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BackTable / Urology / Podcast / Transcript #84
Podcast Transcript: Novel Approach to PCNLs
with Dr. Jason Wynberg
In this episode of BackTable Urology, Dr. Jose Silva interviews Dr. Jason Wynberg, director of endourology at NYU Langone Health in Brooklyn, about his percutaneous nephrolithotomy (PCNL) technique and innovations. You can read the full transcript below and listen to this episode here on BackTable.com.
Table of Contents
(1) Defining Criteria & Patient Selection for PCNL
(2) Supine Retrograde Puncture in PCNL: Technique & Clinical Advantages
(3) The Development & Implementation of the RetroPerc Kit
(4) Safety & Bleeding Considerations in Retrograde PCNL
(5) Streamlined Access Strategies for Complex Kidney Stone Cases
(6) Optimizing PCNL Outcomes in Complex Cases: Techniques & Case Insights
(7) Best Practices for RetroPerc System Implementation in Urology
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[Dr. Jose Silva]:
This is Jose Oche Silva as your host this week. We are happy to have as guest this week, Dr. Jason Wynberg. Dr. Wynberg did his urology residency at University of Manitoba, then continued to do a fellowship from the National Cancer Institute. He is the Director of Endourology at NYU Langone Health. Dr. Wynberg specializes in complex kidney stones. This includes percutaneous nephrolithotomy, where his clinical research has helped to make this procedure safer. Furthermore, he has patented a new PCNL system that we'll talk about that later. Dr. Wynberg, Jason, it is a pleasure to have you as a guest today. Welcome to BackTable.
[Dr. Jason Wynberg]:
Thank you, Jose, so much. I just wanted to clarify that it's an honor to be at NYU. I'm at the Brooklyn site. I'm not for the entire organization. I'm the Director of Endourology for Brooklyn. Thank you so much.
[Dr. Jose Silva]:
From Brooklyn. Okay. How's Brooklyn? Every time I hear of it, there's new stuff going, in general, just the community is getting more and more
[Dr. Jason Wynberg]:
It's very dynamic.
[Dr. Jose Silva]:
Great. How did you become interested in PCNLs?
[Dr. Jason Wynberg]:
Well, my family and I moved to Detroit, Michigan. Dr. Santucci was the chairman, and they did not have a kidney stone surgeon and they had a large volume of stones. My residency was rich with endourology experience, even though my fellowship was in cancer, the clinical opportunity was in stones. That's when I embarked on my PCNL journey in Detroit.
[Dr. Jose Silva]:
This was prior to going to NYU. Right after the fellowship, you went to Detroit with Dr. Santucci.
[Dr. Jason Wynberg]:
Essentially yes, that's right.
[Dr. Jose Silva]:
How long were you there?
[Dr. Jason Wynberg]:
Nine years. Nine great years.
[Dr. Jose Silva]:
Good.
[Dr. Jason Wynberg]:
Yes. That was beautiful.
[Dr. Jose Silva]:
Just because of the volume, it was available, and then you started doing them?
[Dr. Jason Wynberg]:
Yes, PCNL is a very interesting case. It was an intellectual challenge to conquer and learn what's really a complicated and fascinating operation. When I had the opportunity to absorb those cases, I was excited to do that.
[Dr. Jose Silva]:
Yes, for me, personally, PCNL was probably the defining surgery that got me into urology. I couldn't believe that you were navigating in the calyx and the renal system and just breaking stones. I don't do that much, I maybe do three or four a month, but it is something that I truly enjoy.
[Dr. Jason Wynberg]:
It feels like a video game.
(1) Defining Criteria & Patient Selection for PCNL
[Dr. Jose Silva]:
It is. That's probably what got me in. Jason, what are your criteria for PCNL in terms of stone size?
[Dr. Jason Wynberg]:
For me, it's not just the stone size. It's also the patients' wishes. I really do discuss with them what would they rather have. Two-stage procedures or one procedure. Sometimes somebody's got to go out of town and that would push us toward a PCNL, or you could go both ways. Sometimes the stone, you sense if it's a very hard stone or a soft stone. I don't really use a size criteria. I typically will give a good effort doing a ureteroscopy laser because as much as a PCNL can be done safely, generally speaking, if you can do a ureteroscopy laser in one or two cases, sometimes it's a fatigue assessment, because if you're going to spend hours lasering a stone, then boy, oh, boy, that's fatiguing.
[Dr. Jose Silva]:
Do you take how few units into consideration, or the stone density?
[Dr. Jason Wynberg]:
Yes, partly. I would say mostly size and configuration and patient wishes. I really do speak to the patients and say, "Look, there's certain risks you get with a PCNL, but I think they're acceptably low risks, or we could just laser you." I think patients are really good partners in making those types of decisions.
[Dr. Jose Silva]:
Exactly. What patient you wouldn't offer a PCNL? Is there a patient you wouldn't offer a PCNL?
[Dr. Jason Wynberg]:
I think so. I think we all think the same way. We all hate risk. If somebody looks like just a bad PCNL candidate, somebody who's massively obese, sometimes it's easier to just say, "Look, I'm just going to laser your stone twice and make sure I'm not going to embark on something," where you have truly a massively obese patient. You can see that on the CAT scan where the kidney looks very small compared to the size of the patient.
[Dr. Jose Silva]:
I do the same. I guess sometimes I start doing the ureteroscopy, but then those stones maybe don't break, so sometimes you end up just doing the PCNL at some point.
[Dr. Jason Wynberg]:
Exactly. You feel more comfortable converting the patient after you've really tried to do it from below.
(2) Supine Retrograde Puncture in PCNL: Technique & Clinical Advantages
[Dr. Jose Silva]:
Exactly. Definitely. Jason, are you doing your own access?
[Dr. Jason Wynberg]:
Yes, I only do my own access. I don't do antegrade access. I frankly never developed that skill. Going back to the Detroit Medical Center, I spent the day with a world-renowned educator for antegrade puncture where I spent two days. I absorbed everything I could and I came back and I succeeded my first case. Got urine from my first puncture, but the wire fell out and I ended up not succeeding and I had to wake the patient up.
It was at that moment that I recalled my residency program, which is where the endourologist was Dr. Denis Hosking in Winnipeg. He used to use the old Cook Lawson set. My entire residency experience was doing retrograde access in a supine position. When I was in Detroit, and I had the opportunity to capture this line of business, and I was over one with my antegrade experience, I just went back to my experience as a resident and said, "You know what? I was doing them successfully as a resident in that other way." That really started a journey to continue with retrograde puncture.
[Dr. Jose Silva]:
Can you describe, how do you do it supine, and the process, how the patient is positioned for a retrograde access?
[Dr. Jason Wynberg]:
Sure. The first thing is, it really all begins in the clinic with a CT scan review. I prefer looking at the axial images because I can assess the renal rotation, overrotation, underrotation in the axial images. I study not only the stone configuration, but I try to assess the directionality of the infundibulae, and obviously, the perinephric fat and the rib renal relationship. Is it a high kidney, a low kidney? Is the 12th rib attenuated or is it very big and long? You can essentially get a very good sense of the procedure you're going to conduct while you're still in your clinic making a recommendation to the patient.
What you don't have at that moment is a retrograde pyelogram, which can affect your surgical plan significantly. The data from a retrograde can be acquired, either at the time of stent placement, days before your PCNL, or at the time of the PCNL. The decision-making for my puncture is really the assembly of the CT scan information and the retrograde pyelogram, and additionally, a flexible ureteroscope in the kidney. Those are the three domains of information that get assembled into a plan for puncture.
[Dr. Jose Silva]:
You mentioned that the patient is supine while you puncture them.
[Dr. Jason Wynberg]:
Yes, there's nothing wrong with doing a retrograde puncture prone, but there's benefits to the supine position in that so much of the planning is CT scan driven, and of course, the CT scan is acquired with the patient in the supine position. When you study your CAT scan and you're programming your mind and you have the patient in supine position, that data translates to the operating room better than if you put the patient prone where that information has to be rotated back in your mind, 180 degrees.
That's one of the big benefits of the supine position. It's also more amenable, of course, to access to the urethra if you use lithotomy, whatever method you use to access the urethra, whether you use Yellofin stirrups or other methods, it's a little bit easier, I think, in my hands, but other people have other experience, of course, to access from below and above at the same time.
Essentially, patient is positioned supine with some folded sheets under the hips and the shoulders. It's the Barts flank-free position with the ipsilateral arm over a pillow over the chest. Essentially, I put a ureteral access sheath in for ureteroscopy, shoot a retrograde, and then put a flexible ureteroscope into the kidney. Your positioning of the ureteroscope is direct vision and pyelography. When you add those two fields of information to your CAT scan data, you know what you're going to do.
Then there's a puncture wire that is advanced through the working channel of the ureteroscope. An assistant does it, a nurse, or a resident. You don't need skilled assistance for that. The puncture wire is shielded in tip protectors like a long thin Teflon catheter so that while the ureteroscope is held in position for puncture, that puncture-wired device is advanced through the working channel of the ureteroscope until the tip emerges out of the ureteroscope and you see that under direct vision on endoscopy.
Once that comes out, the assistant will unlock a pin vise, which allows the wire to be advanced. Then under the surgeon's verbal direction, the assistant will advance the wire with a very few fluoroscopy shots. You can see the wire advancing through the flank, and you can follow that along the wire advancing with the C-arm by moving the C-arm laterally. AP only. You don't use multi-plane C-arm. It's just single plane.
When you see that the wires tend to the skin, I typically have my assistant hold the handle of the ureteroscope while I leave from between the legs and core on the side and usually, you see the skin tenting and it's consistently in a good location. You cut the skin and capture the wire, and then you've achieved a puncture.
[Dr. Jose Silva]:
Then you just start dilating over the wire.
[Dr. Jason Wynberg]:
Yes. The puncture wire is stainless steel and it has a propensity to kink. It's designed for puncture. It's not really designed for endourology. At that point, you just go through a couple of steps to exchange that puncture wire for an endourology wire of your choice. That's done with a separate catheter at the flank.
(3) The Development & Implementation of the RetroPerc Kit
[Dr. Jose Silva]:
I understand that you develop a system for this and you have a trademark patent going on. Is that what you're using right now?
[Dr. Jason Wynberg]:
It is. NYU was kind enough to allow me to use this product in my practice.
[Dr. Jose Silva]:
Your kit, it includes also the dilators, or it is just the puncture until you have an endo wire there?
[Dr. Jason Wynberg]:
It includes the sharp puncture wire and the sheath that protects the wire, so it doesn't damage your scope. It also includes what's called a coaxial micro introducer, which is basically, a 30-centimeter long 5.0 French, it's almost like a vascular catheter with an inner dilator that tapers right down to the puncture wire. The purpose of that coaxial micro introducer is simply to allow you to remove your puncture wire in favor of an 035 or 038 endourology wire while maintaining the track that you've created.
The kit includes those two items, and whichever endourology wire or sensor wire or any wire, frankly, you can pass that through the outer catheter at the flank once you remove the puncture wire and the inner dilator from a coaxial catheter. It's hard to describe it verbally. You almost have to see a video and then it makes sense.
[Dr. Jose Silva]:
No. Definitely, you create a great picture of going in through the kidney. For patients that have big stones, does it matter? When I say big stones, if you cannot pass the ureteroscope all the way into the calyx.
[Dr. Jason Wynberg]:
I would say that 9 out of 10 of those cases, if you look at the calyx that's at the end of those big stones, 9 times out of the 10, the calyx is collapsed around the stone, which means that the urine that's produced is draining. When you don't have hydronephrosis or dilated calyces, then almost always with a pressure bag, your flexible ureteroscope will get a sufficient distension to allow you to drive right beside the stone to the papilla.
9 times out of 10, big stones, cast stones, staghorn stones are not only not more difficult, but there's even an advantage that people have experienced. That is that if you have a very hydronephrotic kidney, the intrarenal anatomy is a little less supportive of the ureteroscope if it's very dilated. As you advance the wire, the ureteroscope can push back a little bit until it meets some renal architecture that will support it.
If you have a big stone there, like a staghorn, once you position yourself in your chosen papilla, the stone provides tremendous support for the scope. The puncture actually becomes easier than you might think, becomes a very easy puncture. Staghorn stones, in general, are a favorable finding for this. Now, of course, if you have very dilated calyces showing that it's truly a very obstructive stone, then it's possible you have to laser just to get past it, but that's not very much lasering. It's not to disrupt the stone, it's just to allow you to advance your scope.
[Dr. Jose Silva]:
Sometimes with those big stones, even through the antegrade axis, it can be challenging. The wire might not go in, it might just stay in the same calyx, it might not go down to the ureter. I understand what you're saying. How you said, "Okay, I'm going to develop a system." How did that happen?
[Dr. Jason Wynberg]:
Thank you, Dr. Silva. The same evening that I failed in my antegrade PCNL, the patient was fine, but I wasn't used to waking up a patient and apologizing for a procedure that didn't happen. I was in my office, I think everyone had left, and I was just recalling my residency. I guess, different thoughts and ideas were coming and the idea of putting it through a ureteroscope came to me.
From there I called the rep for the Cook Lawson puncture set and took out their wire and it did manage to emerge from the ureteroscope. Then I knew I had a real idea. What's very interesting, Dr. Silva, is that in 1989, Dr. Larry Munch actually published that very same procedure of putting a retrograde puncture wire through a flexible ureteroscope. That was a paper in the Journal of Endourology.
What's interesting was PubMed was not indexing the Journal of Endourology at that time. To this very day, if you know the reference for the paper, you can order it through your library, but if you go into PubMed, I believe it will not pull up. His innovation in 1989 was lost to the urologic community for many, many years. What's also interesting is at the same time that, at the Detroit Medical Center we were doing an IRB on this idea, there's a Dr. Kawahara in Japan who was doing this exact same thing. Dr. Kawahara from Yokohama, Japan, at the same time we were publishing the same surgical modification of the old concepts.
(4) Safety & Bleeding Considerations in Retrograde PCNL
[Dr. Jose Silva]:
Jason, in terms of the procedure per se or using the retrograde fashion, is there a difference in terms of safety or bleeding in terms of the patient?
[Dr. Jason Wynberg]:
I can speak from my experience and I can speak from some anatomic concepts. When you have a ureteroscope that is staring at a papilla, the ureteroscope is in the infundibulum. If the infundibulum is two or three centimeters or whatever, 15 millimeters to 30 millimeters in length, that infundibulum long axis has three coordinates, X, Y, Z in space. When your ureteroscope is in that long axis of the infundibulum to allow you to stare at the papilla with your ureteroscope, your flexible ureteroscope has matched perfectly the infundibular long axis.
It's the ureteroscope that creates the safety. It's not the papillary puncture. Because your ureteroscope is matching the long axis of your infundibulum, the wire that travels through the working channel matches the long axis of the infundibulum and all of the series of exchanges that follow which manifest with a balloon and a nephrostomy sheath or mini-perc set, those will always dock into the infundibulum, matching the long axis, which means that from a surgical experience, aesthetic standpoint, there's always certainty that when you take your balloon down and you remove it from your sheath, for example, there's different technologies, of course, mini-perc, et cetera. You just don't see blood come out. You see air, nothing. It's dry. Maybe you get a bit of urine.
I think that the renal trauma is diminished by virtue of that. Of course, it's a papillary puncture, but it's more than a papillary puncture. It's a papillary puncture that's aligned with the infundibula. Now, of course, there's other ways that you can have bleeding just because you ask about bleeding. If you over-advance your balloon and you sneeze, you'll get bleeding. Of course, if during your nephroscopy, you can cause bleeding. From a tract creation standpoint, I think this is a superior method of nephroscopy creation from an anatomic standpoint.
(5) Streamlined Access Strategies for Complex Kidney Stone Cases
[Dr. Jose Silva]:
Let's go back to your kit.
[Dr. Jason Wynberg]:
With a lot of help from a lot of people from different industries and different knowledge bases, we did succeed in having a kit produced, but Dr. Silva, I would really stress that it was in the spirit of service to my urologic colleagues and community because I felt because we were doing cases in parallel to the development of the product, I felt as-- Of course, it was exciting, but it was also a sense of duty to make sure this was available for the evaluation of other people. Of course, my experience is-- One person's experience is never definitive because all science has to be reproduced and reproducible, otherwise it isn't real.
Ultimately, the goal was to get this to a place that other people could either validate or refute what was my experience. That's been the rewarding aspect is the collegial and camaraderie associated with sharing ideas with my colleagues.
[Dr. Jose Silva]:
If somebody wants to get that kit, how does it work?
[Dr. Jason Wynberg]:
There is a website that people can go to to request it. There are representatives that educate and onboard people into the program so that they can comfortably and safely do the procedure.
[Dr. Jose Silva]:
I'm just curious. You have an idea and who do you go to talk to make it happen? You mentioned there's a lot of people, it takes a lot of people to get it developed. Is there a single company or somebody that you can tell, hey, this is what I want? Does that exist?
[Dr. Jason Wynberg]:
We were essentially unfunded and when you're unfunded, you take the leanest possible way to move things forward. If you have funding, then it's much easier. It's much easier to partner with companies that will work with you and develop everything, and take it from A to Z. This process was very different. It was times with progress, times with non-progress, times with working with some people, times with leaving those people and moving on to other people. Through that period of time, we were again encouraged by the success of the procedure.
It was lot of little things that just kept moving forward and a lot of people guiding and advising who are in the medical device industry. All of those information, steps of information and knowledge, were at points where there was a decision point, or a problem, or a question. It was constant curiosity and people helping, and answering questions.
[Dr. Jose Silva]:
How long did it take to have a final product?
[Dr. Jason Wynberg]:
It took years. I would say probably seven years and the goal was not that. The goal was much shorter than that. The benefit of the long time was that the product was iterated, designs were improved before commercial release, before it was actually released. Thankfully, since that release, there haven't been any changes needed.
[Dr. Jose Silva]:
Let's go back to the retrograde procedure. You mentioned you have an access sheath. What size do you use?
[Dr. Jason Wynberg]:
Well, the kit comes in a fixed size. Are you asking what the dimensions of the kit are?
[Dr. Jose Silva]:
No, no. The access sheet per se.
[Dr. Jason Wynberg]:
The ureteral access sheath?
[Dr. Jose Silva]:
The ureteral access sheath, yes.
[Dr. Jason Wynberg]:
I think that's similar to ureteroscopy for all practitioners. Some use 1113, some 1214. It depends on whether the patient's been pre-stented. Are you asking about length?
[Dr. Jose Silva]:
It doesn't matter. Your kit doesn't matter whether you have the 1214 or the 1113.
[Dr. Jason Wynberg]:
No, no, it doesn't matter.
[Dr. Jose Silva]:
What ureteroscope do you use?
[Dr. Jason Wynberg]:
It can be used with any ureteroscope, although there is a learning curve of a few cases. During your learning curve, it would be wise not to use a $20,000 high def digital ureteroscope because while you're getting a feel for how the wire is handled, it is possible to make a handling error and effectively deploy the puncture wire inside your working channel and your scope will fail the leak test if you do that. After you get a feel for how the product is used after a few cases, the risk of that happening goes way down. A disposable ureteroscope is just a good decision for this procedure.
[Dr. Jose Silva]:
Once you get the puncture wire out, then you said that you advance an access sheath.
[Dr. Jason Wynberg]:
Once the puncture wire comes out, it's a wonderful euphoric feeling. It's a great feeling. What you see is the skin tenting. We typically mark the posterior axillary line and the 12th or the 11th rib. You can see when your puncture wire comes out below the rib and behind the posterior axillary line, it's a very wonderful feeling. What you see is the skin tenting. You use an 11-blade to incise the skin and capture the wire. At that moment, what's good practice is to pause and go through your CAT scan.
Now of course, if you know your anatomy, if you've already programmed your mind, you already know what you have and safe, but it's not a bad idea. You have all the time in the world. You just go and take a look, and you scroll down your CAT scan. You can see your puncture on the CAT scan, but once you've decided that it's a perfect puncture, then you're done. You created your nephrostomy tracts. Theoretically, you could advance your balloon right over that wire because you have your track, of course.
Because we prefer-- I use a sensor wire. I prefer a sensor wire. We use a catheter at the flank to exchange it. This catheter is loaded over the wire at the flank. You draw out puncture wire about 30 centimeters just with your hand, gently. The ureteroscope is still at the papilla. There's no real danger. You're just pulling it through the ureteroscope at the papilla out the flank, so it's very safe. Then you load this coaxial catheter over the puncture wire that's out the skin.
Then you clamp both ends of the puncture wire at the back end of the coaxial catheter at the flank, just so that you have control over things and the wire that's still above the import of the ureteroscope, so that you're not going to pull your wire out, basically. Then essentially you advance your coaxial while you bring the ureteroscope down. Then what you have is your coaxial catheter goes horizontally in the kidney.
It curves down the UPJ and ends inside the ureteral access sheath, so that when you take out your dilator and your ureteroscope, what you have are two things left inside the patient, your ureteral access sheath and the coaxial catheter making a right-angle turn down the order into the upper third of the ureteral access sheath. When you put your new wire in at the side, it's channeled through and comes out the urethral side of the ureteral access sheath. Then you have through-and-through access.
[Dr. Jose Silva]:
Then is the patient at some point prone after this or you use the PERC, same position?
[Dr. Jason Wynberg]:
Same position. It's a single position. It works great. Regarding the position, if you look at your CAT scan and you plan your puncture on your CAT scan, imagine you have an underrotated kidney. Let's say, for example, you have an obese patient and there's a lot of perinephric fat. As you know, sometimes the kidney is a little less rotated posteriorally, it's a little more horizontal, just slightly. Then you know that because your puncture is going to follow the infundibulae, infundibular long axis, you can know exactly where it's going to come out. In a case where you have an underrotated kidney, your puncture wire will come out less posteriorly. When you position the patient, you need to boost them up, boost up their hips and their shoulders less.
Conversely, if you have a very overrotated kidney, for example, in a patient with very little perinephric fat, a very low BMI, sometimes you see that, then you may have to boost their hips and their shoulders a little bit more or slide them to the side of the bed. Once you plan your puncture and your position based on the CAT scan, you don't have to reposition. You almost imagine a three-dimensional box of your working space on the flank skin, and so long as you have the right angles to get to your stone, then there's no need to reposition.
(6) Optimizing PCNL Outcomes in Complex Cases: Techniques & Case Insights
[Dr. Jose Silva]:
For patients that might need multiple access, will you go in? Let's say, you do one part of the kidney, will you go in with a ureteroscope again and do the same thing again?
[Dr. Jason Wynberg]:
I have done it. It's easy. There's no technical reason not to. I do think that when you have such a big stone and you're working for a while on the one stone through a well-selected first access, and you have access from below to do [unintelligible 00:30:36]. You put your ureteroscope up and laser and you can shovel stones out the sheath just with a 1.9 French zero tip basket with your ureteroscope.
A flexible nephroscope, normally, you don't have to do that, but for cases where you really do need it, there's no reason not to. I think it becomes a matter of, have we worked long enough? Is today the day to do this? Do we really want to do a whole other puncture today? It becomes that type of game-time decision-making, but there's no reason not to have done it. That's not very common for me.
[Dr. Jose Silva]:
I completely agree. I will try to use a flexible nephroscope and try to prevent another puncture. If I had to come from the bottom and do something small for the upper part, then I'll do it, rather than just going on with another puncture and risk complications, lung damage, something like that. What situation would you need to avoid your procedure, or is there a different situation from retrograde with an antegrade that you will have to avoid the procedure?
[Dr. Jason Wynberg]:
Boy, I'm having trouble thinking of an aborting scenario. I can tell you some of the punctures that are the most difficult. I can recall a case that was a successful case. I'll just describe to you. It was very difficult. This was a lady with absolutely no intra-abdominal fat and it was a right-sided case. She had virtually an intrathoracic kidney and a full staghorn stone. The space between the tip of her liver and the paraspinal muscle behind the kidney was only 15 millimeters. She had a nephrostomy tube placed because she presented initially with sepsis and she had a tube placed.
On review of the coronal CT scan, the nephrostomy tube did a like W-shape through the parenchyma. Were I to have dilated that tract, I would've basically ripped off a part of her kidney and I didn't want to do that. What we did in that very difficult case was we found what we thought was a good window in the lower pole and we punctured out and we really studied the CAT scan very carefully, and the angle and the trajectory of the infundibular long axis. We thought, "For sure, we're going to miss the liver for sure."
Because the space was so tight, once the wire came out, we captured it with a clamp and I had an ultrasound technician just put the probe on the skin and follow the puncture wire into the kidney. She was skinny, so it was not very far. The ultrasound tech showed this is tip of liver, and you see there's fat there and then you see your wire going straight into the kidney. That was a very challenging case, but that was one very difficult case.
I think another domain of cases that can be very difficult, if you have somebody who's massively obese, then advancing the wire through 20 centimeters of fat, sometimes the wire slows a little bit and it can be sometimes a little challenging to get the wire all the way to the skin because the distance is so far. Sometimes you can take a tonsil and just push on the skin and go, "Oh, there it is." Those are the most extreme difficult cases, but even a standard patient with a BMI of 40 or 45 generally poses no problem. It's really when you get to the radically obese that you can have a harder time. I think if both of those complex cases would be complicated, integrate as well.
(7) Best Practices for RetroPerc System Implementation in Urology
[Dr. Jose Silva]:
Exactly. Definitely. Do you usually put a stent afterwards or a nephrostomy and for how long?
[Dr. Jason Wynberg]:
Because these are generally a clear view, when your nephroscope goes in, it's quite a pleasurable experience that you have no intrarenal collecting system bleeding consistently. You can really work and get as much of the stone from your access site as possible, and so the vast majority of our cases, we have exhausted the potential of the track that we created.
If for some reason we had to abort the case, which frankly doesn't happen, but just to show the other side, and you say, "There's so much potential in this track left and I just couldn't do it," then I would want to keep my access. The vast majority of the time, the tract has been maximized and exhausted, the potential of the tract. My personal practice is to remove the sheath and there's no named vessels where we puncture. There's no named vessels, meaning, there are just small vessels for the parenchyma that is behind the papilla.
I use a 24-French nephrostomy sheath in almost every case. It's a fairly small renal injury and I normally just pull the sheath out and then close the skin with Monocryl. I do put in a stent and a Foley, and then in PACU, I can know exactly what's going on with any bleeding or no bleeding or a little bit of bleeding. Then I'll often leave them there for a few hours and make a judgment. If the urine is light pink, light peach color, like no blood at all, and the case was nothing, then I would send them home. I think I send home most people the same day.
[Dr. Jose Silva]:
With the Foley and the stent?
[Dr. Jason Wynberg]:
I'll take the Foley out. The Foley serves really just as a window so I don't have to have a visit to the patient and have no idea because there's no Foley. The Foley is just really a tool for me to know what's happening.
[Dr. Jose Silva]:
During the procedure, while you're closing the back, the patient still has the ureteral access sheath.
[Dr. Jason Wynberg]:
You mean, how do I actually exit?
[Dr. Jose Silva]:
Let's say, you already pulled the nephroscope out and the sheath and you close the skin. At that time, does the patient already has the stent inside?
[Dr. Jason Wynberg]:
I usually have a juncture where I have two wires in, where I have a wire from below. I stent from below, just like if you're on call, putting a stent in a patient with a ureterocele. Through my ureteral access sheath, I throw a second wire into the upper pole. The beauty of that is I know that my stent will have nothing to do with my nephrostomy tract.
At the end of a case, if you do an antegrade stent placement, it can be very annoying if you don't know if you're in the tract or not. By throwing a wire up to the upper pole from below, it's just a simple stent. I'll have one point where I'm exiting where I'll have just two wires, one wire up in the upper pole and one wire going down. I'll remove the nephrostomy wire inside of a ureteral catheter just to make it smooth and easy. Then I only have one wire in for my stent, and then I just put a regular stent with a cystoscope in and a Foley.
[Dr. Jose Silva]:
Interesting. For the urologists out there that are not familiar with or haven't trained, for example, for me, I haven't done any retrograde cases. I trained in antegrade and that's what I do. What do you recommend? Can we go and see you, something like that?
[Dr. Jason Wynberg]:
Sure. Of course. Yes. There's several people who are doing this around the country that are more than happy to teach. I think that it's worth noting that every urologist that's doing PCNL is bringing tremendous amount of skill and knowledge to the case. It's not just the access. It's everything that follows, like put the balloon, the sheath, the nephroscopy, the lithotripsy.
Tremendous respect for everybody who's doing PCNLs. The reason I'm partly saying that is that just because this kit and retrograde technique can allow a less experienced endourologist or a general urologist to do PCNL, it's very wise to partner with somebody if you don't have experience doing the second part of the procedure because there's lots of risk that's managed by skilled surgeons doing PCNLs.
There's lots of people doing the retrograde access. I think the learning curve is really two domains. The first domain is the careful CT scan study and planning, and assembling that with a retrograde, so you really have confidence with what you're going to experience. I think the second thing is just wire handling, and that takes a couple of cases. There's many surgeons who have a proctor come to them. There's many surgeons who go and see somebody. I think that universally, we have people with very good experiences.
[Dr. Jose Silva]:
Jason, anything else you want to add?
[Dr. Jason Wynberg]:
No, I think this is a pleasure speaking with you, Dr. Silva.
[Dr. Jose Silva]:
Mine also. Thanks for being here. If somebody wants to use your kit, what's the website, or how can they access it?
[Dr. Jason Wynberg]:
Yes, the product is called RetroPerc, R-E-T-R-O-P-E-R-C. There's a website and ways to contact a nurse. There's people who support new surgeons and train new surgeons, and there are surgeons who are willing to speak on the phone in the evenings, just colleague-to-colleague, and discuss their experience. We're happy to have people come and observe. I think it's an exciting time.
[Dr. Jose Silva]:
Great. RetroPerc, just Google it and–
[Dr. Jason Wynberg]:
Google it, yes.
[Dr. Jose Silva]:
If not, you can always find you in social media and send you a text or something. I would like to thank Dr. Rodrigo Donalisio. He was actually the one that reached out to us and gave us your info to do this also. Thank you, Rodrigo.
[Dr. Jason Wynberg]:
I would like to echo that. Thanks to Dr. Donalisio da Silva. I went out to Denver and he's a very intuitive endourologist, and he before you know it was advising on his concepts and understandings, and he's a wonderfully ethical and talented surgeon. It's really an honor to have met people that I probably otherwise wouldn't have met. Thank you, Dr. Donalisio da Silva.
[Dr. Jose Silva]:
Perfect. Jason, thanks again for being at BackTable.
Podcast Contributors
Dr. Jason Wynberg
Dr. Jason Wynberg is the director of endourology at NYU Langone Health in Brooklyn, New York
Dr. Jose Silva
Dr. Jose Silva is a board certified urologist practicing in Central Florida.
Cite This Podcast
BackTable, LLC (Producer). (2023, March 1). Ep. 84 – Novel Approach to PCNLs [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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