Investigational Metallic-Tipped Catheter Shows Early PAD Promise in CTOs, Calcified Lesions

An investigational over-the-wire catheter with a metallic-tip was able to successfully cross a number of calcified lesions and chronic total occlusions in the peripheral arteries that interventionalists were previously unable to traverse with a conventional balloon catheter, according to results presented last week at the International Symposium on Endovascular Therapy (ISET) 2016. 

Lead investigator Johannes Dahm, MD, Heart and Vascular Center Neu-Bethlehem (Göttingen, Germany) presented data on the first 22 patients treated with the catheter and reported they successfully treated 23 of 24 lesions with the device. In the lone case that did not result in success, investigators were able to cross the lesion and complete the angioplasty after resorting back to a conventional balloon catheter following an attempt with the novel device.  

For many of these patients with occluded vessels or highly calcified lesions, where the balloon is unable to cross the lesion, the last resort is often rotoablation, which has its own challenges and complications, Dahm told TCTMD. With the metallic-tipped support catheter, however, the “aggressive” tip abrades the edges of the calcified lesion to make sufficient room to engage the balloon, allowing it to be positioned for angioplasty. For chronic total occlusions, the metallic-tipped catheter is able to generate enough force to abrade the atheroma to achieve successful crossing of the lesion, he said.

Dahm explained that with calcified and occluded vessels, the plastic tip of the balloon catheter is often unable to cross the lesion. Given these challenges, he conceived of and designed this over-the-wire catheter to help facilitate guidewire and catheter access in peripheral and coronary lesions.  At present, there are two iterations of the catheter, with one version a blunt metallic-tip and the other a more active tip. “The active tip is like a little saw,” said Dahm. “You can use it, turn it a little bit, and you can abrade a little bit. The blunt tip is without the saw. It’s just more aggressive than a plastic tip. It’s a little bit sharp to get into the lesion.”

The vast majority of lesions treated were in the femoral or popliteal arteries (87.5%) and nearly every lesion had some degree of calcification. More than half of the lesions were completely occluded. Dahm said these were patients with long lesions, many of whom had no other clinical options. Although the device is still being tested in the periphery, he thinks the catheter could be used in the coronary arteries to treat chronic total occlusions. The main theoretical concern is distal embolization resulting from the debris created as the catheter forces its way across the lesion. However, among the 22 treated patients at their center, the metallic-tipped device was safe, with no reported cases of distal embolization as measured by post-procedure TIMI scores and no arterial perforations. To date, they have not observed any clinical sequelae resulting from shifting emboli moving downstream after the aggressive crossing. 

“I have never seen a distal embolization,” said Dahm. “In my opinion, it’s safe, even if you use the active saw-like tip.” 

Dahm stressed there is a need for many more test cases before such conclusions can be stated with confidence. The company is expecting CE Mark approval from the European Commission later this year and will also be seeking US Food and Drug Approval down the road.

Source: 
1. Dahm J. Metallic-tip-facilitated recanalization: a novel, safe, and effective option for balloon uncrossable CTO lesions. Presented at: International Symposium on Endovascular Therapy; February 8, 2016; Hollywood, Florida.  

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 View ISET 2016 Slides