Q. A friend of mine is a T12 para. It seems about every four or five years he ends up with a major kidney stone that needs to be removed, sometimes with a high tech procedure where they zap the stone with sound waves, other times with a fairly serious sounding surgery.
He says it becomes obvious when he has a kidney stone that starts to move because he gets a massive stabbing pain in his lower back — on whichever side the kidney stone is — that sends him straight to the ER.
I’m a C6 complete quad. If I had a kidney stone, I wouldn’t be able to feel any stabbing pain in my back. Are there other symptoms that show up with a kidney stone? How can you tell if you have one? Is there a way to tell if you have one before gets to the point of needing surgery? And what would happen if you didn’t have a stone removed?
A. Kidney stones are a serious deal, and larger stones can get stuck, which can cause permanent kidney damage. A literature search shows that about 10 percent of all people will have a kidney stone in their lifetime; it also shows if you get one stone you are likely to get another.
Smaller kidney stones may pass unnoticed, and stones that are stable — in the kidney but not moving — may be symptom free. When a larger stone passes it can cause severe pain in the lower back, side or abdomen — often described as sharp, severe, intermittent pain, that doesn’t improve by changing body position — the kind of pain that will make a person race to the ER.
According to Paula Wagner, a urology nurse practitioner from U.C. Davis Medical Center in Sacramento, Calif., other symptoms of a passing kidney stone, or one that gets stuck, include blood in the urine, nausea, vomiting, and urinary tract infection. If you have a spinal cord injury, add dysreflexia and increased spasms to the symptom list.
The best way to avoid this kind of trauma is to catch a kidney stone it when it is small. If it does need to be removed, the smaller the stone, the better the options to remove it.
Wagner says U.C. Davis recommends people with SCI have a yearly ultrasound as well as a KUB — kidney, ureter and bladder X-ray — to rule out stones. The ultrasound will show small stones in the kidney, and the KUB can catch stones in the ureters — the tubes that carry urine from each kidney to the bladder.
If a kidney stone is found, the recommended treatment depends on the size and location of the stone, as well as any symptoms. Wagner says in general the largest stone that will pass through the urinary tract is about 6-7 millimeters (a millimeter is about the same thickness as the edge of a credit card). When a stone grows to a centimeter — 0.4 inch — it may get lodged in the kidney or ureter and can cause serious symptoms and damage.
Wagner says if they find a stone smaller than 6-7 millimeters and the person isn’t having any infections, and the stone isn’t blocking the kidney or causing any problems, they will recommend just monitoring it to see if it grows.
According to Wagner, the time to treat a stone is if it is growing or is larger than 7 millimeters or causing problems or in a location in the kidney where it can cause blockage.
When it comes to treating kidney stones, there are three options.
The least invasive way to treat a stone is extracorporeal shock wave lithotripsy. ESWL uses sound waves to break the kidney stone into small pieces that can pass through the urinary tract. For this procedure, you would lie on a water-filled cushion, and the stone is located with X-rays or an ultrasound. Then a machine focuses high-energy sound waves that break the stone into small pieces. The surgeon will also put in a temporary stent — a small short flexible mesh — in the ureter to hold it open so the small pieces of stone can pass through without causing problems. The stent is put in with a cystoscope — a catheter with a tiny camera on the end of it that goes in through the urethra and bladder into the ureter. The stent is removed two weeks later.
Wagner says the treatment has a 75 percent to 80 percent success rate. It’s an outpatient procedure, takes about an hour, and people can go home or even back to work when it is finished. ESWL doesn’t work on larger stones — one of the many reasons to catch stones early, when they are small.
Another treatment option is called a ureterscopy — a cystoscope that goes in through the urethra, bladder and then into the ureter and up into the kidney. On the end of the scope are tiny pincers — if the stone is small enough the surgeon grasps the stone and pulls it out.
If the stone is too big to be grasped, the surgeon will do a ureterscopy with laser lithotripsy where a laser is fed through the cystoscope and blasts the stone into smaller pieces that can be extracted or flushed out.
A ureterscopy and laser lithotripsy has a 95 percent to 99 percent success rate. Like ESWL, when the procedure is finished, a temporary stent is put in the ureter for two weeks to protect the ureter, keep it open and draining and make sure no stones get caught in it.
The third option for removing larger stones is a surgical procedure called a percutaneous nephrolithotomy. During this procedure the surgeon makes an incision on the outside of the back and into the kidney to remove the entire stone. Then the surgeon places a nephrostomy tube — tube going from the kidney out the skin on the back — to enable to kidney to drain. The nephrostomy tube is left in for 24 hours. A temporary ureteral stent is also put in place. This is a much bigger procedure than the first two, and there is a risk of needing a blood transfusion during the surgery.
Because once a person has had a stone, they are very likely to have another stone, Wagner advises talking with your urologist about doing a 24-hour metabolic evaluation. The test consists of collecting all urine for 24 hours in a single container. The urine is sent to a lab to see if the metabolic make-up gives a person a higher incidence of forming another stone. Depending on the metabolic evaluation results, a urologist may suggest taking certain types of medications to help reduce the chance of having another stone.
Wagner says people who have had a kidney stone should remember to drink enough water to make about 1500cc to 2000cc of urine in a 24-hour period, cut down on salt and eat less animal protein, including chicken and fish.
The real two keys here, as with all good bladder maintenance, is get a yearly urology check-up — preferably from a urologist versed in physical medicine and rehab — and drink plenty of water, A good rule of thumb is drink enough water to keep your urine in the clear to straw-colored range.
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