Kidney Stones

What are the signs of a kidney stone?

A lot of patients may have kidney stones and not even know it. Kidney stones typically become symptomatic for patients when they are passing through the ureter, and become obstructed. These can cause flank pain, blood in the urine, and changes in your urination.

Why do I get kidney stones?

As many as 10% of the population will get kidney stones in their lifetime, and 50% of patients will have another stone within 10 years. Patients can get kidney stones for a variety of reasons which include a family history of kidney stones, not drinking enough water, a diet which predisposes to kidney stones, and infections.

What can I do to prevent kidney stones?

There are numerous things which can be done to help prevent stone disease. In general, kidney stone patients are recommended to drink a lot of water (to make at least 2.5 liters urine/day), and to limit dietary consumption of salty foods, animal protein, and oxalate. Although a lot of stones are composed of calcium, a diet with typical consumption of calcium is still recommended. After a patient has a stone episode, they may be recommended to undergo a 24-hour urine collection, which can help determine which metabolic abnormalities may be responsible for their stone disease. Based on this analysis as well as the composition of their kidney stones, there are several medications which can be prescribed to safely prevent future stone episodes. These include thiazide diuretics, potassium citrate, allopurinol, amongst others.

When is it safe to pass a kidney stone?

If a kidney stone is passing through the ureter, a trial of passage may be an option. During a trial of passage, you are typically given between 1-2 weeks to pass the stone on your own, prior to being recommended to undergo a procedure to remove the stone. You may be a candidate to pass the stone on your own if your pain is controlled with oral medications, if your stone size is less than 1 cm, if you don’t have an infection, and if your labs are normal.

What kind of procedures can treat kidney stones?

There are several different procedures to treat stones, which largely depend on the size and location of the kidney stones. These are all typically done under anesthesia. Shockwave lithotripsy (ESWL) is the least invasive of the options, and uses ultrasound waves to break up the stones into several smaller fragments which the patient will pass on their own in the coming weeks to months. No incision is required for this procedure. It is however better suited for smaller stones (<2 cm), which can be seen on x-ray, and are less dense (<1000 Hounsfield units on CT).

Ureteroscopy is the most common procedure used to treat kidney stones. Just as in ESWL, no incisions are used, however a small camera is inserted through the urethra to eventually access the stone. If the stone is too large to be removed en tact, a laser is used to break the stone up into smaller pieces, which are subsequently removed. A ureteral stent is then left in place for a period of a few days to two weeks to help the ureter heal.

Percutaneous nephrolithotomy (PCNL) is the most invasive of the procedures, and is reserved for patients with large stones also known as staghorn calculi. Prior to this procedure, a tube is placed in the back to drain the kidney. During the surgery, the tube is used to access the kidney and use a larger camera to remove the stones with a lithotripter device. PCNL offers the highest stone clearance rates for large kidney stones amongst the different surgical options.