In an interview with Medical Design & Outsourcing, Tim Laske, VP of research and business development for Medtronic Cardiac Ablation Solutions, discussed Sphere-360’s design and features.
Medtronic designed the Sphere-360 large-lattice, over-the-wire PFA catheter for pulmonary vein isolation to treat atrial fibrillation (AFib). The nitinol lattice collapses down for catheter delivery through a standard 8.5-French introducer.
“We feel that’s an advantage,” Laske said. “Certainly, a smaller introduction size results in fewer complications at the introduction site, and it’s a size and form factor that physicians are generally more familiar with.”
The superelastic nitinol catheter expands inside the pulmonary vein for full contact with the vessel wall. Sphere-360 is a single-shot PFA catheter, which means it can ablate all of the target heart tissue simultaneously, killing cells to block irregular heart signals that cause AFib. Medtronic’s single-shot PulseSelect and Sphere-9 catheters also free physicians from repeatedly rotating the device inside a patient’s heart for ablation.
Sphere-360’s adjustability sets the new PFA catheter apart from the Sphere-9, which Medtronic also acquired from Affera, and Medtronic’s FDA-approved PulseSelect.
Previously: Why Affera’s cardiac ablation technology is worth $1B to Medtronic
Sphere-360 can take the form of a sphere, a linear configuration, a pancake-shape for a maximum diameter of 34 mm, or anything in between.
“It’s infinitely variable between those,” Laske said. “One notion that you’ll be hearing more about in the future instead of pulmonary vein isolation is the notion of pulmonary vein ablation. …The goal of pulmonary vein isolation is to prevent triggers within the pulmonary veins from entering the atrium and creating chaos and atrial fibrillation. Early work was done to simply ablate those triggers. Because that becomes challenging and impractical, the step was made to isolate the pulmonary veins and create this barricade so that these triggers could not escape.”
“With some of the newer technologies, there’s an opportunity to do pulmonary vein ablation where you are entering the vein and you’re ablating these triggers as well as creating an antral isolation,” he continued. “Why that can be done with pulsed field ablation is it appears that it’s not only tissue-selective for myocytes, but it has a very low or no risk of creating pulmonary vein spasm. … The No. 1 complication that physicians worry about are esophageal fistulas and pulsed field ablation appears to be safer in that regard. That’s been our experience preclinically — and that’s the hope clinically as well — is that the worry about esophageal fistulas could be a thing of the past, but that remains to be proven.”
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