Urologist Justin Ahn, MD, answers crucial questions on preventing and managing kidney stone disease – a condition affecting 10% of the U.S population, with young patients increasingly at risk. He presents keys to diagnosis, including imaging tips, and a thorough update on the many high-tech procedures available, describing how to make treatment decisions based on factors ranging from stone numbers and size to the patient’s health issues and lifestyle preferences.
So, uh, hi, everyone. Uh, my name is Justin Ahn. I'm, uh, the new urologist, uh, uh, with UCSF. Uh, I just finished my fellowship in July and, uh, I'll be back in the, um, I'll be practicing full-time in the Peninsula, Redwood City, San Mateo area. Um, my specialization is in kidney stones and laparoscopy, um, and BPH surgery, but I'll be just basically doing general urology as well. Um, so this is meant to be a review, uh, update sort of in kidney stone management and treatment, uh, and then just a little info about myself, as I mentioned before. Um, so without further ado, um, a lot of you already started participating in this, in this questionnaire. So if you are just logging in, um, I'm gonna have some couple of questions just to keep, just for sort of, um, Viewer engagement during a couple of questions throughout my talk. And so you'll be willing to be able to participate. You just have to go to this link or uh sorry, get out your phone, text the message Justin on 664 to this number, uh 223-33. Um, a lot of you have already had a chance to respond and I thought this is a good way to kind of break the ice with this talk, um, to give you a sense of the relevance of kidney stones. Um, And so actually, even here within this population, we have a fair number of you that actually had kidney stones and uh most of, you know, a lot of you have had a close friend or family member that have had kidney stones. Um, so, uh, thank you for doing that and we'll have some more questions uh as we go. Um, So, uh, 10% of the US population over their lifetime is expected to have kidney stones. Um, there's an increasing prevalence over the past 15 years. Um, and, uh, that, and then we talk about it's, and people think of kidney stones as just a one-time event, but it's really a chronic disease. There's a Uh, 50% chance of recurrence of kidney stones in the 1st 5 years and that jumps up to probably closer to 80 in 10 years. Um, it's a huge cost burden on the healthcare system if you, uh, this was database to look at the most costly diseases, uh, for in urology and kidney stones is number 2, like surpassing prostate cancer, BPH, uh, other urethral, um, urinary tract issues. Um, this equates to basically a lot of money, um, potential morbidity, mortality and a lot of visits to, uh, you and to ERs and things like that. Um, so. Um, life, uh, the epidemiology, uh, is much more common in men, uh, than women, uh, Caucasian, more than other ethnicities. Uh, all ages are affected, you know, we're seeing a higher prevalence in children, um, and especially older, like young, older teenagers, younger adults with the kind of concordant with the, uh, obesity and metabolic syndrome epidemic. Um, it's seen more in the southern and the hotter environments. So you can just, they call it the stone belt, basically the deep South, but basically anywhere that it's hot and dry uh hot and arid, um, we're going to see more kidney stones just because we think of dehydration as part of the play, occupational exposures if they work in really hot environments. Um, and we also tend to see a spike in kidney stones towards the end of the summer. Uh, early fall because of, um, because of the, the, the weather conditions. And you can see here the Bay Area is not spared, um, in this heat map, uh, you know, uh, in terms of being close to basically on the border of, um, a high-risk, a higher-risk area for stones. Um, common risk factors we talk about with patients are poor fluid intake, um, high oxalates, or so bad diet, basically, uh, metabolic syndrome, diabetes, uh, recurrent urinary tract infections play a significant role with infection-type stones, specifically struvite. Um, sedentary lifestyle, especially if you're wheelchair-bound or immobilized. Uh, you just absorb lots of, your bones reabsorb lots of calcium, uh, and anatomic abnormalities of the upper urinary tract. So if you have, um, you know, some congenital abnormality or ureter or pelvic junction obstruction or, um, things like that or abnormal anatomy. Uh, inflammatory bowel disease is not to be discounted, can lead to significant acidosis, uh, of the body, which in turn can have significant impacts on the urinary tract. Um, Crohn's, ulcerative colitis. Um, and, um, this is also not to discount the strong, uh, family disposition, uh, genetic predisposition to, uh, when, you know, patients always ask me what's the most common type of stone, it's, uh, always by far most common if you're betting at a, at a, um, if you're betting on it, it's gonna be most likely a calcium oxalate stone, uh, uric acid, struvite, infection stones, those are all tend to be uh less common, um, so. Um, symptoms, you know, you think about the classic renal colic pain. Uh, you know, they can't find a comfortable position. They're writhing around, uh, as opposed to a peritoneal abdomen where they're, they're fine if they sit still, you know, if they go over a speed bump or, you know, you push on their belly, it's really tender, but Uh, renal colic, uh, is, you can't, you're not comfortable at all in any position. And, uh, it's just waves of pain, you know, described as, as, as painful or more painful than childbirth. Uh, uh, the pain is so severe, it causes nausea, vomiting, uh, blood in the urine, sometimes seen microscopic or gross blood. Um, and then, um, you know, the, the class, the, the symptoms can range when you're passing a kidney stone. Um, you know, single thing of flank pain, but it does tend to radiate around to the front. As the stone migrates into the distal ureter just because of the referred, uh, nerve pathways. Uh, and occasionally we'll see, I'll, I'll diagnose a patient with kidney stones, uh, with someone who has, uh, groin or even I've seen men in uh labial, or sorry, in women in labial pain or, uh, men with testicular pain, uh, a deep groin pain that, that can be also from a distal stone that's, that's passing. Uh, always important to ask about medical history, uh, medications like we talked about, uh, a medical history from the prior slide. A strong family history always pretends a higher risk for recurrence and, um, and I, it's seen in about 40% of patients will have some family predisposition, um. Um, in terms of initial diagnostics, you know, everyone gets a urinalysis. Uh, red blood cells, you know, you're always looking for microscopic or growths, um, but you're not always gonna see a positive red blood cells. So if you have a high enough clinical suspicion, don't discount a negative, uh, you know, blood or RBCs, uh, for, you know, that is not having, not being a sign of kidney stones. Um, white blood cells or leukocyte esterase, essentially that's just showing inflammation. It can be suggestive of infection, especially with higher, like if the white blood cell count is more in the 100 range. If it's like in the, you know, low 50s or, you know, or in the low 10s, uh, it tends to be just more related to inflammation of the, uh, literally the, the, the, uh, stone irritating the urinary tract. Uh, nitrites on the urinalysis, I definitely look for because that will tend to indicate there's some form of grain negative bacteria in the urine, uh, that is causing that chemical reaction. And then finally, um, I look at urine pH because that does portend certain stone types, higher pH like in the 7 range or above tends to be calcium phosphate or struvite infection stones. Really low urine pH, um, can be uh portend uh uric acid stones. Um, and then serum labs, um, the things we care about really are what is your renal function doing, you know, what is it currently in terms of GFR creatinine, and also what is your, how's it compared to your baseline? Do you have any underlying CKD and not much renal reserve? Are you solid, you know, are you, were you born with a solitary kidney? Those are important, uh, considerations. And then finally, do you have any evidence of uremia or acid-base abnormalities, electrode abnormalities, uh, such as ure or uremia signs that would warrant, uh, you know, urgent intervention? And then you know, concerns about infection, you know, fever, chills. I was checking a white blood cell count, but sometimes the response for the leukocytosis can be delayed. Uh, and so the next step, you know, probably the one of the most important for us is imaging, and I wanted to comment on each of those studies individually. Uh, KUB or plain film abdominal X-ray. Pros, it's really cheap. It's easy to obtain, you know, if you come to UCSF, you don't need an appointment even. Um, you just walk in, but the cons is, it's not very sensitive. I mean, you can see here that this huge struvite stone is not trivial and you can see it pretty clearly, but, you know, here you can see a small, uh, like a probably a 1, 1.5 centimeter renal stone as well. Um, but not all stones are radio opaque as we may have remembered from our, our med school trivia. Um, uric acid stones tend to, are, tend to be the classic ones we can't see on X-ray. Um, a lot of stones can be mixed composition too. Um, so they're not purely uric acid or purely calcium oxalate. Um, you also don't get any sense of, uh, functional anatomy, so you can't assess for obstruction hydronephrosis, which is one of the important things we want to factor in. So really, uh, KUB X-ray is reserved for follow-up patients with known radio opaque stone disease. You know, they get a CT scan with a scout that shows a scout X-ray that shows, uh, a radio opaque stone, then we'll just follow them with X-rays. Um, it also is used for assessing candidacy for specifically shockwave, uh, lithotripsy treatment because we use X-ray targeting as the main way for, uh, main method for, uh, treating those stones. Uh, renal ultrasound has become much more in vogue, uh, I think with, uh, consciousness about radiation exposure, um, cumulative radiation exposure. Um, uh, the nice thing is it can assess, we can assess basic renal anatomy. We can assess, um, for obstruction, hydronephrosis. Uh, limitations are you can't see the ureter. Basically, the, from the proximal ureter down the distal ureter is sort of this black box that you can't really see, um, without a CT scan. Um, missed it, the renal ultrasound can miss small stones, you know, if they're 1 or 2 millimeters in size. It can also overcall stone size frequently. And so you can see here the, the classic, what we do try to measure is the actual shadow behind these stones is very indicative of an actual renal stone versus, you know, you can see your brighter spots, echogenic that don't have that shadow, uh, behind the stone. And same thing here, you can see a stone that's coming into the, the distal ureter, uh, and here's the bladder. And you can see once again there's this kind of shadow, we call it the shadow sign behind the stone. Sometimes we'll measure the shadow and that gives us a more accurate sense of the size. All that to say is that ultrasound sometimes radiologists can sometimes overcall the size of stones by a couple of millimeters. Um, it's also limited in obese patients, so obviously the more obese you are, the limited, the more limited ability for sound waves to penetrate and get a good diagnostic image. Um, so really the utility for ultrasound that we see now that we're using is for screening for patients. So if you have a, you know, if you have a patient, you, you know, you wanna just check out their kidneys and, or, uh, you know, you have maybe a lower suspicion they have a stone, uh, it's great, just a screening measure. Uh, it also can allow you to assess the bladder, uh, prostate size if you ask for, uh, if you ask for it, and also bladder emptying, plusfoid residual. Um, since they do the bladder and kidneys, but with any ultrasounds nowadays. Um, it's also great for surveillance. So a patient with known kidney stones or a patient who's had stones and now we're just looking for a recurrence, um, we'd like to get ultrasounds annually, once a year, and that, uh, will, um, so that's a great another tool, right? I really, and, uh, also, uh, pediatrics and kids and also in pregnancy, uh, is really our go to. Um, So the next question for everyone is what radiation dosage is considered low dose for a CT scan, uh, for CTKUB? So the classic right no-contrast CT scan you obtained for patients with kidney stones. Um, you know, just to give you a reference, plain X-ray is one millisievert standard CT scan. Um, a non, non-low dose would be 10 to 15 millisieverts. And then a CT scan with contrast is probably closer to 15 to 20. So I'll give you all about maybe 30 seconds to, I'll, I'll put in your answers. Um. And um let's see what we see. Um, Appreciate everyone's participation and uh uh you will not be, you will not be graded on this, don't worry. Uh there's no uh credit for this. Appreciate the uh engagement. All right. So, um, Uh, so it looks like everyone, actually, most of you picked the right answer. Um, so, uh, looking at CT scan, the answer was less than 4 millisieverts. Um, there, um, so let's talk about CT scan for a second and we can go back to that. Um, the gold, the CT remains the gold standard. It has the best sensitivity, over 90%, uh, sensitivity and specificity for detecting stones. It gives you detailed kidney and ureteral. Anatomy, unlike ultrasound. Uh, and it also allows us to assess stone density, which is really important because for us surgical planning-wise, we wanna know if it's a really hard stone or a really brittle soft stone and that can also help. We can even sometimes predict what type of stone we're gonna treat um based on the household units when we uh look at a CT scan. Um, the cons is the radiation and that's why I bring up, um, you know, there's been a lot of concerns about cumulative radiation. So we have moved towards doing low-dose CT scans at UCSF, uh, and we actually, and so less than 4 millisieverts or even 3 is considered now the gold standard. Uh, if you order just a standard CT scan of the, uh, without contrast, it can be, be up to 8 or 10 or it can be up to 10 or 15 millisieverts. Um, so almost double or triple the dose. So, um, I always make a habit when I order scans, CT scans specifically for stones. I always say, assess just for kidney stones, low dose protocol. Um, and so that helps to prompt the the radiologist that, hey, I don't need to, you know, I'm not looking for a small, you know, mass in the, in the colon. I'm just because, uh, you know, that we don't need that greater resolution to pick up kidney stones, uh, and it can significantly lower the cumulative dose a lot of these kidney stone patients get. Uh, in one, I think one study found that in with one kidney stone episode, the average patient, uh, just in a year can get up to 3 or 4 CT scans. Um, so it is significant. Um. And um we actually did a study looking at how well low-dose CT scans have been uptake, uptake, have been taken up at academic institutions here and several on the West Coast. And it was only about 20-30% of the time that patients get for uh kidney stone patients get a low-dose scan or one that met that criteria. So we're really trying to push this and encourage the radiologists to do as well. Um, you, so utility for CT scan is really for those first-time stone workup patients. We wanna get a big picture, uh, view of their anatomy. We also wanna assess, uh, if they, if they had a, if they're passing a stone, is it clear of the ureter, Especially if, you know, if they didn't pass it or they, they don't have a stone in hand or they, they're not sure if they passed, they may be having some residual symptoms. We're gonna get that CT scan to confirm because we don't wanna make, we wanna make sure that stone's not stuck there in perpetuity. Uh, it's also if you want to assess for other intraabdominal or pelvic pathology, right? They come into the ER, ER doc wants to rule out appendicitis, you know, diverticulitis, other things like that, um, which they usually can't pick up with low-dose scans, to be honest. Uh, but that's, that's the radiologists call. And then finally, for any patient we're taking to surgery, most of the time, we want to have some form of CT imaging. But like I said, if someone's had a CT image within the past year and I think an ultrasound is just fine for more updated imaging, there's no need to give them more radiation. Um, so we talked about stone passage and the three places that it tends to get hooked up, uh, hung up is here at the ureterop pelvic junction, uh, is the first road, uh, roadblock here at the, as the ureter crosses the iliac vessels, uh, and then here finally at the ureteral vesicle junction because it has a tunnel through the, the, uh, wall of the bladder muscular wall of the bladder. Um, so once it makes its bladder, the, the stone is home-free and um, even studies have found that the more distal, the more distal the stone is at the time of the imaging, the more likely the chances of successful passage. So if you find someone who has a stone who's already made it down here, by the time they get their imaging, they're more likely to pass it, which makes sense, I think. Um, so this is a rough decision-making tree for what I'm thinking about whenever I see a stone and what hopefully you're thinking about as well. Um, so if someone has, uh, a kidney stone, uh, 1st, 1st of all, I'm asking is it in the ureter or the kidney? If it's in the kidney, now we have to decide if we're gonna observe it based on size, location, symptoms, or treat. Um, if it's in the ureter, now we're asking, uh, we have to make sure that stone gets out of there either by treatment or by passage. So now, based on size, symptom, and patient factors, uh, we decide either one of these. Um, patient factors can be everything from how frail or morbid, morbid, um, risk of morbidities they have, but I've also had patients who are, you know, didn't wanna spend the time trying to pass a stone. Maybe they had a, they lived out in the middle of nowhere and couldn't afford to be near an ER or they were traveling and, uh, wanted to make sure that they were safe, uh, to be in an airplane and weren't gonna do to divert the flight. Um, so it's important always to get that social history component. Um, let's talk about medical expulsion therapy, so really indicated for stones less than 10 millimeters, uh, in, in patients who have well-controlled symptoms, right? They're tolerating the pain or discomfort with some Tylenol, ibuprofen, or, uh, oral medications. They're hydrating, uh, they have good renal functional reserve. Um, you know, they may have a mild, uh, bump in their creatinine, but, you know, they're not nowhere, they're nowhere, they have two healthy kidneys and, you know, they're nowhere near like, you know, fulminant uremia. Uh, and also no evidence of infection. Uh, so I'm, what I'm talking about is, um, infection can, is, we'll talk about later, is probably one of the biggest, uh, concerns, emergencies we have in, in neurology for stones. Um, symptom control. Uh, uh, NSAIDs and Tylenol are great. Uh, Toradol works, is one of the, probably one of the best medications and it's every, it's what, you know, it's the only thing that ER docs give and it has the best relief. So if you can give patient PO or IM or even an IV injection of it when they're having acute colic, uh, it'll really help them out. Uh, just making being cognizant of their renal function because if they, um, and not to give sort of chronic long-term doses of it, especially if they already have an AKI. Um, narcotics, you know, we try to limit those as much as we can, uh, anti-emetics as needed. Um, this chart here shows why we, why these, why have, we have these numbers. Uh, you can see that the, if the stone is less than 5 millimeters, there's over a 50% chance of it likely passing. Uh, once it gets into the 67 millimeter range, now your, your, your chances are significantly going, uh, dipping lower. Um, and so that's where, that's really why we use that as sort of a cutoff for intervention. Um, we say 5 to 6 millimeters is really the cutoff, uh, where you should consider seeing a neurologist to consider treatment. Um, um, in terms of Flomax, you know, there's been debate back and forth. Right now, the established dogma for urologists is that Flomax, yes, it's relatively low risk and it doesn't have really much side effects, maybe some mild hypotension, um, but it's the best, the most benefit that they've seen for it is in distals, stones in the distal ureter and also for larger stones. So above, uh, you know, 6 above 56 millimeters in size. Um, if you wanna give it to patients with proximal stones or less than 5 millimeters, you know, I think it's not gonna hurt and it's a relatively cheap medication. So, um, you know, if, if you ask 10 neurologists in the room, 5 will tell you yes, 5 will tell you no. Uh, and then finally, 4 weeks for trial of passage of a stone, um. I really don't, uh, we always worry about chronic obstruction or stones getting lodged in the ureter. It causes this bad inflammatory response that can lead to, uh, stricture disease, um, uh, long-term issues, and also, uh, affect renal function. We think that after about 4 to 6 weeks of an obstructed or partial obstruction even, that you start to lose nephrons permanently. So we really want to get these patients, uh, evaluated, counseled, and also set up in case they don't pass their stones in that 4 to 6 week period. Um, so next question for you guys is, what is the chance of an asymptomatic renal stone? So renal stone, not renal stone, under 5 millimeters requiring intervention, uh, over a 5-year period once diagnosed. Um, so this is actually just a recent study that came out, uh, in 2020, um, by, uh, actually a Japanese group, um, I think, um, Some results, so. Give you 30 1020 seconds for people to respond. Mhm Good. Um, so, a common question I get asked by patients is, doc, my stone is, uh, you know, It is like that, 54 millimeter, you know, what are the chances that this is gonna cause problems in the future, you know, am I really safe to watch, to keep it, just to observe the stone and not treat it? Um, so, um, so the, the answer for that question was about 20%. Uh, and, um, that was, uh, you know, there have been a, there's a lot of studies in the past are variable. It depends on methods and there's some, uh, you know, a lot of patients end up getting treatment anyway, even though it could be because they're just nervous. They don't have hard indications. Um, but overall, it tends to be about for under 5 millimeters, you're looking about a 20% chance of some sort of intervention or uh needing the stone treated. Um, above 5 millimeters, that jumps up to probably 50% over 5 years. So I think that helps just to kind of frame things for patients. Um, you know, we really save the observation of stones for those that are asymptomatic. They're not causing any obstruction or blockage, so they're usually in the kidney, not in the ureter. Um, and, um, you know, and the patient's reliable. They, you know, they're, they're nearby to a healthcare fac they have access to healthcare, um, right? I would not, you know, I would be much more proactive with someone who lived, you know, in the middle of nowhere or you was homeless or, you know, um, uh, low socioeconomic status. Um, urinary tract decompression. Um, we think about really the hard indications for urgent decompression are, uh, having a ureteral stone. And either infection, compromised kidney function, uh, which can also means that they have a solitary kidney or intolerable, uh, symptoms. So nausea, vomiting, uh, uh, pain, basically that's refractory oral medications. Um, I've, some of the sickest patients I've seen with, uh, with acute kidney stones have been young, healthy patients, uh, and in their 20s or 30s who have, uh, some who have a urine infection with an obstructing stone. The problem is this, the, the, because of the obstruction, you have all this trapped urine. And then bacteria can get up into that system and now you basically have, you have it by definition an abscess because of trapped bacteria that then causes this, you know, under pressure and basically sees the, the bloodstream and causes a really horrible, uh, sepsis bacteremia. So it's really important that patients are, um, with signs of infection or that are at risk for infection like HIV, diabetes, very frail elderly, uh, that we lean more towards, uh, some sort of intervention for them. Rather than conservative observation or trial of passage. Um, the main, they come in, uh, decompression comes in two flavors, uh, urinal stenting or nephrostomy tubes. Um, they are both plastic and they are both temporizing. We, you know, we eventually do have to treat the stones. Um, so these are just what they look like, um, as you may have, you're all likely are familiar with, um, just little pieces of plastic that, um, can assure, uh, drainage of the kidney. Um, so next question is, how long can a typical, you know, plastic ureteral stent or nephrostomy tube be left in situ or in, you know, in the body? Um before needing to be removed or exchanged. Uh, and I, I wanted to comment that when I talk about infection, I'm talking about, they don't necessarily have to have fevers and chills. If they have a positive urinalysis with bacteria or nitrates, that's usually someone I'm, I'm not feeling as comfortable sending home or I wanna make sure they're on on antibiotics and they're reliable, and they're gonna come right back to the hospital if they have symptoms. Um, infection, I, I, is not just fevers, chills, and classic, you know, pyelonephritis symptoms. It can just be having some pos, you know, traits, some. It's questionable UA and, you know, being at risk for infection. So thanks everyone for responding and uh uh uh 46% of you got it right. So the answer is 3 months is the average that we can leave stones, uh, stents safely. Um, for patients that we leave chronic tubes in place, we can stretch that out. The reason that we don't leave tubes in for too long is this exact problem. Basically, uh, basically encrusting calcifications that form on the stents. Um, and so we start with about 3 months for the first interval changes. Some patients tend to form encrusting more fat more quickly on their stents, like, uh, immobilized, wheelchair-bound, uh, uh, spinal cord injured patients, um, This is just a CT scan showing this, this is a really bad case for a bit, essentially you can't even see the curl of the stent because it's, the entire kidney has now formed this stone or uh filling the entire kidney cayes and then there's also simultaneous two bladder stones um that have also formed from it. So this is kind of worst-case scenario. It can in really bad circumstances lead to basically us having to remove the kidney. Um, so don't forget about the stents. We do have, there are some. You know, for patients who do well at 3 months, we will start to space them out to every 4 or 5 months. Um, we even have metal stents or certain stents we can leave it up to a year for those chronic obstruction patients like those, um, uh, chronic hydro like in a really bad abdominal uh cancer patient. Um. Um, so let's talk about treatments first and then we'll talk about the, the 3, just a brief overview. Extra shock wave lithotripsy has been around for a long time. Uh, it's still a great modality in my opinion. Uh, it's 20 to 3000 shocks, ultrasound waves. Takes about 45 to 50 minutes. It's under general anesthesia done as an outpatient. It's nice. It's non-invasive. You don't have to stick any cameras anywhere inside. Um, it has the lowest complication rates, um. You know, um, and, um, this is just a picture of what it used to look like. You'd sit in this big bathtub, um, this is probably more accurate what the machine looks like. I can tell you that the patients are usually not this good looking and they also probably don't look this comfortable because it literally feels like you're getting hit by a 4x4, you know, 1000 times, which is, um, so you're pretty sore, that's why in the US at least we put patients to sleep for it. Um, the cons of treatment are, um, fragments are not necessarily you have, the fragments have to pass on their own spontaneously. So there's an increased risk you might need multiple treatments to fully clear out a stone. Uh, it's not great if you have more than 2 or 3 stones because you have to divide the shock, you can only shock the kidney so much you have to divide the shocks amongst multiple stones. Uh, and it's not great in obese patients because the sound waves can't penetrate a lot of that tissue. It's great for skinny patients. Uh, and finally, it's contraindicated in pregnancy, we don't want to shock the baby. Um, the ideal patient, uh, for shock wave is really the single, you know, under 10 milli, you know, maybe 10 millimeter or less stone that's radio opaque cause we used X-ray targeting usually, uh, rarely ultrasound targeting, uh, in the kidney or upper mid-kidney or proximal ureter. Uh, by the way, the reason I say upper. Mid-kidneys because the lower calyx of the, of the kidney uh tends to be an area where the fragments just pool and collect. They have to go up and over to pass, um, so you know, patient wants to go ride a roller coaster, lay lay upside down for a couple of days, they can do that, um, but lower chances of passage for lower pulse stones. Um, or, you know, moving. Uh, ureteroscopy is the tried and true and is probably now the most common treatment for kidney stones surgically. Um, we use a home, we use a laser, we use a basket, we use this very small, uh, scope called the ureterscope. Uh, and we go in and we break the stone up into a bunch of pieces and we pull all the fragments or flush them out as best we can. Outpatient general anesthetic usually takes 1 to 2 hours. Uh, we do go through the natural orifice cause there's no incisions, which is nice. Uh, it is both diagnostic and therapeutic, so we can visualize the urinary tracts. We can also do biopsies. We can also see if, confirm if they're actually stones or not. It was a false positive. The cons are as the stone size goes up, um, your, the, the, the chances of being completely stone-free after these procedures starts to go down. Um. And because we break the stone up into a bunch of fragments, you can't always get every single fragment out and we know that leaving behind residual fragments are is potential nitis for future stone regrowth and uh and uh it's always, it's never fun to tell a patient we didn't get all the stones, you still have some leftover. Um, so risks, also, you're instrumenting the ureter. The ureter is a very fragile, uh, organ, right? It's 5, it's about 5 millimeters in width and it's, uh, it's very easy to injure. So, uh, repeat instrumentation can be a risk for strictures or injury to the injury. Uh, finally, infection risk. Um, and finally, uh, urinal stents, uh, which we frequently will leave after temporary for 5, you know, 5 days, a couple of days or up to 1 to 2 weeks, RMD can be significant source of morbidity, uh, pain, urgency, frequency, uh, hematuria for patients after this. Um, we call it the necessary evil neuro in endourology in my field because it's assuring the kidney drains, but it causes a lot of, uh, a lot of discomfort for the patient. So the ideal patient for uroscopy is really less than 10 millimeters in size in the ureter or the kidney or multiple small kidney stones. Um, so now we get to the bigger guns. Percutious nephrolithotomy. This is going through a direct puncture through the back, uh, where we dial it, we obtain access into the kidney with a needle and then we dilate up about an 8 millimeter tract. Used to be even a, uh, a 30 French or closer to a 10 or 12 millimeter tract in the past. We are, have gotten smaller and then what having a bigger access tract allows us to do is to put in, is to use, um, more advanced, basically ultrasonic or ballistic drills. That can basically break up the stones really quickly, uh, large volumes, and then suck out all the fragments at the same time. Um, so it's a much more efficient and faster stone clearance rate, great for those patients with much larger stone volumes. Um, otherwise, we'd be doing uteroscopy for, for, uh, for days or even weeks, um, repeat, repeat treatments. Um, it also avoids ureterary sturmentation, so patients who have abnormal anatomy and the, uh, uh, it's great. The cons are it's a little more invasive. It is a puncture through the back directly into the, the most vascular organ by, you know, by weight, I think. Um, so bleeding risk is not insignificant. Um, the patients spend a night in the hospital at least. Um, they usually have a temporary nephrostomy tube and it's can be annoying cause they have urine leaking out their back. Um, and then we talked about risks, uh, there is always a small risk of lung or colon injury and then always small risk of bleeding. So the ideal patient for this is really those large stones, complete Staghorn stones where you just gotta clear a lot of stone, uh, efficiently. Um, so that being said, um, we are at UCSF trying to, you know, think of always move the ball and be more advanced. Um, and so this is, I always think of this skit from by Will Ferrell from SNL. It's like this really tiny cell phone, uh, as we, you know, we're making a commentary on how small technology is becoming. Um, but anyway, we are, that is the name of the game with, uh, with endo, with our field with endourology. We're trying to be less invasive and make everything smaller, less smaller incisions, smaller punctures, and so that's what, uh, mini or micro PCL, it, it's almost considered a separate type of procedure, but essentially we are going through the back but with much smaller tracks. Um, so 12 or 16 French, which is like a 4 to 5 millimeter hole instead of an 8 or 1 centimeter hole, which can make a difference, uh, because it's You still get all the benefits of the PCNL where you get to get large volume stone removal, um, but you have less risk and morbidity, uh, shorter hospitalizations, quicker recovery times, uh, and also we don't have to leave tubes in these patients as often. Um, so really this kind of helps to bridge the gap between those 10 and 30 millimeter stones. Um, so we don't have, you know, poor stone-free rates, um, but, you know, we don't have the morbidity with the more aggressive. of, uh, piece of the larger PC regular PCNL and this is just a photo highlighting, um, the, um, uh, one of the, one of the miniature percutaneous you can see here. Um, it's very fulfilling for us when we get these stones out of there, uh, just can have these collection devices. Um, but you can see here the difference in the track size, uh, just relatively, uh, from conventional PCNL, uh, versus the mini that we now are able to offer patients. And then And finally, we're also using more ultrasound. We're trying to go less radiation, less fluoro. Um, so we are, uh, uh, Doctor Chee, uh, here has really pioneered, one of the, my, my fellowship, um, mentor who was really a pioneer in ultrasound treatment, ultrasound, uh, intraoperative ultrasound use, uh, for getting not only access but also the visualization of the kidney, uh, and also for putting in nephrostomy tubes ourselves if, uh, interventional radiology is not available. Um, so we're actually labeled to go use, uh, do cases basically with minimal fluoro or even without any fluoro, uh, for a lot of these, uh, PCNL cases and some ureteroscopy cases, um, like pregnant patients or kids. Um, so other surgical approaches, these are more rare. Um, laparoscopic robotic removal, um, is usually done in the simultaneous sense of if someone has a a congenital abnormality like a ureterop pelvic junction obstruction, uh, where we have to go in and do a reconstruction repair. Uh, these patients commonly also have, uh, kidney stones. We'll removed, we'll cut into the, uh, collecting. Cyst to remove the stone, and then also do the reconstruction of the obstruction. Uh, nephrectomy is the last really resort we, you know, we try to avoid if we can. It's really for those patients with, that have lost their renal function, uh, based on a, an renogram, nuclear medicine renogram study, uh, and they're also symptomatic. They're having pain, they're having infections, um. And really what this is all, this usually is a result of what we call silent hydronephrosis. Basically, the patients develop some form of mild obstruction. They may have some temporary flank pain or symptoms, but after a while, the, the pain seems to go away and the patient doesn't feel it anymore. So they have this chronic obstructive process where the stone is causing it, like obstruction. They have hydronephrosis. And they're not symptomatic from it. So they never seek treatment or they dis discount it. Um, and so this is why we talk about, you know, only really a lot waiting 4 to 6 weeks for patients to get their treatment. Don't sit on a, on a ureteral stone or, you know, obstructing stone for, you know, 2 to 3 months because, uh, this is our worst nightmare really of patients coming in and they already have a dead kidney. Um. Um, so let's, um, so just moving in now. This is, you're asking, OK, this is how we treat and manage stones. How can we prevent stones? So, hey, don't have to do any of this in the first place. So, uh, we do, uh, metabolic evaluations, um, which we talked about the, the, the goal really is still the gold standard is getting a 24 hour urine collection. We personally at UCSA. to use the Litholink company, which gives you patients all done by the mail. Uh, this, and you send, the patient doesn't have to bring their jug of urine into the lab. They just send a little alo clot back to this lab in Chicago through the shipping. Um, and it gives us this nice report card of kind of where they stand in terms of their kidney stone risk. Um, so it's really nice, you can kind of custom type, we, I tell patients to do at least one or 21, if not two of these first, uh, before we really make any changes to their diet or, uh, hydration or even medications because I, and then it would abnormally affect their, you know, there is some, you know, observation bias where they know they're being assessed and, you know, we really want to assess what is their underlying predispositions. It's not perfect, but it's the best we have. Um, finally, a basic meta metabolic panel assessing for any signs of acidosis. Also, um, um, uh, serum calcium if you think, uh, as a screening measure, we're looking out for, uh, primary hyperparathyroidism, which is a great reversible cause of kidneys, of hypercalcereia or kidney stones. Um, and, uh, parathyroidectomy essentially will cure some cure someone from getting any more kidney stones. Not very common but always good to screen for it. Um, and so if elevated calcium, we get a PTH. And then finally, if any suspicions for uric acid stones, checking a serum uric acid, um, to see also if any or if they have any history of gout, um, for uric acid type stones. Uh, interestingly, uric acid stones don't necessarily always correlate with high serum levels. It is mainly dependent on urine pH which I'll get to in my next slide. Um, so, diet-wise, uh, people always ask, oh, what should I be doing? So, I tell everyone, drink 2 to 3 L of fluid a day. You really want, you know, patient, patients are like, OK, what is that? How many glasses? Well, just drink enough until, you know, basically, don't make yourself happen in treatment and then drink enough so that your urine looks, you know, really clear or light colored. Don't, you know, we don't want it really um uh concentrated looking like orange or dark yellow. Uh, try to limit your salt intake. Um, you know, very hard to do with an American diet, but But we know that sodium, uh, increases, uh, calcium passage into the urinary tract. It drags calcium into there. So if, if they have hypercalcereia, I'm telling them to really cut back on their sodium. Um, limit your animal protein intake, any sort of animal protein, you know, I have patients who are like, yeah, doc, I cut back on steak and I'm just having fish now. And I'm like, it's really any animal intake. So, uh, eggs, uh, chicken, and, uh, eggs, um, fish, um, you know, uh, dairy products. Um, the, all of these are really, it's just causing a more of an acidotic state, which is not great for kidney stones. Um, we tell our patients, you know, increase your fruits and vegetables. That's all great, great alkaline sources. Um, and, uh, citrus is a great way to do that. We, Doctor Stoller here, uh, published on orange juice, uh, but also, you know, lemon juice, um, and there are, uh, we also will prescribe medications for that too. Um, a lot of patients they hear, I have calcium oxalate stones. I should be taking, I should be cutting back on my calcium and we've actually studies have actually shown that if you limit your calcium, you're actually gonna hurt yourself because, because of the calcium oxalate interplay in the intestines, if you limit your calcium, then more calcium, more oxalate will be absorbed into your, uh, from the GI tract. If you have calcium with Uh, and with your oxalate sources at the time of, uh, your meals, you actually, it stays bound in the gut and is excreted, uh, excreted in the gut. Um, so that's a common misconception that patients have. So I, I tell everyone, you need, you know, there's the AUA guidelines. You want to maintain a sort of a normal dietary calcium intake. Have about one or two servings of yogurt a day or, you know, a glass of milk. Um, don't limit yourself. And with patients who have actual hyperoxalidation. Urea. Um, I'll advise them to, uh, take some calc dairy or calcium source with their meals, especially if they have, are taking a lot of oxalate-type rich foods. Um, so sometimes, or I'll have them take a Tums tablet even for, uh, if they don't have a, a calcium source. So one or two Tums tablets a day. Um, patients always ask me, doc, I looked up what a low oxalate diet is, and everything in the world has oxalate. You know, are you basically telling me to not eat anything? No. It's really avoiding those oxalate dense foods, um, that are out there. And, uh, this link that, you know, will be in the slideshow, you can look at later, really points to what the more dense oxalate, uh, foods are. Um, you know, a lot of, a lot of great fruits and vegetables have oxalate, and patients shouldn't necessarily be cutting those out. Um. Um, so last question, I think below what urinePH do uric acid stones typically form? So, it's, it's in the name that your urine pH should be acidic, but um, I have a, I have a point to make because with this uh question, so. Someone chose E and then changed their mind. Your finger slipped. OK. So yeah, most people hit it on the hit the nail on the head. Uh, it is 5.5. And so I wanted to briefly talk about medications for, uh, in the home stretch here, medications for, um, uh, kidney stone. So we talked about prevention if they have hypocitraturia, low citrate in the urine, uh, we want to boost that. So we give them potassium citrate or some alkaline source like sodium bicarb. We, you have to keep an eye on, we have to keep an eye on their potassium levels, uh, usually one or two weeks after they started. Uh, we do sometimes have to titrate. We will get usually repeat 24 hour urine collections on medications to sort of track their progress. Um, and then if they're hypercalceric, right, we make sure they don't have, uh, any, uh, hype, you know, hyperparathyroid. We will, our go-tos are Weak thiazide type diuretics. Uh, um, if you know, for a patient that you're managing on with with hypertension, that's great. We can coordinate, um, you know, adapamide or chlorthalidone, hydrochlorothiazide, those are all great for, um, reducing calcium excretion in the urine. Uric acid stones are the one stone that can be, you know, that can be treated. Patients ask me, doc, is there anything I can take to dissolve my stones? Um, there has been like a supplement called Shanka Piedra that has been shown to have some benefit and prevention, but really uric acid stones are the one that we can dissolve, uh, because they only form in, uh, acidic urine environment. So, pH less than 5.5, um, Uh, if you give potassium citrate and alkalalize the urine, those stones will dissolve, uh, over like weeks to months, uh, on that, and then patients who have uricosis stones, we usually put, keeping them on some sort of maintenance therapy chronically to prevent the stones from coming back or unless they can reverse the underlying predisposition, the underlying, uh, elevated uric, uh, uric acid levels. Um, allopurinol is indicated if their serum uric acid's elevated, not if, uh, but if it's normal, I don't give it. Um, and, um, yeah, it's, it, it's really if you should suspect that if the urine pH is really consistently less than 5.5. So if they have one urine pH that was below 5.5. I don't really think too much, but if they are like, if you look back at their history and every urinePH has always been, you know, less than 5.5, and I'm, I'm more suspicious and we can also tell by the CT scans based on how dense the stones are. They, they can be very uh uh non-dense stones, very light, very brittle. Uh, the other thing that, uh, can't be discounted is avoiding carbonic anhydrase inhibitors. I, it's not every, it's not uncommon that I see patients come in with kidney stones and they are on, uh, topiramate, Topamax, acetazolamide, Diamox, onisamide, um, not the eye drops, but the oral medications, and these all result in a metabolic acidosis that will result in, um, Um, in kidney stones because it, it induces a hypocitraturia, low citrate levels in the urine, and can also lead to bone absorption because of the acidosis. Um, so it's really important that if, and, and, you know, they're on these medications for different reasons, so I think it's a, you know, it's kind of a risk, risk-benefit, a balance of, would you rather have kidney stones or rather have, you know, the other issue. Um, but something to keep an eye out on the med on the. The med list. Uh, so takeaways, uh, in conclusion, really consider ultrasound for screening or surveillance, uh, really annually. Any kidney stone, any patient with chronic kidney or recurrent kidney stones should really get a screening once a year with ultrasound, I think. Uh, limit CT radiation always request a low dose when able if you're ordering for kidney stones. Uh, patients should pass or treat uterine stones within 4 to 6 weeks. Don't wait. any longer. Obstructing stones with infection, compromised kidney function or intractable symptoms, uh, should come to the ER. Uh, and then finally, as you've seen really a heart, I tell all patients a heart-healthy diet, uh, and good hydration are really the best stone prevention diet, but let's do the 24 hour urine to see if there's any really cust any really specific outliers that we can work on. Um, so that, that's my talk and just a brief shameless pitch for myself. So this is our new clinic down in uh San Mateo, Redwood City area. It's just off, uh, there's Ortho, ENT and myself. I'll be down here full-time, um, uh, Monday through Wednesdays. Uh, there's free parking, um, and it's a one-stop shop. There's a grocery store. coffee store, or Starbucks, lots of things to do. Um, and, uh, right now my availability is great so I can see people same week. Um, uh, really, and we're really trying to make access easy to get in. Um, so we have a separate phone line. Uh, I see a lot of patients who work, who live in the city and also commute down to the South Bay. So that's stopping here on their way is no problem at all and we're doing a lot of virtual visits, of course, as well. Um, so, um, yeah, that being said, uh, and this is a non-exhaustive list of, you know, basically, we are designed to be a general urology clinic here. We will offer all the common general urology procedures like vasectomy, prostate biopsy, cystoscopies, um, testosterone, sexual function, things like that, urodynamics. Um, and then, uh, finally that, uh, let's thank you, everyone.
