THE FIVE STEPS TO STONE PREVENTION

CoeTie4At the end of it all, the science, the medical visits, the surgeries, what we really want is to prevent new stones. That is the main goal. Modern surgery is a blessing for those with stones. But no surgery is far better than even the most skilled and effective surgery.

Prevention of stones is orderly and occurs only over time.

Here is how to do it.

This article is designed to go with my other one which tells how to organize your medical visits so as to achieve these steps. 

What is the Science of the Five Steps?

Stones are made of crystals.

Supersaturation drives crystal formation and growth – this is a physical law that must always apply.

Supersaturation measurements are widely available from commercial vendors.

Because people who are actively forming stones are forming crystals their supersaturations are too high – crystals are forming – with respect to those crystals.

Lower the relevant supersaturations and you must lower formation and growth of those crystals in their stones.

With respect to the most common stones, calcium oxalate and calcium phosphate, and uric acid, supersaturation in urine depends mainly on volume, calcium, oxalate, citrate, and pH. You can lower supersaturation by altering any or all of these in a given person and so far as crystals are concerned the effects are much the same. 

1. Know the Stone Crystals

Stones are made of crystals: No crystals no stones. Prevention is prevention of crystals.

Analyze Stones

The proper way to know the crystals is analysis of stones and their fragments. Stone analysis is not expensive. If imperfect, it is the best we have, so use the service liberally. Stone crystals can change, and therefore prevention can need to change direction. There is no reason to discard a stone without analysis just because we think we know the answer.

Uric acid stones are remarkably easy to treat by raising urine pH and require little more discussion.

Cystine stones arise from hereditary kidney transport disorders and require special management.

Struvite stones arise from infection and require special combined surgical medical management.

Drug stones, ammonium acid urate stones, and rare stones – eg. 2,8 dihydroxyadenine stones require special management.

The vast proportion of kidney stones are calcium oxalate and calcium phosphates and uric acid, and this article refers mainly to them.

Guess if You Have To

Red or orange stones probably contain uric acid. Likewise, stones that do not show up on simple abdominal flat plate x rays are probably uric acid. These are easy to prevent, and recurrences are unnecessary.

Allow me to elaborate on this. Pure uric acid stones are almost all due to an excessively acid urine pH, and will stop if you raise that pH. Potassium citrate tablets, 10 mEq size, 2 twice daily is almost always enough. Sometimes it takes 2 tabs 3 times a day. Crystal light lemonade has in one liter about the same amount of alkali as two of the tablets. I could say that there is little excuse for another uric acid stone.

If stones contain uric acid and other crystals, those other crystals need to be dealt with on their own. They may not respond to higher urine pH, and could be worsened.

Yellow stones are probably cystine, and due to cystinuria, a complex disease with its own special treatments. Because almost all kidney stone panels include a cystine screening test, cystinuria is almost never missed. A positive test, however, can reflect cystine trait and the stones can be something else. So it is the negative test that is fully informative.

Small black stones are probably calcium oxalate, and large very homogeneous hard stones are probably brushite. But one cannot be sure.

Big stones that fill up the interior of the kidney are usually cystinestruvite – from infection, or calcium phosphates from alkaline urine and hypercalciuria.

But guessing is not a good way to achieve prevention. Find out whenever possible what crystals you are trying to prevent. Any stone fragment can be analysed. Never pass up an chance to be sure.

2. Obtain Proper Blood and 24 Hour Urine Measurements

I prefer two 24 hour urine kidney stone risk panels as a minimum along with at least one set of fasting blood measurements.

Screen for Systemic Diseases

Here is a table of systemic causes any physician can follow using the blood and 24 hour urine testing. This is not something a patient can do anything about except see that it is accomplished.

Revised Table for Evaluation for Systemic Causes of Stones

The bowel diseases that cause enteric hyperoxaluria – small bowel resection, malabsorption, are usually obvious, as are ileostomy and bariatric surgery.

Medullary sponge kidney and nephrocalcinosis are complicating features physicians need to deal with. Medullary sponge kidneys actually form tiny micro crystals in their dilated ducts. Whether these grow to become clinically important is not clear.

Nephrocalcinosis simply means many crystals are present on x ray images. During ureteroscopy these crystal deposits can be sorted out into real stones and plugs within the terminal ducts of the kidneys. Pain without obstruction is widely described in both of these conditions which complicates management.

Measure Urine Supersaturations of the Stone Crystals

Standard 24 hour urine kidney stone risk panels give supersaturations along with the urine chemistries that control those supersaturations. These are the keys to prevention. Supersaturations control crystallization and can be measured reliably in people. If crystals are being formed the supersaturation is too high and we need to lower it.

Read Your 24 Hour Urine Reports

Your physician will take care of you but a prepared and educated patient can make that care vastly more effective and reliable.

You can understand your 24 hour urine tests and follow along with your physician during your visits and when treatment has been introduced and your urine chemistries change as a result. The details of interest are different for calcium stones and uric acid stones, so I have put them in two separate articles. Do not be put off by all the numbers. Follow the articles with your test panel in hand and you will find things are not so difficult.

Stone prevention is long term and involves changes in diet and behavior and, often, medication use. If you can read your own report you will have a first hand sense of why your treatments are good for prevention and whether your treatments have achieved what they were designed to achieve.

3. Lower By Half the Supersaturations for the Crystals in Stones

There is no one way to reduce supersaturations. Every patient will have a characteristic pattern of abnormalities and supersaturation can be lowered by changing any number of those abnormalities present. Below is my general strategy, but it may not apply to you. If your urine volume is already very high, for example, to raise it would be silly. So consider my ‘strategy’ a general set of rules, easily modified to fit the individual situation.

Raise Urine Volume as High as is Practical

Above 2.5 liters daily is ideal. The site is very rich in advice for fluid treatments. How to drink more. How to get variety. How to avoid low flow periods. Being without cost or risk, fluids are always my first choice.

Reverse Urine Abnormalities Raising Supersaturations for the Crystals in Stones

urine calcium oxalate volume and citrate vs risk of stones from Curhan plotted with identical risk axesIdentify the factors in the 24 hour urine beside volume that are raising supersaturations for the crystals in stones, and act so as to reverse them toward normal. Common ones are high urine calcium, high urine oxalate from diet, low urine citrate, and low urine pH – for uric acid stones. High pH is a risk factor for calcium phosphate stones but one cannot lower urine pH under most circumstances.

Bang For the Buck

A vulgar phrase, if you think about it. Here are the relative risks of becoming a stone former in the three cohorts of nurses (red) and physicians (males, blue) Dr. Gary Curhan followed. You might say relative to what. For each risk factor it is different: Calcium – less than 100 mg/day; Oxalate – less than 20 mg/day; Citrate – less than 300 mg/day; Volume, less than 1 liter.

The average relative risk is at the end of the crosshatched bars. The ends of the solid bars are the 95th percentiles. When the solid bars are above one risk is certainly present, so you can see the safe ranges for calcium, oxalate, citrate, and volume. Because the plots all have the same risk ranges you can compare these four risk factors. Calcium has the widest  effect range. Oxalate is next and increases risk at even 25 mg/day. Citrate causes risk only when below 400 mg/day, and volumes above 2 – 2.24 liters lower all three cohorts into a low risk range.

Although urine volume confers relative risk equivalent to high urine calcium and oxalate only when below 1.25 liters daily (see graph at left), one always wants to raise it as much as is possible because such treatment is without risk or cost. Above 2.25 liters daily is ideal. The site is very rich in advice for fluid treatments. How to drink more. How to get variety. How to avoid low flow periods.

Obtain New 24 Hour Urines to be Sure Supersaturations Have Fallen

There is no point to changing diets or medications without proper follow up to determine if what was done had the desired effects. Six weeks is a good time for the first follow up measurement. Continue measurements until the supersaturation goals have been achieved.

4. Obtain more 24 Hour Urines if New Stones Continue

Crystals follow physical laws and supersaturation is what drives them to form and grow. Continued stones with reduced supersaturations means either supersaturations need to be lower, the 24 hour samples are not being taken on representative days, or the days themselves have periods of low urine flow or other breaks in treatment.

Crystals do not sleep nor do they make mistakes. Any chances they get, they use.

Physicians are trained to ferret out the details of a patient’s history that matter here. It is my main clinical expertise. 

Patients are not trained but they are the ones sitting up close at the 50 yard line. So they know more than anyone else. They just may not know what is important for stone prevention.

5. Follow Up Every Year Thereafter Even If Free of New Stones

OH, you might say, those urine measurements cost money.

They do, hundreds of dollars for each one.

The merest surgery can cost near to or even above ten thousand dollars when you consider the total of medical, operating room, anesthesia, and pre and postoperative imaging costs, and the inevitable emergency room visits that provoke the surgery in the first place. This is not to mention lost time from work.

And, did I speak about pain, misery, infections?

It it time for blunt talk. Lab measurements are the compass and altimeter. Flying blind is silly.

A Good Way to Get All This Done

You cannot do the five steps alone, your physician is crucial. He or she cannot do them either; you are crucial. In case you missed it, here is my view on how a patient and physician can best partner for stone prevention

That’s It

This site is far from complete but it already has a lot of what one needs to carry out these five critical steps. Do them and new stones will cease altogether or at least greatly reduce in frequency. If it does not work, one or more of the steps need correcting. After nearly 45 years preventing stones, I have become bold enough to say this, and mean it.

Good Luck, Fred Coe

105 Responses to “THE FIVE STEPS TO STONE PREVENTION”

  1. Brian Smith

    Hello Dr. Coe. I’m not sure why there is no push for research on Phyllanthus Niuri (Chanca Piedra) given anecdoctal results and use in south america for so many years. I would urge you to look at a few studies, limited as they are, that indicate at least some preventative function and help with clearing stones after ESWL treatment. I have provided links to four studies/articles below.

    http://onlinelibrary.wiley.com/doi/10.1046/j.1464-410X.2002.02794.x/full

    https://www.researchgate.net/publication/6895645_Can_Phyllanthus_niruri_Affect_the_Efficacy_of_Extracorporeal_Shock_Wave_Lithotripsy_for_Renal_Stones_A_Randomized_Prospective_Long-Term_Study

    http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-55382010000600002

    https://link.springer.com/article/10.1007%2Fs00240-004-0432-8?LI=true

    I’d like to know what you think after reviewing these articles.

    Reply
    • Fredric Coe, MD

      Hi Brian, The reason is that the data do not support a role. I already reviewed the trial – it was negative; subgroup analysis – decided on after the trial showed a p value < 0.05 but that kind of fishing for a p value is nonsense. Here are all 13 entries for this topic in PubMed. None but your trial has any clinical interest. Some are in vitro some in rats etc. The hype on the web is all about selling stuff. But you have aroused my sense of fair play. I will do an article on this stuff – not right now but I will do it. And I will review as I always d0: Data first, nothing second. Thanks for bringing it up – again. Best, Fred

      Reply
      • Brian Smith

        Hello Dr. Coe,
        I understand the confidence level was only sufficiently high enough to be significant for the subgroup, but don’t you think that could be fleshed out more with a larger sample size? The entire group, both treatment, and control was 150 patients, wouldn’t a larger group, say 500-1000 patients, potentially provide a result with much greater statistical significance (if the hypothesis is correct)?

        Correct me if I’m wrong, but the only other post ESWL treatments to help promote stone-free rates is a prescription for tamsulosin, which has a number of side effects, or the placement of a ureteral stent, which has been shown to sometimes have lower stone free rates and has a number of complications/pain associated with it?

        In the studies done so far, there don’t seem to be any major side effects of Phyllanthus niruri (except for possibly mild hypotensive effects) and is incredibly cheap (15 or so dollars for 90 500mg capsules). What harm is there in trying to see if it would be effective or to encourage an additional, more rigorous study of its effects?

        Reply
        • Fredric Coe, MD

          Hi Brian, In fact two potassium citrate trials were done showing reduced new stones etc, and worked reasonably well with adequate significances. As for another and larger trial of the Phyllanthus, someone would have to pay for it. The makers even less so given no monetary value. I must say the evidence in the 13 or 14 papers I have seen is not very compelling. But if money came along I am sure physicians could organize a trial. NIH is not likely to do it except through their alternative medicine program. I am not against any possibilities, just aware of the vast trouble and cost of trials, and the rather meager data thus far. Best, Fred

          Reply
          • Brian Smith

            Yes, I did see all of the evidence behind citrate and I found your article on it to be very helpful. I am also using citrate in my diet to help prevent future stones. I know you mentioned crystal light as a cost effective alternative to potassium citrate, but another one that I’m trying is True Lemon, a more natural product that is simply crystalized lemon in powdered form. On their conversion chart, 4 teaspons of powder = 1/2 cup of lemon juice, which I think is a sufficient amount (although I’m sure it depends for each patient). If you buy the value pack of 6, 10.6 oz shaker’s, (each of which should last about 20 days), then you would have a four month supply for 107.95. Even better, if you apply the 50% coupon code I used, LETSTRYTRUE5017, the total for a 4 month supply is on 53.97, with free shipping.
            https://www.truelemonstore.com/product-p/81-1030.htm

            Reply
            • Fredric Coe, MD

              Hi Brian, The amount of citrate – the ionized form of the citric acid /citrate couple depends on the pH of the final solution. Citric acid is useless for your purposes. SO Isuggest getting a 24 hour urine in followup to be sure your urine citrate has risen to above the risk threshold. I presume citrate was low to begin with and that is your main problem. In case you have any questions about the range of testing here is a good summary. Regards, Fred Coe

              Reply
  2. JAY

    Dear dr coe, i have read about using chanca piedra for dissolving stones .. do you know anything about this .. ?? thankyou..

    Reply
    • Fredric Coe, MD

      Hi Jay, I do. No article as yet, but my reading is that the stuff is nothing at all. Just a way to get some money in exchange for claims. I know I need to write a well referenced article about it and delay out of boredom. There is no science to it that I found thus far. Regards, Fred Coe

      Reply
      • Ross

        There may be minimal scientific study in the US, but apparently there are many, many people in other countries who have used it for generations, with success. They don’t take Phyllanthus because of the result of scientific research, but because of the collective experience of their ancestors. To me, that is very weighty. I was prescribed Phyllanthus by my ND – it’s fairly inexpensive, and in the short time I’ve taken it, I’ve had a few resident stones released (this was after several ER visits, regular visits to a Urologist, several courses of Tamsulosin, CT scans, etc.). Another such item is drinking tea from corn silk. A close Egyptian acquaintance of mine has first hand testimony of generational use and success with using this to help pass and then prevent stones. We’re so advanced in medicine in this country, but we’re often unwilling to learn from the extensive history and experience of other countries that are much older than ours. Is it because of disinterest, money, pride? At any rate, I very much appreciate the ongoing studies on oxalates available on the internet, as well as the information you’ve posted in this thorough article, which I came across in my search. My urologist recommended I manage my oxalate intake, after a recent laser lithotripsy procedure, and it’s been quite an education!

        Reply
        • Fredric Coe, MD

          Hi Ross, I will take on the Phyllanthus story when I can. I have read the 12 or 13 PubMed articles about it. As for your own stones, long term prevention of stones is part of a larger story. Stones identify people at risk for bone disease, high blood pressure, and kidney disease, as other articles on this site point out. Proper prevention considers all of these together using what data we have. Regards, Fred Coe

          Reply
  3. deborah

    Hello… I have a double collective system on my left kidney. there are two tubes from my kidney that join together just above the bladder, forming a Y. About 10 years ago I had kidney stones, but could not pass them because they got stuck at the join. I had to have them surgically removed. It was horrible, My urologist put a tube into my back, to my kidney, and I had a bag on it. He needed to create a pathway to the kidney for the surgery. I wore that thing for 2 weeks. He went in and broke up the stones and removed them. Now, about 10 years later I just learned that I have another stone in the same kidney. The stones were calcium oxylate. I am 67 yo and devastated by the news. I can’t take going through that again. Please tell me there are less invasive procedures now. I can’t pass stones because of my double collective system. I am terrified. And does eating nuts really cause kidney stones?

    Reply
    • Fredric Coe, MD

      Hi Deborah, I understand your worries. The article is a great plan for evaluation and prevention. As for the surgery I would think a modern flexible ureteroscope should navigate the join with a bit of guile. I gather the join is just above the bladder, but that seems odd; perhaps you mean just below the renal pelvis. In any event, instruments have improved massively since your prior procedure and I am hopeful your surgeon will not have to do so much this time. But prevention is orderly – follow the article. Best, Fred Coe

      Reply
  4. Bob

    I posted my case of bladder stones here and asked for advice yesterday. But my post has been deleted without explanation.

    -Bob

    Reply
  5. Bob

    Corrections: In the previous post, the length of my bladder stone should be 2 cm, not 2 mm.

    Reply
  6. Bob

    Hello Dr. Coe,

    Thank you for the article. I had bladder stones removed in March. The stones consist of 15% calcium oxalate dihydrate, 70% calcium oxalate monohydrate, 15% carbonate apatite, stone weights 0.287g. The length is about 2mm. My kidney shows no stones.

    The subsequent 24-hour urine tests (w/o creatinine) shows:
    oxalic acid: 76 mg/24 h ref: 3.6-38
    magnesium: 72 mg/24 h ref: 28-180
    calcium: 117 mg/ 24 h ref: 55-300
    uric acid: 632 mg/24 h ref: 120-820
    total voume: 2296 mL

    24-hour urine tests (w/o creatinine) shows:
    citric acid: 647 mg/24 h ref: 100-1300
    citric acid: 357 mg/g creat ref: 60-660
    vreatinine: 1.81 g/24 h 0.63-2.5
    total volume: 1915 mL

    I used to eat high oxalate food a lot, such as yam, almonds, pecans, berries…
    Now I changed my diets to lower oxalate intake.
    Since I have no kidney stones, are there any other tests I should take to identify the cause of my bladder stones? Any other measures shall I take to prevent it?

    Thank you so much for your time and help!

    Reply
  7. Ness

    Hello I am hoping you can help me with your expertise knowledge but not for myself but for my companion fur baby, female dog. She was diagnosed with a stone in her ureter measuring 6mm then on second ultrasound it measured 10mm. She has a bacterial infection unidentified at the moment, and passed mucous and blood clots in her urine for 2 days. This has now cleared. Her alkaline phosphatase in her blood test was high. Measuring 220 U/L which is outside the normal range (1-120). Anion gap was also high 29mmol/l just slightly over normal range (15-25). I am wondering if with this information we could know what kind of stone she has so I can adjust her diet. We are giving her lots of fluids, and she is taking Prazosin. Calcium was normal 2.53mmol/l (2-2.8 is normal). Thank you.

    Reply
    • Fredric Coe, MD

      Hi Ness, Veterinary medicine is complex, specialized, and far out of my league. The animals – apart from humans – are off limits because I just don’t know enough to be helpful. You need the right professional here, and I gather you have one. The kind of stone cannot be deduced from what you have provided, and the use of stone analysis in dogs lies outside my range of professional knowledge. Sorry, Fred

      Reply

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