Casey Kowalik: All right, thanks Alan for having me on UroToday. So I just want to give a little bit of background and I'm sure that this audience knows what videourodynamics is, but it is a multi-channel urodynamic pressure-flow studies that become integrated with simultaneous real-time fluoroscopic imaging and the term video actually is a historical term back when they would be sort of recorded onto video cassettes. Of course now everything is digital, but the name has still stuck as videourodynamics shortened for VUDs at many places. And like Alan said, I think that this can add a lot of value to not just the diagnosis but also management for patients with neurogenic lower urinary tract dysfunction, female bladder outlet obstruction, and then any congenital lower urinary tract anomalies. I don't think every patient needs to have videourodynamics, but these subgroups of patients, I think it adds a lot of value and that's because it provides direct anatomic visualization in addition to that functional information that you're getting from the urodynamics. And so it can help localize if there is an area of obstruction. So for example, in female bladder outlet obstruction, you can localize that obstruction to the bladder neck, which you wouldn't be able to do on just a traditional urodynamics. Other value added with the video component is being able to detect and grade vesicoureteral reflux and have that bladder pressure correlation at the same time. You can confirm detrusor sphincter dyssynergia with fluoroscopic evidence.
Also, it also allows you to see bladder wall changes, so like trabeculations, diverticula on the fluoroscopy and in some instances can help identify fistula. One of the disadvantages of videourodynamics could be that it requires additional equipment. I do think that this is usually achievable and overcomable by most practices, but you do need, of course, to have a CRM or some kind of fixed X-ray unit with image intensification, a lead-lined room, and of course the urodynamics apparatus and then you want to have access to some iodinated contrast in order to be able to see the bladder on fluoroscopy. From a practical standpoint, videourodynamics is going to be higher costs than your conventional urodynamics and may require two personnel in the room depending on your state laws, whether you can have the same person that's doing the urodynamics also be administering or clicking on the fluoroscopic button. And then any woman of childbearing potential, you'd want to exclude pregnancy prior to proceeding with videourodynamics. At the bottom of the slide here, I put in the ALARA principle just as a reminder that radiation is a risk with videourodynamics and particularly to the staff that may be doing the majority of the videourodynamics. And so using that principle of as low as reasonably possible in terms of radiation doses and using reduction strategies can help to protect the staff. I mentioned earlier that one of the populations that I find videourodynamics to be particularly useful in is in the neurogenic population. VUDs can help you identify any bladder wall changes, so trabeculation, cellules, diverticula. This is where you may see that pathognomonic Christmas tree bladder that is indicative of a hostile bladder. This can be combined with that functional data. So if you're also getting a detrusor leak point pressure that's over 40 centimeters of water, this of course we know puts that patient at increased upper urinary tract risk.
You can get poor or you can see poor compliance with a steep rise in Pdet during filling and this may be offset by the detection of vesicoureteral reflux. So I think it is important to have that video component because you may not otherwise see that the bladder is poorly compliant if all of that fluid and pressure is being disseminated up to the upper urinary tract. VUDs also allows you to confirm detrusor sphincter dyssynergia, so you may see that the EMG activity going wild, but then you can confirm it fluoroscopically. This is a table that I put together just highlighting some key videourodynamic findings and what their clinical implications may be. And so for example, on videourodynamics, you might see Pdet spike during filling and contrast leakage indicating detrusor overactivity and that'd be sort of the most basic of abnormal findings that you may see on videourodynamics. Other ones like I mentioned, would be an increase in the EMG activity with a concurrent sphincter closure during a Pdet contraction in a neurogenic patient would indicate DSD or detrusor sphincter dyssynergia. In a non-neurogenic patient may indicate dysfunctional voiding. I think the other real value to videourodynamics can be localizing an area of obstruction, particularly in men. So you could have your usual urodynamic findings of obstruction being the high pressure, low flow, but then on the video component you can actually localize where that anatomic abnormality is, whether it's at the bladder neck, maybe it's from an enlarged prostate or even more distal from a urethral stricture. Utilizing videourodynamics in the female lower urinary tract dysfunction population can also give us a lot of additional information. It can help differentiate intrinsic sphincter deficiency from urethral hypermobility or even from that stovepipe urethra that you may see in patients who have had prior stress incontinence surgery or other pelvic surgery or pelvic radiation, and then can also help diagnose bladder outlet obstruction in women. We all know that there are urodynamic criteria for men, but there's less well-established criteria for women.
And so this can be helpful to have that video component of seeing that the bladder neck does not open during an attempt to void. And then video can also help with that critical distinction between bladder outlet obstruction and detrusor underactivity because they are going to result in vastly different management strategies. If you have a female with sort of obstructive symptoms, it could be that they have bladder outlet obstruction, but maybe they have slow flow because they have detrusor underactivity and again, you're going to do completely different management strategies depending on what the cause of that symptom, the low flow would be. In men I mentioned localizing the obstruction at either the bladder neck, at the prostate or at the urethra. I think VUDs can also provide a lot of value in the post-prostatectomy incontinence population. They can help differentiate between intrinsic sphincter deficiency or detrusor overactivity. Can have an anastomotic stricture after a prostatectomy and then even detrusor underactivity is quite prevalent in a lot of post-radical prostatectomy patients. In the peds population, you can also utilize fluoroscopic imaging to help identify and monitor posterior urethral valves, so you may want to monitor their bladder function post-ablation, you can assess their compliance and then any persistence or resolution of vesicoureteral reflux and see what their emptying efficiency is like. In patients with complex vesicoureteral reflux, this may help determine at which pressure and volume the reflux starts and can highlight an anatomic versus a functional etiology for the reflux. In terms of future directions, so some studies out there are being done with contrast-enhanced video ultrasound, so basically like an ultrasound-based videourodynamics where they're using these microbubble contrast agents in combination with ultrasound at the same time as doing the urodynamics to help detect for vesicoureteral reflux.
It's ideal for the pediatric population because there's no ionizing radiation and those patients who are going to probably be getting repeated urodynamic studies over their life and imaging or radiation exposure for other reasons, this is a nice option or could be a nice option in the future. It also provides continuous imaging, so as opposed to fluoroscopy where a lot of times you're just hitting that button intermittently to try to save radiation exposure, the ultrasound will provide continuous imaging to capture the exact timing of certain events like bladder neck opening. Another modality that's been investigated is transperineal Doppler ultrasound. This has not yet been combined with urodynamics, but it can be a good option for a catheter-free study and they do use physiologic filling, so maybe more physiologically accurate. And then in terms of artificial intelligence, it feels like in some ways this is going to be taking over the world, but may also be used in videourodynamics. You can have automated segmentation of bladder, bladder neck and urethra from the fluoroscopic or ultrasound images, automated detection of reflux, bladder neck descent, or even DSD patterns. And then one group used this information as predictive models to see who would have hydronephrosis in a group of spina bifida patients. And so in summary, VUDs integrates real-time imaging through fluoroscopy with functional data, so pressure-flow data that gives additional information that conventional urodynamics would not otherwise be able to give us. I use it as my evaluation strategy for patients with neurogenic urinary tract dysfunction because it can help me determine what their risk is and then guide management options. In both men and women VUDs can help localize any sites of obstruction and help differentiate between bladder outlet obstruction from detrusor underactivity, which as I mentioned is critical for making sure you're doing the correct surgical or medical intervention.
I do think that not every patient needs videourodynamics and so smart patient selection is essential because videourodynamics does have increased cost, higher resource utilization and then radiation exposure. And then lastly, there are emerging technologies with the contrast-enhanced ultrasound as well as the use of artificial intelligence that will hopefully help automate the process and also provide radiation-free imaging. I think really the gold standard, that would be awesome some days to be able to achieve some kind of ambulatory videourodynamics so that you get a physiologic and anatomic assessment, but that's still not yet been developed.
Alan Wein: Terrific. Well, that was a great summary about all aspects of video. Now, would it be correct to say that the use of videos essentially does away with the necessity for any kind of EMG recording because what you're really looking for is DSD and that's better demonstrated on a video study.
Casey Kowalik: I think that although the EMG comes with its own set of challenges, the pads are not always sticking, sometimes the data's not the most accurate. I still think having the concurrent EMG with the fluoroscopic images can be helpful as an additional data point.
Alan Wein: It sounds like this requires a much higher trained person than the standard urodynamic studies and for the exact time at which you do the fluoro spots, are you there or do you have a technician who's so well-trained that they can do it, that they actually know when to press the button? Obviously I think you don't want to leave the fluoro running throughout the whole study.
Casey Kowalik: Yeah, so in my particular practice, I am the one doing the fluoroscopy. So we have the nurse who sets up the urodynamics. I mean she's great. She gets everything all teed up, gets the arm in position, but then I am the one in the room clicking the button when I feel like it would be helpful for me to snag a fluoroscopic image. And I think the advantages to that are that I am able to limit the radiation to the patients because I know what I'm looking for and what my clinical question is, which I think a lot of times can be hard to convey to a technician. Obviously the drawback is that my time is valuable and so being in that room can sometimes take away from other things, but I do think that it's for me, the best use of that technology.
Alan Wein: Do you have any idea what the breakdown is for urodynamics without video and urodynamics with video? I mean, are you the only person who uses it or do other people refer their patients, let's say the people that see mostly men with lower urinary tract symptoms?
Casey Kowalik: Yeah, that's a good question. So there are three of us urologists who will do the videourodynamics, and so we do get a lot of internal referrals from our partners who may have a patient that they want to get videourodynamics done in, and so they'll send them to us. But there are still way more conventional urodynamics that are done. The exact number I'm not sure of. I would guess that of all the urodynamics that are done in the department, probably 15 to 20% are done with video. And again, it's really kind of limited to that neurogenic population or somebody that we have a real concern for vesicoureteral reflux or that we really want that anatomic imaging concurrently.
Alan Wein: Yeah, the great thing is it really does give you sort of all the answers at once if you know what to look for. I mean, that's the really nice thing about it. Now, do you use that room for other things during the day or is it pretty much a fixed room that can be used only for that?
Casey Kowalik: We do use it for overflow, so I've definitely done quite a few Botox procedures in there when the procedure rooms are otherwise full. If there's a delay, I love to blame my oncology partners on their long prostate biopsy or something. So yeah, we do use it for other things, but mostly for an overflow situation. It is primarily marked as the videourodynamics room.
Alan Wein: Yeah. How many video studies can you do a day? I mean, what's the usual length of time by the time you get the setup done, by the time you get the study done, etc. How many can you do in that room in one day or how many do you do?
Casey Kowalik: We have it right now, our schedule allows for three in a day. I think we could do four, two in the morning, two in the afternoon. But just the way that the procedure room nurse is assigned, we currently have three openings per day for that room.
Alan Wein: So the average 70-year-old man that comes in with lower urinary tract symptoms, both filling symptoms and voiding symptoms, does that person get a urodynamics study or a videourodynamic study generally?
Casey Kowalik: Generally I would say that person, just the average male, no other complicating factors like being hospitalized for UTIs or prior surgery is going to get a conventional urodynamic study.
Alan Wein: So it really makes a difference. So when people look at videourodynamics, they have to look at videos in the light of really what it's extremely useful for and what no other study can do. And really there isn't another study that can duplicate the results of that. So it's interesting. I mean, how many video units do you have, one just at the base hospital, do you have one at any of the satellite places that you have?
Casey Kowalik: Yeah, that's a great question. So we only have one room amongst all the satellites that we have, and that's at the main campus. So anytime we have a patient that needs videourodynamics, like if I see them at a satellite place, then they have to drive to the main campus to get scheduled for their videourodynamics, which of course they hate to do, but that is our only, we've centralized that because of the large resource need in terms of having a lead-lined room and the Sonesta bed and the fluoroscopic equipment.
Alan Wein: And all the neurogenics pretty much get videos, even the stroke, even the simple cerebral ones like stroke, et cetera?
Casey Kowalik: I do, just because I've been surprised in some of those patients where I think that it's like detrusor overactivity that's going on, but turns out that it's not.
Alan Wein: Yeah, I guess it's especially useful in differentiating Parkinson's from multiple system atrophy and that sort of thing.
Casey Kowalik: Right, and really getting a good assessment of their sphincter and when it's relaxing.
Alan Wein: Right. Well listen, thanks so much. That was a great discussion. Really appreciate it and if something else interesting comes up, let us know because we'd love to have you back on the channel.
Casey Kowalik: Awesome. Well thank you so much for this opportunity.