Substances in the urine (calcium, oxalate, phosphate, and uric acid, in particular) can crystallize within the kidney and form rock-like particles (calculi) called stones. The medical term for this condition is nephrolithiasis or renal stone disease. Kidney stones may be as small as a grain of sand or larger than a golf ball. They may be smooth, round, jagged, spiky, or asymmetrical depending on their composition. Most stones are yellowish to brownish-black in color, but variations in chemical composition can produce stones that are tan, gold, or black.
Diagnosis & Treatment
Large or Complicated Stones
If your stone is too large to pass, blocking the flow of urine or causing other complications, your doctor may recommend one of these treatments.
Larger stones in the kidneys can usually be treated with a procedure called lithotripsy. This is a way to break up the stone in the kidney without making any incisions or utilizing any scopes. In an outpatient surgery center, your urologist uses a machine called a lithotriper to direct ultrasonic shock waves to hit the stone repeatedly until it crumbles into small particles that you an pass in your urine. This is the most frequently used procedure for eliminating kidney stones.
A small stone in the ureter (thin tube connecting the kidney to the bladder) can be treated with a procedure called ureteroscopy if it does not pass on its own. In this procedure, your urologist passes a flexible tube with a camera through your urethra. A wisk-like basket on the end of the scope snares the stone and removes it. If the stone is too large, the urologist can use a laser inserted through the scope to break the stone apart. After a ureteroscopy, the urologist places a stent in the ureter to hold it open until the swelling subsides. The stent is removed a day later.
Percutaneous Nephrolithotomy/Stone Extraction
For large stones that can’t be effectively treated with lithotripsy or ureteroscopy, your urologist can perform a minimally-invasive surgery through a 1 centimeter incision in your back. Using a scope and special tools, the urologist can break apart the stone and suction it out. Typically requires hospitalization at least overnight.