So, what we do is, first of all, we decide whether we're going to fracture up front. So this notion of doing the valve-in-valve TAVR and then deciding if you're going to do BVF based on the hemodynamic results is problematic because you have to decide if you're going to do it. That's what determines what size valve, what type of THV you're going to put in, and what balloon you're going to use. So an example would be that if you, for example, have a 21 magna with an ID of 19, okay, if I'm not going to do BVF, I'm going to put a 20 sapien in, okay, it'll only be minimally constrained and, you know, I'm not doing it because of, you know, anatomy, because of whatever reasons. If I'm going to do BVF, now I've got options, so I can put a 23 sapien in, I can put a 23 core valve in, I'm going to use a 23 or 22 balloon to do BVF, but if you put a 23 sapien in and then, no, I'm sorry, if you put a 20 sapien in and you don't like the hemodynamic results, you're done. I mean, BVF's not going to help you. You've got no option. So let's just put it this way. So you can get, you know, somewhere between two to four millimeters of extra diameter by doing BVF. The balloon you use is going to be based on the valve you put in and the anatomy, and you have to kind of plan for it ahead of time. That's what I think. And let's just say you've got an internal diameter on the bench, right, on the surgical valve. Right. How, two millimeters, three millimeters, four millimeters, what do you use above that size? So if it's a smaller valve, so if it's like a 1921ID, two to three millimeters. If it's a larger valve, a 23 millimeter ID, I think we can get four to five millimeters out of it. Keith? Keith, that's a good question. The key is what the fracture threshold is. So if you're trying to fracture a 22 atmosphere, the minimum size will be three millimeters larger than the true ID. Let's say you're fracturing a mosaic or a microglow, you might get by with a balloon that could be two millimeters bigger than the true ID. But in general, a balloon three millimeters, but we will expand a true ID from 21 to 26. We'll get five millimeters. We do that not on time, but in general, we're looking to gain three or four millimeters at least. Yeah, I mean, I'll say that. I'll just do the caveat that that, so we're not measuring that, right? So that's in the body. We, you know, we're looking at the valve and we think it's reasonably well expanded, but you know, we don't have exact measurements. And one other, remodel versus fracture. Here is a mosaic. So we don't, we didn't know, we didn't know what type of mosaic we had. Okay. So if it's going to fracture, a mosaic is a relatively low fracture threshold. So it would have fractured around 10 atmospheres. You basically dial up the pressure when the needle drops, you know, one of two things has happened. Either the balloon has failed or the valve has fractured. And that's why the pressure drops. So here the pressure didn't drop. So we just kept, you know, I just kept inflating to 20 atmospheres. And it's, so there's no, it's not like this when it, when it fractures, it like releases, the waste releases. This is just a slow increase in the diameter. And you can see that the valve is fully expanded, foreshortens like it's supposed to be, and the gradient went from 14 to three. So it's either, it's a pop or a slow stretch. Yeah.

valve-in-valve transcatheter aortic valve replacement

balloon valve fracture

hemodynamic results

valve size

fracture threshold