Multilayered stent heralds “paradigm shift”


Benjamin Rush told delegates at the International Congress on Endovascular Interventions this month that the multilayered stent may prove to be a revolution in the treatment of aneurysms.

Presenting the results of an investigational study undertaken for the US Food and Drug Administration exploring the feasibility of the new multilayered stent, Rush said: “Previous anatomical considerations may no longer apply, and this may actually be a paradigm shift in aneurysm surgery in the future.”

Rush provided a description of the concept behind the multilayered stent, which is designed to disperse laminating arterial flow, leading to thrombosis of the aneurysm.

“Interestingly enough,” added Rush, “it also preserves flow through side-branches coming out of aneurysm that are covered by proximal and distal landing zones of the stent.”

The study was an initial look at the feasibility of the stent, to determine whether further studies are justified.

In a project led by Ted Diethrich, the stent was delivered in a porcine model and data was collected on deployment as well as short-term and intermediate patency of the stent. Researchers also tested for toxicity or abnormal tissue changes in organs and blood vessels.

In 13 animals, the one death was attributed to complications with anaesthesia, and a 100% procedural success rate was recorded.

Animals were maintained for one to six months, and were then harvested and tissue samples taken.

“Final data showed continued patency of all vessels, including covered vessels, at the one and six month periods,” said Rush. “Also, when renal arteries were covered, which was done in two pigs, there was absolutely no change in the kidney function from their baseline.”

No tissue abnormalities were found in subsequent tests.

Rush did highlight that this was a small study of non-anuerysmal animal models, but said that there is one extant example of use in a human.

“There was actually a compassionate use approximately a year ago in France in one patient who had too many comorbidities to undergo open operation for a thoracic abdominal aneurysm. To date this patient is doing fine and is being followed.”