Shape-Shifting Robotic Catheter to Make Heart Surgery Safer

Presently, open-heart surgeries comprise a significant share of cardiac procedures and offer surgeons substantial control but involve lengthy recovery times and are unsuitable for certain high-risk patients. Alternative less invasive techniques involve threading catheters through the body’s vasculature to the heart. However, these instruments often lack the necessary size and dexterity, as they can be easily displaced by the heart's movements and surgeons have to struggle to precisely target tissue. Meeting these conflicting requirements of size and flexibility has proved to be a significant challenge for researchers developing new surgical tools. Now, researchers have developed a new robotic catheter that could help surgeons perform cardiac procedures with greater ease.

The novel catheter, designed by a team of physicians and engineers at Boston University (Boston, MA, USA), is equipped with a shape-shifting feature, enabling it to navigate complex anatomies while providing the stability needed for heart surgeries. The key to the catheter's design is its air pressure-operated, flexible tip. This allows it to be slender enough for vein insertion yet capable of inflating inside the heart for necessary tasks. An expandable ring added to the catheter provides stability by anchoring it against the vein walls near the heart's entrance. This combination of a stabilizing mechanism and an inflatable tip allows the catheter to exert sufficient force for surgical tasks in the heart without being knocked back by its beats, and then retract for easy removal. The device's potential was demonstrated in a study simulating two cardiac procedures using animal tissue, indicating its future role in making heart surgeries safer and less physically demanding.

The team tested this device on an ex vivo pig heart, targeting the right atrium. One test involved a pacemaker lead placement, where five novice operators completed the procedure using the robotic catheter, matching the time taken by an expert with a conventional catheter. The second test simulated the initial stage of a tricuspid valve repair, a more complex operation typically requiring open-heart surgery. The researchers attached a pig's tricuspid valve to a motor to mimic a beating heart and successfully conducted the anchoring step of the procedure. The next phase for this innovative technology involves trials on live subjects and more complex procedures. The ultimate aim is to reduce reliance on invasive open-heart surgeries, thereby transforming cardiac care.

“As we discuss these results with physicians working in the field, we see a high level of enthusiasm and hear of more and more applications for this technology,” said senior author Tommaso Ranzani, Ph.D., a professor of mechanical engineering at Boston University. “I think generally that this strategy is taking us in the right direction.”

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