"This scope allowed me to maintain the intrarenal pressures lower than I would originally have done," says Naeem Bhojani, MD, FRCSC.
The FDA recently granted 510(k) clearance to the LithoVue Elite System for ureteroscopy. In this video, Ben H. Chew, MD, MSc, FRCSC, and Naeem Bhojani, MD, FRCSC, discuss how the tool has impacted their approach to treating patients in practice since they have been able to use it for over 50 cases. Chew is a urologist at the University of British Columbia and Bhojani is an associate professor of urology at the University of Montreal.
Dr. Ben Chew: Now we have a tool in order to measure what intrarenal pressure is, and I think we need to measure outcomes. Two of the biggest outcomes we're looking at for internal pressure, obviously, is sepsis, as well as pain, perhaps, and one of the theories is that increasing intrarenal pressure will increase people's pain during the operation. So Naeem, you had a case where you had a very septic prone woman who came in in her 60s and, and you actually used the scope to your advantage to try and reduce her risk of getting septic again. Tell us about that.
Dr. Naeem Bhojani: Yeah, we've done a couple of studies looking at sepsis after ureteroscopy. So we know there's a number of risk factors for sepsis after ureteroscopy. I did have a patient who had a number of risk factors. I was worried that she might go into sepsis. This scope allowed me to maintain the intrarenal pressures lower than I would originally have done. I was able to aspirate during the case to keep the pressures low. I think that's one of the nice, possible benefits that we need to prove. The other side is also true. We're able to use this scope to keep our pressures low, but in a specific case I had more recently, the pressures were very low, and I was able to actually increase the pressure during laser lithotripsy, in order to see better. Again, as I could measure the pressure, I could manipulate it as necessary. Ben, has this ability to measure pressure changed your practice at all and the way you approach patients?
Dr. Ben Chew: Yeah, that's a good question. I think that it has a little bit because we didn't really know what pressure is. Now, we have to do a caveat on this, we don't know exactly what effects these pressures will have in the end and in the end goal here, in terms of getting sepsis and pain, and things like that. We need to study that more. But I think that basically, common sense tells us at a lower pressure is going to be better, it's always been a caveat that we think that lower pressures will end up with decreased infections and decreased amount of pain. So before this, I would say I was maybe about a 20% ureteral access sheath user, so 80% of the cases, I wouldn't use it. I would say that I am tending to do it a little bit more, particularly in cases where I think I might be up there for a longer time. That's something that has changed in my practice a little bit. Also, I got to tell you, I've never aspirated through a ureteroscope as much as I have as when I have this ureteroscope. When I see the pressure is really high, the kidney’s like a balloon that fills up, and then we can aspirate it to empty it a little bit. Then the pressure gets lower, and then you can fill it up again with the irrigation, just trying to reduce the amount of pressure you're subjecting that patient to. That's one thing. What remains to be seen as what the clinical end effect of that will be. We're going to be more data for that obviously. There was one case that I did where the patient was under a spinal anesthetic. The ureter was a little bit tighter. I didn't want to do too much manipulation, so I just went up with the scope without a ureteral access sheath and the patient started having pain. I could see what the pressure was, and I could see there was 140 millimeters of mercury. That's the other thing, we didn't even know what pressures were. If you go in, most people are between, I don't know, anything 10 to 30, somewhere around there in that range, if you're not doing anything, even a bit lower. Once you start gravity irrigation, it goes up a little bit. But if you use pressure irrigation, it can really go up to 200. This lady was around 140, she was getting pain. Anesthesia was saying she's having more discomfort. So, we stopped, put up a ureteral access sheath, and then the pressure went down to about 30. Then the patient was fine. Now you could argue, did I need the pressure measurement in order to do this? I could just ask the patient. But it was really interesting to correlate the symptoms because the patient could feel this because of the spinal anesthetic with the actual pressure that I was getting the reading from. It was just neat to correlate that A.) it did change the pressure and B.) her pain went away. Has it changed your practice at all?
Dr. Naeem Bhojani: Yeah, definitely. It’s really made me rethink my evaluation of my patients. I've seen patients who are at risk of infection. These are patients that I want to use ureteral access sheaths in, bigger if I can, maybe use hand irrigation, just trying to control the pressure, antibiotics, possibly as well. [It] allows me to rethink how I evaluate my patients before I operate on them. You made a good point about the peak pressures that can cause pain. I think that's another area that's going to be interesting. We've discussed this. Is it a peak pressure? Is it a high pressure over a certain amount of time that causes us pain? Or possibly infectious complications? I think it's a really exciting time. We're going to be able to do so much to try to figure out and answer all of these questions. It's going to be great having this new tool.
This transcript was edited for clarity.