Kidney stones are solid formations of minerals and salts that develop within the kidneys. While many stones pass without issue, an “obstructed” kidney stone is a serious medical concern. This occurs when a stone blocks the flow of urine, requiring prompt medical attention.
What an Obstructed Kidney Stone Is
An obstructed kidney stone refers to a stone that has moved from the kidney and become lodged in the urinary tract, most commonly in the ureter, the tube connecting the kidney to the bladder. This blockage prevents urine from draining normally from the kidney, causing a buildup of pressure within the kidney. This condition, known as hydronephrosis, can lead to swelling of the kidney. If left unaddressed, the obstruction can impair kidney function and increase the risk of severe infection, potentially leading to kidney damage or acute kidney injury.
Recognizing the Symptoms
An obstructed kidney stone causes sudden and intense pain, frequently described as renal colic. This severe pain originates in the flank, the area between the lower ribs and the hip, and can radiate to the lower abdomen and groin. The pain often comes in waves, intensifying and subsiding as the body attempts to dislodge the stone.
Individuals may also experience nausea and vomiting. Blood in the urine is a common symptom, resulting from the stone irritating the urinary tract lining. Should an infection develop behind the obstruction, symptoms like fever, chills, and cloudy or foul-smelling urine may occur.
How Obstructed Kidney Stones Are Diagnosed
Diagnosing an obstructed kidney stone typically begins with a physical examination and a review of the patient’s medical history. This initial assessment guides further diagnostic steps to confirm the stone’s presence and location. Urine tests are commonly performed to check for blood, signs of infection, or stone-forming crystals. Blood tests may also be conducted to assess kidney function and detect elevated levels of substances like calcium or uric acid, which can contribute to stone formation.
Imaging studies are important for visualizing the stone and the extent of the obstruction. Computed Tomography (CT) scans are a standard imaging method, providing detailed images of the urinary tract and helping to determine the stone’s size, shape, and exact location. Ultrasounds are another imaging option, particularly useful for pregnant women or children, as they do not involve radiation exposure and can show stone location and fluid buildup in the kidneys.
Treatment Options
Immediate treatment for an obstructed kidney stone focuses on relieving the obstruction and managing symptoms. A common initial procedure is the insertion of a ureteral stent, a thin, flexible tube placed in the ureter to bypass the stone and allow urine to drain from the kidney to the bladder. This helps to alleviate pressure, reduce pain, and prevent kidney damage or infection. In cases where a stent cannot be placed, or for more severe obstructions, a percutaneous nephrostomy (PCN) may be performed, which involves placing a drain directly into the kidney through the back to divert urine.
Once the immediate obstruction is addressed, various methods are employed for stone removal. Ureteroscopy involves inserting a thin, lighted scope through the urethra and bladder into the ureter to directly visualize and remove the stone, often using a basket or laser to break it into smaller pieces. Another option is extracorporeal shock wave lithotripsy (ESWL), an outpatient procedure that uses high-energy sound waves to break the stone into smaller fragments that can then pass more easily. For larger or more complex stones, percutaneous nephrolithotomy (PCNL) may be necessary, which involves a small incision in the back to directly access and remove the stone from the kidney. The specific treatment approach is tailored based on factors such as stone size, location, composition, and the patient’s overall health.