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Kidney Stone Management & Prevention
Thomas Stormont, MD
Immediate care of the patient with a kidney stone depends upon the size and location of the stone, whether there are any complicating medical conditions such as infection, the degree of blockage seen on x-ray, and how much pain is present.
Outpatient Management
For the otherwise healthy person with an acute stone <5mm in diameter, trying to pass the stone at home is appropriate. Patients are instructed to drink plenty of fluids, strain the urine to catch and save the stone for analysis, and take pain medication as needed. Tamsulosin (Flomax) is sometimes prescribed to help pass the stone. Follow-up should include an x-ray every week or so, to monitor progress of the stone. Stones larger than 5mm are unlikely to pass, and these patients should consider earlier intervention. Rarely, certain stones (uric acid) can be dissolved with medication.
Inpatient Management
High grade obstruction, as seen on x-ray, or stones >5mm should consider early intervention. High fever, uncontrollable pain, severe nausea with dehydration, diabetics and those with a single kidney should be admitted to the hospital and subsequently treated.
Surgical Treatments
- ESWL (ExtraCorporeal Shock Wave Lithotripsy) uses sound waves that is focused on the stone, breaking it into small pieces that can pass. It requires an anesthetic, but is usually an outpatient procedure. It is safe and effective for most kidney stones.
- Flexible Ureteroscopy with Laser Lithotripsy uses a thin fiberoptic scope to locate a stone, then a Holmium laser to break the stone into small enough pieces to remove with a basket or pass. An ansesthetic is need for this outpatient procedure which requires a temporary ureteral stent.
- Percutaneous Nephrolithotomy is a more invasive procedure using a small incision through the back to allow access to the inside of the kidney. It is usually only necessary for the rare, large or dense stone that is could not be successfully treated with the less invasive methods such as ESWL or laser.
Prevention
Stones recur in up to 50% within 5 years, if no preventive measures are taken. The main preventive strategy is to drink more fluids, but it may also require avoiding certain foods and/or medications.
It can be difficult to know why stones have formed, and this is why an evaluation at a stone center can be so helpful. This evaluation includes a stone analysis, dietary and medical history, and a specific metabolic evaluation that often includes special blood and urinary tests. Once a predisposing cause is found it is easier to treat with dietary counseling and if indicated, medications. The Stone Center has registered dieticians on staff to provide detailed nutrition counseling, if necessary. The following article is a general overview on the dietary prevention of most kidney stones: "Eating Right to Prevent Kidney Stones".
Frequently Asked Questions About Ureteral Stents
Thomas J. Stormont, MD
How does a kidney become obstructed and what are the effects?
The kidneys produce urine, which passes to the bladder by a thin, muscular tube called a ureter. The bladder acts as a reservoir for the urine, which eventually empties by the urethra. The most common causes of obstruction of the ureter include a kidney stone, stricture (scar), or swelling after surgery. This blockage of urine can then cause the kidney to swell, which can lead to intermittent pain, blood in the urine or infection. Rarely, over a prolonged period of blockage (weeks to months), the kidney can be damaged.
What is a ureteral stent?
Obstruction is most commonly relieved by a ureteral stent. This is a hollow, flexible, soft plastic tube that is placed in the ureter, making a channel for the urine to pass and allowing the kidneys to drain. It is necessary to have a stent in place after an operation on the kidneys or ureters to allow healing. A stent may also be necessary as a rapid and safe method to temporarily unblock a kidney before the eventual treatment is performed. The stents are typically about 12 inches long and stay in place since both ends coil. The top end coils in the kidney and the lower end coils in the bladder, thus they are sometimes called double J stents or pigtail stents.
How is a ureteral stent inserted and removed?
A stent is placed by a urologist at the hospital and requires a brief anesthetic. No needles or incisions are needed; it is done by passing a cystoscope into the bladder through the urethra. The procedure is painless and usually takes less than 10 minutes. Almost all stents are removed within a week or two after the kidney blockage is resolved. This is usually done in the office using a cystoscope, and takes about one minute. Rarely, if a stent only needs to stay in a couple of days, it is sometimes left with a thread attached to its lower end that exits the urethra and stays outside the body, taped to the skin. Removal of this type of stent is then done by either the patient or nurse pulling the thread. It is best to follow the removal of a stent with drinking 2-3 large glasses of water to help flush any debris from the ureter. It is not unusual to experience some increased aching in the side a few hours after the stent is removed, due to a spasm of the ureter. Shortly after stent removal (hours or rarely a couple of days) all the side effects (urinary symptoms, blood and pain) from the stent are resolved.
What are the side effects of a stent?
Stents protect the kidneys and allow people to lead as normal a life as possible; however, there can be some bothersome side effects while the stents are in, which resolve shortly after the stent is removed. How stents are tolerated varies amongst individuals. While some patients don't even know the stent is in place, most people are aware of its presence most of the time. Because the lower part of the stent coils inside the bladder it may cause an increase in urinary frequency, more sudden urges to urinate, or pink or reddish colored urine. There may also be some fatigue, aching or mild pain (groin or side), which is often worse with a lot of physical activity or after passing urine.
What physical activities are restricted with a stent?
Most patients can carry on with normal physical activities while the stent is in, provided the underlying kidney condition and their health allows it. There are normally no restrictions on work, exercise, sexual activity or travel plans with a stent. However, the side effects previously mentioned may be worsened with more activity and may require temporary lifestyle adjustments.
What complications can occur from a stent?
Although stents are commonly used, complications from them are relatively rare. The presence of a stent, along with the underlying kidney problem, increases the likelihood of developing a urinary tract infection which would require antibiotics. Symptoms of a urinary tract infection include an elevated temperature, or a significant increase in urinary symptoms or pain, which do not improve with rest. Occasionally a stent will encrust with crystals, urinary debris or a blood clot causing an increase in pain. Very rarely, a stent may become displaced or migrate out of the kidney. Stents are always temporary and usually are removed within a week or so, but sometimes they may need to stay in longer. It is important to have the stent removed or exchanged at least every six months, since they can become brittle, encrusted and difficult to remove if left in too long.
What care does a stent require?
It is essential that you drink enough fluids daily (8 cups or more) to try to keep the urine clear, or at least light pink. This reduces the chance of a stent becoming encrusted or clogged, and decreases the chances of an infection. The best fluids to drink are water or juice, since caffeinated beverages and alcohol can irritate the bladder. If there are bothersome symptoms, physical activity needs to be reduced and painkillers can be taken as needed. Phenazopyridine, an over-the-counter medication (AZO, Uristat) can help if there is a lot of burning, urgency and frequency of urination. Try to avoid aspirin or ibuprofen as they tend to increase the blood in the urine. Acetaminophen (Tylenol) or pain killers prescribed by the physician may be necessary. If a stent is left on a thread coming out of the urethra, take care especially in the bathroom so that it is not accidentally removed.
When is help needed?
- If a patient experiences constant, severe pain, despite medications and rest.
- If a patient experiences a temperature over 100 degrees.
- If the urine becomes thick, dark red and clotty, despite increased fluids and rest.
- If the stent falls out early (this is rare, but more common when a thread is left on the stent).
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