Excruciating Unbearable The worst pain imaginable. That's the way patients often describe the symptoms of kidney stones, a problem diagnosed and treated in more than a million men and women each year.

“Stones that form in the kidney are one of the most painful disorders to afflict human beings,” said Duke Herrell, M.D., assistant professor of urology. Herrell specializes in urinary tract stone disease and endourology—the use of scopes, lasers and minimally invasive devices. He helped develop MUSC's Kidney Stone Center, which concentrates on the diagnosis, treatment and prevention of stone disease. MUSC's stone treatment program has expanded into one of the state's most comprehensive.

Recently, Herrell and his colleagues employed a powerful and accurate laser, called Holmium, to destroy kidney stones. Although similar systems are available in other settings, MUSC's recently constructed endourology and laser suite houses the most powerful and accurate technology available in the area.

Kidney stones occur when calcium or other urinary substances collect and crystallize. A stone can become lodged in the kidney or ureter, and pain occurs as it's squeezed along the too-narrow path on its way to the bladder and uretha. Signs of kidney stone irritation and blockage include sharp pain or cramping in the area of the kidney, back or side, nausea or vomiting, burning or blood with urination, or the need to urinate frequently. Diagnosis is usually made with ultrasound or X-ray technology, and important information about the stone's size, shape, location and composition is obtained.

“The art of helping people with kidney stones is in finding the right option for each person and helping them choose,” Herrell said. “If a stone is under 5 millimeters, it will usually pass on its own with fluids and pain medications. Larger, painful or impacted stones often need treatment. Luckily, a variety of treatment options can be considered, and we offer all of them here.”

For stones that do not pass on their own, surgical removal of some type is necessary. Extracorporeal shockwave lithotripsy is one of the most frequently used procedures. Shockwaves from outside the body are directed toward the stone with the hope that it will break apart into small sand-like particles and pass through the urinary tract.

Unfortunately, stones present in the lower part of the kidney may not pass even after lithotripsy. When a stone is too dense, large or in a location that doesn't allow use of extracorporeal shockwave lithotripsy, endourologic procedures are considered.

The use of small scopes and the laser passed up through the urinary tract without incisions—called ureteroscopy—has been mostly used when other treatments have failed to break apart or dislodge the stone. But increased use of the Holmium laser has lead Herrell to consider it as a first line of treatment. “Because the scope has become flexible and smaller, the use of the laser through the urinary tract offers us a highly effective option that's easier on the patient. In the past, laser was used to follow a failed lithotripsy treatment. Now we're seeing the advantages to using it first. We're able to treat stones even in the lower part of the kidney using the flexible scopes and laser fibers.”

For some extremely large kidney stones, a small tunnel directly into the kidney through the patient's back—called percutaneous lithotripsy—may be necessary. The tunnel, which allows small scopes and instruments to directly treat and remove the stone, has replaced the large incisions and operations of the past.

Herrell is also involved in patient follow-up and counseling. “The recurrence rate of stones is high,” he said. “That's why it's important to offer guidelines for prevention. Once patients have been treated for kidney stones, it's important to help them cut the risk factors.”

If a stone is passed or removed, laboratory tests can determine the composition. That information can help patients alter diet, fluid intake and lifestyle factors that can help prevent recurrence. Medicines can also be prescribed to help control the development of stones by regulating the buildup of certain elements in the urine.

Reasons for kidney stones are not always known.

They may result from: q an abnormal kidney

• too little water intake or dehydration
• dietary problems like eating too much calcium, salt or protein

The most noticeable symptom of a kidney stone being passed is excruciating pain that begins in the lower back, and moves to the abdomen and down toward the groin. Other symptoms of a kidney stone may include:

• nausea
• vomiting
• blood in the urine
• frequent urination
• A stone is passed from the body during urination and may resemble gravel or sand.

The cause of kidney stones vary widely. Consult your doctor before making any dietary changes.

Editor's note: The article is reprinted from Checkup newsletter, produced by MUSC Creative Services.