Why calf-only arterial pumps are missing out

ArtAssist®…The Arterial Assist Device® Compression Sequence

Calf-only arterial pumps are missing a key component because foot compression is essential to improving circulation in the skin of the foot. Good circulation is vital to the successful healing wounds and ulcers. ACI Medical’s ArtAssist® device went through numerous clinical trials in order to optimize compression therapy for treating peripheral arterial disease of the legs and feet.

Researchers and engineers optimizing the ArtAssist® device not only discovered the importance of compressing the foot in addition to the calf, but they also designed this arterial pump technology to imitate the physiological act of walking as closely as possible.

A bit of background

An early study to determine the physiological effects of  intermittent pneumatic compression therapy focused compression on the calf, foot, and both simultaneously.

Although significant increase in arterial blood flow was recorded for individual compression areas, the simultaneous combination yielded disappointing results because blood was not flowing back to the heart as anticipated.

After the conclusion was drawn that simultaneous compression did not produce the desired augmented blood flow for all tissues below the knee, researchers realized that the answer lay in a time delay. Strong, encompassing foot and ankle compression that boosts foot skin perfusion would come first, followed then by calf compression to amplify popliteal flow.

That magical formulation

In essence, foot/ankle compression + calf compression with time delay = successful emptying of venous blood, resulting in improved circulation.

The optimization study led by K. T. Delis, et. al. determined that this foot, ankle and calf compression sequence, applying 120-140 mmHg at a frequency of 3-4 impulses per minute, “provided the optimum intermittent pneumatic stimulus.”

The next logical step was a prospective randomized controlled trial to solidify the efficacy claims.

And the rest is history…

One example of such a trial studied not only the effects of the previously mentioned IPC method, but also the long-term effects on treated claudicants. The results indicated that treated claudicants still retained their ABI’s and walking benefits one year after the end of IPC application.

Following the numerous physiological and optimization studies for the ArtAssist® device, research facilities continued to explore the possibilities of arteriogenesis, therapy for patients with intermittent claudication, and limb salvage.

The ArtAssist® device is currently the only IPC device with this thorough progression of clinical studies and randomized controlled trials to support its efficacy.

References

1. “Improving Popliteal Artery Flow with Intermittent Pneumatic Foot and Calf Compression.” Delis, K.; Labropoulos, N.; Nicolaides, A.N.; Stansby, G.; and Lumley, J. Irvine Laboratory for Cardiovascular Investigation and Research, Academic Surgical Unit, Imperial College School of Medicine, St. Mary’s Hospital, London, UK.
2. “Enhancing Venous Outflow in the Lower Limb with Intermittent Pneumatic Compression. A Comparative Haemodynamic Analysis on the Effect of Foot vs. Calf vs. Foot and Calf Compression.” Delis, K.T.; Slimani, G.; Hafez, H.M. and Nicolaides, A.N. Irvine Lab for Cardiovascular Investigation and Research, Academic Vascular Unit, Imperial College School of Medicine, St. Mary’s Hospital, London UK. Eur J Vasc Endovasc Surg 19, 250-260; 2000
3. “The Acute Effects of Intermittent Pneumatic Foot and Calf Compression on Popliteal Artery Hemodynamics: A Comparative Study.” Delis, K.T.; Nicolaides, A.N.; Labropoulos, N.; and Stansby, G. Imperial College School of Medicine, St. Mary’s Hospital, London, UK. J Vasc Surg, 2000; 32: 284-92
4. “Intermittent Calf and Foot Compression Increases Lower Extremity Blood Flow.” Eze, A.R.; Comerota, A.J.; Cisek, P.L.; Holland, B.S.; Kerr, R.P.; Veeramasuneni, R.; Comerota, A.J. Jr. Presented at the 24th Annual meeting of the Society for Clinical Vascular Surgery; March 1996. Am J Surg 1996; 172:130-135
5. “Optimum Intermittent Pneumatic Compression Stimulus for Lower-limb Venous Emptying.” Delis, K.T.; Azizi, A.A.; Stevens, R.J.G.; Wolfe, J.H.N.; Nicolaides, A.N. Eur J Vasc Endovasc Surg 19, 261-269 (2000).
6. “Improvement in Walking Ability, Ankle Pressure Indices and Quality of Life in Vascular Claudication Using Intermittent Pneumatic Foot and Calf Compression; A Prospective Randomized Controlled Trial with 1 Year Follow-up.” Delis, K.T.; Nicolaides, A.N.; Cheshire, N.J.W.; and Wolfe, J.H.N. Academic Vascular Surgery, St. Mary’s Hospital, London, UK. Presented at the Vascular Surgical Society of Great Britain & Ireland, Nov. 2000, London Arena.