Endovascular Interventions: Treating PAD Below the Knee

There’s increasing evidence to support endovascular intervention for patients with PAD below-the-knee. The challenge? Engineering a device that can safely and successfully navigate that area of the body. Learn more about overcoming this challenge in this below-the-knee application guide.

Given availability of both endovascular and open surgical options, a 2017 research program* used population-based data to demonstrate that an endovascular approach is associated with improved amputation-free survival over the long term with only a modest relative increased risk of subsequent intervention.

The mainstay of endovascular treatment to increase circulation blood flow is typically balloon angioplasty, atherectomy, and thrombectomy, followed by stenting in more serious cases. Recent advances have broadened the options for treating PAD, including the use of drug-eluting stents and drug-coated balloons to deliver effective therapies.

When compared with open surgery for PAD, catheter-based treatment offers a much lower periprocedural risk, but is limited by lower initial success, requiring repeated procedures for effective treatment, particularly for infrapopliteal (below-the-knee) intervention.

For example, blood vessels in the foot are smaller in diameter and highly tortuous, making them difficult to access and navigate. This, in addition to the fact that lesions in these body parts are often severely calcified, can mean repeated procedures are required for effective treatment. However, extensive infrapopliteal stenting in conjunction with poor outflow may actually elevate the risk of stent thrombosis or distal embolization complications.

It is clear that a reliable endovascular treatment for PAD in the lower extremities will be largely dependent on, and aided by, the availability of more advanced device design.

The challenge for engineers remains: creating a catheter that offers the right mechanical properties of strength and flexibility, and that is small enough for successful below-the-knee intervention.