Using a Pneumatic Compression Device for Lower and Upper Extremity Peripheral Arterial Disease | FAIM.org

ArtAssist®…The Arterial Assist Device®

by Steven Kavros, DPM

Intermittent pneumatic compression (IPC) of the lower limb is a well-documented method of arterial leg inflow enhancement in patients with peripheral arterial disease (PAD). The mechanism of action parallels the natural muscular contraction of the leg stimulating blood flow. There are three very short compression cycle per minute inflating a cuff encompassing the legs and or feet simulating the beneficial effects of walking. The rapid rise of the cuff pressure assists with emptying of the venous blood of the extremities and allows oxygenated blood to move down the limb delivering nutrients to deprived tissues. This simple mechanism of action also allows edema or swelling of the extremity to be relieved. By relieving swelling, additional oxygenated blood can be delivered to the ischemic limb. Additionally, there is an increase release of nitric oxide and certain tissue and platelet derived growth factors. The nitric oxide has a positive effect on the internal cells that line the vessel wall, enabling relaxation and improved flow. Other tissue and growth factors lead to the development of new blood vessels and therefore, improve the delivery of additional oxygen and nutrients to the extremity.

Read the rest via Using a Pneumatic Compression Device for Lower and Upper Extremity Peripheral Arterial Disease | Foundation for Alternative and Integrative Medicine.

Since the Internet is all about getting info quickly and moving on, here’s what this medical jargon means in plain English…

Dr. Kavros is talking about a leg pump (what we’ll refer to as an arterial pump) that is proven to improve circulation to the legs and feet when the arteries are blocked. When your arteries are significantly blocked, your muscles start sending pain signals to your brain. This is called PAD – think of it as a heart attack of the legs.

The way this arterial pump technology works is by simulating walking for your blood-deprived muscles. Instead of making you get up and walk, this therapy happens while you’re sitting in a chair. When you walk, blood in the veins travels up to your heart, gets refreshed and loaded with oxygen/nutrients, and then comes back down to feed the starving muscles. The better circulation you have in your legs, the less they will hurt.

Dr. Kavros says that this compression sequence can also reduce swelling. This pump compresses your leg three times per minute. If you use the pump for three hours a day, imagine how much more blood flow you’re getting!

A fringe benefit to this therapy that was recently discovered is your body’s natural release of nitric oxide. This substance is not to be confused with nitrous oxide, which is what your dentist will give you to make you laugh at his dumb jokes while he’s working on your teeth. When nitric oxide is released by the lining of your arteries, your blood vessels temporarily open up to accept more nutritious blood. Again, this happens three times a minute so that your blood vessels are constantly widened throughout therapy.

This is the compression technology Dr. Kavros is talking about: The ArtAssist® device. To learn more, click the picture!

Update: Dr. Paul van Bemmelen has also written an article for faim.org about pneumatic compression device therapy for PAD. Read it here

ArtAssist®…The Arterial Assist Device®

Compressing Ischemic Limbs and Why It’s Beneficial

To download a printable PDF of this article, click here: Compressing Ischemic Limbs and Why It’s Beneficial

The Misconception

Is it true that arterial occlusive disease is an absolute contraindication for intermittent pneumatic compression (IPC)?

The Answer

Not at all!

Unfortunately, many medical professionals are under the impression that applying even a small external pressure to an ischemic limb with reduced distal arterial pressures may serve to reduce or completely stop the already-compromised blood flow. This article presents strong evidence that, contrary to popular belief, IPC can bring life-changing benefits to those who cannot undergo revascularization.

History

Part of the reason this dogma exists is because, for many who consider it, applying IPC to ischemic limbs seems counterintuitive and likely dangerous. Also contributing to this myth are the literature reviews written by investigators as far back as 1934 who showed a poor understanding of the physiological mechanisms. Though these measured acute effects of compression on increased blood flow in ischemic limbs and relief of symptoms, the assessments made about IPC therapy were muddled due to the use of a great variety of compression schemes and devices. This lack of clarity resulted in literature that only served to feed misgivings about IPC as a treatment modality.

Physiological & Optimization Studies | ACI Medical

To demystify the true value of IPC, our goal was to determine the physiological mechanisms of action, to optimize IPC design for maximal acute effect, and to determine if there is a clinical benefit to patients with lower extremity ischemic disease.

We started with physiological studies¹ with compression applied to the dependent limb, which showed these acute mechanisms:

Increased arterial-venous pressure gradient
Reduced peripheral resistance
Abolition of the veno-arteriolar reflex

Further studies² concerned optimization:

Pressure: at least 120 mmHg
This high pressure is required to empty the veins in the dependent limb, which temporarily reduces venous pressure to near zero and increases the arterial-to-venous pressure gradient and therefore, flow. Reducing venous pressure also serves to temporarily abolish the veno-arteriolar reflex, which allows for arteriolar dilation.
Timing: 3 second pulses followed by 17 seconds of low pressure
An essential requirement for an arterial pump is the ability to quickly reach inflation and deflation pressures with rise times of 0.25 to 0.30 seconds and fall times under 0.5 seconds. This rapid squeeze and release creates blood velocities that apply shear stress to the endothelium which releases nitric oxide and further supports the large acute vasodilatory effect in the arterioles.
Compressed tissues: foot, ankle and calf regions
In order to maximize blood flow through the major arteries and to the toes where ischemic disease often presents, we found that a circumferential foot bladder including the ankle should be compressed first, followed one second later by compression of the calf with a relatively large asymmetrical bladder.

Randomized Controlled Trials | ACI Medical

Intermittent Claudication

Once the arterial IPC device was optimized, three randomized controlled trials³ were performed on patients with intermittent claudication. Not only did these trials yield significantly increased walking distances of two to three times, but also sustained “permanent” improvements begged the question, “What long term mechanisms might be at work?”

Limb Salvage due to Arteriogenesis

Further studies⁴ showed that arteriogenesis (the opening of collaterals) was responsible for improved ABI’s, PVR’s, toe pressures and popliteal flow. A recently published study from 2010⁵ reported a 94% limb salvage rate at 3.5 years in patients who were unable to undergo revascularization procedures.

Arterial Assist Device, NOT Lymphedema Pump

ArtAssist®…The Arterial Assist Device®

Today, it is widely-known that IPC devices are designed for prophylaxis against deep vein thrombosis (DVT) and for treatment of lymphedema. However, the understanding behind these devices does not coincide with our exploration of IPC to treat severe forms of arterial disease. Lymphedema and DVT devices do not apply enough pressure to the dependent limb to adequately empty the veins, nor do they apply and release pressure rapidly enough to stimulate release of nitric oxide (NO). While such devices will not significantly improve blood flow in the ischemic limb, it is difficult to say whether they would be harmful without further study.

References in this Publication

Effect of intermittent pneumatic foot compression on popliteal artery haemodynamics. Delis, K.T.; Labropoulos, N.; Nicolaides, A.N.; Glenville, B.; and Stansby, G. Imperial College School of Medicine, Academic Vascular Surgery, St. Mary’s Hospital, London, UK. Eur J Vasc Surg, p. 270-277, vol. 19, no. 3, March 2000.
Optimum intermittent pneumatic compression stimulus for lower-limb venous emptying. Delis, K.T.; Azizi, A.A.; Stevens, R.J.G.; Wolfe, J.H.N. and Nicolaides, A.N. Irvine Lab for Cardiovascular Investigation and Research Academic Vascular Surgery, Imperial College School of Medicine, St. Mary’s Hospital, London, UK. Eur J Vasc Endovasc Surg 19, 261-269 (2000).
Improvement in walking ability, ankle pressure indices and quality of life in vascular claudication using intermittent pneumatic foot and calf compression: a randomized controlled trial. Delis, K.T.; Nicolaides, A.N.; Cheshire, N.J.W.; Wolfe, J.H.N. St. Mary’s Hospital, London, UK. British Journal of Surgery December 2002; Volume 88, Issue 4:605-606.
Angiographic improvement after rapid intermittent compression treatment (ArtAssist®) for small vessel obstruction. Van Bemmelen, P.; Char, D.; Giron, F.; and Ricotta, J.J. Dept. of Surgery, Div. of Vascular Surgery, State University of New York at Stony Brook, NY. Ann Vasc Surg 2003; 17:224-228.
Sequential compression biomechanical device in patients with critical limb ischemia and nonreconstructable peripheral vascular disease. Sultan, S.; Hamada, N.; Soylu, E.; Fahy, A.; Hynes, N. and Tawfick, W. Department of Vascular and Endovascular Surgery, University College Hospital, Galway, Journal of Vascular Surgery 2011; 54:440-447.