ACR Codes: 8.2
Classic symptoms include renal colic and hematuria while other less typical symptoms include vague abdominal pain, acute abdominal or flank pain, nausea, urinary urgency or frequency, difficulty urinating, penile pain, or testicular pain.
Eighty percent of kidney stones are comprised of a calcium precipitate, primarily calcium oxalate or less frequently calcium phosphate. These stones are radio-opaque and can therefore be seen on x-ray or CT imaging w/o contrast as the contrast would obscure the stone). Other compositions include uric acid, struvite (magnesium ammonium phosphate), and cystine stones with the only other radio-opaque stone being struvite. Pathogenesis of calcium stones is under some debate, however, it is agreed that once crystal formation begins progression into a large stone tends to take a relatively long time (months to years). Struvite stones are often a complication of recurrent or chronic kidney infection. Uric acid and cystine stones are generally due to an excess of those components in the blood either due to metabolic errors or excessive intake of foods that have those components.
Most stones ŠˇŠ¬4 mm in diameter pass spontaneously. Renal stones larger than 4 mm in diameter are less llikely to pass spontaneously. It is is unlikely that stones ŠˇŠ10 mm in diameter will pass.. Proximal ureteral stones are also less likely to pass spontaneously. Stones greater than 10mm in size will need some sort of intervention in greater than 95% of case. The complication of nephrolithiasis in untreated cases which is most severe is obstruction with permanent renal damage.
Reference(s): 1. Johnson, CM, Wilson, DM, O'Fallon, WM, et al. Renal stone epidemiology: A 25-year study in Rochester, Minnesota. Kidney Int 1979; 16:624.
2. Coe, FL, Parks, JH, Asplin, JR. The pathogenesis and treatment of kidney stones. N Engl J Med 1992; 327:1141.
3. Teichman, JM. Clinical practice. Acute renal colic from ureteral calculus. N Engl J Med 2004; 350:684.