Stone removal
Stone removal refers to medical procedures aimed at eliminating stones, or calculi, that form in the urinary tract or gallbladder. Urinary tract stones can develop in the kidneys, ureters, or bladder, often composed primarily of calcium oxalate, while infective stones can arise in patients with chronic urinary infections. Symptoms may vary depending on the stone's location, with renal colic presenting as sharp pain from the back to the groin. Diagnosis typically involves urine tests, imaging like X-rays or ultrasounds, and potentially blood tests for metabolic disorders. Small stones may be managed conservatively, but larger or problematic stones often necessitate surgical intervention, using tools such as cystoscopes or ureterorenoscopes to visualize and fragment the stones. In the case of gallstones, while many asymptomatic stones may not require treatment, symptomatic cases may lead to cholecystectomy, the surgical removal of the gallbladder. Advances in technology, such as lithotripsy, offer noninvasive options for breaking down both urinary and gallstones using sound waves. Overall, while complications can arise from these procedures, they are generally performed successfully with favorable outcomes for the majority of patients.
Stone removal
Anatomy or system affected: Abdomen, bladder, gallbladder, kidneys, urinary system
Definition: An operation that extracts solidified substances (stones) from an organ; typically, these stones block the organ’s ability to release fluid.
Indications and Procedures
Urinary tract stones can occur in the kidneys, ureters, or urinary bladder. These stones, or calculi, are caused by substances that precipitate in the urine. The most common substance that solidifies in the urine is calcium oxalate. Stones referred to as infective, however, are present in about 20 percent of patients with urinary tract stones. These stones typically occur in patients with chronic urinary tract infections. Bacteria in the urinary tract produce ammonia, which combines with calcium or magnesium. Infective stones have the potential to block large areas of the urinary tract.
Patients with urinary tract calculi may experience a variety of symptoms depending on where the stones are located. If a stone is in the ureter, then a sharp pain that extends from the middle of the back to the groin is felt; this pain is called renal colic. Bladder stones are usually not as painful, but they may obstruct the flow of urine from the urinary bladder.
The patient’s physician will have the urine examined for the presence of blood (hematuria) and crystals. X-rays and/or ultrasound will show the location of the stone. Blood tests may or may not be ordered depending on whether a metabolic disorder is suspected. Hypercalcemia and hyperparathyroidism can be detected by a blood test; both indicate a problem of excess calcium.
If the urinary tract stone is relatively small, the renal colic is treated with bed rest and an analgesic, along with adequate fluid intake to promote passing of the stone. Larger stones, infective stones, or severe obstruction of urinary flow require surgery to remove the stone. The patient is usually under general anesthesia and has a small surgical scope (a cystoscope for the bladder or a ureterorenoscope for the ureter) passed up the urethra. These scopes give the surgeon the ability to visualize and crush the stones with attachments on the instruments.
The gallbladder, which stores and concentrates bile, also has the potential for stone formation. Gallstones are usually composed of cholesterol and may be found in the ducts that connect the gallbladder to the small intestine or liver. If a stone has obstructed one of these ducts, the resulting symptoms can include intense pain known as biliary colic. This pain is usually felt in the upper right side of the abdomen or between the shoulder blades.
Ultrasound scanning of the upper abdomen can almost always detect the presence of gallstones. If the gallstones do not cause symptoms, they may be left alone, or drugs, such as chenodiol and ursodeoxycholic acid, may be tried to dissolve them. When symptoms are severe, removal of the gallbladder (cholecystectomy) is indicated. This surgery involves an incision under the ribcage on the right side. A laparoscope may be used or a larger incision made for an open procedure. In either case, the liver is gently lifted to expose the gallbladder, and the blood vessels and cystic duct are tied off so that blood and bile do not leak from the excised organ. The wound is then closed, and the patient may return home within a week.
Uses and Complications
Complications from removing urinary tract stones include infections, scarring, bleeding, and anesthesia risks. These complications are rare when the operation is performed by a competent surgical team. An uncommon but significant adverse result from obstruction relief is an excessive amount of urine loss, sometimes greater than 10 liters per day, which places the patient at risk for dehydration. Reducing fluid intake helps the kidney return to normal function slowly. Occasionally, this complication does not resolve. If the obstruction is not removed, however, the patient is at risk for developing chronic urinary tract infections and even renal failure.
The major risk in performing cholecystectomy is damage to the bile duct that leads to the small intestine. If scarring or inflammation occurs in this duct, it may lead to obstruction of the flow of bile from the liver. This, in turn, may lead to obstructive jaundice, in which pigments normally released into the intestines accumulate in the liver and blood. The patient may have a yellowish tinge to the skin and eyes until the obstruction is corrected.
If there are no complications during the cholecystectomy, then the outcome of the surgery is usually good. Approximately 90 percent of the patients have no further symptoms and recover completely in about three weeks.
Perspective and Prospects
Advances in medical technology have aided physicians in the removal of stones. Kidney and urethral stones can be broken up using a technique called lithotripsy. An ultrasonic lithotripsy probe can break the stones using externally applied sound waves that penetrate the skin and other soft tissues. For some patients, a noninvasive technique takes advantage of sound waves transmitted through the abdominal cavity and directed at the stones. This procedure is known as extracorporeal shock-wave lithotripsy. The latter technique is also used to treat some patients with gallstones.
Bibliography
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Parker, James N., and Philip M. Parker, eds. The Official Patient’s Sourcebook on Kidney Stones. ICON Group, 2007.
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