PAE Procedure Workup: The Role of Uroflow and Pre-Procedural Imaging

[Dr. Michael Barraza]
To take this a step further, let's talk about cone beam CT. That's technically pre-procedure imaging and you had brought this up, it is something we should talk about and I agree. A lot of people just going straight to angio doing the embolization and that's it. You and I both agree on cone beam CT.

[Dr. Sam Mouli]
I think in the beginning, cone beam was deemed as something to make sure that we are indeed in the prostate, you're not embolizing the bladder, you're not embolizing some other structures, and that it was like a confirmatory tool. What we found from the initial experience on a lot of the reported literature is cone beam's really valuable, not just for that, but also identification of other supply and collaterals, and so early papers have reported collaterals in the realm of 20% to 40% of patients. I think in my own practice I see them in 60% to 70% of patients.

So why is that important? When I take somebody to angio, what I tell them is, I want to get you to a five-year success rate that matches Tiago's work and matches Carnevale's work, which is basically in the recurrence rate is under 20%. In order to do that, you want to treat everything that's going to the prostate at the same time, identify the major blood supply, but any collaterals that might crop up, and then feed the gland after you've done the embolization. To do that, I really rely heavily on cone beam to make sure that there aren't actual prostatic sources that I need to coil off and such. Yes, I see those in 60% to 70% of cases and I'm doing a lot of coil embolization before we do the particle embolization to facilitate that.

[Dr. Michael Barraza]
You're able to see them a lot of time on your cone beam CT. I don't think that gets talked about enough is using cone beam as a tool to identify collaterals that either need to be embolized or something you got to look out for during the treatment.

[Dr. Sam Mouli]
The way I've been using cone beam, and I think a lot of people started doing it this way is rather than using it once you get into the prostate, I do like basically a pelvic cone beam CT to get a lay of the land, the anatomy, and then look at everything that is going towards the gland. My, "search pattern" for this is I look at what's perfusing the penis on both sides first and then making sure that there isn't a distal pudendal branch that's coming back up towards the prostate or feeding the prostate." Once I've cleared that, if there is, then I try to get into that and coil it off, to begin with. Once I've cleared that, then I look at what's going to the gland on both sides.

Is there stuff from the rectum, stuff from the bladder, et cetera, where's the origin? Then trying to treat all of those vessels at the same time. What we found is once you get over 80 to 100 grams, you're usually going to have two arteries on the right, two on the left, some asymmetry that you just got to get into all of these different vessels.

[Dr. Michael Barraza]
Are they usually big enough to identify the ones that you're going to have to treat, or are they hard to distinguish from some of these collaterals, as you said, from a pudendal that you would coil rather than infuse particles through?

[Dr. Sam Mouli]
Yes, so basically what my goal is to get into all the little ones, if they are several, coil all those off, basically skeletonize the gland, so to speak, and then get into the main supply embolize that with particles to stasis.

[Dr. Michael Barraza]
Going after those at the beginning rather than during your treatment, do this prostate, pelvic and prostatic arteries, do they respond the same way they do in the liver where you could do an embolization and then 30 minutes later, you get redistribution of flow into the rest of the gland?

[Dr. Sam Mouli]
Yes, so that's basically what we've seen in our own experience and then in others have reported this that where do early recurrences come from? It's usually these collaterals that you either didn't treat the first time or didn't see or you missed or whatever. Now, I'm just really vigilant about getting into them, coiling them off up front such that once you treat the main one, you're getting feeling that inflow is cut off, so to speak. You're getting filling of the whole gland. You're not having any missing pieces, et cetera. It's like, as I'm doing the case, it's like a jigsaw puzzle, and I'm trying to piece it together side to side and make sure everything is covered and not missing anything.

[Dr. Michael Barraza]
Do you ever see these collaterals that are big enough that you decide you need to particle embolize as well?

[Dr. Sam Mouli]
Yes. I think the key is you see how much tissue it's perfusing, what's its size relative to your microcatheter, and then when you inject, are you getting antegrade flow, or is it mostly refluxing into territory that you don't want to treat from? One way is you can just do that with the catheter. The other things that I found is using vasodilators, nitroglycerin, verapamil, things like that can help you and redirect the flow such that you can embolize with particles from these collaterals if it's appropriate, and then coil them off when you're done.

[Dr. Michael Barraza]
Now, one more question about cone beam. Not using it so much anymore to confirm. Do you ever do them after you get the microcatheter in and do another one to show how much gland you're perfusing?

[Dr. Sam Mouli]
Typically not. I think the pelvic cone beam gives you a really good lay of the land. Just from a time standpoint, if you want to just move and be efficient, you can estimate from angio how much land you're covering once you've picked everything off that you need to. I think early in your experience, in your first 20 cases or so, you really need it. After that, it gets really second nature.

[Dr. Michael Barraza]
Yes. I'm not at a point where I am interested in getting rid of cone beam in really any sense. Certainly not at the beginning. I'm doing them the way you are. Asked our friend Dave Johnson his protocol and stolen that, for me it's invaluable.