USC News

Menu Search


Fernando Godinez had never endured such a jolt of pain in his life.

“It was so bad, I got physically sick. I didn’t want to do anything but go see a doctor,” says the 59-year-old Godinez.

The cause of his pain was a common one: kidney stones. Affecting as many as 720,000 Americans annually, kidney stones are nuggets of accumulated calcium than can block the ureter and cause painful swelling of the kidneys. Left untreated, the stones can cause renal failure and death.

Jeffry Huffman, M.D., professor of urology and CEO of USC Care Medical Group, Inc., says the good news is that stones are usually easy to treat with a technique known as lithotripsy.

Greek for “to fragment a stone,” lithotripsy uses powerful, focused pressure waves to smash kidney stones without harming the body. The sand-like granules of stone are then passed from the body during urination.

Introduced in the U.S. in 1984, lithotripsy provided a revolutionary treatment for kidney stones that all but eliminated the need for surgery, Huffman says.

Early versions of the device included a large, water-filled tub in which the patient remained during treatment, but later versions required no immersion. In 1987, USC began operating the second “dry” lithotriptor in the U.S. Both versions are effective and in common use today, although the dry version causes less discomfort and, as a result, requires less anesthesia.

The lithotripsy device looks similar to an X-ray machine. During the procedure, the patient lies face up on a table above the cylindrical shock wave tube. The tube, which is about eight inches in diameter, is placed against the patient’s body. The tube is capped with a collapsible, accordion-like plastic membrane that is placed in contact with the patient’s back to deliver the shock waves. After the patient is properly positioned, the physician guides the procedure from a console inside the same room.

“You target the kidney stone using fluoroscopy, which uses X-ray to project the stone’s shadow on a screen. Treatment consists of about two shock waves each second for up to 30 minutes. It feels like a hard finger flick against your back. It is tolerable, but starts to ache after a few minutes,” which is partly why patients receive mild anesthesia, Huffman says.

Side effects that patients may experience include some bruising or discomfort on the back or abdomen from the procedure, and traces of blood may be found in the urine for a few days. Some patients experience pain when passing the stone fragments, which are usually expelled from the body within a few days, Huffman says.

Lithotripsy candidates are screened for their body size, stone size, stone composition and location. About 80 percent of all kidney stone patients can be treated successfully with lithotripsy. More than 95 percent of treatments on patients with stones less than one centimeter in diameter-slightly smaller than a marble-are typically successful.

Some patients cannot undergo lithotripsy, including those who are pregnant, suffering from urinary infections or are morbidly obese. The shock waves can harm a fetus and encourage the spread of infections. People who weigh more than 350 pounds are too big for the table on which the procedure is performed.

Lithotripsy offers vast improvements over surgery. It is non-invasive, requires less anesthesia and has fewer side effects and complications.

It also permits the patient to return to work within two days and costs about one-fifth as much as surgery. Fewer than one percent of all kidney stones require surgery, Huffman says.

Because lithotripsy is still relatively unknown to the public, some patients approach the procedure with trepidation. “But afterwards, they’re always surprised that it was so simple,” Huffman says.

Anyone can get kidney stones, although they are most common in males and young adults, Huffman says. Once a person gets more than one stone, others are likely to develop. About half of all patients with kidney stones have some defect in the way their body processes calcium, although many can be helped with medication or dietary changes, Huffman says.

Kidney stones develop when crystals separate from urine and build up on the inner surfaces of the kidney. Normally, urine contains chemicals that prevent or inhibit the crystals from forming, but when those inhibitors fail, some people form stones. If the crystals remain small enough, they often travel through the urinary tract and pass out of the body in urine without being noticed.

The symptoms of large kidney stones vary, but generally the first symptom of a kidney stone is the sudden onset of severe pain in the back or side that is not relieved by changing positions.

If the stone is too large to pass easily, the pain continues as the muscles in the wall of the ureter try to squeeze the stone along into the bladder. As a stone grows or moves, blood may be found in the urine. As the stone moves down the ureter closer to the bladder, a person may feel the need to urinate more often or feel a burning sensation during urination.

If fever and chills accompany any of these symptoms, an infection may be present. In this case, a doctor should be contacted immediately.

To lessen the chances of suffering a kidney stone, Huffman recommends drinking eight to 10 eight-ounce glasses of water a day, about double what the average person is likely to consume. Water is best because other fluids such as coffee and sodas are diuretics and eliminate fluid from the body.

Still, when prevention efforts fail and a stone requires medical intervention, patients like Fernando Godinez are relieved to know that lithotripsy offers a quick, effective path back to health.

Godinez praises the procedure and says the best part was that “the pain from the stones stopped right away, and that made me very happy.”

Top stories on USC News