Transcription:
Avoiding Kidney Stones

Bill Klaproth: So when it comes to kidney stones, how do you know if you have one, how are they diagnosed and treated, and is there a way to avoid them? Well, let's find out with Dr. Patrick Bennett a urologist at MarinHealth. This is the Healing Podcasts from MarinHealth. I'm Bill Klaproth, Dr. Bennett thank you so much for your time. It is great to talk with you, first off could you give us a brief background on yourself? 

Dr. Patrick Bennett: Well, I grew up here in Marin County, went back East for college, but came back to the Bay Area for medical school and then went back again to the East coast for training in urology, then I returned in the late nineties and I've been practicing here for about 24 years. 

Host: Well, that's a great story. And we're glad that you're back on your home turf. So your expertise in the urinary system includes kidney issues such as kidney stones. Is that right? 

Dr. Bennett: That's correct. I practice in a group with several subspecialists and a few of us, in that group, really focus on kidney stones among other things. 

Host: So as we were talking about kidney stones, what exactly are they? 

Dr. Bennett: So kidney stones are essentially concretions that form in the kidney due to crystallization. If you think of the kidneys as very powerful filters. They're taking out of our bloodstream, excess salts, and those salts can crystallize together in the urinary tract. And it's remarkable that this doesn't happen to everyone all the time, but some individuals do develop these crystals that over time get larger and larger and where they get large enough to sort of crack off of the wall of the kidney. They fall into the ureter, the tube that drains the kidney, and  they block the ureter and cause a lot of pain and can lead to all sorts of troubles at that point. But they're really, just large crystals that form from the salts that we normally excrete in our urine on a daily basis.

Host: Really interesting. So does this happen to women and men? 

Dr. Bennett: This is an interesting sort of trend. It used to happen much more common to men than to women, but over the last 20 years or so, a large study looking at the prevalence of stones suggested its nearly equal distribution of men and women. Now there's been all sorts of studies to look at why that is, but it seems that the major risk factors for stone formation, include, excess dietary protein and some dietary changes that now maybe women are encountering just as often as men have historically. 

Host: You just mentioned dietary changes. So I imagine lifestyle plays into someone's risk. And then what about specific age groups or other indications or risks such as genetic, hereditary, or even ethnicity? 

Dr. Bennett: Yeah, this really cuts across all ethnicities. There are some dietary issues and I'm gonna come back to those in a minute. In terms of hereditary contributions there was a funny observation years ago that some families were predisposed to stones, but it often it would skip generations so you'd have a patient whose grandparents had stones, but parents didn't. There's really not a major hereditary contribution as there is with you know, many other types of diseases. What we really think contributes to this in the majority of cases is the environment and by that, I mean, dehydration and diet and overall health of the patient. We know that diabetes, for example, is a significant risk factor. There may be some patients with hypertension who were at higher risk. Many of the dietary factors that contribute to  stones such as elevated dietary sodium, or elevated animal protein in the diet contribute to obesity, they contribute to heart disease, other conditions and they also contribute to stones. And this may be why the prevalence systems is getting greater and greater and why women have caught up to men in the prevalence of stone disease. 

Host: So lifestyle then does play a major factor in this. And you mentioned a diet of high sodium an influence of other diseases. Dehydration. What about exercise or lack of exercise or vitamins, minerals, supplements, medications? Can all of that play a factor in the development of kidney stones? 

Dr. Bennett: These areas have been studied in some cases the evidence is quite clear, in some cases it's quite murky. If a patient, for example, is taking in excessive vitamins, vitamin C is sort of a classic example. Much of that vitamin C cannot be utilized by the body and the vast majority of it ends up going out in the urine. The body says, hey, too much vitamin C here, we're going to excrete it in the urine. Vitamin C can be broken down into oxide, which is a major contributor to stones. And that can contribute to a higher stone risk. Conversely, we often think about calcium oxalate stones, most common type of stone, you know, has this element of calcium. And so there was a belief at one time that folks should reduce their dietary calcium. Well, paradoxically, it doesn't work that way. Moderate calcium diet is in many cases better than a low calcium diet and that was picked up in some long observational studies of stone prevalence and diet and it has to do with the way that calcium and other components are absorbed in the intestinal tract. If folks really cut down on their calcium, they tend to absorb too much of the other things that cause stones, particularly oxalates, and then the calcium is just leeched out of the bones to cause the stones. So in a short form, we do not typically tell patients to cut down on calcium, but looking at things like vitamin C and other supplements that may be taken in excess, it's worth looking at, and again, salt, which, you know, of course, is implicated in high blood pressure and other conditions. That will promote the loss of calcium into the urine and form stones. So low sodium is just as much a part of a recommendation from a urologist as is high fluid intake. So those elements can really reduce the likelihood of a fellow or a woman getting stones in the future.

Host: Okay, so as we're talking about potential ways to lessen the likelihood of developing kidney stones. Are there other ways to help avoid getting kidney stones or having a reoccurrence? 

Dr. Bennett: Well, one type of stone forms when they're are urinary tract infections. So if a patient is getting recurring urinary tract infections, that individual's physician might be thinking, could there be stones that are playing a role either as a result of the infections or in some cases harboring an infection and, allowing infections to resist treatment. But other than that, you know, attending to diet, maintaining a healthy lifestyle overall, there aren't really any ways to prevent stones beyond those measures. 

Host: So are there any symptoms when it comes to kidney stones? 

Dr. Bennett: Well, that's the tricky thing. And that's in fact, that's part of the challenge of knowing how prevalent they are because stones remained entirely asymptomatic until they fall off the wall of the kidney and block the ureter. So, healthy folks are walking around and they have stones forming. In many of these stones will never cause a problem, but some of them will eventually get large enough to fall from the wall of the kidney into the ureter and cause symptoms. And the symptoms of kidney stones are sort of classic. It's a severe sort of internal flank pain in the back, but not in the rib cage, deeper than that, often you can see someone sort of writhing about or squirming about trying to get comfortable, but it can't be relieved. My patients who've also delivered babies, women who've had children often compare the severity of the discomfort. So yeah,  it can bring, it can be a very strong person to their knees. And it's usually the initial presentation when that stone first goes into the ureter. Usually, that's the most severe pain patients have, and that's what brings patients right to the emergency room. 

Host: So are the symptoms different in men and women? 

Dr. Bennett: For the most part, not, there is an interesting phenomenon that when stones get down further in the ureter on their way to the bladder, sometimes men will complain of testicular discomfort because the stone is irritating an area where the nerves mistake the area of irritation to be that testes. But for the most part, men and women present with similar, types of calla. I would add one caveat that all e urologists think about is that women are more prone than men to having typical urinary tract infections, normally not a complicated medical problem. However, if a urinary tract infection occurs while there was a stone blocking the ureter that can turn into a medical emergency. So while the presentation may be the same, physicians should be very attuned to whether or not this patient is at risk of a urinary tract infection, and that tends to be more prevalent in women than in men.

Host: So if someone recognizes they may have these symptoms, the excruciating pain, what should they do? 

Dr. Bennett: Well, if they have a medical facility available to them, I think that is the right thing to do because, with the onset of pain, it's really not possible to know either how large the stone is or where it is located. The severity of the pain is not an indicator of how big the stone is. But the size of the stone is important because that'll tell us whether it's likely to pass or not. So for any given patient with severe pain, getting an evaluation that would include an X-Ray or an ultrasound or a CT. That could be very helpful to predict the course of that stone. So in short, most physicians, most urologists will suggest to a patient who thinks she or he has a stone to get a medical evaluation, and due to the severity of the pain that's often the emergency department. 

Host: And then you diagnose this, you said, using either an X-Ray, ultrasound or a CT scan? 

Dr. Bennett: Right. CT has emerged as the definitive study. That will be the most sensitive for even the smallest of stones. In cases where a CT is not available, then an ultrasound and a plain x-ray can provide a lot of useful information. 

Host: And then how about the treatment options? 

Dr. Bennett: Well, fortunately, the vast majority of stones we'll pass on their own. And a physician can provide an estimate to the patient, the likelihood of a stone passing and based on its size and its location when they present. So we provide pain medications, particularly anti-inflammatories, like Advil and sometimes anti-nausea medication. But just fluid and those interventions and rest will deal with most stones. Stones that aren't going to come out can be treated through a variety of minimally invasive procedures involving either a very fine telescopes combined with lasers or the so-called shockwave lithotripsy machine that uses shockwaves from outside of the body, or in cases of very large stones going directly into the kidney with a telescope through the back. All of those procedures require a general or a spinal anesthetic and are done in the operating room setting. So most stones will pass on their own. Sometimes patients will benefit from taking medication to help them pass. And those that do not pass, or very unlikely to pass, we can treat through one of these minimally invasive procedures.

Host: Right, so once someone has passed the stone if you will, can that person get them again? 

Dr. Bennett: Well, it appears that about 50% of patients will develop another stone in 10 years. And this is the motivation that patients have to adjust their diet and their fluid intake. And you make those, kind of lifestyle adjustments that might reduce their chance of getting stones again. And it looks like those adjustments might cut that 50% in half again. So I tell patients, chances is this is going to come back. There's some very simple things you can do that probably have other health benefits that, you might want to adopt. 

Host: Well, it sounds like the pain is so excruciating, someone would not want to live through that again and make the necessary lifestyle changes. 

Dr. Bennett: Yeah, and that's often the case, patients if we prescribed for patients really complicated regimens of special medications to adjust their oxalates and so on and so forth. The compliance tends to diminish over time. You know, people get a few years out from it and they don't really feel like taking medication, but if it's something as simple as reducing salt and increasing fluids that will help them in other ways as well, like their blood pressure and so on, patients are much better at complying with that. You're mindful of their wish to not get another stone. 

Host: Absolutely. So then I know you discussed the different treatment options. Are there any new treatments coming on the horizon? 

Dr. Bennett: I would say that the developments that people are working on most now and that have come down the pike in the last few years, more have to do with sort of refinements of the minimally invasive techniques that we have. So lithotripsy that are better able to break up stones noninvasively through the skin or finer smaller telescopes and finer lasers and better endoscopic graspers, and these very, very precise delicate instruments. They're all getting much better through technology and that's really the thrust of things. Because stones form over such a long period of time and because many stones remain asymptomatic, just sort of in the kidney forever, we're not really focused on medications that patients would take on a daily basis to prevent them because it's just, you'd have to treat many, many patients to prevent a few stones. So much of the effort and the advances have come from just making minimally invasive procedures all that much better. 

Host: Well, Dr. Bennett, thank you so much for this expansive and informative look at kidney stones and what they are and how to avoid them. Dr. Bennett, thank you again for your time. We really appreciate it. 

Dr. Bennett: Oh, it's been a pleasure for me. 

Host: That's Dr. Patrick Bennett and to learn more, please visit MyMarinHealth.org. And if you found this podcast helpful, please share it on your social channels and check out the full podcast library for topics of interest to you. This is the healing podcast brought to you by MarinHealth. I Bill Klaproth. Thanks for listening.