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The systolic pressure observed in 150 patients with peripheral arterial disease has been compared to their symptoms and signs. In patients with claudication the ankle mean pressure was 58 mmHg. In patients with rest pain it was 33 mmHg and in patients with chronic ulcerations it was 20 mmHg. In these 3 groups the mean ankle-foot pressure gradient was low (2-10 mmHg) were detected at the level of the iliaco-femoral and femora-popliteal segments. In the group of diabetic patients an high gradient was observed. Patients with peripheral arterial disease can be divided in four symptomatic groups but the angiographic and physiological patterns of patients with rest pain and ischemic ulcerations are similar and they are the best candidates to reconstructive arterial surgery.

The tissue-to-blood partition coefficient for Xenon (lambda Xe) in the subcutaneous tissue in the forefoot was determined by physical and chemical analysis. The difference between patients with normal circulation (n = 10) and serve ischaemia (n = 13) was insignificant; pooled mean: 7.42 +/- 1.57 ml x g-1. The lambda Xe in the forefoot was significantly lower than lambda Xe of the abdominal wall (lambda Xe - abd: 8.67 +/- 1.27 ml x g-1; P = 0.03). The influence of oedema on the local blood flow [in ml x (100 g x min)-1] and on the post-reconstructive hyperaemia (in ml x min-1) is discussed. It is concluded that local blood flow determinations, based on 133Xenon wash-out rates, in individual cases, are not possible. In subcutaneous tissue with low lipid contents, the ratio between the post- and preoperative wash-out rates tend to underestimate the post reconstructive hyperaemia. This is due to the volume increase of the subcutaneous tissue being larger than the decrease of the tissue-to-blood partition coefficient due to the oedema.

In a double-blind cross-over trial an oral thromboxane synthetase inhibitor (TSI) or placebo was given to 15 patients with severe foot ischaemia. After TSI therapy, rest pain remitted in nine out of 14 legs, while remission during placebo was seen in three out of 11 legs (NS). The ankle and toe systolic blood pressures remained constant during both study periods. Nocturnal adipose tissue blood flow in the forefoot was measured by the xenon wash-out method. A significant increase of the nocturnal perfusion rate constant during TSI therapy was found. A slight oedema developed during TSI therapy. This causes a change of the composition of the tissue under study and thus of lambda-xenon. The perfusion rate in the present study thus merely illustrates the latter and not a true increase in blood flow.

Simultaneous measurement during 24 h of mean arterial blood pressure (MABP) and forefoot subcutaneous adipose tissue blood flow (SBF) was undertaken in eight patients (15 feet) with different degrees of arterial insufficiency. The recordings were undertaken with the patients in the supine position only. The MABP decreased by 19 +/- 9% from awake to asleep independently of symptomatology. In two limbs with normal circulation, SBF decreased by 8 +/- 7%. In five limbs with arterial insufficiency but no rest pain SBF decreased by 16 +/- 8%, and in eight limbs with ischaemic nocturnal rest pain, SBF was reduced by 32 +/- 12% during sleep. It is concluded that nocturnal hypotension is the major aethiological factor for the symptom ischaemic nocturnal rest pain.

Twenty-four hour continuous recording of xenon (133Xe) wash-out from the forefoot was performed on patients with normal circulations (n = 10) and on patients with different degrees of arterial insufficiency (n = 36). During day hours the calculated subcutaneous blood flow in the forefoot was on average the same in patients with normal circulations and in patients with different degrees of arterial insufficiency (mean: 2.0 +/- 0.8 ml min-1 100 g-1). During sleep the blood flow nearly doubled in patients with normal circulations; no systematic change was seen in patients with intermittent claudication. In patients with severe ischaemia, i.e. having rest pain, the blood flow decreased by approximately 50%. The changes in local blood flow may be due to changes in local sympathetic tone and to changes in local perfusion pressure.

A double-blind, parallel group, multicenter clinical trial of pentoxifylline compared with placebo enrolled 150 patients with moderately severe chronic occlusive arterial disease (COAD) at three centers in Scandinavia. The study consisted of a 4-6 week single-blind, placebo-controlled run-in phase, during which the stabilization of the initial claudication distance of all patients was assessed before randomization to a 6-month double-blind observation period. The diagnosis of COAD was established by clinical findings, conventional angiography, and noninvasive peripheral Doppler pressure assessment at rest and after exercise. The results of the overall intention-to-treat analysis of the study population show statistically significant superiority of pentoxifylline over placebo for all absolute claudication distance summary and end point measures. By using two clinically relevant parameters, which are a resting ankle/arm pressure ratio 0.8 or less and a duration of COAD for greater than 1 year, a target population could be defined in whom trial results became highly significant. For nontarget patients with mild COAD, we conclude that basic therapeutic measures should include the treatment of risk factors and the initiation of physical training. For target patients, however, a multifactorial therapeutic approach, including the use of pentoxifylline, is justified.