Tacks vs Stents For Arterial Dissection Treatment

[Dr. Aaron Fritts]
Traditionally, we've used bare metal stents, sometimes covered stents, sometimes coronary stents below the groin. What makes Tack so different, just at a high level, for those of us who haven't used it or used it very little, what makes it so different than just a typical stent in the leg?

[Dr. John Phillips]
Well, a couple of things. It is very short so you're getting, let's say you're going to use the bigger ones, the 4-millimeter to 8-millimeter, those are 8-millimeter in length. Basically, the way I describe it, there's two little crowns soldered together basically. It's very short. Very, very little radial strength, but enough to, I think, seal a dissection where there is some residual plaque, but not enough to, say, treat somebody that has coral reef calcification in a fem-pop region because you can get into trouble with them because after you deploy them you have to post-dilate them with a fresh balloon. You don't want anything winged because they can catch and tumble on you.

The ones in the tibialis , the smaller ones, the one five to four fives, those work well also, but again, the tibialis , I think there's a fair amount of calcification in those, whether we see it or not. That medial calcification is always a problem. You have to be careful when you use them down there. I think the sweet spot for them, in my opinion, is some of these no-stent zones as well as the tibialis, below that upper one-third because I've put in a fair share of coronary stents in the tibialis and they come back crushed. I've got one guy that he needed an amp and they put a tourniquet on his leg and he lost the toe and then we lost his stents as well because it was crushed.

[Dr. John Phillips]
…So the 4 to 8-millimeter sizing lumens, you get six Tacks on the catheter, and it's a pin-and-pull system. And so basically, you have the device and what you need to do is, under fluro or having talked to the rep ahead of time, you have to understand there's a lot of markers and the catheter itself is kind of busy. The Tacks themselves, the radiopaque portion of the Tack is actually in the middle of the two crowns. That, in and of itself, is a little bit of a hurdle because when we're putting stents in, our eyes look for the radiopaque marker.

But in most stents or all stents, the radiopaque marker is distal and proximal. This is a little bit different. There are little radiopaque bands between each Tack. So ultimately, what you have to do is loosen the tuohy and then you-- I describe it like popping a bottle of champagne and trying to pull that cork out. You don't just necessarily crank the—You kind of have to massage it sometimes. You are pinning and pulling, but sometimes you're pushing as well on the deployment device, and so, there's nuances. You shimmy it out.

[Dr. Krishna Mannava]
Some of my ultrasound techs are now asking me, "Did you deploy a Tack or a stent or what do I need to look for?" Is there any differences you've seen or heard of on surveillance duplex imaging with these?

[Dr. John Phillips]
No. I mean it was interesting that you hear, across the country, that docs were reporting lack of use because there was acute or subacute closures and a lot of restenosis or occlusion where I've seen them restenose, and it's in the tibialis. It's between the two Tacks. I think the closures are probably related to just, in my opinion, failing to see or treat another dissection or some plaque disease that the thing was going to fail either way.

I think if you size a vessel appropriately, prep the vessel and treat it appropriately ahead of time, and if you do have a dissection, putting them in specific spots along the way without having to, again, stack a bunch of them, it leads to pretty good results.

When we scan the folks at the one-month, six-month, year, whatever, no difference. I have not, in my knock-on wood, seen any issues with it or at least any reports from our ultrasound staff.