7 – Compression therapy
Elastic compression and intermittent pneumatic compression
Moderators: G Geroulakos (UK), J Caprini (USA)
Participants: J Caprini (USA), G Geroulakos (UK), S Kakkos (UK), H Partsch (Austria)
This very instructive session about the role of compression therapy in prevention and treatment of different vascular disorders started with J Caprini’s. presentation, which dealt with intermittent pneumatic compression for the prevention of venous thromboembolism (VTE). He first emphasized the importance of history taking and physical examination for every patient in order to assess individual risk using validated scoring systems. It is also mandatory to have a checklist of bleeding risk in these patients including the platelet count, renal function, and use of concomitant medications that might increase bleeding. Precautions for the use of intermittent pneumatic compression (IPC) include severe peripheral arterial disease, active leg deep vein thrombosis (DVT), the presence of chronic skin conditions, open ulcerations, and severe eczema. The results of clinical trials from 1983 show a clear benefit of IPC regarding the reduction in incidence of VTE in general surgery patients. There is also a strong history regarding the use of combining IPC with pharmacologic prophylaxis in high-risk patients. A thrombosis rate of <2% has been seen in patients receiving combined therapy following stroke, cardiac, general, or orthopedic surgery using venographic end points. The use of graduated compression stockings has also been associated with a reduced VTE incidence compared with control populations, but their effects are much less robust and well studied than IPC devices. One recent study shows in patients with intracerebral bleeding the addition of IPC to graduated stockings reduces the ultrasonic DVT rate by 50%. In the final analysis, the choice of prophylaxis should be based on the patients’ level of risk and those at lower risk may need only IPC whereas those with a very high risk may benefit from combined prophylaxis. G Geroulakos from the UK afterwards three smallish but consistent studies supporting the benefit of IPC treatment in stable peripheral arterial occlusive disease. Three different research groups (Kakkos et al, Dellis et al, and Ramaswami et al) each published in 2005 data on the efficiency of intermittent pneumatic compression (IPC) devices in stable peripheral arterial occlusive disease patients compared with unsupervised and supervised exercise programs, in terms of initial claudication distance, absolute claudication distance, ankle brachial index, air plethysmography measurements, and QoL improvement. All three studies show a significant improvement in initial claudication distance, absolute claudication distance, and quality of life in IPC-treated stable claudicants compared with unsupervised or supervised exercise programs alone. Although supervised exercise programs showed some benefit in these terms, this benefit was significantly weaker than in the case of exercise and IPC therapy together. The unsupervised exercise program, which is unfortunately the most frequent daily practice, shows no benefit at all in peripheral arterial occlusive disease patients. Larger well-designed studies are needed to confirm this beneficial effect of IPC therapy in stable intermittent claudication.
S Kakkos from the USA talked about the effect of elastic compression on the prevention of venous thromboembolism (VTE) alone and in combination with other modalities. It has been known since 1971 that full-length stockings can significantly reduce the incidence of deep vein thrombosis (DVT). Their mechanisms are complex: reducing the cross-sectional diameter of the veins and shunting the venous flow from the superficial to the deep system increases the blood flow velocity, prevents operative venodilatation, reduces leg swelling, and activates the tissue factor pathway inhibitor . Graduated elastic stockings (with 18 mm Hg pressure at the ankle and 8 mm Hg pressure at the thigh) are more efficient than uniform compression stockings. One can use preventive and therapeutic compression grades also. Correct sizing of the stocking is very important. The effectiveness of graduated elastic stockings alone or in combination in VTE prevention is supported by 14 nonorthopedic randomized clinical trials. The major advantage of the method is the absence of bleeding. Among disadvantages are inapplicability to peripheral arterial occlusive disease patients in the case of ulcers, diabetic foot, or pressure sores, and they are difficult to get on and off. Full compression (thigh) is better than calf compression (Howard, 2003). In low-risk patients, elastic compression can be used as alone or combined with ambulation and hydration. In high-risk patients, elastic compression should be combined with heparins, with or without intermittent pneumatic compression (IPC) therapy. In bleeding risk patients or in case of active bleeding, elastic compression should be combined with IPC devices only. Finally, Dr Kakkos underlined that despite these clear recommendations in the real world this simple and cost-effective preventive method is clearly underused.
At the end of this session H Partsch from Vienna summarized the hemodynamic effects of different compression therapeutic modalities in chronic venous diseases. According to basic biophysics, he stressed the large difference between venous pressure values in different positions of the human body. If external compression is applied it is efficient when it exceeds the intravenous pressure. In the supine position, venous pressure at the ankle is about 10-20 mm Hg. That is why the preventive methods using elastic stockings are highly efficient only in this body position. In the upright position the ankle venous pressure rise to 90 mm Hg and the thigh pressure to 30-60 mm Hg. In sitting position there is a need for at least 50 mm Hg external pressure to temporarily occlude the calf veins, as Professor Partsch demonstrated in his various magnetic resonance imaging and ultrasound studies. During the exercise, when the calf muscle contracts only in the case of short-stretch, non-elastic bandages, with high work pressure, raise the external pressure to 90 mm Hg. This is not the case with graduated elastic stockings with higher resting pressure but low work pressure. The application of short stretching bandages during walking produces pressure peaks of 80-90 mm Hg, which cause intermittent venous occlusion, which is beneficial in treatment of severe chronic venous insufficiency. This effect is mainly due to intermittent venous occlusion and not to adaptation of the valves, as the benefit of non-elastic bandages can be seen in avalvular patients also. Finally, Professor Partsch highlighted that in daily practice the applied external pressure has to be adapted to the severity of ambulatory venous hypertension.