[Pain in chronic arterial occlusive disease--the effect of improved macrocirculation on pseudo-radicular irritation]

In chronic obliterating arteriopathy the maximum walking distance does not correlate well with the ankle arm index of arterial pressure measured by Doppler ultrasound. Beside reduced macrocirculation and microcirculatory maldistribution in skeletal muscle, pseudoradicular irritation was established as a relevant factor for the onset of pain during walking. The present study investigates the influence of the macrocirculation on hyperalgesia at rest in intermittent claudication. In 35 patients with chronic obliterating arteriopathy of the lower limbs (stage II according to Fontaine) the ankle/arm index of arterial pressure and the walking tolerance, as well as the pain at rest on applying pressure to the calf muscles were determined before and 3 weeks after percutaneous transluminar angioplasty (PTA). All 3 parameters improved after dilatation. Improved macrocirculation leads not only to a decreased production and improved clearance of pain-inducing metabolites in muscle tissue, but also--through a decrease of sympathetic stimulation of the muscle--to an elevation of the pain threshold. Apart from the reduction in pain-inducing metabolites, an absence of booster effects on pseudoradicular irritation and the regeneration of sensitive cutaneous afferents with resultant inhibition of reflex pain development are considered as possible factors in the achievement of pain relief following PTA.