Surgery Usually Not Needed to Treat Kidney Stones

You have excruciating pain in your back or side that brings you to your knees. It is a kidney stone, and it's clear that it's stuck. What can be done? Most kidney stones pass out through the urine after a day or two, says Jeffry Huffman, M.D., urologist at the University of Southern California (USC).

But pain is so agonizing, these patients often end up in emergency rooms. Patients should see a doctor to be monitored, get help with pain until the stone passes and make sure no infection is present. Kidney stones form when certain natural chemicals in urine, such as calcium, crystallize and clump together.

They usually form in the center of the kidney, on the ends of tiny collecting tubes. These tubes lead down into the ureter, the larger tube that drains urine to the bladder. Stones more than 5 mm across can get stuck in the ureter as they move toward the bladder, and are too big to pass on their own, Huffman says.

Two to three people of every 10 with kidney stones have this problem.

"The good news is that there are excellent treatments available," he says. Most people can undergo lithotripsy, a non-invasive surgical procedure. Urologists usually do these procedures in outpatient centers. They use an x-ray to help locate the stone and then fire high-frequency sound waves at it, pulverizing the stone. The small particles then pass through urine.

One of every five people who need treatment for large stones can't be helped by lithotripsy, though. Those patients opt for a urologic endoscopy. In this procedure, a physician snakes an endoscope, or very thin tube with a light and miniature camera equipment, up through the urethra and bladder, or through a small perforation in the skin directly to the kidney.

Urologists then see the stone on a monitor and use a tiny claw device to grab it, detach it and remove it. "With the new options," Huffman says, "open surgery is very uncommon now." After a stone passes or doctors remove it, the doctors may analyze it to understand its cause.

They may also analyze blood and urine to look for abnormalities in metabolism, leading to recommendations on diet and medications to try to deter stones from forming in the future.