Update on the Management of Kidney Stones

Dr. David Hernandez joins us today to discuss dietary and medical prevention of kidney stones, review surgical treatment options, and to discuss complex stone disease and treatment by endourologists. 

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Update on the Management of Kidney Stones
Featuring:
David Hernandez, MD
Joining USF in 2009 as an Assistant Professor, Dr Hernandez was promoted to Associate Professor in 2016. A native of Tampa, he studied Molecular Biology at Vanderbilt University and completed Medical School and Urology Residency at Johns Hopkins University. In 2022, he was appointed the inaugural chief of the division of endourology for the USF Health Department of Urology and director of the USF Health Kidney Stone Center of Excellence. His main areas of interest are kidney stones and BPH.
Transcription:

Joey Wahler (Host): Kidney stones are common for people, so we're discussing how they're managed and treated. Welcome to MD CAST by Tampa General Hospital, a go-to listening location for specialized physician to physician content, and a valuable learning tool for world class healthcare. Thanks for listening. I'm Joey Wahler, our guest. Dr. David Hernandez. He's Chief of the division of Endo Urology at USF Health Chief of Urology at Tampa General Hospital. Also director of the USF Kidney Stone Center of Excellence and Associate Professor of Urology at USF. Dr. Hernandez, thanks for joining us.

Dr David Hernandez: Oh, my pleasure. Thank you.

Joey Wahler (Host): My pleasure as well. So first, what is Endo Urology?

Dr David Hernandez: So Endo urology. A subspecialty within urology that has to do with surgeries that are typically endoscopic or percutaneous. So a lot of our kidney stone surgeries, as we perhaps are gonna discuss includes procedures done through the urethra, through the urinary tract without any incisions and others that are done with a very small incision in the back. In addition to treating kidney stones, Endo neurologists are very adept at endoscopic procedures on the prostate and the bladder. So a lot of trans urethral procedures, that don't involve any incisions.

Joey Wahler (Host): Gotcha. Well, glad to add that to my medical dictionary, if you will. So, how common are kidney stones and what causes them in the first place?

Dr David Hernandez: Well, unfortunately, kidney stones are very common and their incidence is increasing over time. In our country, but honestly, throughout the world, it's very common. In the United States, about 10% of patients will be diagnosed with a kidney stone. And, unfortunately the south has a higher likelihood of having stones for a variety of reasons, primarily climate and perhaps diet. There's a lot of things that contribute to stones, but certainly diet and hydration are the main factors that contribute to stones. Certainly there are many other medical conditions and even some medications that can increase, your stone risk. So quite a few things to discuss today.

Joey Wahler (Host): Indeed. So when you say that kidney stone instances around the rise, is it safe to say that in large part that's because of the way people are eating and how much medication they're taking?

Dr David Hernandez: Yes. Certainly I think, many things contribute. The reality is that few people drink as much water as they should. And as simple as that sounds, it's something that I repeat to perhaps a hundred patients a week. The other thing is that our diet has very high levels of, sodium and salt significantly increases our risk for stones. The recommendation to all stone patients is to increase hydration, particularly water and to lower salt intake. For some patients, they don't have enough fruits and vegetables and fruits and vegetables, especially citrus fruit can reduce stone risk and a lot of people have way too much animal protein.

So non-dairy animal protein also increases our risk for stones. So yes, there's plenty of dietary things that contribute. In addition, there are some medications. In high doses, certain supplements can increase your risk for stones, for example, high levels of calcium intake, high levels of vitamin C, like two grams or more per day. And finally, high levels of vitamin D could increase your risk for certain types of kidney stones.

Joey Wahler (Host): Now I know personally I sometimes use protein powder before working out, which happens to be chocolate in flavor. And from what I understand, if you don't drink enough, especially when you've taken that in, that can be a contributing factor over time. Something like that. Right?

Dr David Hernandez: That is true. I would agree. I have many patients who bring that up and I would tell them and I would tell you as well, and hopefully you never need to be a patient. That you should chase it with extra water. I don't really have an issue with, you doing so in moderation as far as protein shakes and powders and trying to, maintain a healthy diet. But you gotta chase that with at least an extra eight ounces of water.

Joey Wahler (Host): Gotcha. Understood. So for those uninitiated like myself, I feel like I've beaten the system already after listening to the checklist of reasons that you might get one of these in the first place. How do you know that you may have a stone? What are the symptoms? What does it feel like? It can be, from what I understand, extremely painful. If you're unfortunate.

Dr David Hernandez: Yeah, so classically kidney stones, as they start to move, especially, as they become ureteral stones, the uretors, the tube that's quite small actually from the kidney down to the bladder, patients will present with renal colic. So this is classically described as very severe and sudden. But intermittent flank pain, which over time may start to radiate down towards the lower quadrant on that side, towards the front. And then sometimes patients will feel it kind of referred towards their genitalia. Typically it's associated with severe nausea with or without vomiting, and it tends to come in waves. There's no comfortable position. So unlike some other conditions where you just lay still and you'll feel better, that's not the case with this.

There's no comfortable position. Patients can be riding in pain. For others, however, it's not such a classic, presentation. They may have more smoldering, kind of mild discomfort in the flank. Just general feeling a little bit off. Perhaps just having some mild nausea here and there, so it can be a little bit more subtle for some patients. And in addition, a lot of patients haven't yet developed symptoms, but these stones are detected because cross-sectional imaging with CT scans or ultrasounds as well as x-rays, will sometimes pick up on stones before they become an issue. Or some patients who are completely asymptomatic. Who actually do have significant stones that could be causing some backup of urine or other conditions.

Joey Wahler (Host): So could someone come to you and ask for imaging to sort of proactively see if any of these are on the horizon and head them off at the past before they come to a head, so to speak?

Dr David Hernandez: Well, typically we only would see patients who either have personally had stones or who have already had imaging, whether it be through their primary doctor or through the emergency room. But if somebody were to call and say that they had, flank pain, perhaps they already have some blood in their urine, something that like substantially increases their likelihood of having stones. Then yes, we are the ones to do the further workup. But typically most patients would get imaging through a doctor they were already established with before coming to us because there's plenty of other things that can contribute to flank pain. And as a urologist, I know a lot about the kidney, but I'm not an expert in musculoskeletal back pain for example. Which also enters into the equation.

Joey Wahler (Host): Makes sense. Understood. So if you do get a kidney stone, what are the ways that that's usually managed and addressed?

Dr David Hernandez: Well up in the kidney, stones can vary from one millimeter, a tiny little punk tape stone up to stones that fill the entire kidney, what we call stag horn stones, or stag horn, calculi. So we've seen stones that branch into every area of the kidney. They're more than 70 millimeters in greatest dimension, and those are obviously very complicated. At USF Health and at Tampa General Hospital, we see that, several times a month easily. So, small stones that are non obstructing up in the kidney, sometimes are observed, meaning to avoid, undergoing anesthesia or surgical procedures will just monitor them. Medium size, stones up in the kidney, we typically would recommend treating, so these are stones that are greater than five millimeters, but perhaps up to about one and a half centimeters.

With minimally invasive procedures such as shock wave, lithogypsy and ureteroscopy, shockwave, lithogypsy is the least invasive procedure we have for stones. We send sound energy through the body to the stones in an effort to break them up so the smaller fragments can then more easily pass. Ureteroscopy is a classic endoscopic or endo urology procedure where we go through the urethra, up through the bladder, up the ureter, up to the stone, use lasers to break up the stones, and then very small baskets to remove the pieces. And so for medium to, slightly larger stones, those are the main stays of how we treat. For those who have much larger stones, greater than 1.5, and certainly more than two centimeters, where it's really feeling a large area of the kidney.

We recommend percutaneous nephrolithotomy, which is a small incision, about one centimeter in length in the flank, in the back, and entering with small wires and then dilating a track directly into the kidney. We can use ultrasonic energy and pneumatic energy to basically jackhammer through the stone. And then that one has the advantage of having suction like a little vacuum cleaner, and we can remove all the stones through the back, and it's way more efficient than removing all the stones through the urethra. And so many patients, require surgery, although small stones in the kidney that aren't obstructing may sometimes be. For stones that are starting to pass, we may decide to allow patients to try to pass a stone.

Because, stones that are up to five millimeters and slightly bigger in some situations may pass without needing a procedure. And certainly we, encourage patients to typically try as long as their pain could be controlled. We try to use multimodal therapy. Basically medications an alpha blocker tamsulosin, which relaxes the ureter a bit. Tylenol, non-steroidal anti-inflammatories in combination. And some other medications can be utilized to try to get the patient through their episodes of pain and trying to avoid narcotics. Typically within four to six weeks, we'll of know whether the patient's gonna pass the stone or not. If however, during that time, they develop refractory pain, persistent nausea, especially with vomiting or any fevers.

It does become an emergency essentially, and they are typically, treated expeditiously through the emergency room or with a direct admission to the hospital. Stones in the ureter can typically be treated with either shock with the lithogypsy in some cases or more commonly ureteroscopy, a similar procedure as I described before.

Joey Wahler (Host): Wow. So it sounds like there are a number of different options depending upon what your particular situation is. Couple of other things, once you've had kidney stones, does that necessarily mean you're more likely to get them again? And if so, how likely?

Dr David Hernandez: Oh, it definitely increases your risk. The biggest risk factor for forming stones is already having had a stone previously, studies have shown that if you've had a kidney stone, the likelihood of having another stone within five years is 50%, and it's 75% likelihood of forming another stone within 10 years. And this is one of my biggest passions is trying to educate patients on their diet, on what they need to do, and in some situations actually utilizing individualized, stone risk assessments to allow us to come up with a patient-centered individual approach. including And could include sometimes supplements or medications to specifically help them not have more stones.

I know that's a lot to take in but it is clear to me that we can make a huge difference and certainly at USF Health and our Kidney Stone Center, we are taking the steps to really educate patients who are higher for stones, to help them prevent future stone. Because again, it can be very painful and sometimes costly and unfortunately, oftentimes completely unpredictable. If you have a stone, it may not bother you until somebody's wedding or when you're traveling or you just can't predict when they're gonna move. And so again, it's critical to try to prevent future stones.

Joey Wahler (Host): I'm sure there's no good time, quote unquote, to get one, especially if it's painful. Right. Finally, you mentioned that you're so passionate about this. Do you find that when you sort of warn people in advance, hey, you can take control and either avoid these altogether or help to try and also, Possibly avoid getting another one if they've already had one? How many patients seem to be taking you up on that?

Dr David Hernandez: Oh, there are many. I've been at USF Health and at Tampa General Hospital for over 13 years and have seen thousands of patients, with kidney stones. And many of whom I know we've made a difference in, the vast majority have, but there are certainly ones who have had stones multiple times a year, and then they come back and say, Hey, since I've seen you and you treated me, you did my surgeries and you got me, let's start on this medication. You spent that extra time with me. I haven't had another stone in five years. We're just monitoring them to make sure that they don't form one and medical preventive strategies to avoid further stones.

There are other patients who have been referred specifically for surgery who I have diagnosed based on some high suspicion based on their imaging of having uric acid stones, and I've been able to avoid surgery by actually dissolving those stones. Those uric acid stones are the only semi common stones. About 7% of stones are uric acid in nature that you can actually adjust the urinary pH, make their urine less acidic and actually have the stones just go away. And there have been patients who have been referred from three hours away to have major surgery.

And because again, I'm dedicated to stones we've been able to avoid surgery for them. And so again, there are many reasons why patients are very grateful for us having such an active, and even research interest in stone disease.

Joey Wahler (Host): Doc, we certainly now know why you have so many different important roles and titles to go along with them. You've gotta keep track of a lot of stuff here.

Dr David Hernandez: Fair enough. Yes, sir.

Joey Wahler (Host): And we're certainly grateful that you have those various abilities. Well folks, we trust your now familiar with both Kidney Stone Management and treatment as well, Dr. David Hernandez, very valuable information. Thanks so much.

Dr David Hernandez: Thank you. My pleasure.

Joey Wahler (Host): And thanks again for listening to MD CAST by Tampa General Hospital, available on all major streaming services. For free to collect your cme, please click on the link in the description for other CME opportunities, including live webinars, on demand videos, and local events offered by Tampa General Hospital. Please visit cme.Tgh.org. Again, cme.tgh.org and thank you.