Kidney Stones

Treatment

Mayo Clinic specialists evaluate each patient to determine the most effective kidney stone treatment, based on the type, size, location and cause of a kidney stone. They also recommend measures to prevent future stone formation. Because most kidney stones are small enough to pass through the urinary tract on their own, watchful waiting is the most common treatment.

Mayo Clinic urologists rely on several minimally invasive procedures to remove kidney stones that are too large to pass naturally. For example, Mayo urologists have extensive experience in researching and performing percutaneous nephrolithotomy, an especially effective procedure for treating large kidney stones.

Watchful waiting

About 85 percent of the time, kidney stones are small enough to pass during urination. This occurs usually within 72 hours of the start of symptoms. The best treatment for these small stones is to drink plenty of water (as much as 2 to 3 quarts per day), stay physically active and wait to pass the stone. Doctors may prescribe painkillers to help alleviate discomfort associated with passing a stone. They may also prescribe medicine to relax the ureter and facilitate the passage of the stone.

If it seems likely that a patient can pass a stone without medical treatment, the physician may ask the patient to urinate through a strainer, so the stone can be retrieved and analyzed for its mineral composition. Urologists use this information to better tailor follow-up treatment and suggest preventive measures.

Watchful waiting is not used for patients who have a fever, urinary tract infection, pain that cannot be controlled by pain medication, or persistent nausea and vomiting.

Surgery

Surgical treatment may be necessary for kidney stones too large to pass naturally or that may cause bleeding, kidney damage or ongoing urinary tract infections.

Minimally invasive surgical treatments

• Extracorporeal shock wave lithotripsy (SWL)
  Extracorporeal shock wave lithotripsy uses shock waves to break kidney stones into tiny pieces that are then passed in the urine. Physicians often use this procedure to remove stones about 1 centimeter in size or smaller. Mayo Clinic was among the first medical centers in the United States to use shock waves for kidney stone treatment.

  During SWL, patients are either submerged in water or lie on a cushion. Patients receive sedatives, local or general anesthesia to alleviate pain. The shock waves pass through the body until they hit the kidney stones, causing the stones to break apart. The procedure usually takes 45 to 60 minutes. The sand-like particles that remain afterward are easily passed in the urine.

  Side effects can include blood in the urine for a short time after the procedure and minor bruising on the back or abdomen. Some patients may experience discomfort as the stone fragments pass through the urinary tract. Some stones are resistant to shock wave treatment, and patients may require additional treatment if the stone does not shatter completely. There have been reports of possible risks of increased blood pressure or diabetes associated with SWL treatment, but other reports have refuted this information.

  Most patients resume normal activity in a few days. It may take several months for all stone fragments to pass.

• Percutaneous nephrolithotomy
  Percutaneous nephrolithotomy (PNL) is an option when shock wave lithotripsy is not effective or if the kidney stone is too large for extracorporeal shock wave lithotripsy to effectively treat. Mayo Clinic is a leading institution in PNL research and practice.

  Patients undergoing PNL receive general anesthesia. Urologic surgeons perform PNL through a small incision in the back and into the kidney, using an instrument called a nephroscope to break up and extract the stones. Urologists attempt to remove all the stone fragments through the nephroscope during the procedure, leaving none to pass through the urinary tract. Patients usually stay in the hospital for one to two days following PNL, with additional recovery time lasting one to two weeks.

  Mayo Clinic physicians developed many of the tools used during PNL. Mayo physicians also were the first to publish the results of 1,000 patients who underwent PNL.

  Over the past three decades, thousands of patients with kidney stones have been treated at Mayo using PNL. Mayo physicians often recommend this procedure for people who need to be stone-free either for health or professional reasons. For example, patients in professions where sudden pain due to passing stone fragments would endanger the person and others (mass transit workers, for example) require the complete removal of all stone pieces.

• Ureteroscopic stone removal
  Urologists perform ureteroscopic stone removal to remove stones lodged in the ureter or in the kidney. Patients undergo this outpatient procedure while sedated with general or local anesthesia. A urologic surgeon passes a small ureteroscope into the urethra, through the bladder into the ureter to break up and snare the stone. In some cases, stones are shattered using a laser. Fragments may be passed by the patient or they may be extracted. The surgeon may place a small tube (stent) in the ureter to relieve swelling and promote healing.

  Mayo Clinic urologists were among the first in the world to perform ureteroscopic stone removal and were also instrumental in refining and improving the procedure.

Parathyroid surgery

Some calcium stones are caused by overactive parathyroid glands — four small endocrine glands located behind the thyroid gland that are responsible for the amount of calcium in the blood and bones. A small benign growth in one of the parathyroid glands can cause the glands to become overactive, raising the body's calcium level, which can lead to kidney stone formation. Removing the growth from the gland stops the formation of kidney stones. General surgeons, rather than urologists, perform parathyroid surgery.