Fluoro-guided access is still the norm for minimally invasive PCNL. Is ultrasound a better option? In this master class, Dr. Roger Sur from UC San Diego shares his experience using ultrasound, with practical tips for success.
the technique that I utilized takes advantage of the supine. But the techniques, the stuff that I'm gonna teach each day can be used for pro Nas. Well, because ultrasound is ultrasound, whether you have in a supine or in the prone position, here is the position that I've been utilizing. This is a slide borrow from Dr Guido Joist E. You can see there in the supine with the it's lateral leg is straight. The contra lateral leg is in with autumn E. And what this affords you is a combination of endoscopic combined in Torino surgery so you could get the puncture on the side. And if you wish, you could also put up a euro scope from below. It's not required, but that is an option in this positioning. It's, um, next slide. Am I taking over here? You have control. Okay. All right. So here you can see I have three towels, actually, slightly different than Dr TUI Si's pick. Sure, but there's three towels. One is underneath the shoulder, the other one is under the buttocks and the third is under the leg. And what this gives you is a slight bump s O. That you could get the renal puncture access. The arm is gently draped over the chest and the patients secured to the table. And again, you have also access from below. Okay, this is a picture of what the room looks like. Um, if you want to take a picture of it's probably not a bad idea if you want to use a supine positioning, Um, there is a surgeon who's standing on the side of the patient, and then you have an assistant who's at the leth Autumn E Side. Behind the surgeon is the equipment table, and in between the surgeon and the assistant is where the ultrasound is positioned, which you can also see here is that the surgeon looks at a mantra across the table, and similarly, the assistant looks at a mantra across from that person. And then, lastly, you can see that I still have the C arm in there for a single shot or whatever I may need if I have problems with ultrasound guided access. So it's Ah, it's nice. Does have that available. One thing to keep in mind in the supine position is, um, anatomical pearls here is you have the 12th rib, as you all know right there, but also keep in mind the so as tilts up. So keeping that in mind helps us when we're putting in our probe, because it reminds us that when we put our probe up to the patient, we keep it at a slight angle in line with the so as because that's how the kidney looks like. And that will give you the best chance of having a nice satchel view of the kidney if you're gonna adopt the prone positioning instead of supine, keep in minds and other couple landmarks here. The Paris spinal muscles in the 12th rib, which you're familiar with for fluoroscope E but the kidneys actually at a slight tilt. It's not straight up and down, so in a similar fashion, when you put the probe on, you don't want it up and down like this, but you want it slightly twisted to be in line with the kidney. That will afford you a nice saddle view of the kidney. So why are we still doing complete fluoroscope guided access? Why? I believe there's actually two reasons the first one is We can't see the kidney. Um, and what I mean by that is we're not terribly familiar with all the things that an ultrasound tech is familiar with. And what I do is I actually brought a tech spent the morning with a tec one day and actually maybe only about an hour or two. We saw a couple of patients, and that person took me through five settings that I feel like you should know. And if you understand these settings and can utilize them, this will dramatically improve your visualization. Help you see the kidney. So the first one is just frequency. It's important to know that the type of probe you you should be a low frequency probe. The 3 to 6 millimeter, uh, megahertz probe. Don't use the high frequency probe. The low frequency probe affords you to see deep structures like the kidney. The other thing is, make sure that you have the depth Correct. Because of the depth is incorrect. You may have too large of a structure. So where you can see here? We're ultrasound in Tesco looks be too large, and here it's too small. So you want to be in the correct size. What's the correct size the correct size. What looks good to you? I think we all know what's too big and too small. But just right is what's what you like. Simply adjust the death, and you will get the organ to be the correct size that makes sense for you. The next one is focus, um, focal zones, as you can see here on the right, the two triangles. You wanna make sure that your region of interests in between the focal zones because the organ that's in between these two triangles here will be seen best by the probe. So if you have an organ below the triangles or above the triangles, you won't get the best image. The next thing and lastly, is the gain and time gain compensation. This is the game is a simple knob, and the T G C is those funny. There's, like usually like 5 to 7 them on the top of your of your monitor. The gayness simply, uh, controls the sensitivity of your probe. As you know, your probe emits acoustic waves. It hits an object and then bounces back, much like a dolphin or a bat is sending out signals. They wait for the echoes to come back and the sensitivity or probe can be altered. And by having it really high, you'll create like this white light picture you soon left where there's too much gain, there's too much sensitivity. Or if this if it's insensitive, it will be a dark picture. So what is the right amount again? The right amount is what's good for you. But you can see here on the left um, that there's too much gain at the top as well as the bottom of this bladder, so we can alter the game with the dial. And what you can also do with the T G C. Is. Each of these levels can be changed with the T g. C. So here you see that the top of the bladder and the bomb, the bladder is kind of bright and hyper co IQ maybe too bright. So we simply move. The lever is over, and then the picture becomes more like, um which you know to be is the bladder mhm. And the second reason I feel like that we're not adopting ultrasound Guided access is we can't see the needle, can't see the kidney, can't see the needle you don't wanna do ultrasound puncture. Right. So how do we optimize seeing the needle? That's like 11 thing you can do here, you can put a scope in from below on and creates. Um, artificial. Hi, Jennifer Asus on, then you, And actually find the ideal kill its of interest. Put that scope right where you want it and puncture right onto the scope. Not the scope itself, but where the scope is located. The second thing you might want to consider is Do you want to use a needle guide or do you want a free hand? There are pros and cons to each thing. I have a bias towards using the needle guide because I have a lot of trains. I feel like it's easier to teach, but that is simply my opinion. Um, I think it does kind of level out the learning curve and makes it easier for people to adopt ultrasound guided access because you know exactly where you're gonna be putting your needle and you don't have to see your needle. In a sense, you just have to fall. Just put it into the guide, and it's gonna go where you're putting it just much like when you're doing a prostate biopsy. The disadvantages is it does limit you because you're limited by the needle guide itself on DSO some people say who do freehand that it becomes then a crutch. If here you can see my technique of using the Tachia Loca Uh, in this case, I injected methylene blue. This is earlier in my experience, when I was not putting a scope up from below. I used also a balloon occlusion occlusion balloon to maintain the hydra Infosys. I was pre load the needle into the guide because once you see the target, what you don't want to do is have to fiddle foul to tryto get the needle in there. Then you lose your the target again. I was kind of a little bit parallel to the the rib notice that the picture is kind of dark here, So I turned up the game so I can see things better. And once I turn up the gain, I try to tell anesthesia to create some apnea so the kidneys not moving And then I, um, advance my needle. I like this navigate needle. Um, it in my mind is very hyper quick. It is made by Boston Scientific. Um, and I like to use a staccato type movement. I feel like with a staccato type movement of the needle. You can see it easier as opposed to a slow, um, non staccato type movement. So here you'll see. I'm going through the needle guy. You have the lines, just like in a prostate biopsy. Not sure that really showed Oppa's well as I would have liked, but nevertheless that Trust me on this, Um, And after I get the needle into the kidney, I will sometimes take a 11 shot with the X ray just to confirm that everything looks good. But you don't have to obviously, on with the blue methylene blue. Um, you're able then to know whether you're really seeing your and sometimes there's a question is the blood is a urine? Well, when you use methylene blue is either blue or it's not, can't I think that kind of move kind of quick for us, but the Freehand approach again advantages. You could get any angle you want. Needle holders can be clumsy. Uh, cons is that maybe it's a steeper learning curve course Real stable hands again. I find it can be challenging to see the needle. The needle is not terribly hyper quick, as much as you would think for a metal object beyond the scope of this discussion, Suffice to say, the needle is not easily seen. And one thing, if you're gonna use a free hand approaches to recognize that the acoustic waves come out of the out of the probe like a laser, not like a flashlight. So it doesn't light up everything. It comes on Lee um, in the in the plane of the probe. So that being said, if you're going to use a free hand approach, I like to put in, you know, not there, but actually here at the top at the polar ends of the probe. Because in that way it takes advantage of the fact that you'll see the needle the entire time when you're placing it. Whereas if you put it on the side like here, you'll only see it for a brief moment. Where is over there? You'll see it the entire time. And again, that takes advantage of the way that the acoustic waves come out of a probe like a laser. Not like a flashlight. So, in conclusion, um, practice, practice, practice when? Beginning of my learning curve. I didn't use that. I just put the ultrasound probe out. I would look at the kidney when Andi just and just stare at the kidney. Every single piece. You know, I did. I would just look at the kidney and then after I was like, You know what? I think I could just stick the needle in here. I see the hydroids right there. Why don't I just put it in there and she Sure enough, I put it in. I saw your eyes like la la I think doing it in the clinic. If you have a patient, you know, going to do a PCL on, go ahead and practice. You know, that's the patient. You cannot right on your mind. Will put the probe on the patient. Uh, you can practice on your colleagues. They can practice on you if they're willing. I think another, uh, nice nice thing to do is if you have a prior ultrasound done by a radiologist and you have the images now you actually have Ah, go to that. You can compare. So if you have the images, go and take a look on your patient in the clinic, the patients love it. Actually, for some recent when you do ultras and they're like, Oh, you're looking my kidney. Yeah, I just want to take a look at it. And in my mind, I'm thinking I just want to compare what I saw on the on the radiology images because every told me what to see, and then I could see if I could replicate that. I think the thing that really helping mostly spending time with an ultrasound technician, even one hour seeing a couple of patients goes a long way. And again, practice, practice, practice. If you want my slides, feel free to email me. I'm happy to share things with you. You can email me, WhatsApp, me, twitter, whatever you wanna dio. I'm happy to share whatever I have with you on. Um, thank you very much. Well, great or