Kidney Stones

Renal calculi also called Kidney stones:  Kidney stones may form anywhere in the urinary tract but usually develop in the renal pelvis or calyces.  Such formation follows precipitation of substances normally dissolved in the urine ( calcium oxalate, calcium phosphate, magnesium ammonium phosphate, or, occasionally, urate or cystine ).  The causes are unknown, risk factors include: 

 * Dehydration - decreased urine production concentrates calculus - forming substances. 

 * Infection - damage and infected tissue serves as a site for calculus development; pH changes provide a favorable medium for calculus formation (especially for magnesium ammonium phosphate or calcium phosphate calculi ); or infected calculi (such as; magnesium ammonium phosphate or staghorn calculi ) may develop if bacteria serve as the nucleus in calculus formation.  Such infections may promote destruction of renal parenchyma ( functional elements of an organ ).

 * Obstruction - Urine stasis ( as in immobility from spinal cord injury ) allows calculus constituents to collect and adhere, forming calculi.  Obstruction also promotes infection, which in turn, compounds the obstruction.

 * Metabolic factors - Hyperparathyroidism, renal tubular acidosis, elevated uric acid levels (usually with gout ), defective metabolism of oxalate, genetically defective metabolism of cystine, and excessive intake of vitamin D or dietary calcium may predispose to renal calculi.

Kidney stones or renal calculi vary in size and may be solitary or multiple.  They may remain in the renal pelvis or enter the ureter and may damage renal parenchyma.  Large calculi cause pressure necrosis, and may cause obstruction depending on location.

Symptoms:

Symptoms varies with size, location, and cause of the calculus.
Pain - the pain of classic renal colic travels from the costovertebral angle to the flank, the supra pubic region, and the external genitalia.  The pain fluctuates in intensity and may be excruciating at its peak.  If the stone or calculi are in the renal pelvis and calyces, pain may be more constant and dull.  Back pain occurs from calculi that produce and obstruction within a kidney.  Nausea and vomiting usually accompany severe pain.  Patient may have abdominal distention, fever and chills, with possibly hematuria (blood in urine), pyuria (pus in the urine), and rarely, anuria (suppression of urine).

Treatment:

Because 90% of renal calculi are smaller than 5 mm in diameter, treatment usually consists of measures to promote their natural passage.  Along with increase, vigorous hydration, such treatment includes antimicrobial therapy for the infection, varying with the cultured organism.  Your doctor may prescribed an analgesics for pain, and diuretics to prevent urine stasis and further calculus formation.  Prophylaxis to prevent calculus formation includes; a low calcium diet , and daily intake of ascorbic acid to acidify the urine.

Stones (calculi) too large for natural passage may require surgical removal. When calculus in in the ureter, a cystoscope may be inserted through the urethra and the calculus manipulated with catheters or retrieval instruments.  Extraction of calculi from other areas may necessitate a flank or lower abdominal approach.  Percutaneous ultrasonic lithotripsy and extracorporeal shock wave lithotripsy shatter the calculus into fragments for removal by suction or natural passage.

Latest Article: Kidney Stones

Renal calculi also called Kidney stones:   Kidney stones may form anywhere in the urinary tract but usually develop in the renal pelvis or calyces.  Such formation follows precipitation of substances normally dissolved in the urine ( calcium oxalate, calcium phosphate, magnesium ammonium phosphate, or, occasionally, urate or cystine ).  The causes are unknown, risk...

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