate of the pedal arch was similar in all three symptom groups (p greater than 0.05). Two separate analyses were performed. The first was based on symptoms. Critical ischaemia was present in 18 limbs (13%), claudication in 69 limbs (52%) and 47 limbs were symptomless (35%). The second analysis was based on the sites of major occlusion. Occlusions were already present in 81% of the symptomless limbs, predominantly in the distal vessels. In limbs with claudication or critical ischaemia there were more occlusions above the knee (77 and 89%, respectively) than in limbs without symptoms (36%) (chi 2 = 27.60, p less than 0.001). Occlusion of the popliteal artery was significantly more frequent in the patients with symptoms of critical ischaemia (50%) than in either of the other two groups (chi 2 = 15.61, p less than 0.001). Atherosclerosis appears to develop in the small vessels of the calf and foot at an early stage. The extent of this involvement may influence the progression of symptoms and the outcome of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)