Surgeon: Dr. Khurshid Ghani
Dr. Ghani is an Associate Professor of Urology at the University of Michigan. He has authored over 150 peer-reviewed publications, and is the co-editor of a textbook, Endourology: A Practical Handbook. Dr Ghani serves as the Director of the Michigan Urological Surgery Improvement Collaborative, which is a consortium of over 40 urology practices aiming to improve the quality of urologic care for patients in the state of Michigan. Dr Ghani is also the Course Director of an international symposium on ureteroscopy: Developments in Ureteroscopic Stone Treatment (D.U.S.T.). In particular, Dr Ghani has been focused on advancing a Dusting technique for endoscopic stone surgery and has extramural funding to study optimal parameters for holmium laser lithotripsy.

Moderator: Dr. Evangelos Liatsikos
Dr. Liatsikos is a world renowned Endourologist from Greece who will moderate this session on dusting techniques during ureteroscopic laser lithotripsy.

 

Webinar Transcript

Jared Winoker:

Good afternoon, everyone. I'm Dr. Jared Winoker from Johns Hopkins. And on behalf of Dr. Joyce and Dr. Chu my pleasure as well as the Endourological Society, it's my pleasure to welcome you to the latest installment of this wonderful educational initiative, the Masterclass in Endourology and Robotics. Of course, we'd like to thank our sponsor and friends over at Lumenis for their grant in supporting this activity. So for your reference, this is just an overview of our CME program for this webinar today, and this will all be recorded so you'll be able to look back at this. And certainly what would a masterclass be without its masters of surgery? For today's session on the Dusting Technique for laser fragmentation, we're privileged to have Dr. Khurshid Ghani from the university of Michigan and moderating Dr. Ghani's prerecorded semi-live surgery will be Dr. Evangelos Liatsikos from the university of Patras in Greece.

Jared Winoker:

But before we get started, I'd like to just make special mention of next week's webinar, which will be on Thulium laser in the treatment of BPH. Where we're going to be joined by doctors, Zeph Okeke and Andreas Gross. And you can go ahead and register for this session and other sessions, as well as review recorded previous webinars that we've had by visiting into endourology.org. Simply click on the education tab, and then you'll find masterclass in endourology. So with regards to continuing medical education for today's webinars as well as other seminars, you're going to receive a survey from Michele Paoli by the end of each month. And when you receive that survey, just go ahead and indicate which seminars you've actually attended, and then you will be emailed a CME certificate to the email that you have on file. I do want to just let you know, please fill out the evaluation questionnaire that'll pop up at the end of this webinar as well as all of our webinars as this is important for your CME credits.

Jared Winoker:

And finally, I do encourage all of you to use the Q & A function to ask questions today and also participate in our poll questions as they're certainly going to only enhance what I'm sure to be a lively discussion. So without further ado Dr. Ghani, I will turn it over to you.

Khurshid Ghani:

Thank you, Jared. And thank you for the invitation. Can you hear me, Jared?

Jared Winoker:

I can go ahead.

Khurshid Ghani:

Okay. So I will share my screen and let's, I will start. Can you see the slides? Okay. Good.

Evangelos Liatsikos:

Yes we can see them.

Khurshid Ghani:

Thank you. So thank you. And thanks. So thanks to Endourological Society Dr. Joyce and leadership for the opportunity to share our technique the semi-live video, which we presented at the World Congress endourology in Abu Dhabi. And it's a great privilege to be able to do this with Dr. Liatsikos, who'll moderate this. So what I'm going to do is just over the first few minutes, just go through of the technology and the innovation around the Moses technology, which is a pulse modulation system. And then we're going to switch to the video where Liatsikos will be moderating it as we go through the technique. The Moses technology is the patented pulse modulation system from Lumenis. And what it has done for the holmium laser systems is, it's taken us from a standard single pulse mode. Whether that's a short pulse or a long pulse to a split pulse mode where the holmium pulse is split into parts. And what you see here are the optical pulse profiles. And you can see that the long pulse has a little bit of a plateau. These pulse durations vary depending on the pulse energy and the system, but they can vary from 200 to 500 to 700 microseconds.

Khurshid Ghani:

And then what you can see in the Moses distance optical profile, you have two pulses that are equally weighted. And I call it the double bubble. And these are high speed imaging videos on the right, just give you an example of what a long pulse and a Moses distance bubble look like. In a little bit more detail, the thing to know about the short pulse bubble is that usually it's a rounded shape. It has a significant bubble collapse. It has a high peak, as you can see on that graph. And you can't see that graph, right? Yes, of course. I've just, suddenly I've lost my screen of everything, but okay. I've got it there. And then you have the longer pulse, which is a longer pulse duration. It has a pear shape to the bubble, and a less of a bubble collapse, a lower peak power. And that's why long pulse is very good for reducing retropulsion. And that's why long pulse mode is good for reducing fiber burn back because of the lower peak power.

Khurshid Ghani:

The Moses technology comes in two bubbles options. One is called Moses contact and the other one is called Moses distance. And if you look at the Moses contact, they're both two bubbles. But in Moses contact, the first bubble is small. And then the second bubble is much larger. Versus in Moses distance bubble, there are two bubbles but they're equally weighted. So they're both of equal size. So this is what we have. We have these split pulses, but what do they actually do for laser lithotripsy? And we studied these in the laboratory, and this is a video of all the sequences together. And this is a still shot of maximum bubble expansion. And you can see here that difference between the Moses distance bubble on the far right where that first bubble is much bigger and equally weighted with all the optical pulse profiles provided on the far right in that graph. So what do these split pulses do? Well, when we tested this in the laboratory over control conditions, using vogel stones, we found that actually the Moses distance bubble led to around 30% more fragmentation when breaking up the stone.

Khurshid Ghani:

And I don't want to confuse the audience by thinking that meaning that you have to touch the stone at distance. No. In this, we actually did experiments where we broke the stone with the laser fiber touching the stone on contact, but then we just used four different pulse modes. And we were surprised to see that the Moses distance mode led to more fragmentation. We then did experiments actually on distance. So this is where the laser fiber is either on contact with the stone or one millimeter or two millimeter away. Well, you can see here that as the laser fiber distance increases, the ablation is decreased and that's because of fluid absorption. But the Moses distance bubble at one millimeter distance led to a 100% more fragmentation on a single pulse measurement compared to a standard short pulse. So there is some advantage in using a pulse modulated system like this. And what we think in my personal view, I think the major advantage is around kidney stone dusting. Because when we do kidney stone dusting, we're always moving and interrogating the laser fiber on the stone.

Khurshid Ghani:

We may not always be on contact with the stone. We may be one millimeter away. We may be two millimeter away. We may even be four or five millimeter, we're constantly moving. And so if you're going to use a wave form that gives you an advantage when you're a distance, I think that will be helpful. We don't know how often surgeons are using this type of distance. I'd be curious to think what Dr. Liatsikos says when we start looking at the video. But my partner in our laboratory here, university of Michigan Will Roberts, recently did some very nice experiments and found that 34% of the time the laser fiber, when doing a dusting technique was around 0.5 to one millimeter, and you can see the breakdown. So for these reasons, we use the Moses distance mode for kidney stone dusting.

Khurshid Ghani:

So let's begin with a case. So this is a patient who has multiple stones in the left kidney. The sizes are 14 millimeter, 12 millimeter, and seven millimeter and some smaller stones. And she'd been ignoring these kidney stones for some time. She'd refused, absolutely refused a PCNL, which I would have recommended. But because patients have different decision-making points, and one thing that this patient did not want was an overnight stay in the hospital. Absolutely refused that. So the other thing is for a stone at this type of stone burden, as you can see here on the CT scans, I usually do recommend patients that they might need a second procedure to get maximum stone clearance. And she only wanted a single procedure. So you can see here, the stone volumes are 1,145, 110 and 761 millimeter cube with Hounsfield units of around 1,400, 1,250, et cetera. So a couple of stones, harder stones, and we did it as a ureteroscopy, flexible ureteroscopy and laser lithotripsy. So I'm now just going to move to the video.

Evangelos Liatsikos:

Khurshid.

Khurshid Ghani:

Yeah.

Evangelos Liatsikos:

Just a question on what, so the people understand exactly practical aspects. So if one would want to use the Moses distance, then he would use it for dusting more and Moses contact for fragmentation. Is this what you're saying?

Khurshid Ghani:

Yes. That, in a simple nutshell, distance for kidney stone dusting, Moses contact mode for fragmentation and especially in the ureter. So even if I'm dusting in the ureter which I do, I don't use the distance mode. I have found that this double pulse, the longer pulse duration with that can actually launch urothelium when you're not expecting it to. So for safety reasons, I don't use Moses distance in the ureter. I use Moses contact, but I keep it on contact with the stone.

Evangelos Liatsikos:

Okay.

Khurshid Ghani:

So I've just started the case. Can you see the case recording?

Evangelos Liatsikos:

Yes. We can see it.

Khurshid Ghani:

Okay. So for a stone of this size, multiple stones, I have to do a lot of dusting, prolonged operating time. I always try and use an access sheath.

Evangelos Liatsikos:

Sorry for interrupting. There's the poll. So people should, let's try and see, respond to the poll questions guys. And they're simple questions, but we want to see how you're moving on. So do you typically stand before you typically stand after? Which of the following is best describing the access sheaths? We want to see if you're using access sheaths, if you're not using access sheaths. You're using double-J stent, or if you're not using double-J stents. Please vote and see what we have of this. Please, this question.

Khurshid Ghani:

So can I close this screen of the poll now?

Evangelos Liatsikos:

Yup.

Khurshid Ghani:

So we'll, I know you had it as a poll question. So this is a maneuver that I do when I do kidney stone dusting. I placed the patient in a head down Trendelenburg position. It helps me sort of herd and try and avoid fragment distribution in the lower pole. You can see on fluoroscopy that and maybe because I'm sharing the full screen, I'm going to remove everyone's faces. So that would be better. Is that better Evangelos?

Evangelos Liatsikos:

Yeah. That's good. That's very good.

Khurshid Ghani:

Okay.

Evangelos Liatsikos:

That's-

Khurshid Ghani:

All right.

Evangelos Liatsikos:

What kind of irrigation are you using? Are you using forced irrigation pump or what are you using?

Khurshid Ghani:

So we use a saline bag that's kept at a liter height with pressurized, so it's pressurized at 150 millimeters of mercury. And that is our standard set up for irrigation. It's not machine, it is higher flow rate. It's around 38 MLS per minute. But then I modulate it on the tip, where in the outlet of the scope where I can tweak on and off. But that's the flow rate that we're using. That's equates to around 304 centimeter height of a water bag.

Evangelos Liatsikos:

Okay.

Khurshid Ghani:

So here's the panel of the P 120 Moses system, a dual panel system that many people are familiar with. So I start with, can I close this poll?

Evangelos Liatsikos:

Let's see the results of the poll-

Khurshid Ghani:

Let me put there. Okay.

Evangelos Liatsikos:

Typically stent before flexible? No, is the majority. We have 41% no. And it would be interesting to know what these selected cases are the 30%. Typically stent after? Yes, it's almost 80%. So more or less, most of the people stand and which I almost always use an access sheath. So 55% use an access sheath before doing flexible ureteroscopy. And before inserting an access sheath, do you inspect the ureter? Yes. The majority. Now Khurshid, I have a comment and a question for you on this.

Khurshid Ghani:

Mm-hmm (affirmative).

Evangelos Liatsikos:

How can the majority of people use an access sheath with no prestenting? Because we have a discrepancy between the access sheath here, and the prestenting. What do you do in your practice? Do you put an access sheath if you haven't prestented before? Or what do you do? Let's give an advice to the people.

Khurshid Ghani:

So in this video, I just placed an access sheath. The patient was not prestented. I use a for, because I'm not doing retrieval, I don't need a large access sheath, but I needed one that's good enough for my particular scope and the outflow. So in this case, it was an 1113 French. It went in very well. I have a safety wire when I use an access sheath, I put all my patients on preoperative [inaudible 00:14:13] an alpha blocker to help facilitate this strategy. It's something I do. I've seen some of the literature around it, it's mixed. But that's something I do to help facilitate that.

Evangelos Liatsikos:

What do you do when you cannot insert your access sheath? You see there's some friction, do you go without an access sheath?

Khurshid Ghani:

Yup.

Evangelos Liatsikos:

Do you change your strategy? What do you do?

Khurshid Ghani:

So it's a good question. So I will go in, I will get into the kidney and I will dust. But I do a couple of things. I'll make sure I have a safety wire in the kidney, because I want to sort of open up the UPJ as much as possible to allow drainage from the kidney for a lower pressure. Next I have a small catheter placed in the bladder, red rubber just allow constant bladder decompression. I'm very conscious about intrarenal pressure and those risks. And then I time myself. I won't do more than 30 minutes of a laser lithotripsy when I don't have an access sheath. And that's just what I do. It is not really based on strong evidence, but everyone will have a different viewpoint. And then I'll stop and then I'll stent. And then I know that I have to come back and clean up with the second [inaudible 00:15:27].

Evangelos Liatsikos:

Okay. Now, I will be introducing also the questions by the audience to you. And this is a very nice way of doing interaction. There's two nice comments. One is that there is a lot of people advocating that they are breaking big stones, bigger than two centimeter stones in the kidney. And does the Moses change anything on this? And is it going to be competing PCNL in the future? What do you think?

Khurshid Ghani:

Oh, I don't know if you want me to stop and start. I think these systems like the Moses, and especially when they brought out the high power system with higher frequencies allow you to tackle bigger stones. And I've definitely found that with the Moses systems, I can't tackle harder stones. I still have my cutoff of two centimeter. I prefer to do PCNL in those patients. But I am-

Evangelos Liatsikos:

I fully agree with you. I fully agree with you that this needs to be a message. Flexible is not a toy that you can play for hours there. And any kind of technology that we may have now, we need to keep in mind the pressures inside the kidney. And there's another colleague here saying that 150 millimeters of fluid is high. So there's a concern on the pressure. No one can answer what is the pressure? A lot of us are using different kinds of systems and it's really, really a debate on this. That's what I think.

Khurshid Ghani:

And so, when the video you'll see that one of the things I'm very conscious about, I always check my outflow in the access sheath and I'm checking for drainage. I'm feeling that there's drip, drip, drip, and then that makes me feel I'm mitigating.

Evangelos Liatsikos:

Another very, very interesting question that I have here is, and I agree with that. Do you always use a rigid scope to do an endoscopic view of the ureter before you insert your access sheath?

Khurshid Ghani:

No.

Evangelos Liatsikos:

What if you have a stone in the ureter that you haven't seen? A smaller stone. Won't the access sheath embed it inside the urothelium?

Khurshid Ghani:

If I have a small stone, I am very gentle with the access sheath. If I feel there's any resistance, I'll stop. That's the time then I'll go and look up with the semi-rigid scope.

Evangelos Liatsikos:

Okay.

Khurshid Ghani:

And the number of times I have discovered, in the modern day, we all have CTs that were done very recently for these patients. And of course, if the patient you see them they say, "Look, I'm having increased pain." You would suspect they may have dropped a stone in the-

Evangelos Liatsikos:

So let me ask you on what you're doing on the video now? You're using 28 Watts, 70 frequency and 0.4. Okay? And you have a high power laser?

Khurshid Ghani:

And this is, yeah. And then I'm using the Moses distance wave form. And I'm just, this is a stone in the lower pole. There is some respiratory interference. In fact, usually I like one of the things I like to do is to make sure in these difficult cases that the anesthesiologists give a GA endotracheal and control the tidal volume makes it easier for us. But in this case, it wasn't. So I'm sort of making do with the kidney sort of bouncing up and down. And I'm just trying to ablate the stone in a very strategic manner. I want to just keep shaving it and keep moving to all the points, trying to sort of debulk and strategically see that stone vaporize. And I think-

Evangelos Liatsikos:

Few questions.

Khurshid Ghani:

Yup.

Evangelos Liatsikos:

Few questions, one from me and two from the audience. You are using a high power laser, why don't you increase the frequency to the maximum that you can get with that laser fiber? What is your fear?

Khurshid Ghani:

Okay. So first of all, I'll pick the settings that I think are working well. What I don't want is massive chunks falling off. So if you put a higher pulse you're going to get bigger chunks. What I want to see is real vaporization and ablation. Where everything that I'm breaking off, I know is things that I don't have to worry about from a residual fragments status. And so that's one of the reasons of picking my settings, I like low pulse and then higher frequency. I could have gone to 80 Hertz and the system will allow me to, but it's maxed out at 80. The second reason why I'm sort of managing my power output is if I start with a very high power output from the word go, with a 200 core fiber, and this one's a 230 core Moses fiber, you want to manage your fiber burn back. And so I'm very strategic in terms of I'll start like 28. And then I start working my way up as needed.

Evangelos Liatsikos:

It's very impressive. This comes to another question also that the audience is asking, what happens with temperature? And this is an amazing question. And it's very impressive how different we are all are with what we are doing. I have a device that gives me the possibility to go up to 60 Watts. And we've discussed this in the past many times, I will go with 60 Watts and bombard the stone and [inaudible 00:20:18] the fragments earlier. And this is a different concept. What do you think about temperatures? Are you creating high temperatures now with what you're doing on 45 Watts?

Khurshid Ghani:

Yeah. So right now I'm using what? 28 Watts. And I'll go up to 40 in this case and I'll end up at 48 at some point. So we've done work here at Michigan, led by my partner Will Roberts, where we've done both in vitro and in vivo evaluations. And what we found is 40 Watts is a significant amount of heat generation if your flow rates are low. So the flow rate that I'm using in the studies that we've done are safe. And they don't lead to heat generation.

Evangelos Liatsikos:

Would you still do the same thing if you didn't have an access sheath inside?

Khurshid Ghani:

I would still, as long as my flow rate is mitigating that.

Evangelos Liatsikos:

Okay.

Khurshid Ghani:

So, and I do. Because I do you, I routinely, and that polled question about do you use stents? If I have an eight millimeter, one centimeter kidney stone, those are the cases that I will dust without an access sheath and leave the patient without a stent. And I may only need to use 40 Watts for one or two minutes, right at the end. And at that stage, I'll have my higher flow rate . So I can, I mitigate that.

Evangelos Liatsikos:

It is impressive and we've discussed this before, that we've extensively studied this. And people think that if they go with a low power laser, low flow, passive flow, no access sheath that it's safe to go inside the kidney and bombard with a laser. This is completely false. The temperatures that you generate with no access sheaths with 20 Watts and with a passive flow can reach up to 50 degrees, 55 degrees. It's impressive. Huh?

Khurshid Ghani:

Yes. So I think-

Evangelos Liatsikos:

So the key point is if you're using high energy access sheaths, high flow of irrigation, and you do not activate, I cannot work at like what you're doing. You are continuously working with your stone.

Khurshid Ghani:

Yeah.

Evangelos Liatsikos:

I have to work and stop work. Work and stop. Let's see the polls that the people have answered here.

Khurshid Ghani:

Okay.

Evangelos Liatsikos:

What is your go to setting for dusting technique for a one centimeter kidney stone dusting, that was flexible [inaudible 00:22:23]. Majority 39%, 0.2 to 0.3 with 50 to 80 Hertz. This is interesting.

Khurshid Ghani:

You can see so not many people said they wanted to use the high upsetting from the word go, right? Look, 18% wanted-

Evangelos Liatsikos:

This is interesting. What is your preferred setting for non-contact laser lithotripsy popcorn technique? So that's one joule, 15 to 20 Hertz on short pulse at 31%. So there's a cutoff there. And then what methods of irrigation do you use? Forced or manual 40%. Now look, there's 32% of people using passive irrigation. And this is, I would be curious to see if this 32% of people are using access sheaths. Because if they're not using access sheaths, and they're lasering even with a small laser, with a small power laser, they're generating temperatures. And this is something that needs to be noted. And do you find the bolt tip lase of fiber useful? Unsure it's 56%. Why do you think it's useful? Khurshid the bolt tip?

Khurshid Ghani:

I think in the lower pole for those cases, it's helpful. I don't think it's critical. So it just, this particular fiber comes as bolt tip. It doesn't come as any other option. So I do think for the difficult cases... But if you're using a single use ureteroscope, a bolt tip fiber is really of no value, right? Because the whole thing about the bolt tip is it protects the scope. It allows you to advance the fiber when the scope is deflected. So I think it's a 50-50 option here.

Evangelos Liatsikos:

Don't you find it's easier once you've localized your stone with your scope on your lower calyx and you have an acute angle or whatever that you don't need to go back, straighten your scope again. I think it makes it, it's-

Khurshid Ghani:

Absolutely.

Evangelos Liatsikos:

[inaudible 00:24:08].

Khurshid Ghani:

But the number of cases where that happens, you sometimes can't predict. But it's helpful for the lower pole, for sure.

Evangelos Liatsikos:

And what people also need to understand is that the bolt tip is good for the beginning of the case. You can't just take it out and put it in again afterwards, because most of the times there's no bolt anymore.

Khurshid Ghani:

Yes. As you can see, the bolt tip here it has now gone, which is sort of happens. Which happens.

Evangelos Liatsikos:

Another question from the audience which is interesting is you're using, what kind of scope are you using now?

Khurshid Ghani:

This is a Olympus V2 digital scope.

Evangelos Liatsikos:

So the V2 comes out from the nine o'clock, the fiber.

Khurshid Ghani:

[inaudible 00:24:47].

Evangelos Liatsikos:

Do you think that in a department, you need to have scopes that come from nine o'clock. The other ones that come from three o'clock?

Khurshid Ghani:

Yes.

Evangelos Liatsikos:

You find it difficult to adjust in some scenarios with a scope like this, that would be helpful having another scope?

Khurshid Ghani:

Yes. So in fact, in one of our centers where I work at the VA hospital. We have Olympus with a working channel at nine o'clock. And we have [inaudible 00:25:10] with working channel at three o'clock. And it allows us to strategically choose when we're doing left and right kidney surgery and location. So I do think as an endourologist that's a very nice add on. I don't think it's essential, but it's nice.

Evangelos Liatsikos:

We have a question here by the people saying that the 200 nano meter fiber can only transmit up to a certain point. You're dealing in a... 200 fiber in high power lasers can transmit up to 60 Watts. It's not limited. I'm just answering to the people. Because they're saying that you can only transmit up to 18 Watts effectively. And in high power lasers, this is not a limit from what I understand. Do you agree with this? It delivers up to 60 if you want.

Khurshid Ghani:

Yes. So this fiber is tested so up to 60 Watts.

Evangelos Liatsikos:

Okay. And then the other question is what setting is used to completely dust and not leave any fragments. What is your opinion on this? Do you think that you can only dust a stone or only break a stone? Is this ever possible?

Khurshid Ghani:

No. In my mind, it's never been possible just to obliterate, vaporize and the stone's gone. At some point, you always have some chunks and crumble of fragments. And then you have to then do popcorn technique to sort of break those into even smaller and smaller pieces. If at that stage, you're fine and happy with the fragment size, that's when you may then have to get the basket out and do a little bit of retrieval and pick out the larger fragments. So [crosstalk 00:26:43]-

Evangelos Liatsikos:

Another interesting-

Khurshid Ghani:

Complete dusting technique, but I don't think it's possible just to get complete vaporization where everything's just disappeared.

Evangelos Liatsikos:

I completely agree with you. Another question is, do you have an experience with a Wolf dual aluminum endoscope that has channels on both sides one at 12 o'clock and one at four o'clock.

Khurshid Ghani:

Yes. So yes. I've used it and I actually thought it would be very helpful for that very reason. In fact, the working channel if I recall when I trialed it, actually comes out at six. And so it wasn't as what we imagine where it does three and nine. There isn't, as far as I know a working, a dual channel scope that does a three and nine option. And in terms of, I do think that the scope from Wolf is helpful in the sense that you could have a fiber and a basket at the same time. So that's definitely a scope that I felt was quite attractive from that perspective.

Evangelos Liatsikos:

A colleague is asking us, why didn't you relocate this stone to the upper pole? Is there any, what is your indication for relocating a stone to somewhere else? The middle pole or upper pole for you to treat?

Khurshid Ghani:

Okay. So that stone was pretty big. It was at least 12 millimeters in the lower pole. Once it gets really big like that, I find it quite cumbersome and challenging to get the stone in the basket, then move it and actually then get it released. So I just don't bother. The second thing is I look at the angle of the lower pole and if it's not a challenging angle, I just read the high power lasers now. I just do [inaudible 00:28:21] lithotripsy. And then and once I do pop dusting like here, where I'm just staying a couple of millimeters off the stone, and I'm just firing away. You can look at fluoroscopy. That stone was a hard stone in the beginning, and there's not much on fluoro now. And now I'm using my higher power setting of 40 Watts 0.5 and 80 Hertz. Again, using Moses distance mode. And this is where I'm pop dusting. So I'm just keeping the fiber still. And I activate the pedal on and off on and off. And it's not continuous fire.

Khurshid Ghani:

Contact laser lithotripsy, like you saw Evangelos, when I'm breaking the stone in the very beginning is a, my foot is on the pedal constantly. And that's why I like to keep the power a bit lower, like 28 Watts, 24 Watts, et cetera. But pop dusting where it's on and off on and off high intermittent bursts. And the aim here is just to be patient and just keep grinding away the stone until you look at the laser fiber tip, you look at the fragments that you see and you say, "What is the size of the fragment?" And then at the end, you'll see, I do flush these calyceals with saline. So I don't, but now if the stone is a six millimeter stone in an acute lower pole angle, for sure I'll use a basket and move it. But for this particular case, I didn't.

Evangelos Liatsikos:

So a couple of questions are coming in. First of all, do you have experience with using baskets, at lasering through dropping baskets? These devices that you can put the laser through the baskets and laser it inside in situ. Have you done this? Do you have any experience with this?

Khurshid Ghani:

Yeah. I did it some time back. I haven't done it in the kidney. I was more interested in doing it in the ureter. In the kidney, what I had tried to do is I used BackStop Gel. What Boston scientific had made some years back. And I thought that would be perfect to just sort of fix your kidney stone and then it doesn't move it. You can just contain it and blast it and dust it to smithereens, but it didn't work out the way I imagined.

Evangelos Liatsikos:

The difference of what you're doing to what I'm doing is when you're pop corning and you have a calyx and you stay in the middle, why not take advantage of your whole power? And you're stepping the pedal, I see that you're stepping on the pedal for a certain period, and then you stop. So why do you want to stay at 45? And you don't get the maximum from your fiber? I find it that when I am in the middle of my calyx, it reduces the surgical time drastically. For me, at least. This is a game changer.

Khurshid Ghani:

No. And believe me, pop dusting at 40 Watts, is phenomenal. It has to be done safely. So that's what we do. I intermittently fire. Plus sometimes with these very high powers, you get a significant... And that's the video to show. Look at my outflow. Do you see how much outflow I'm getting through the sheath? I always check that because I've got a high flow rate, I want to make sure I'm mitigating myself and so I feel confident. That allows me to know that I can go for 45 minutes, 60 minutes, whatever for laser lithotripsy as a single procedure. But sometimes if you've got excessive power, you get the extreme movement of all the fragments colliding, et cetera, you can't see. So you have to balance the safety parameters against the calyceal wall, being able to see and as we know the data around heat generation and thermal toxic doses. So it's a balance of all of those factors. But in this case, I do ramp up the power at the end towards 48 Watts.

Evangelos Liatsikos:

It's interesting. It's interesting the different patterns, I use it differently but some other questions. What happens when you have the wire in front of you and your safety wire is in the same pole. Let's say this would be an upper pole or something like this, and you break your wire. What do you do?

Khurshid Ghani:

I haven't done that. Of course.

Evangelos Liatsikos:

Do you pull your wire back at all when you have it in the middle of your stone? Do you just bring it back?

Khurshid Ghani:

Yeah. The wire is in my way, just bring the wire back. If the wire is annoying you, I just bring it back. But you really have to blast that wire for a long time for it to break.

Evangelos Liatsikos:

I know.

Khurshid Ghani:

You can get a little nick on it, but yeah. I just bring the wire back.

Evangelos Liatsikos:

Another question is a thulium laser, the new kid on the block now. Any experience with that?

Khurshid Ghani:

My clinical experience is very limited with that. And I'm looking forward to using it clinically to get a sense, to get a sense of that. Do you have experience with it Evangelos?

Evangelos Liatsikos:

I have seen people using it. I have no personal experience. It's very effective. And I know people that are using it are happy with it, very happy with it. So, but there are still questions to be answered like heat temperature, how much heat generation it produces, all of these issues. But clearly it's something new that everyone is looking at. There's no doubt on this. And it's one of the debates, whether you need a high power laser a holmium laser or thulium fiber laser. So this is an interesting thing. It's a very interesting discussion.

Khurshid Ghani:

One thing I want you to see about the Moses distance mode, and this is something that I've noticed is that it's very good at sort of melting and ablating especially the harder surface. And so, I think as we learn more and more about how stones break up with the laser, whether it's a photothermal predominant, which is what we all think, how much element is there a photo mechanical? Is there any elements of how much contribution is there for explosive vaporization with when the pores of the [inaudible 00:34:11], There's lots of competing theories. I think there are multiple factors at play. And I do think that different wavelengths and different modulations, et cetera, may harness one over the other.

Evangelos Liatsikos:

Two questions two. I can't stand... The questions are coming, they're coming, they're flowing in so I have to group them up.

Khurshid Ghani:

All right.

Evangelos Liatsikos:

One question is what happens when you have bleeding inside? So you have some kind of bleeding and you can't see any tips and tricks on what you should do.

Khurshid Ghani:

Yeah. So bleeding is the enemy, right? So that's why again, you asked what's your power settings. I like to start not such a high power. Because if I accidentally blanch and hit a papilla and it bleeds, it's going to limit my ability to complete the case with confidence that I got all the fragments. So I'd manage my settings, I manage my distance of fiber tip to surrounding structures. I would point out that with Moses distance, you just have to watch out that it can't blanch the calyceal wall. Now it doesn't, it hasn't led to bleeding. One could argue that with the high-flow that we're providing, you may not see the bleeding. But even at the end when we stop the flow and look around, we don't see much bleeding. So it's all about managing your laser settings and your technique.

Khurshid Ghani:

And I tell you these low pulse settings, dusting at to 0.2, 0.3 and higher Hertz, 30, 40, 50, 60, whatever you choose. Even if you end up hitting the urothelium at a low pulse, there's very little bleeding. It's not like the old days where we used to do pure fragmentation. 1.2, 1.4 joules. And if you accidentally hit the wall that higher pulse energy led to bleeding.

Evangelos Liatsikos:

Another question is, where do you place your access sheaths? Is it always under the UPJ? Do you ever place it inside the UPJ? How do you address this?

Khurshid Ghani:

Okay. So in this particular case, the access sheath could not go beyond the point you see there in the fluoroscopy because the ureter was a little bit narrow out there and you'll see that on the way out. So I didn't want to push it to be safe. But I like to get it high up in the upper ureter. I think Dr. Clayman was the one many years ago, who did some nice studies on intrarenal pressure and found that the way you place your access sheath in terms of the ureteral location, will impact the intrarenal pressure. So I do like to get it as high up as possible. I don't technically like to get it beyond the UPJ because I think that can be problematic. It all depends on the kidney. Some UPJ are very open and some of them are very hydronephrotic and compatious. And sometimes having the access sheaths beyond the UPJ at that stage is okay. But I think if we were teaching, we like to say my view is to keep it underneath the UPJ.

Evangelos Liatsikos:

What do you do in case you have a broken tip of the laser fiber? So you see the glass inside the kidney, do you take it out or you leave it in until it flushes all out by itself? What happens if it stays in?

Khurshid Ghani:

Yeah. Again, I've never had the tip break like that, but I've seen a case where we've gone in to break up a stone. And then when we started to break up the stone, what we saw behind the stone is this long, transparent laser fiber tip. Which was the nidus for stone formation. So ever since I've seen that, I felt that if you do break a significant fracture of the laser, you should try and retrieve it.

Evangelos Liatsikos:

Okay. And what do you do with timing? This is a very important question. Do you have a limit for your flexible ureteroscopy? Is there a time limit? Does your nurse inform you that this is one hour and?

Khurshid Ghani:

Yes.

Evangelos Liatsikos:

What is the time limit?

Khurshid Ghani:

Yes. So just like with partial nephrectomy, when you start ischemic time and they tell you have 10 minutes. My OR team know, all right Dr. Ghani. You're at 10 minutes, you're at 20 minutes and I'm talking about total lithotripsy time. So that means the moment I started the pedal, just because I like to get a sense of how long I'm in there. And if I've got a sheath, my timing can be 45 minutes. It can be 60 minutes. If the patient doesn't have let's say risk factors or sepsis. But if they don't have a sheath, I don't like to be there beyond 30 minutes. And for that reason, I keep very close account of the time.

Evangelos Liatsikos:

Do you have any experience with a ClearPetra, the suction system? So, that you can actually aspirate stones out? Have you used that for the ureter?

Khurshid Ghani:

So we haven't used it clinically because we don't have it on file here. But I have used it in the laboratory and I think it's pretty, my view from seeing it in the lab and the amount of force that you need to go to do that. I think it just seems quite aggressive to me. And I think afterwards at the end, I just wonder what the state of the kidney would be with that inflow, outflow, aggressive force with the syringe that needs to be done to evacuate fragments in that way. So what, I don't know if you've used it. I know you've had [inaudible 00:39:06].

Evangelos Liatsikos:

No. I know I used it, but I agree with you. I didn't like. I'm not a fan of it. Two other questions, antiplatelet therapy, do you stop it always before doing flexible?

Khurshid Ghani:

So we are actually presenting our work from the state of Michigan from the music group. They set the EAU virtual meeting. And we found that for anti-coagulated patients, there was no risk of bleeding events and from [inaudible 00:39:38] unplanned encounters in the hospital. But for anti-platelet there was. And so I do stop antiplatelet therapy if possible. But if the patient's medical condition dictates that they cannot, I just do it on it. But I explain the higher risk of bleeding associated with that. This is-

Evangelos Liatsikos:

What about zero? Sorry.

Khurshid Ghani:

I just want to point out, this is a point where the stone's tucked away in a difficult corner and I'm using the Moses distance pulse. And it allows you to sort of try and reach areas that you would normally find difficult to reach. As you see the stone is up there at that top corner. But carry on.

Evangelos Liatsikos:

What about zero fluoroscopy? Are you a fan of, have you ever done that? Your CRM breaks. Will you go... Doesn't function. Would you go in with no fluoroscopy? And there's some people are advocating that.

Khurshid Ghani:

Yeah. And so Duane Baldwin here in the US is a expert and champion of this. And when he spoke about it at our dust meeting I was really attracted to it. I think overall many of us use or probably use radiation and fluoroscopy a lot. I've been conscious to try and limit my use. I do think that is an innovation in the future. All the time in endourology we're getting better and better. And we're thinking outside the box and saying, "Do we really need that? Do we really need that?" So I do think that we will become a bit more refined with our use. Of course, there'll be scenarios where you have to. If it broke, your question, if it broke down in a real case, I would try and pursue in a safe manner if I felt if it was feasible. But we definitely know we can do certain things without fluoroscopy, if needed.

Evangelos Liatsikos:

What are the settings that you would actually incise tissue to access a diverticular stone?

Khurshid Ghani:

So that-

Evangelos Liatsikos:

So you see the opening and then you need to cut the tissue? What are your settings there?

Khurshid Ghani:

So I will use I will switch between 0.5 and 80 on a long pulse. Or one and 20, on a long pulse. To try and cut tissue when I do diverticular incisions. I have both pedals. I prefer to use that lower pulse energy in higher frequency mode.

Evangelos Liatsikos:

Okay. Do you really think that you need a hyper... Someone needs to buy a laser. And he wants to go up and do great work with his lithotripsy. Do you need a 100 or 121 Watt holmium laser? Because you go up to 45. Could you go up to 45 with a smaller energy laser?

Khurshid Ghani:

So I'm just going to pause it for a second. The systems might be 120, might be a 100. But from a kidney stone perspective like you said, you only need a shorter range. The problem is if you went to say, I want a 60 Watt laser, because I only going to use 30 Watts or 40 Watts of energy. The 60 Watt lasers don't allow you to get beyond 40 Hertz. They don't allow you refine settings for pulse energy. They don't allow you, some of those systems don't allow you differences in pulse duration. I personally think it's those things that have really improved lithotripsy. Whether you use 50, 60, 70, 80, 40 Hertz that's surgeon choice and dependent based on your irrigation. How can you use high Hertz settings and use passive irrigation? You won't be able to see anything. You can't dust in that environment. So I think you have to pick your laser strategy and settings based on the system you have and your philosophy.

Khurshid Ghani:

Like you said, from the poll we've just seen great differences and people use forced irrigation pumps or passive. And I think, especially in this era where we are seeing [inaudible 00:43:27] systems like this, and then we have thulium coming on with everyone's. And there's dusting, dusting, dusting. Well, okay. How are you going to see you? You have to see. And so I think you have to balance that too.

Evangelos Liatsikos:

Let's see the poll responses. Do you use a high power holmium laser? 46%, no. 43%, yes. Whether one can afford to buy one. So we should have asked this question also. The other polling question is, have you used the thulium fiber? No. Would like to 48%. Clearly, it's not accessible yet to everyone. So two questions that are very important. Sepsis, what is your experience with sepsis? How do you avoid it? How do you suspect it? When do you suspect it?

Khurshid Ghani:

So we have a study that's currently under revision again from our state of Michigan music group that looks at this. And in the state of Michigan we found that around 2 1/2% of patients are hospitalized because of an infection related event after straightforward ureteroscopy in an ambulatory center, for example. And the risk factors were prior urinary tract infection, positive urine culture. So I definitely think if I have a patient with that, I do mitigate it. So I always want to make sure we have a urine culture result. We didn't always... Not all institutions follow a pure urine culture. I'll be curious to know, do you get always a urine culture before ureteroscopy? Or do you just do urinalysis?

Evangelos Liatsikos:

No. We do. We have a urine culture, but sometimes this can go... We give antibiotics, but in my center we always pre-stent. Always. So I'm one of the big fans of pre-stenting.

Khurshid Ghani:

Yeah.

Evangelos Liatsikos:

Because I want to make sure that this system is nicely dilated and there's nice evacuation and I've standardized this and this is a rule in our department.

Khurshid Ghani:

Yeah. We just don't pre-stent at all. And I think that practice is not so common in the US. We have so many problems with just the stent itself. We would create a new population of patients who are complaining of stent related.

Evangelos Liatsikos:

I understand.

Khurshid Ghani:

[inaudible 00:45:46].

Evangelos Liatsikos:

What about, and especially in the COVID era, we have a question about spinal anesthesia. Do you ever do flexible under high spinal anesthesia?

Khurshid Ghani:

Yes, I do indeed. In fact, some of the patients I get referred a lot are COPD severe respiratory disease patients. This has nothing to do with COVID. And those patients are not appropriate for PCNL and they may have partial stags. And I have routinely been doing them under spinal anesthesia. It's something that I learned when I was at Guy's Hospital, where nearly all the ureteroscopies, when I was there at that stage was under spinal. The patients tolerate it very well. Couple of tips are that I always tell the patient, listen, if you've got a cough or sneeze or something, let me know. Because there you are lasering away in the kidney, and you need to get that warning of any sudden kidney movement. The second thing is they all get a Foley catheter at the end of the procedure because they're not going to be able to avoid. So they have to be prepared to go home with a Foley. Because we don't admit patients unless they have high risk [inaudible 00:46:50].

Evangelos Liatsikos:

Do you give Lasix after your treatment or during your treatment?

Khurshid Ghani:

Yeah. Great question. So at the end of every ureteroscopy towards the end, I'll tell the anesthesiology team to give 10 milligrams of Lasix. I love the diuresis, especially if they don't have a stent. I want as much as those fragments in the diuresis effect. And I give everyone intravenous nonsteroidal, like a Ketorolac IV for pain relief. And so yes. Those are two parts of my standard protocol.

Evangelos Liatsikos:

Two questions. What is your definition of dusts? This is a very nice question. What is the definition of dust? And when do you evaluate your patient to check if he is stone free?

Khurshid Ghani:

So, there's no consensus definition. But initially if you asked me a couple of years ago, I would say I want to get everything under one millimeter. I think work from Olivia's group has shown that 0.25, 0.4, is that threshold where the fragments will float as you can see. And so that's what we want. So definitely getting it less than 0.5 millimeter fragment is good. But if you look at the work from Ben Shoe's group with the edge, with their residual fragments is two millimeter and above where you're going to get risk of events, regrowth, et cetera. So definitely you want to get it less than two millimeter, less than one millimeter is great, but less than 0.5 in my mind is what we should be aiming for.

Evangelos Liatsikos:

What antibiotics are you using before, after, during? What is your regime?

Khurshid Ghani:

So if the patient has a negative urine culture, I will just give them a standard intraoperative antibiotic that's broad spectrum. And then postoperatively, I don't give any antibiotics. Even if they have a stent and even if they have stent on a string, for example. But if they have a positive urine culture, I'll treat it, and then I'll repeat the urine culture. And if I repeat the urine culture and it's negative, I'll proceed without any antibiotics. But if that second culture is positive, I will then give a period of preoperative oral antibiotics for three to five days, depending on the risk factors for the patient [inaudible 00:49:01].

Evangelos Liatsikos:

Two questions. There's a group of people asking us, what do you consider as a safe intrarenal pressure?

Khurshid Ghani:

Less than 40 centimeters of water.

Evangelos Liatsikos:

And how do you evaluate this?

Khurshid Ghani:

Difficult to evaluate. We don't have a way of evaluating that right now. I just based it on clinical impression of outflow coming from my access sheath, compliant, every different kidneys have different compliance. We've done cases without an access sheath, where the bladder fills up so quickly because the fluid is just falling out of the kidney, ureter into the bladder. In some cases, it doesn't fill up so quickly. So it's very independent. And I think we'll learn more and more about this as more advances in the field come to tell us about that.

Evangelos Liatsikos:

Yeah. Do you ever ask your anesthesiologist to give apnea on your patients when you want to work some places and what are your criteria to do that?

Khurshid Ghani:

Yeah, so that's very good question. Because especially when you asked about calyceal diverticulum stones, that's where I'll say I need apnea. So I do in general, for kidney stone dusting, I do tell my anesthesiologist to try and give me an endotracheal tube and control the tidal volume and consider it. They're very used to speaking to urologists about TURBTs. Right? Oh, you got have a tumor. You want paralysis. Right? They know that. But for me, kidney stone is like that. So I like to have that discussion. Ureteral stone, I don't find it too much of a problem. I can do it in any anesthetic scenario.

Evangelos Liatsikos:

Okay.

Khurshid Ghani:

So you can see that, I've been I've interrogated. That's the lower pole where the stone was, we flushed it all out and you just got a lot of dust. And now we're on the way out of the kidney, but we always assess the ureter and you can see here where it's a little bit tighter there. That's where the actual sheaths wouldn't go beyond. But we'll always check for injury. I always have a safety wire when I use an access sheath. And then in this case, we then stent it. And the patient had the stent for around 10 days.

Evangelos Liatsikos:

Why did you stent in this case? And not in another case, what is your criteria of stenting?

Khurshid Ghani:

So criteria for stenting for me is a large stone burden where I'm worried about the size of the fragments, the bolus and I need a dilation of the ureter. So you do pre-stenting. So your ureter is already dilated. A lot of these ureters are not dilated. So I will stent for that reason. But if there's small stone volume or broke down beautifully into tiny fragments, I don't stent. If I use an access sheath like I did here, I have to stent. That's sort of, and maybe we can challenge that dogma. I don't know if anyone... I'm not talking about in the pre-stented scenario. But right now I think most of us who are in an unstented ureter, they go up with an access sheath. Most of us really leave a stent in for a couple of days, at least.

Evangelos Liatsikos:

So you leave a string on the stand and you pull it out? Or you go in with a flexible scope and take it out, or what do you do?

Khurshid Ghani:

So in some patients who, if the stent not only needs to be in there for five to seven days, I will leave it on a string. And those who I consider who have a stent IQ. In other words, they have to be able to feel confident to manage the string and plus are happy with the string. Many patients actually decline the string option. They just say, "I don't want that. Please don't do that for me." So in those cases, if I'm not using a string I actually use a Silicon stent, because I found that the silicon stents cause less discomfort, than the standard polyurethane.

Evangelos Liatsikos:

Okay.

Khurshid Ghani:

So I can just show you... Do you see this slide set Evangelos?

Evangelos Liatsikos:

Yes.

Khurshid Ghani:

Okay. We did a total lithotripsy time around 42 to 45 minutes. That means with all the maneuvers of stopping, starting, looking around for stones> The total lasing time is 32 minutes, 42 seconds that's computed from the computer log. And then the operator duty cycles. So that whole, that's the lithotripsy and lasing time that ratio varies from 71 to 76%. And I'd ask the audience to keep a note of that when they do their cases. How long am I doing lithotripsy full, but how long did I actually use the laser? Because I used a lot of energy in this case because you can see that when I do contact laser lithotripsy, I just have my foot on the pedal. So and then of course, I'm using higher power settings at the end for pulverization. And you use much higher settings. Now this is the patient who then had a CT scan at three weeks though. The question you had about imaging, I don't do a scan at three weeks. I wait at least six weeks. I prefer to wait eight weeks.

Khurshid Ghani:

Because I know I have patients, who've had sequential scans that had residual fragments at a six week scan, and then at a 12 week scan and the residual fragments are gone. So I know that the longer you wait, you'll get a better result in terms of residual fragments. I do do CT in patients that have had complex large volume stones like this patient. This particular patient was getting a scan for something else. So we didn't want to do double CT scans. So we got a CT scan at three weeks. But I do think imaging is something that's important to document and monitor the outcomes.

Evangelos Liatsikos:

Do you give out her blockers after your case. You said you give them before, but you give them after the case?

Khurshid Ghani:

Yes. Everyone gets a 30 day supply, they start seven days for me, for my patients they start seven days before surgery. And then they will keep that until the tablets are gone. Because, couple of things, most of them will have a stent for these cases. And we know the data that these agents reduce stent related symptoms and there's data in the literature from Shock Wave lithotripsy that they help with residual fragment expulsion. So for that reason, I keep it going for-

Evangelos Liatsikos:

Only on for blockers or also combine it in a combination drugs with anticholinergics.

Khurshid Ghani:

So if they have a stent, our routine protocol... Again, this is developed by a group here in Michigan at the music group. Everybody who has a stent in my patients will get an anticholinergic and I'll give one tablet longer lasting anticholinergic. Everybody gets to Flomax if they're able to tolerate it. They get nonsteroidal for pain relief. And then they get also Tylenol. We don't give opiate medication for pain relief here.

Evangelos Liatsikos:

Do you send your stones for analysis and for a culture after your procedure to see... So there are some people that send them, not only for analysis, but also they want to see if there's any positive bacteria there, presence of bacteria. Do you do that as a routine?

Khurshid Ghani:

Not culture as a routine, no. Not culture, in PCNLs yes I do. The reason I don't do it as a routine for ureteroscopies, I don't hardly use a basket. So I don't like to use a basket. It's another expense. So I'm thinking about my costs in the OR. So I will take a sample at the end if it's a first time patient who want to have a stone analysis. But if they're a known stone former, I don't take another stone sample unless there's something that's different about the stone. We can work out the stone composition just by visualization.

Evangelos Liatsikos:

What do you think the future of laser technology is and the flexible urethra? How will flexible ureteroscopy advance in the future according to you?

Khurshid Ghani:

So I'm just [inaudible 00:56:41] texts from our organizers and so looking. Okay, good. That's a great question. Dean Assimos when he gave a talk to one of our sectional AUA meetings a couple of years ago, had a quote that said "In the future, all stone surgery will be retrograde." And so we have seen the increasing conservatism of renal stone surgery. We've gone from, big open kidney stone surgery to the open nephrolithotomy by sir Henry Morris. And then of course, the pioneering inventions of PCNL with Smith andClayman and [inaudible 00:57:18] and the team. And now we're doing flexible ureteroscopy. I do think we will increasingly treat more and more of these stones flexible. They have their challenges. When I do the staghorns, partial staghorns, flexible ureteroscopy, I may have to do three procedures. The patients have to have stents for those durations. It's not easy.

Khurshid Ghani:

And I think that's where the future for us is to improve those aspects. And that means better lasers to pulverize the stone, vaporize it, to get the damage threshold just right. Where we don't get chunks, we just get a melting ablative effect on the stone that's consistent. So I do think there are some exciting developments from lasers that will help us there. Then of course, ancillary devices better ureteroscopes and better systems that allow suction for example. The suction I think, is a big growing area of investigation. And we're going to see many exciting advances in that.

Evangelos Liatsikos:

Did you do any [inaudible 00:58:17] ureteroscopy together.

Khurshid Ghani:

Yes. I just operated yesterday and we did a couple of combined procedures. I think that has been a great advance that colleagues like sesar, scophony and Italy has pushed which will allow you to try and get optimal stone, complete stone clearance in a single sitting. Again, it's not something that I think is easy for the mass majority of practitioners, because you have to have a second surgeon. We're working in teaching centers where we can rely on resident help or maybe a colleague of ours can come and help. But I think for bread and butter of normal stone surgery that's going out there, it's harder to do combined procedures. But it's definitely something that has its advantages. And I'm increasingly doing it.

Evangelos Liatsikos:

Good. I think we're heading towards the end of our webinar. I just want to make a final comment. What we said, flexible ureteroscopy is easy to do. It's quite easy to do in relation to PCNL, but people should not exceed time. They should not be there. The good surgeon is not the guy that is doing flexible or PCNL for two or three hours. This is dangerous and it can really create huge problems. And this needs to be clear message. Technology will change and everything will change, but this will not change. You're working inside the kidney. You're increasing pressures, generating temperatures, whatever you're doing, you need to have a time limit. I think we agree on this. Huh?

Khurshid Ghani:

I agree. And I agree that you can't go up into the kidney and use 80 Watts without an access sheath, without higher flow, understanding the space that you're in. Is it a tight renal pelvis of capaci-

Evangelos Liatsikos:

Correct.

Khurshid Ghani:

All of these things matter because we have to be very careful with that. All of these tools that we're getting can cause harm. So we have to... It's about safe dissemination of these techniques. And of course, this is what the Endourology Society is putting for us today, and allows us to do this. And as you can see, there is great variation in practice, even in the polls. There is no right answer, I think from the safety side. Yes. The things you say, but there are other things that you do differently that I do differently. And I think, more work, more research, more study is needed.

Evangelos Liatsikos:

Correct.

Khurshid Ghani:

But definitely we have to do, like you said, I like to do PCNL when the stone is bigger than two centimeter. And I think those are the guidelines and they're there for a reason. But nevertheless, I do think the future is retrograde into renal surgery, but we need to get it better and better.

Evangelos Liatsikos:

Okay.

Jared Winoker:

Excellent. I think that's a great point. I don't know if there's any final words. It feels like a good wrapping up when I know the questions are just kind of rolling in and I appreciate everyone for participating all the way through this session. I don't know if doctor Liatsikos or Ghani, you have any final comments you want to make?

Evangelos Liatsikos:

No. I'd just like to thank everyone for the nice, very nice exchange of ideas. I apologize for the questions I could not answer. I could not ask. I could not address, but I tried to group them up. I think I probably grouped up around 80% of them. So I think that everyone should be happy. And thank you Khurshid.

Khurshid Ghani:

Thank you, Evangelos. May I make a comment to Jared and the organizers which is, thank you very much for putting this on. But any of the questions that we cannot get to, we should collate this as a repository and I'd be happy to answer it with Dr. Liatsikos. And whenever you put this out on the website, we have some of the answers to these FAQs.

Jared Winoker:

Excellent.

Khurshid Ghani:

It'd be a wasted opportunity not to address the people who logged in and with questions, which is always nice to see. We appreciate that.

Jared Winoker:

Certainly. Well, we appreciate everyone's time. We'll certainly find a way to make those questions available along with this webinar will be available on the website that you can see on the bottom of this screen, as well as all of our prior webinars. Again, thank yous to Dr. Ghani and Liatsikos for their help. And of course, our grant support from our friends and supporters over at Lumenis. Just a quick reminder about next week, we're going to be discussing thulium laser in the treatment of BPH. We're pleased to have doctors Zeph Okeke and Andreas Gross for that. And you should be seeing emails but if not, you can feel free to go to the endourology.org website to register for that. And with that, I will just leave the the guidelines for our CME in case you have any final questions. Otherwise, thank you everyone for joining, and we'll see you next week.

Khurshid Ghani:

Thank you.

Evangelos Liatsikos:

Thank you very much.

Khurshid Ghani:

Thank you, Evangelos. Thank you. Bye-bye.

Evangelos Liatsikos:

Bye Khurshid.