Riding Rollercoasters With 3D Printed Kidneys, Passing Stones

Citizen science isn’t limited to the nerd community. When medical professionals get a crazy idea, their options include filling out endless paperwork for human consent forms and grant applications, or hacking something together themselves. When [David Wartinger] noticed that far too many of his patients passed kidney stones while on vacation, riding rollercoasters, he had to test it out.

Without the benefit of his own kidney stones, he did the next best thing: 3D printed a model kidney, collected some urine, and tossed a few stones that he’d collected from patients into the trap. Then he and a colleague rode Big Thunder Mountain Railroad sixty times, holding the model in a backpack at kidney height.

The results? Sitting in the car at the back of the train, they passed the stones 64% of the time. Sitting in the front only managed to shake 17% of the stones free. That was enough data to get a paper out, and presumably to never want to see a roller coaster again. But science is science: [Dr. Wartinger] has since run more than 200 “stone rides”.

We think this is awesome. [Dr. Wartinger] is now going through all of the requisite rigmarole for human trials. But if you’ve got small kidney stones (under 5 mm), and you don’t hate roller coasters, you’ve got basically nothing to lose. Except maybe your lunch.

31 thoughts on “Riding Rollercoasters With 3D Printed Kidneys, Passing Stones

  1. The real impressive part is one person riding a Disney ride 60 times before the heat death of the universe. He must have gotten help from the cast members (speaking as a former Disney ride operator myself)

  2. Does this mean, the stones leave the kidneys, but would still have to travel through your “other pipes”?
    Or does the roller-coaster reduce the pain in some way and you can physically piss it out?

    I’m 29 and I’ve passed 2 kidney stones in the last 5 years [ONLY 3-4mm as well]. It was fucking agony.
    I’d rather shoot myself in the stomach on a roller-coaster than feel THAT pain at THAT time, haha. :P

    Also, I’m scared of heights and probably roller-coasters too [Because of nausea], can the same effect be achieved with a massage chair on full power, or the subway? Or holding a dualshock controller to your back?

    TL;DR: Do you actually piss out the stone on the roller-coaster or does this just get you past the “It feels-like-a-gorilla-is-squeezing-my-balls-every-5-seconds” stage?

    1. This study was looking at passing stones through the kidney. As a male you will still have the extra “tubing” the stones will need to travel through as they make their way out of the bladder. (Sometimes its better to be female)
      The good news is that you can pass them while they are smaller since there isn’t much of a down side to this treatment.

      1. The “extra tubes” (urethra) don’t actually cause that much pain. The ureters (tubes from the kidneys to the bladder) is where the pain typically is. While passing the stone through the urethra isn’t comfortable, patients have told me it is nothing compared to the passage through the ureter.

    2. Adjustments to your diet and water intake (drink more) is probably all you need to do, but if you are forming stones at such a young age you really do need to do something. And more is not always better for multi vitamins, guess what vitamin C is metabolised into, and then guess what a concurrently high intake of calcium and vitamin D will cause to form.

      1. The reason doctors want you to capture/collect/save your kidney stones is to analyze them.
        There are different causes of kidney stones, and a chemical analysis will help determine their particular origin.
        Once the cause is known, then adjustments to diet, fluid intake, etc. will be considered.

        1. To be honest, medicine doesn’t fully understand why certain populations are more affected by kidney stones than others. There’s a “Kidney Stone Belt” through the US (I think it’s actually the SE, but it’s been years since I had this lecture), with a dramatic increase in kidney stones. Numerous studies have been done to determine why some people are more likely to get stones than others, and the evidence is pretty solid that dietary intake alone doesn’t account for the majority of the kidney stone cases that we see (Now, if your uric acid level is off the charts, that may be a different thing…).
          The functional unit of the kidney, the nephron, is an amazingly complicated biological apparatus. We just really need more research.

    3. I think the roller coaster would help with pain as well because the person would be scared and trigger the release of endorphins from the fight-or-fight response. As an aside, my dad told me that back in the day, if you had an annoying kidney stone, the doctor would just hand you a pack of beer and tell you to sit in the backroom and drink all of it. The beer worked as a pain killer, diuretic, and probably kept you quiet.

    4. Sorry to hear about your experience, Ben. I’ve been in your shoes. The first two times the pain was excruciating. After that I decided to change my life style. I started drinking more water (no more pop for me!), running regularly, and reduced % body fat. Probably this did the trick — I still pass stones occasionally, but the pain is minor. My hypothesis (which I could not test) was that running helps tiny stones dislodge and pass. The rollercoaster study seems to confirm it.

      I really hope modern medicine will come up with prophylactic procedures soon. Unfortunately, at this point those with small kidney stones are pretty much on their own — at least in the case of calcium oxalate formations, doctors can offer no remedy other than surgery (when absolutely required).

    5. It helps to shake it out of the kidney, also when the stone is in the pipe between the kidney and the bladder, which if it blocks the flow, can be problematic. Once it’s in the bladder, it’s not a problem anymore, (it’s peenuts).
      I’m getting used to it, 8 in 15 years, ask your doctor for powerful liquid pain reliever that you keep in the fridge.
      I don’t have access to a roller-coaster, but our public transportation works too, also does hopping stairs down.
      If their too big, or you get to the limit of the pain killer dose, seek a doc, and get them blasted with ultrasound at the hospital.

  3. The snake charmers also recommend sexual intercourse for helping dislodge kidney stones, in case you don’t have a roller-coaster handy, and speaking of handy, no that sort of sex probably will not help, with the kidney stones that is…

  4. While this is a clever hack, males suffering from kidney stones probably don’t have easy access to a rollercoaster. I had a kidney stone ~4mm and I did a “kidney cleanse”. It involved boiling a bunch of herbs, straining it and bottling the liquid. Drank 12oz/day in tiny sips and passed the stone without any pain roughly three days later. I examined it afterward – the outside was like fine wet sand and a light gray color and the inner core was darker. My doc agreed it was definitely a stone.

  5. Ah, I too have passed some stones in my days.

    They were a year apart to the day, and how I knew was when the ER nurse says “Ah, back ago so soon?” and in my writhing and near vomiting I ask what she meant. And she says “you were here at 9:45 this morning… OH! That was a year ago, TODAY! CONGRATS!!!”

    The first one I was pretty sure I was dying, because I had the worst headache of my life for like 3 days prior and nothing would touch it and then I start pissing blood, but the flank pain hadn’t started yet, so I of course think I have cancer or something.

    But then I was awoke on the 4th day of never ending headache by what I had imagined in my dream-to-waking haze to be someone dropping a small car on my side. No car, just major fucking intense pain that had zero mercy on my poor soul.

    I nearly blacked out it hurt so bad… Like the kind of pain you’d gladly cut out of your own body yourself because you know sawing away at your own lower back is probably going to hurt less than whatever the fuck that real pain is!!!

    Dilaudid was enough to make me not give a fuck about the pain as much, but the pain was still very much there, pulsating with every beat of my heart. I could see myself (in some near death, third person shit) floating in the clouds above the hospital gurney with a chain woven through my side as a tether to the ground, and every time I’d bounce on the tether, the pain would break through and remind me I was not in fact, a dirigible and still very much alive.

    The second one I knew exactly what was going on, and it didn’t have a lead up headache with it or anything, just instant flank pain and bloody piss. I thankfully had leftover medication from the first one, a year earlier. I’ll never throw out old pain medication again because of that fact. But honestly, it did nothing to touch the pain either. Just full force, please shoot me now, agony. A return trip to the ER and the ER staff being amazed at the timing vs. the last one. Assuring me more would follow…

    I passed both the old fashioned way, and caught them all!!! (like some kind of sick poke’monsters) in a mesh filter funnel. I have too high of uric acid. Now days, instead of stones, I worry more about gout, which is the second worst pain you can endure, probably. Don’t care to find out of there is anything worse!!!

  6. 64% sounds impressive, until we look at the data. Let me see… Samples size of 4? Of 1???
    Come on. The paper is a great example of bad science. The results have absolutely no statistical significance at any confidence level, but we’ll massage the data, tell journalists that 64% of stones were passed, and we can claim a success. I’m surprised that the paper has been accepted for publication.
    It is a hack. But has very little of scientific value.

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