Definition & Overview

There are different ways to remove or destroy kidney stones. One of them uses ultrasonic energy or high-frequency sound. This kidney stone remedy can be performed in two ways: first, the ultrasonic probe is inserted into the kidney to deliver high-pressure waves directly to the stone to destroy it. The other method is known as extracorporeal shock wave lithotripsy. The ultrasound or pressure wave is delivered from outside the body to break the kidney stones into small pieces. Most doctors today prefer the second method since it is non-invasive, but there are cases in which inserting a probe would prove to be more beneficial.

The kidneys are a pair of organs within the retroperitoneal space in the abdominal cavity. Their functions include:

  • Regulate electrolyte balance in the blood

  • Remove waste products resulting from metabolism

  • Contribute to maintaining the acidic and basic balance of the body

  • Secrete urea and ammonium through the passing of urine

  • Produce several hormones that are important for bodily functions, such as calcitriol that regulates calcium in the body and erythropoietin that controls the production of red blood cells. Renin, an enzyme also produced in the kidney, is involved in the regulation of the body’s mean arterial blood pressure.

What Causes Kidney Stones

Causes of kidney stone include the increased presence of mineral and acid salts inside the kidney could lead to the formation of small mineral deposits known as kidney stones, sometimes called renal calculi. One of the most common kidney stones causes is the concentration of urine that allows these minerals to bond together and harden. Kidney stones are classified according to their composition.

  • Calcium stones, which are mostly composed of calcium oxalate

  • Struvite stones, which typically form after urinary tract infections

  • Uric acid stones, which affect those who have gout

  • Cysteine stones, which are made up of certain amino acids

Early intervention for this condition includes drinking a large amount of water to help these stones pass through the urinary tract naturally and be excreted with the urine.

Treatment for Kidney Stones: Who Should Undergo and Expected Results

Kidney stone treatment using ultrasonic destruction is typically recommended for the treatment of kidney stones in men and women. It is considered when the condition can no longer be managed using conservative methods and if the stones have already blocked urine flow, resulting in the following symptoms:

  • Severe pain in the flank that travels to the abdomen and the groin area

  • Kidney stone pain during urination

  • Blood in urine

  • Nausea and vomiting

  • Fever

The ultrasonic destruction of kidney stones is a relatively simple and safe procedure. If the noninvasive procedure is performed, the patient gets to go home afterwards. The procedure lasts for about an hour. Meanwhile, patients who undergo the procedure that involves inserting an ultrasonic probe might need to stay in the hospital overnight. The expected outcome of these procedures is the passage and removal of fragmented stones through urination. In cases where the kidney stones are larger, the patient may need to undergo the same procedure several times until complete kidney stone removal is achieved.

How is the Procedure Performed?

If the procedure involves the insertion of an ultrasonic probe, the patient is asked to lie down on a water-filled cushion, positioning the body to easily target the stones. Anaesthesia is administered and the injection site is cleansed. The surgeon makes a small puncture below the rib area where a needle catheter is inserted. It is advanced until it reaches the area where the stones are located. To track the needle throughout the procedure, a fluorescent agent is also administered. A guide wire is then inserted through the catheter and guided into position. Another catheter is guided down into the ureter. Any stone lodged in the ureter may be pushed back into the renal pelvis. A nephroscope is also inserted to allow viewing and imaging. The nephroscope also allows the entry of the ultrasonic probe, which is then positioned against the stone. Once contact is made, ultrasonic energy is generated and it travels to the tip of the probe. The kidney stone absorbs the energy and gets fragmented into smaller pieces. Using irrigation and suction, these fragments are removed through the hollow probe. Once destruction of the stone is complete, the surgeon withdraws the nephroscope. The surgeon may perform another fluoroscopy to determine if proper drainage in the ureter has been achieved.

The second method also requires the patient to be sedated and placed on a water-filled cushion. A fluoroscopic x-ray system and fluorescent agent are used to locate the kidney stones. Once the stone is located, a focused shock wave is emitted from the machine known as a lithotriptor. The pulses are emitted at a slow rate and released several times until the shock waves fragment the stone into powder.

Possible Risks and Complications

The ultrasonic destruction of kidney stones is a safe procedure. However, there are certain minor risks and possible complications. These include:

  • Bleeding and infection among patients who undergo the invasive method

  • Pain, which is a common complaint among patients, especially during the first few days when the fragmented stones are voided

  • Adverse reaction to anaesthesia and staining agent

  • Rupture of the renal pelvis

  • Excessive bleeding following the external application of shock waves

  • Damage to the capillaries and interior parts of the kidney

  • Liou LS, Streem SB (2001). "Long-term renal functional effects of shock wave lithotripsy, percutaneous nephrolithotomy and combination therapy: a comparative study of patients with solitary kidney". J Urol. 166 (1): 36. doi:10.1097/00005392-200107000-00008.

  • Macaluso JN, Thomas R (1991). "Extracorporeal shock wave lithotripsy: an outpatient procedure". The Journal of Urology. 146 (3): 714–7.

  • Macaluso JN (1996). "Management of stone disease—bearing the burden". The Journal of Urology. 156 (5): 1579–80. doi:10.1016/s0022-5347(01)65452-1.

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