Ask KidneyStoners.org

On this page we previously took questions about kidney stones from visitors to the website.

We are unfortunately not taking any new questions or comments on this page at this time.

We apologize for the inconvenience and invite you to browse the questions and answers already listed.  

______________________________________________________________

 

June 26, 2012

Question about basketing a stone:

When your doctor says he’s going up with a basket to get a kidney stone what does that really mean?

Answer:

A basket is a small metallic device which is used to grasp a stone and remove it. (Click to expand)

Your urologist will use a ureteroscope to visualize the stone and will then use the basket to retrieve it.

Here is a picture of  a basket next to a pen:

Here is a link to the product page from a manufacturer of retrieval baskets
http://www.cookmedical.com/uro/dataSheet.do?id=5295

To see a picture of a ureteroscope, here is our page on ureteroscopy:
http://www.kidneystoners.org/treatments/ureteroscopy/]

______________________________________________________________

June 6, 2012

Question about whether water additives can increase the risk of stones:

I’m a 34yr old female that suffers from calcium oxylate stones. I have been taking potassium citrate for the last year…(Click to expand)

….and it has helped immensely as I haven’t formed any NEW stones since I’ve been on it. { I have passed some of the ones that are still in there lying in wait though.}


Anyways, my problem is drinking enough water. I work as a shift manager at McDonald’s & I am on the floor for at least 8hrs every day in an immense amount of heat. There are very limited breaks in busy customer flow to be able to hydrate myself properly. I am working on that problem, but I also find that I drink more when I can flavor the water with additives.

I’m not as fond of the powders as I am the new liquid Mio that you can squirt into your water, but I have heard that it’s very unhealthy for your kidneys, and the high levels of citric acid in it can cause more stones to form. I was wondering if this was true and if it’s better to just drink plain old water?

Answer:

Being able to drink enough fluid as a stone former is a challenge and we applaud you for committing to making that change. (Click to expand)

The increased fluid intake increases your urine output, diluting out the substances that form stones. As you’ve pointed out though, some patients run into the problem of dealing with all the output that inevitably follows the input – it’s not always convenient to get to a restroom often enough in order to empty your bladder when you are taking in your recommended amount of fluid. In some cases, we’ve found that a doctor’s note might help your school or workplace better understand your situation.

Anything you can do to get your fluid intake volume up is of benefit – it’s more about the volume than the type of fluid that you drink. That said, we usually recommend plain water first because it avoids calories, is readily accessible, and is inexpensive (if you use filtered or tap water). However, if you don’t like the taste of plain water you are not alone. Additives (such as crystal light, kool-aid, juice, or your preference – Mio) can make water more palatable and can be an effective strategy in overcoming the taste barrier. Some patients we know will gradually decrease the amount of additive they use over time so that they eventually are using only a small amount or none.

Citric acid, listed as an ingredient in Mio, has actually been associated with a decreased risk of stones, not increased risk. This is because citric acid intake can increase urinary citrate, which is an inhibitor of stones. Common natural sources of citric acid include citrus fruit juices and tomato juice. Although Mio also contains citric acid, we’re not necessarily recommending that you take Mio for this purpose – Mio also contains artificial colors and preservatives in it’s list of ingredients which may be a turn off for some people. This gets to another advantage of water – it only contains one ingredient and you don’t have to play a guessing game about whether it’s good for you or not.

We would also point out the potassium citrate you are taking will already be increasing your urinary citrate – so you probably don’t need an extra source of citric acid.

______________________________________________________________

June 3, 2012

Question about delaying treatment for a stone:

Hello, My husband just passed another stone and the Dr ordered xrays which showed two smaller ones in his left kidney…(Click to expand)

…he could pass but in his right kidney there is a stone too big to pass and it is low in his kidney. The Dr said wait and check it again in 4 months.Why wait. It will not get smaller and could make him very ill.

Answer:

There may be several reasons for waiting if a stone is not currently causing symptoms. Here are just a few. (Click to expand)

From a patient’s standpoint, waiting on surgery may be done to choose a date that is more convenient in terms of work or other commitments. Also, waiting can allow a stone to possibly pass (although you mention that the stone in your husband’s case may be too large for this). Also, some patients elect to wait and deal with a stone when it causes symptoms, as some stones can remain in place for many years without causing symptoms.

From a urologist’s standpoint, waiting might be done to see if the stone changes size. If it remains stable, continuing to observe it is an option. In other cases, if it is anticipated that future stone surgery may be inevitable, waiting can allow other stones to develop, therefore making each surgery more “worth it”. Finally, stones that may be too small to easily see for shockwave lithotripsy rule out this out as a good surgical option. Waiting can allow the stones to become large enough to see and treat effectively.

As always, we recommend that you consult with your doctor in order to develop a treatment plan you are all comfortable with.

______________________________________________________________

June 3, 2012

Question about passing a stone without realizing it:

I have a 6mm kidney stone confirmed by a CT scan with contrast. At that time, my stone was near my bladder opening…(click to expand)

I just had an xray done today, to see where it is now for a decision making appointment tomorrow with my urologist. The xray tech said it is gone. She doesn’t see it on the xray. My question is: Is it possible to pass a 6mm stone without feeling it? I have been using my strainer but admit to not using it here and there this week because it was my time of the month but I always searched for any stones that may have passed. I never saw/felt anything that would make me feel like it was passing. Could it be hiding in the urethra and not visible somehow?? I really feel like this was anit-climactic if it did really pass.

Answer:

1) CT scans will detect stones in greater than 96% of cases. Plain x-rays, on the other hand, can often miss stones…(click to expand)

Plain x-ray are successful in detecting stones in only 50-60% of cases. Therefore, the fact that your stone was not visible on the plain x-ray does not necessarily mean that it has passed.

2) Stones can indeed pass without symptoms. Once the stone makes it to the bladder, it can easily pass through the urethra, which has a much larger opening than the ureter (the tube connecting the kidney to the bladder). If you happen to not be paying attention, a stone can drop out and go to the bottom of the toilet without you noticing it.

______________________________________________________________

May 29, 2012

Question about prevention of stones:

“My question is what are all the options to get rid of kindey(sic) stones?…(Click to expand)

  I’ve been drinking lots of water, I’ve had lithotripsy done to clean out one kindey.  I almost always have some blood in my urine.  At one point I had 6 stones in one kidney and 8 in another.  In the past year in a half i’ve been passing one every two months like clock work.  I worry because my dad went through the same thing and eventually it got so bad he was getting stent replacements every three months just keep its kidney open.  He recently had surgery and a had a new ureter tube built.  I worry because he didn’t start having the problems I’m having till he was in his forties and i’m 28 and am just looking for more options, anything that will even give me a few years of no stones.”

Answer:

For patients with multiple stones and a strong family history, a complete “metabolic” stone evaluation is usually recommended.… (Click to expand)

This will include a complete history, a 24 hour urine collection test, and some blood tests. This will allow your doctor to determine whether there are any underlying issues that are contributing to your stones. Depending on the results, some patients may benefit from dietary changes while others may require medications to help reduce the number of stones that you form.

______________________________________________________________

May 16, 2012

Question about a wandering stone.
“What causes a stone to go back up the ureter and back into the kidney (4mm)?”

Answer

There are a few potential reasons we can think of for why a stone may move up from the ureter back into the kidney… (Click to expand)

1) The kidney stone has caused dilation in the collecting system, allowing the stone to “float” back up into the open space above it.

2) The stone developed in a kidney that was dilated for another reason (such as ureteropelvic junction obstruction). Because the collecting system is already dilated, the stone is mobile, and can move freely up and down. It causes obstruction when it settles down at the outlet of the system – like a too large piece of sand getting stuck in the neck of hourglass.

3) The stone was pushed back during surgery. This is sometimes done to relieve obstruction or as a side effect of stent placement. The stone, now in the kidney, can then be treated with shockwave lithotripsy or ureteroscopy.

______________________________________________________________

April 8, 2012

Question about pros and cons of treatment options for four kidney stones.

“I just found out that I have two  mid pole calculi  8×7 and 6×6 .(Click to expand)

in my right kidney. I also have a 6×5 in my mid to lower pole of my left kidney. I had a stone 3 years ago that was stuck and became infected so they put me on antibiotics and  I underwent a uteroscopy in hopes that my urologist grab the stone in

the basket but the stone went back up,  then I underwent a lithotripsy to break it which worked and I passed 3 pieces. They found out the stone was calcium phosphate.

Now 3 years later I am in this situation.  I am in no pain at present.  My question is what plan of action  should I take.   I have an appointment to go back into see my urologist

and I just completed a 24-hour urine test showing low uric acid levels, borderline calcium and high ph.  I am worried about lithotripsy because of the risks (i.e. Type II diabetes

which runs in my family, high blood pressure which I already have).  Since I am not in pain right now.  I wanted to know all the points I should consider to make a my decision. 

Also, can any of these stones pass on their own w/o intervetion (the 6×6, 5×5, and 6×5?).  Can the urologist go in and get all 3 in the right kidney or is that too risky?  Also, should I

start drinking lemonade and cherry juice or add high doses of vitamin C to shrink the stones along with lots of water?  Please advise.  Thanks.”

Answer

Stones of the size you have are less likely to pass spontaneously.(Click to expand)


Typically, success of spontaneous passage decreases when stone size increase above 5mm (stones 5mm in size have a 50-70% chance of passage).

Your treatment options include continuing to observe, undergoing shockwave lithotripsy, or ureteroscopy. With observation, you are at risk of your stones getting larger (and becoming more difficult to treat) or developing another episode of infection or blockage. Because you’ve developed your new stones in just 3 years, observation in your case may not be the best option.

You urologist can potentially treat all three stones in the right kidney with ureteroscopy in one surgery, which is one advantage of that approach. Success rates for stone clearance can be higher with ureteroscopy as well. One downside is more discomfort and slower recovery after surgery.

It may be more difficult to treat all three stones with shockwave in one surgery as the number of shockwaves used in each surgery is limited in order to minimize risks of bleeding or damage to the kidney. Shockwave lithotripsy has been reported to have a potential low risk of causing kidney damage but most reports suggest this risk is low. You have to counterbalance this risk with the risk of untreated stone disease, if your stones cause problems such as infection or obstruction. Shockwave lithotripsy usually has faster recovery and lower amounts of discomfort. We have a chart going over the three surgical options here: http://www.kidneystoners.org/treatments/comparing-ureteroscopy-shockwave-lithotripsy-and-percutaneous-nephrolithotripsy/

We advise continuing with increased fluid intake in order to help reduce your future risks for stones. The amount of fluid is likely more important than the type of fluid that you drink. Lemonade may increase citrate levels, which can help prevent recurrence of stones – so if you like drinking it, that may be a good choice. We are not aware of cherry juice having an impact on stone risks. Calcium phosphate stones unfortunately cannot be dissolved with medications.

______________________________________________________________

March 16, 2012

Question about whether to get a repeat x-ray and taking a wait and see approach for stones:

In mid-November I began to have episodes of blood in my urine.(Click to expand)

I went to a urologist who did a CT (with and without contrast), a cystoscopy, and a urine cytology as well as cultures. All the results were negative for growth, etc. However, the CT scan determined I had 4 kidney stones. The largest is 5mm and is located in the left lower renal pole with two other smaller stones in the left kidney and one tiny stone in the right kidney. There is no obstruction or hydronephrosis. 

The urologist wanted me to come back in three months, for a KUB. I did not agree with that as I felt it was too much radiation in a short amount of time and requested an ultrasound which the urologist refuses to perform. 

My question is, with the size stones should I be able to pass these stones? I am not having any pain or discomfort. I did notice one or maybe two episodes of gross hematuria which the urology staff said was due to the stones possibly moving.

I do not want to cause myself further harm, but I feel that the urologist is itching to blast my stones as she seems to practice big medicine and doesn’t have a wait and see approach. Am I safe to continue to watch the stones and only return if I have great pain, etc?”

Answer

Your urologist’s suggestion to get a KUB in 3 months is not unusual…(Click to expand)

Radiation exposure:
 A plain x-ray (KUB) carries a dose of 0.7 mSv as compared to a much higher dose of 15 mSv from a CT scan. For comparison, the annual background radiation most individuals experience is 3.86 mSv just from the environment. Therefore, getting a KUB carries a relatively low dose compared to getting a repeat CT scan. A KUB is also useful in determining whether you are a candidate for ESWL (which uses plain x-ray to aim the shockwaves), as not all stones that are visible on CT are visible on KUB. Ultrasounds are not generally useful for following stones as they are not very accurate at determining the size of stones. This is likely why your urologist does not recommend an ultrasound. An alternative you can consider is waiting longer to get a KUB or repeat CT scan (6, 12, or 24 months).

Stone size:
Stones smaller than 5mm are more likely to be able to pass. As yours are also 5mm or smaller, they can potentially pass successfully (but this does not mean that they won’t hurt while they are passing). Based on one study, 5mm stones have a 50-70% success rate for spontaneous passage. If your stones increase in size over time however, this may no longer be true as the rate of success drops off as stones get larger.

Likelihood that your stones will cause you problems in the near future:
Based on a study of 5,047 adults who underwent CT colonography screening,  asymptomatic stones, such as yours, are found in 8% of American adults. In that study, the average stone size was 3mm. Over 10 years, 20.5% of patients with stones, or 1 out of 5, developed a symptomatic “stone episode” requiring intervention. The other 4 out of 5 patients did fine without experiencing a stone episode. This rate of 20% of small stones requiring treatment when observed is consistent with other studies with similar patients. Note though that your stone is slightly larger than 3mm and your corresponding likelihoods may be different.

Hopefully this information can help you to make an informed choice in consultation with your treating urologist.

______________________________________________________________

February 24, 2012

Question about whether stents are a requirement:

“I have been diagnosed with an 8mm stone in my left kidney and told I would be going for lithotripsy to have is broken up… (Click to expand)

…and will need a stent inserted for about a month or so. I have a huge concern with the stent portion of this. After much research on and off the web, it seems out of all patients that have had a stent inserted post lithotripsy, about 80% to 90% of the time it has resulted in extreme pain and discomfort. To me, it seems like this “technology” is not yet ready for prime time. I am now going to forgo the lithotripsy and deal with the stone just to avoid having the stent! So my question is, can you offer any comfort on this seeming archaic practice of stenting. Is it a requirement? What is the down side of not stenting after the lithotripsy?”

Answer

Stents have been used for decades and are not a new technology. Although much effort has been placed in trying to develop a pain-free stent…(Click to expand)

…that goal has not yet been reached. As you point out, many patients do experience discomfort when stents are placed, although the percentage who experience “extreme” pain is likely lower than 80-90%.

Urologists will make a decision on whether to place a stent based on the type of surgery that is planned, the size of the stone being treated, whether a stone has been lodged for a period of time, the presence of other patient factors (renal impairment, solitary kidneys), and based on their own professional experience. Whether a stent is a “requirement” therefore can vary based on the patient, the stone, and the urologist.

The potential downside of not placing a stent is the risk of obstruction of the ureter due to either residual stone fragments or temporary swelling of the ureter after surgery. There may also be an increased risk of long term blockage (stricture) of the ureter if a stent is not placed in certain situations. However, a recent review article in the Journal of Urology found that among those undergoing uncomplicated ureteroscopy for stones in the ureter that were stented versus those that were not stented, there was no difference in the stone free rate, development of fever, unplanned medical visits, requirements for pain medication, or long term complications. Stented patients as expected had more stent related discomfort. Note though that these findings don’t necessarily apply to all stone patients as the study only included stones treated in the ureter with “uncomplicated” surgeries. (Pengfei and colleagues, “The results of ureteral stenting after ureteroscopic lithotripsy for ureteral calculi: A systematic review and meta-analysis”, Journal of Urology
2011.)

Ultimately, discussing with your urologist whether you are a candidate for having a procedure without a stent may be your wisest choice. An 8mm stone is large enough that it is not likely to pass on its own and in some cases an untreated obstructing stone can lead to kidney damage or other problems if it is ignored.

 

______________________________________________________________

February 24, 2012

Question about needing a stent for a “tight” ureter:

“I have had two ureteroscopies in the last 5 years. In 2008 the procedure was a piece of cake with a 6mm stone lodged in the upper portion of the left ureter. (Click to expand)

In 2011 I had an approx. 8mm one stuck in the upper right ureter.  This took the urologist three attempts over like 2 weeks to get the stone blasted. He said basically my ureter was tight and he didn’t want to risk damage, so he left the stent in, tried a week later, couldn’t get it, put another stent in and tried yet again after a week. The third time went well, but the stents caused me alot of trouble when they were in. So 2 questions…. is this common? And secondly I have passed a new stone, probably no larger than 3mm now 7 months later with very little blood. Could this be just a fragment or a new one?”

Answer

The placement of a stent to passively dilate a tight “difficult” ureter before going back…(Click to expand)

for a second procedure is called by some authors “pre-stenting”. It probably occurs in about 5-10% of cases. A recent article from the UK* reported that they needed to pre-stent 8% of 119 patients undergoing ureteroscopy with them over a 2 year period. Pre-stenting avoids the need to more aggressively dilate a tight ureter with balloons or other devices and may decrease the risk of long term complications such as strictures (scars) occurring in the ureter. Other authors have also found that it can decrease operative times and improve stone clearance.

It’s hard to say whether the second stone you passed was a new stone or a residual fragment. It’s more likely that it’s a residual fragment but the only way to have known for sure is if you had a CT scan soon after your last surgery to see whether there were any remaining residual fragments.

*Cetti and co-authors, “The difficult ureter: what is the incidence of pre-stenting?” Annals of the Royal College of Surgeons of England, 2011.

 

______________________________________________________________

February 22, 2012

Question about the oxalate content of instant tea:

“i was just in the hospital for the 2nd time with kidney stones. My question is, is instant tea as bad for you as real tea? Also what are some main foods and drinks i should avoid to prevent getting them again?”

Answer

Instant tea has a similar amount of oxalate as regular tea. (Click to expand)

Below, in order of decreasing amount of oxalate, is a list of different foods and types of teas containing oxalate.

Food item Oxalate Content Equivalent to
Spinach (frozen) 1236 mg per 200 gm One box spinach
Chocolate 126 mg per 90 gm About one bar
Black tea (loose) 5.11 mg per gm 12.21 mg per cup
Black tea (bags) 4.68 mg per gm 9.54 mg per cup
Instant tea 6.6mg per gm 4.62 mg per cup
Green tea 0.68 mg per gm 1.36 mg per cup

For most stone formers however, the three most important things to remember are to increase the amount of water you drink, decrease the amount of salt you ingest, and decrease the amount of meat protein you eat. Guidelines for salt and meat intake are similar to what is advised for all adults (2300mg salt and 6 oz of meat a day).

In addition to this, keep a normal calcium intake and a moderate oxalate intake. You may also want to undergo testing with your doctor to see if a high oxalate level in the urine (hyperoxaluria) is truly an issue for you. Unless you have hyperoxaluria, restriction of oxalate containing foods may not be of much benefit.

______________________________________________________________

February 6, 2012

Question about having ureteroscopy on both kidneys at once:

“I’m having a ureteroscopy next week to remove a stone stuck in my left ureter (although causing me no pain).  (Click to expand)

My consultant says I also have stones in my right kidney, but appears reluctant to remove them for some reason, preferring them to “pop out on their own” (his words). Do you know why this is? Would you see any problem with having all the stones (in my left ureter and right kidney) being removed in the same operation? I would love to be stone-free after this one operation!”

Answer

Many studies have been performed that demonstrate the safety of operating on both kidneys at the same time.  (Click to expand)

Despite this, I usually counsel patients that it is “best to have one kidney working well while the other is healing”.  Any surgery carries risk; in the case of ureteroscopy the primary risk is an injury to the ureter.

What do do about your right kidney stones depends on the size and location of the stones.  Typically I will recommend shockwave lithotripsy for stones larger than 4mm, but observation for stones smaller than 4mm as these would have a high likelihood of passing spontaneously.

______________________________________________________________

February 4, 2012

Question about calcium supplements:

“i recently had another small stone that passed easily (thank you, God!). . . but i’m trying to prevent even those from passing/forming. (Click to expand)

i take 500 mg. calcium citrate daily and in one vitamin (antioxidant): 150 mg. calcium carbonate/daily and in another vitamin: 500 mg. calcium/daily (as calcium carbonate, dicalcium phosphate, calcium citrate, calcium gluconate, calcium amino acid oligofructose complex)

i really like taking those vitamins, but do you think i should cut them out because of the calcium carbonate?”

Answer

In general, most individuals do not need to limit their calcium intake. (Click to expand)

Surprisingly, attempts to restrict calcium can sometimes lead to an increased risk for stones. That’s why a normal calcium intake is usually recommended. While calcium citrate is preferred because of its citrate content (which can help inhibit stones), this does not necessarily mean that you need to cut out your calcium carbonate intake as it is not inherently bad.  

You may have read our post on calcium supplements already, but if you haven’t it’s located here:
http://www.kidneystoners.org/prevention/calcium/

In your situation, your personal total calcium intake may be higher than most individuals with the three supplements you take but it may still not be excessive, depending on your other dietary intake. The National Institutes of Health has a webpage that lists recommended daily allowances for calcium. Their recommended daily allowance is 1200mg for most women.
http://ods.od.nih.gov/factsheets/calcium/

To get a more accurate answer to your question however, you may want to consider undergoing a 24 hour urine collection test through your doctor to determine whether the total amount of calcium in your urine is higher than normal. Based on this information, you can then decide whether you need to adjust your supplement intake.

______________________________________________________________

January 13, 2012

Question about residual pain after passing a stone from a stone former in England, UK:

“I am 61 years old and have never had a kidney stone before last Saturday (almost 1 week ago). (Click to expand)

I was hit with sudden, excruciating pain in my kidney area. I went to hospital and was treated with pain meds and kept in over night. The pain was so bad that I thought I would pass out with it. The following day the pain had subsided and I had a full bladder CT scan (no medium used). The scan showed a swelling below the kidney, indicating that I had had a stone but that it had passed. The doctor could not see any sign of any more stones although the CT scan had not yet been reported by a radiologist. The problem is that I seem to have some dull pain still around the same kidney and fear it being another stone. I wonder if there would be some residual pain after passing a stone for a week or so? Or could it be more trouble?”

Answer:

The experience that you described is consistent with a stone episode.   (Click to expand)

Although a stone was not seen on your CT scan, it is not uncommon for patients to have already passed a stone by the time a CT scan is obtained. It is also not uncommon to have residual discomfort after a stone has passed. We aren’t aware of good data on this phenomenon but we have seen patients complain of mild discomfort for up to several weeks after passing a stone. This discomfort may be due to remaining inflammation or swelling in the ureter and kidney area and should resolve on its own.

There are also some less likely reasons why someone may have persistent pain. Some of these include:

1) A stone was “missed” on the CT: While CT scans are highly accurate for detecting stones, there are a few scenarios where a stone can go undetected. A CT that does not include images of the entire length of the ureter but that instead stops before reaching the bladder can miss a stone that is further down. Also, a stone in the lowest part of the ureter near the bladder can sometimes be confused for calcifications known as phleboliths that can look similar on a CT scan.

2) There was another cause for your pain, unrelated to stones: Congenital obstructions of the ureter, known as ureteropelvic junction obstructions, can cause pain similar to a stone episode and will demonstrate swelling in the kidney on a CT scan. However, other clues on the CT scan will usually allow your physicians to determine whether this scenario is a possibility. Other uncommon causes for kidney swelling and pain that may not be easy to detect with a non-contrast CT scan can include passing a blood clot or piece of kidney tissue down the ureter, having a scar or other obstruction of the ureter, and very rarely, having a tumor involving the ureter.

It would be advisable for you to followup with your physician to review the radiologist’s report. Some physicians, including most urologists, may also review the actual CT scan images. You can consult with your physician to determine whether a followup ultrasound or CT scan is necessary to insure that the swelling in the kidney resolves. It should resolve if what you had was actually a successfully passed stone.

Please note that this information is not intended to represent medical advice or professional opinion. Each patient’s case is unique and we recommend that all patients seek care with a local medical professional who can thoroughly review the circumstances and details of their case.

______________________________________________________________

January 10, 2012

Question about options for a 6mm kidney stone:

“About 10 years ago, I had a kidney stone that passed over the course of a few days. (Click to expand)

It was also on the right side, but I never found out how big it was or what kind of stone it was.

I recently had severe pain on the right side of my back for a few hours.  The pain went away.  I had a CT Scan of my Urinary Tract which revealed:

“There is a right ureteric calclus measuring 3mm in diameter at the level o the L4/L5 intervertebral disc.  There is mild prominence of the right pelvicalyceal system and proximal ureter above this.  There is no other reteric calculus but the is a 6m calculus in the right lower pole calyx.  The kidneys are otherwise normal in appearance.  The other solid viscera of the upper abdomen are normal allowing for the non contrast study. Conclusion: 3mm mid right ureteric calculus, with mild prominence of the right ureter superior to this.  second non obstructive calculus in right lower pole calyx.”

I don’t know if the 3mm stone has passed yet. I only have intermittent very slight aching on the right side of my back. I am more worried about the 6 mm stone. What would be the best treatment for the 6mm stone?  I have read that stones in the lower pole can be more difficult to successfully blast. Would blasting be an option? What are the chances it will pass on its own?  Is there anything I can do to encourage it to pass on its own safely?  If I do nothing, what is the likelihood it will remain asymptomatic indefinitely?  Is watch and wait a safe option for me? ”

Answer:

First step is to make certain you pass the 3mm stone.   (Click to expand)

If you don’t pass it then you could undergo ureteroscopy and the 6mm stone could be addressed at the same setting.

Next, on the CT one would measure the stone density and skin to stone distance. This would further guide us as to whether shockwave would work. For a 6mm stone in the lower pole success with shockwave would be 70% if the density and distance were favorable. Other options are to observe the stone if it is not causing pain or ureteroscopy which has a 90% success but is more invasive.

A previous question on our website may be of interest to you when considering observing the stone. While the question then was about a 3mm stone, the information also applies to a 6mm stone such as yours.

(UPDATE 1/11/12) Additional comments from Dr. Marshall Stoller: I would also bring to light that your stones have always been on your right side.  We have undertaken some studies that have shown most patients with recurrent unilateral stones sleep stone side down. Studies have shown dramatic changes in renal blood flow resulting in a hyperfiltration phenomenon.  I would recommend that you attempt to change your sleep posture, if indeed you do sleep on your right side. Additionally, I would reduce your sodium intake, reduce animal protein consumption at individual meals, and ensure that you drink enough fluids to void >1.5 liters per day.

 

______________________________________________________________

December 16, 2011

Question about removing ureteral stents:

“(M)y boyfriend went to his urologist yesterday to have his stents removed… (Click to expand)

I am confused because the research that I have done would suggest that since he had strings attached to his stents that it should have been a fairly simple process, however, this is not the case. The urologist did not have strings to pull out the stents? Did the strings coil back into the bladder? He used a scope to go in and he said locate the strings which he could not do? He pulled the scope out had my boyfriend empty his bladder then went back in again VERY PAINFULL!! again said he could not find the strings due to too much blood? Why at this point would he be looking for strings? shouldn’t he be looking in the bladder for the stent itself to pull out? I wish I would have researched this prior to our appt. so that I knew to ask questions, he now has to go back to a hospital OR setting and have to be put under to have the stents removed, it this a common occurance or should we be concerned? HELP!!”

Answer:

Most ureteral stents come from the manufacturer with long strings attached. These strings can be left intact, shortened, or removed entirely. (Click to expand)

If the string is left intact, they will usually extend all the way out of the urethra, where they are visible. For various reasons, urologists often instead either shorten the string or remove them entirely. When this is done, because the string is not visible outside the urethra, a cystoscope will need to be advanced into the bladder where the string or stent is grasped and the stent removed.

While the process of stent removal in the clinic using a cystoscope is often straightforward, it can be made difficult or unsuccessful when there is blood in the bladder or when the stent retracts back into the ureter. In the first instance, blood can make it very difficult to see the stent or string. Because strings in the bladder are longer than the visible portion of the stent itself, a urologist may choose to look for the strings instead of the stent. When this still fails, going to the operating room will allow larger instruments to be used that provide better irrigation/flow to successfully visualize and remove the stent(s). In the second instance, stents can sometimes withdrawal back into the ureter after they are placed. This means no stent is visible in the bladder. Removal of these stents also usually requires going back to the operating room where a ureteroscope can be used to go up the ureter and grasp the stent.  Both these situations unfortunately can occur commonly. The good news is that removal of the stent(s) in the operating room is usually straightforward.

Please note that this information is not intended to represent medical advice or professional opinion. Our comments are intended as general information, and are not specific to your boyfriend’s case. Each patient’s case is unique and we recommend that all patients seek care with their local medical professional.

______________________________________________________________

November 29, 2011

Question from a patient with a stent:

“I have another question regarding the stent I’ve had for almost two and a half months. Should I still be bleeding and burning as well as having a discharge at this time?”

Answer:

As long as a ureteral stent remains in place, it can cause symptoms. (Click to expand)

These symptoms can include blood in the urine, burning, sensation of the need to urinate, pain in the bladder, and pain in the back. Once the stent is removed, these symptoms should resolve.

If you have other symptoms such as fevers or severe pain or nausea, you should contact a medical professional to make sure you do not have a urinary tract infection or other problems.

______________________________________________________________

October 18, 2011

Story from a recurrent stone former in Ontario, Canada:

“I have suffering from what I know as kidney stone pain in my back, flanks, and lower abdomen, for just over a year now. (Click to expand)

I passed a stone in October 2010, and then one on June 27th 2011. Ultrasounds didn’t see anything at first, but in more recent scans calculi have been seen in both kidneys. They are, of course, non obstructing, and should not be causing any pain according to doctors and specialists here. CT scans have missed the stones or under estimated the size everytime, according to my most recent scan it said there is something small in one kidney and I do believe it was less than a month later I passed a stone that was approximately a quarter of an inch in diameter. I will attach a picture of it. My physicians here will not do anything as the scans show nothing, but as I have shown them there are relatively big calculi there. I am not looking for medical advice just sharing my story. I have been using percocet (oxycocet) to control pain along with an anti-inflammatory……… however the pain meds have lost their effectiveness and doctors here are so hesitant to prescribe anything to help so I am left to suffer while trying to work as a mechanic at a (——-) dealership, also my doctor won’t allow any time off to cope with the pain. I have passed out in ditches and vomited in the service truck while trying to work through this.”

Response:

Thank you for sharing your experience. While CT scans are the most accurate means we have for detecting and measuring kidney stones. (Click to expand)

It may be the case that you form and pass stones so quickly that the scans do not always detect every stone that you are forming.

In situations such as yours, prevention becomes the most important priority. Dehydration (especially if you work outdoors) can play a major role in the formation of stones and increasing your fluid intake may help reduce the number of stones you form. You may also want to consult with your doctors on whether pharmaceutical treatment would be indicated to again reduce the number of stones your form.

Pain from non-obstructing stones is a frustrating situation that we have seen in several of our patients. Traditional urology teaching would say that these stones should not cause pain (because they are not obstructing the ureter). It is unclear why some patients in this situation truly do seem to have associated discomfort and may even have relief when the stones are treated.

 

______________________________________________________________

October 12, 2011

Question from a cystine stone former:

“I have cystineuria and am struggling to control it I have tried most
things. (Click to expand)

I average one stone approximately 14mm smallest to the 3.5cm that
blocked my left kidney. I have put a stop to my treatment. As you seam to
know alot more that most was wondering if I keep refusing treatment, how
many long would you estimate I have left?”

Answer:

Cystinuria is a frustrating disease.  There are times when stones are silent
and other times when stones recur quite frequently.  (Click to expand)

The good news is that it is extremely rare that cystine stone formers will
progress to require hemodialysis or renal transplantation.

We also have published data showing that cystinurics frequently form stones on just one side.  This has been well established.  One may try to sleep such that the stone side is more commonly on the “up” side rather than the down side.

Bottom line:  you need to drink lots of water – 24-hours per day.  We
recommend having a few additional alarm clocks to awaken you in the middle of the night to ensure that you void and re-hydrate.

 

______________________________________________________________

October 11, 2011

Question from a stone former in the UK:

Does chronic use of Potassium Citrate (to keep the pH alkaline) have any long term drawbacks?

Answer:

Long term potassium citrate therapy is generally well tolerated and safe but can carry some potential side effects and risks. (Click to expand)

Some patients may experience gastrointestinal upset with the medication. Taking it with meals can help alleviate this. There also appears to be conflicting evidence about whether potassium citrate can increase the risk of calcium phosphate stones by causing the urine to be too alkaline. If there is an increased risk of calcium phosphate stones, it appears to be small. Finally, potassium citrate therapy can cause an abnormally high blood potassium level in certain situations. According to the manufacturer of Urocit-K, “Conditions that may put you at risk include kidney failure, uncontrolled diabetes, severe dehydration, strenuous physical exercise if you’re unconditioned, extensive tissue breakdown, or adrenal insufficiency”.

References: Campbell-Walsh Urology, 10th ed. and Mission Pharmacal prescribing information

______________________________________________________________

October 11, 2011

Question from the UK:

“How common is it for a patient with homozygous cystinurea to never form a stone?”

Answer:

Cystinuria is a rare cause of kidney stones overall, accounting for 1-2% or less of all stones. (Click to expand)

In children however, it accounts for up to 6-8% of stones. It is caused by a defect in the transport of amino acids across the cellular membrane of the renal proximal tubule and small intestine. Cystinuria is an inherited disorder.

Because of the relative rarity of cystinuria, there is limited reliable, long term data on the risk of stones. A review of the literature found the following:

Most but not all patients with homozygous cystinuria (carrying two copies of the abnormal gene) appear to develop stones throughout their lifetime. A study by the International Cystinuria Consortium reported that only 6% of individuals with homozygous cystinuria did not produce stones. The age at which individuals first formed stones also varied, with many experiencing stones between 11 and 20 years of age but with some forming stones before the age of 3.

Complicating matters, cystinuria is classified into types A, B, and AB, depending on the specific combination of two known inheritable genes (SLC3A1 and SLC7A9) that can cause the disease. The risk and age of onset of developing stones varies with which type an individual has.

References:
Pathophysiology and Treatment of Cystinuria. Chillaron et al. Nature Reviews Nephrology. 2010.
Cystinuria Subtype and the Risk of Nephrolithiasis. Goodyer et al. Kidney International. 1998.

______________________________________________________________

July 26, 2011

Question from a stone former actively passing a stone:

I have been diagnosed with a kidney stone.  I am experiencing pain that has now moved to my side.  (Click to expand)
Occasionally I will get waves of overall abdominal pain, but the sharp pains are still generally located to the side.  How will I be able to tell when the stone has dropped to the bladder?
I’ve been drinking 4L of water (at least) a day for 8 days now and the stone still has not passed. I would rather now go into work and keep on with my life until the stone passes – I am just concerned with knowing the warning signs of when the stone is very close to passing.

Answer:

During stone episodes, stones generally cause a predictable sequence
of symptoms as they move down the ureter.
(Click to expand)

Initially, pain is located in the back when the stone is located up near the kidney. As the stone moves further down, the pain can also be located in the side and in the abdomen. When the stone is in the lower part of the ureter, the pain moves toward the front of the abdomen. Once a stone is entering into the bladder, patients may also feel the urgency to urinate and can feel pain in the groin. Once the stone makes it into the bladder, there should be a relief of pain. While this sequence is typical, some patients may experience different symptoms. We have more information on this on our “What causes kidney stone pain?” page.

Staying hydrated is a good idea but it is not clear if it speeds the
passage of stones (make sure though to not drink more than about 1
liter in an hour, as water intoxication can occur with intakes of 2
liters an hour or higher). Use of certain medications, such as
tamsulosin, does appear to shorten stone passage. You should know
though that use of this medication for this purpose is “off label” and
should be discussed with your treating physician. Other factors that
influence the likelihood and speed of stone passage includes the size
of the stone and its location. Stones can take up to 6-8 weeks to
pass. If they have not passed by then, treatment may be required.

______________________________________________________________

July 22, 2011

Question from Minnesota about the need to treat a small stone:

I have a 3mm to 4mm stone in my right kidney, which has been there since 2003.  (Click to expand)

It originally was very high up in the kidney, but moved to the lower part of the kidney in 2006. I just had another CT done, and it is still in the same place and the same size.  Because the stone is in the lower part of the kidney versus the higher part, is it less likely to pass, because it would have to go up to get into the ureter versus down? Because I’ve had this stone so long with no changes, what are the chances that it will just continue to sit there and never pass?  It has caused me no pain other than occasional blood in my urine. I was told by my doc that I could wait and watch the 3-4mm stone in my right kidney or proceed with ureteroscopy to remove it. It’s been sitting there since 2003 without giving me any discomfort. How painful is having a stent put in to promote healing after the ureteroscopy and is it really necessary?

Answer:

Many patients are found with small stones and it can be confusing deciding on what to do. (Click to expand)

Several factors need to be considered to help make a decision on whether to proceed with treatment or to continue observing the stone(s).

1)    Size: Stones that are smaller than 5mm are more likely to be able to pass successfully without requiring surgery. When a stone is larger (>6mm) and unlikely to pass successfully, it may make more sense to intervene. In your case, the stone is small and if it were to start moving down the ureter, it would have a good chance of passing spontaneously. However, successful passage does not mean non-painful passage as even small stones can cause significant discomfort when they move down the ureter. Because of this, patients who have already experienced a stone episode in the past are usually more motivated to have an early intervention so that they can avoid another stone passage episode.

2)    Stability: Stones that are growing are more likely to lead to problems while stones that stay the same size are less likely to become symptomatic. As your stone is stable over 8 years, one could argue to continue to watch it.

3)    Location: Stones that are not obstructing, like yours, are generally asymptomatic. Stones that are floating in the renal pelvis or ureter are more likely to cause obstruction and more likely to require intervention. Stone fragments in the lower pole are generally felt to be less likely to pass. However, in addition to whether the stone is in the upper pole, middle-pole, or lower pole of the kidney, researchers have focused on the “calyceal anatomy” which can be though of as the length of the “tunnel” and the angle of the “tunnel” that the stone would have to travel to end up in the center part of the kidney where it could start making its way down the ureter.

4)    Symptoms: Stones that cause symptoms such as pain, recurrent infections, or significant bleeding would be more likely to require intervention than stones that are causing minimal symptoms.

5)    Other things to consider: Certain individuals will be advised to have their stone treated even if it is small and asymptomatic. This includes pilots, who would put themselves and their passengers at risk if they were to experience a stone passage episode while flying, and travelers to remote locations, where modern medical facilities may not be available if they were to suffer a stone attack.

The short answer as to how likely your stone is to remain there without causing problems is 80% over the next 3-10 years. Another way of looking at this is that 20%, or 1 out of 5 patients in your situation will experience a stone passage episode over the next 3-10 years while 4 out of 5 will do fine without experiencing problems. Here’s the long answer: Based on a study of 5,047 adults who underwent CT colonography screening, asymptomatic stones, such as yours, are found in 8% of American adults. In that study, the average stone size was 3mm. Over 10 years, 20.5% of patients with stones, or 1 out of 5, developed a symptomatic “stone episode” requiring intervention. Alternatively, 4 out of 5 patients did fine without experiencing a stone episode. This rate of 20% of small stones requiring treatment when observed is remarkably consistent with multiple other studies where patients with small stones were observed.

Finally, as to your question about ureteral stents, stents are often required after ureteroscopy surgery because of the ureter’s tendency to swell temporarily and become blocked after this type of surgery. This swelling can cause pain similar to a stone episode. We’ve found that this is more likely to occur in patients who have not had prior ureteroscopy surgery. Note though that this is a “surgeon’s preference” as some urologists will be more likely to perform ureteroscopy without leaving a stent. Stent pain can be mild or can be very uncomfortable. While some patients do not even realize a stent is there, most can’t wait to have them removed and some patients will say that the stent was worse than their stone. One way to potentially avoid a stent is to consider shockwave lithotripsy (ESWL) if the stone is easily visible on a plain x-ray.

_____________________________________________________________

July 21, 2011

Question from a father of a cystine stone former:

I have a five year old son who is suffer from 100 % cystine kidney stone. (Click to expand)

He is totally four time operated for this but no any permanent solution.The stone size is genarally 30 mm in six month and specially in right side kideny.The doctor suggest me for Urinary cystinine 24 hr test i dont where it’s best laboratory.kindely suggest me the treatment procedure or suggest me the best Doctors name where i can foun my solution. [sic]

Answer:

Cystine stones are caused by an inherited condition. These stones can be very difficult to treat as they are very likely to recur. (Click to expand)

The 24 hour urine test is used to determine whether your son has inherited one gene (heterozygous) or two genes (homozygous). Homozygous patients have the more severe form of the condition, making their treatment more difficult. I would recommend you discuss with your local doctor where to send the test because not all laboratories will be able to run this test.

Surgery can remove stones once they develop but cystine stones will always redevelop. Therefore, medical treatment is an important part of cystine stone management. There are three strategies that make up medical therapy for cystine stone formers:

1) Alkalinization
Cystine solubility (how likely it will dissolve) is dependent on the pH of urine. A high pH (alkaline) can cause cystine stones to dissolve and make new stones less likely to form. Medications can be used to change the pH of a patient’s urine. Common medications include potassium citrate tablets, powders, or oral solutions. The goal pH for cystine stone formers is between 7.2 and 7.5.

2) Binding
The solubility of cystine can be increased by binding it to other molecules. Two medications have generally been used for this purpose. The first is D-penicillamine (Cuprimine). However, it is poorly tolerated by patients because of side effects, and over 50% of patients discontinue the medication. The second binding medication is alpha mercaptopropionylglycine (Thiola). This medication has similar effectiveness to D-penicillamine but has lower side effects and is better tolerated.

3) Fluid intake
Increasing the amount of fluid drank throughout a day will cause the urine to become dilute, which lowers the concentration of cystine. The goal is to keep the urine clear. Fluid intake alone will usually not halt cystine stone formation but can be effective when combined with alkalinization and binding medications.

We suggest that you work with your local doctor to not only treat your son’s stones surgically but to also decrease future stones with the three strategies above.  

______________________________________________________________
July 1, 2011

Question from a family member of a stone former about treatment options:

Is there any treatment for a stone that is currently in the kidney? (Click to expand)

My husband had lithotripsy on June 2, of this year, for an 8mm stone that was in the kidney.  After the procedure, his doctor told me that he got the stone and blasted it into powder.  After two weeks of still having pain, the doctor sent my husband for an ultrasound.  The doctor’s office called and said that the same stone is still in the kidney; that the procedure did not work, and that there was nothing else that could be done.

Answer:  

For stones of that size, there are usually two surgical options for treatment…(Click to expand) 

The first is extracorporeal shockwave lithotripsy (ESWL), which we assume your husband had. This option benefits from being performed externally through the use of shockwaves. Patients typically have less discomfort with this approach. However, the success rate of ESWL is lower, and depending on who you ask, is around 70%. That means that 30% of stones may not respond to the shockwaves because they are too dense, because there is difficulty accurately targeting the stone, or because the fragmented stones do not “flush” out of the kidney but stay in place.

The second option for a stone of this size is ureteroscopy and laser lithotripsy. In this approach, a small camera is advanced up into the kidney where the stone can be directly seen. A fiberoptic laser fiber is then used to fragment the stone into small pieces. The pieces can be left to pass on their own or a small wire basket can be used to grasp and remove the fragments. This approach has a higher success rate, around 90%. The disadvantage is more discomfort, primarily because of the potential need for a temporary ureteral stent after surgery. In situations where ESWL doesn’t work, ureteroscopy is the next best option.

Finally, the other two choices are waiting to see if the stone will pass by itself or treating it with percutaneous nephrolithotripsy (PCNL). For a 8mm stone, neither of these options are very good. 8 mm stones will usually have difficulty passing spontaneously and will more likely get stuck, requiring something be done surgically. Percutaneous nephrolithotripsy might be “overkill” for a stone of this size. This approach involves making a puncture directly into the kidney to allow insertion of large instruments that can be used to break up and remove a stone. PCNL is usually reserved for larger stones that would be difficult to treat with ESWL or ureteroscopy.

In summary, your husband’s next best option may be ureteroscopy with laser lithotripsy. As always, we advise that you discuss your husband’s options with a urologist that knows his specific circumstances.

______________________________________________________________

June 13, 2011.

Question from New Jersey about cycling with a stent:

“I just had my 2nd kidney stone (5mm) removed through ureteroscopy. (Click to expand)

Like my first procedure, they inserted a stent which will be removed 3 weeks after my surgery.

The question I have is I am an active cyclist, and my doctor recommended that I not cycle until the stent is removed.  I looked at various web sites, and could not find any sports related restrictions because of a stent.   Most sites say that you can carry on normal sports activity. I feel fine.  The stent does not bother me much.  I am wondering if you are aware of any risks associated with stents and cycling?

Also I found the stent removal procedure to be very painful my first time around.  I believe they gave me some numbing gel, which did very little to alleviate the pain during the procedure .  Is there anything that you can suggest to make the stent removal procedure less painful?  The stent I have does not have a string sticking out, and must be removed using an instrument inserted through the urethra.  Ouch!”

Answer: 

We are not aware of any specific risks related to stents and cycling…(Click to expand) 

You will not “break” anything inside by doing this. However, there is a potential risk of stirring up bleeding from the movement of the stent which in severe cases can lead to urinary clots. These clots could then make it difficult to empty your bladder. Ultimately, in these situations, we recommend that you follow your treating doctor’s advice or clarify with him/her whether they will clear you for increased activity.

Stent removal procedures are unfortunately uncomfortable for many patients. That said, we’ve had many patients that are surprised to find out that the procedure is already completed-they were expecting more discomfort than was actually the case. The lidocaine jelly helps a little but as you have experienced, will not completely take away sensation. In men, increased discomfort is often related to tightening of the urethral sphincter as the scope is passed into the bladder. Trying to relax, take a deep breath, and not “clench” down during this process can sometimes make things less uncomfortable. Anticipation and perception also seem to play a role: Researchers have found that patients who watch their own cystoscopy procedure on the screen experienced less discomfort than those that did not. Hopefully these steps (relaxing as much as possible, taking a deep breath during the passage of the scope into the bladder, and asking to watch the screen if available) may make your next stent removal less uncomfortable.

______________________________________________________________

March 23, 2011.

Question from Tucson, AZ about small stones:

“On a recent CT scan, my left kidney has a three very small stones in it (1 to 2 mm in size). They were there a year ago and have not changed. Should anything be done or just keep a eye on them?”

Answer:  

There have been several studies where researchers followed small stones…(Click to expand) 

The stones were smaller than 5 mm and were followed in patients without doing surgery. The patients’ chances of later requiring treatment ranged from 20% to 40% at two to three years. In other words, among five patients found to have small stones in the kidney <5mm in size, one to two will either experience a stone passage or require surgery for the stone over the next two to three years.

Your stones are much smaller than the stones in the studies so your likelihood of needing something done over the next two to three years is also much smaller and likely closer to 10%. Therefore, surgery is not needed now or hopefully ever. However, because stones can grow over time, it would be safest to check periodically with x-rays to monitor for stone size and location. This can be done with a plain x-ray in one year and a CT scan in two years to limit your total radiation exposure.

References:

Yuruk et al, A prospective, randomized trial of management for asymptomatic lower pole calculi. Journal of Urology, 2010

Osman et al, Five-year-follow-up of patients with clinically insignificant residual fragments after extracorporeal shockwave lithotripsy. European Urology, 2005

Streem et al, Clinical implications of clinically insignificant store fragments after extracorporeal shock wave lithotripsy. Journal of Urology, 1996.

______________________________________________________________

59 Responses to Ask KidneyStoners.org

  1. Helmet Kumar says:

    My doc attempted to remove a kidney stone that was stuck in my ureter, but pushed it up futher. He then placed a stent in. He never came to see me after my surgery so I had no opportunity to ask any questions. I’m wondering what happens now. My stone is 4 mm. Will it pass through the ureter with the stent in place?

    • KidneyStoners.org says:

      A stone of that size can potentially pass along a stent but this is less likely if the stone was pushed back into the kidney during placement of the stent. Having the stent in place will however cause your ureter to dilate, making it easier for a stone to pass.

      You generally have three options that your doctor will discuss with you. This can include removing the stent and seeing if the stone passes successfully through your now dilated ureter, performing ureteroscopy to remove the stone, or performing shockwave lithotripsy to treat the stone.

  2. melissa says:

    I go to a highly respected urologist, but I always know if i have a larger than 5mm stone due to pain. I had a 9mm nonobstructing and I doubled over in pain, thinking my appendix burst. I had a 5mm instructing and my pcp told me i had a uti for 2 months, then I had to have surgery due to lodged stone, backed up urine, and infection. Now I have a 6mm nonobstructing and I went in with that and an infection. I knew it was there, I have pain.

    My highly respected urologist says it’s impossible to have pain with a stone in the kidney if it’s non obstructing, so he can’t explain my pain. I can. I only have pain if there’s a stone. The question is why, if It’s not possible? Also, why would one of the biggest docs in this area not have any explainations or ideas? I hear others complain of this issue. I’m not crazy.

    • Dr. Mike Nguyen says:

      Your experience is not unusual, opinions vary among urologists as to whether a non-obstructing stone can cause pain. Based on my experience in treating patients and my reading of the literature, I am of the opinion that non-obstructing stones can indeed cause pain in some but not all patients. Treating such stones can relieve pain but I usually counsel patients that their pain is not guaranteed to be resolved even if their stone is successfully removed. Each patient’s case has to be considered individually.

      Several authors over the years have described successfully treating non-obstructing “caliceal” stones suspected of causing pain resulting in pain relief among the majority of patients. These publications are listed below.

      Unfortunately, the research into this topic has not been definitive and opinions among urologists will continue to vary until conclusive research can be done. In order to perform conclusive research, an ideal randomized trial would need to be done where patients with non-obstructing stones suspected of causing pain are randomly assigned to having their stones removed (group A) or not having their stones removed (group B). Careful pain assessments would then be done to determine which group had less pain at the end of the trial. In a surgical trial like this, adequate “blinding” of the patients would necessitate bringing both groups to the operating room and having them both undergo anesthesia whether or not they were in the stone removal or non-stone removal group. Additionally, both groups A and B would need to have stents placed. This type of “sham surgery” blinding would be necessary because otherwise patients would know which group they were in and this could confuse their results. You can imagine that convincing enough patients to agree to enroll in this kind of trial would be difficult. Institutional review boards charged with protecting the rights of research participants may also argue that the risks involved of performing this type of sham surgery would be too high to justify conducting the trial.

      1) Brannen GE, Bush WH, Lewis GP. Caliceal calculi. J Urol 1986
      2) Mee SL, Thuroff JW. Small caliceal stones: is extracorporeal shock wave lithotripsy justified? J Urol 1988
      3) Coury TA, Sonda LP, Lingeman JE, Kahnoski RJ. Treatment of painful caliceal stones. Urology 1988
      4) Andersson L, Sylven M. Small renal caliceal calculi as a cause of pain. J Urol 1983
      5) Brandt B, Ostri P, Lange P, Kvist Kristensen J. Painful caliceal calculi: the treatment of small nonobstructing caliceal calculi in patients with symptoms. Scand J Urol Nephrol 1993
      6) Lee MH, Lee YH, Chen MT, Huang JK, Chang LS. Management of painful caliceal stones by extracorporeal shock wave lithotripsy. Eur Urol. 1990
      7) Gdor Y, Faddegon S, Krambeck AE, Roberts WW, Faerber GJ, Teichman JM, Lingeman JE, Wolf JS Jr. Multi-institutional assessment of ureteroscopic laser papillotomy for chronic flank pain associated with papillary calcifications. J Urol. 2011

  3. cecilia says:

    i have a stent that was placed two months ago i dont have the money to get it removed how long can i have it before it cause any damage

    • KidneyStoners.org says:

      Most stents should only remain in for up to three months before being removed or replaced.

  4. Debra says:

    I had an x-ray taken last week and it showed ~6mm kidney stone. Went for my Lithotripsy this morning and it did not show up on today’s x-ray. I am still having pain in my left flank area and pretty sure I did not pass it. I would think if would have been painful. I am getting a CT scan in the morning. Is is normal for a stone to show up and then not? Still having pain and no pain as if I passed it. Can the stone be “hiding” that an x-ray is did not detect it?

    • KidneyStoners.org says:

      Some stones are not visible on a plain x-ray but if your stone was visible on a prior plain x-ray we would expect it to be visible on a repeat x-ray. However, bowel gas or your body’s bones can hide a stone on an x-ray image, especially if the stone has moved into another location.

      CT scans however are very accurate for detecting stones and should be able to resolve the issue.

Comments are closed.