Corinn Cross, MD (Host): Welcome to Peds Cast, a podcast brought to you by Children's of Alabama. I'm your host, Dr. Cori Cross. Today we are joined by Dr. Carmen Tong, who is an Assistant Professor of Pediatric Urology at the University of Alabama at Birmingham. Dr. Tong, thank you so much for being here with us today.

Carmen Tong, DO: Thank you very much for having me.

Host: Let's start with a broad overview. What is kidney stone disease in children and how prevalent is it?

Carmen Tong, DO: I think that's a really great question. I get asked this all the time by parents. I think there's this sort of misconception that kidney stones only form in adults and that children can't have kidney stones. And that's absolutely not true. Kidney stones are essentially rocks, uh, usually calcium, calcifications that have formed in the kidney.

If they stay in the kidney, they don't usually cause any trouble. But, the only sort of issues that we get with kidney stones are usually when they drop from the kidney down into the ureter, which is the kidney tube that drains the kidney. And if there's blockage of urine draining from the kidney, usually the patient can experience a lot of pain, discomfort, nausea, and they can get quite sick, if they have infected urine behind that stone.

Host: Is it equally common in boys and girls? And what age do you see it present at?

Carmen Tong, DO: I think this really depends on multiple factors. Some of it depends on family history, the hydration of the patient, their medical history, what kind of surgeries they've had. For the most part, we do mostly see this in both girls and boys and they can happen at any age.

But the studies have shown that the more common age group or the more at risk age group are indeed the adolescents and patients who previously have had a kidney stone, which makes sense. We don't really know why adolescents are more likely to have kidney stones. I have my theories. I think my colleagues have as well; has a lot to do with hydration, how active they are at school and with after school activities. And they are also a difficult age group to try to get them to drink more and eat better, eat the right things. So they are proven to be the most at risk pediatric age group.

Host: As a mom of three, I would agree with you. So long term follow up though is important, right? Once a child has had a kidney stone, it's really important for these patients to follow up because I think like you just said, somebody who has had a stone, they're 50 percent more likely to form another stone in the next three years, correct?

Carmen Tong, DO: Correct. And so a large part of our studies, or studies in kidney stone are focused on prevention, proper dietary habits, but also, identifying if they're at additional risk because of their genetic makeup. But, prevention is really the only way to reduce the risk of recurrence in this age group.

Host: And then, so prevention would be obviously staying hydrated and maybe eating differently. What else can people do to prevent kidney stones?

Carmen Tong, DO: Well, sometimes it's eating less salt. People don't realize that salt is a big predisposing risk factor for kidney stones. And of course salt can make you dehydrated. So that is a problem on its own. Certain medications that people take, they don't realize that it can cause increased risk of kidney stones.

There's a lot of studies sort of linking antibiotic usage with kidney stone risk, changing the gut microbiome or the good healthy bacteria in the gut and causing malabsorption of certain chemicals and components in our diet that can lead us to have more kidney stones. And then of course, certain patients that are born with an abnormality or anatomic abnormality of their kidney. If their kidney was formed with a certain kind of kink, that could put them at higher risk of kidney stone formation from urine not draining well from that kidney.

Host: Got it. And then, tell us a little bit about Children's of Alabama has joined forces with Pediatric Kidney Stone Care Improvement Network, or PKIDS. Tell us a little bit about PKIDS and why this is such an important partnership for Children's of Alabama.

Carmen Tong, DO: This is a very, very exciting research, that is spearheaded by the Children's Hospital of Philadelphia or CHOP. Gregory Tasian, the lead principal investigator does a lot of pediatric stone research. He is actually the leading expert on this topic, internationally. And PKIDS is essentially a network, an organization of over 30 institutions now, really trying to connect each other to understanding pediatric kidney stone disease a little bit better, and then also have a strong focus on patient related outcomes. Understanding patient and family experiences with kidney stones, particularly after surgery, and their outcomes as well, their clinical outcomes, so that we can better target the at risk groups, patients that really need to be more focused on to reduce their risk of kidney stones.

Host: And then it's my understanding that you're doing a QI project. Can you tell us about how that is addressing follow up?

Carmen Tong, DO: That stemmed from our work with PKIDS and with CHOP, in collecting all this data for them and enrolling patients into the study, we've noticed that there are a good number of patients, particularly from our institution compared to some of the others around the country, where our follow up after kidney stone surgery is abysmal.

And it's not due to the lack of trying on our part to get these patients to come back. And so this quality improvement project is trying to focus on adherence with follow up after stone surgery.

And the guidelines recommend that follow up is within four to six weeks after surgery to bring the child in for an ultrasound or some sort of renal imaging to make sure that we've taken care of all the stones.

Looking at our numbers, probably a good 10 to 15 percent don't come back. And so, our quality improvement project is one, trying to see if there are ways or resources that we can dedicate to improving our adherence rate and then also reducing unintended post op visits. We've noted that parents come back with their patients because of for instance, pain, poor pain control, or issues with infection.

And so we're looking at ways that we can improve our communication and education to this population so that they're better equipped with taking care of their children.

Host: Is there a take home message that you'd like our listeners to leave with today?

Carmen Tong, DO: I think a good take home message would be that, pediatric kidney stone disease is certainly a public health burden. The incidence increases about 10 percent every year across the country and the south where we are, is considered the stone belt where patients are more likely to form stones because of our geographic location.

A lot of that has to do with the heat that we get during the summer, but some of that may have to do with medical education. And so, as important as it is to treat stone pain and acute stone events, it is equally if not more important to emphasize on preventive measures. And the only way that we can emphasize on preventive measures is to have good long term follow up with these patients so that we can educate them and help tailor their dietary habits to prevent future stone episodes.

Host: Dr. Tong, thank you so much for taking the time to share your expertise with us today. I am certain that many people don't realize the prevalence of kidney stone disease in children and the fact that it's increasing. And just you speaking about it and letting us know what we can do to prevent it and hopefully not have it impact us, is just great.

Thank you very much for your time.

Carmen Tong, DO: Thank you so much for having me.

Host: If you would like to learn more or to refer patients to Children's of Alabama, please visit www.childrensal.org. That concludes this episode of Children's of Alabama Peds Cast. If you found this podcast helpful, please share it on your social channels and be sure to check out the entire podcast library for other topics that might be of interest to you.

Please remember to subscribe, rate, and review this podcast. Thanks for listening to this episode of Children's of Alabama Peds Cast. I'm your host, Dr. Cori Cross.