Optical-imaging method could improve angioplasty

An optical-imaging technique developed in Canada could improve angioplasty, a surgery commonly performed to treat patients with a partially or completely blocked coronary artery that restricts blood to the heart.

Angioplasty involves threading a slender, balloon-tipped tube from an artery in the groin to the trouble spot in the artery of the heart. The balloon is then inflated to compress the plaque that is blocking the artery. These balloons can also be used to deploy a stent, which is a wire-mesh tube sometimes inserted into the artery during an angioplasty procedure to keep it open and prevent reblockage.

In both cases, an optimal balloon design is critical to the success of an operation.

Researchers at the National Research Council of Canada have now developed a deployment tester equipped with a system to monitor the outer diameter of the balloon.

With the goal of improving balloon deployment, the researchers investigated obtaining a more precise monitoring of inflation by combining a deployment tester with an optical coherence tomography (OCT) imaging system. OCT allows imaging over a depth of a few millimetres in a tissue or material.

By performing a pullback, which is rotation and translation, of a catheter OCT probe in a balloon, they discovered that it’s possible to obtain a precise measurement of the balloon’s diameter and thickness over the entire balloon.

Guy Lamouche, research officer at the National Research Council of Canada, explained: ‘Combining OCT with a balloon-deployment system provides an improved platform for angioplasty balloon development and can also be used in the development of next-generation minimally invasive devices for percutaneous – through the skin – coronary interventions.

‘It’s now possible to monitor balloon inflation within an artery phantom (model) or an excised artery to assess the efficiency of innovative balloon-angioplasty or stent-deployment procedures.’