A kidney stone stent is a flexible plastic tube inserted between a kidney and the bladder to facilitate the passage of a kidney stone. Also known simply as a stent, a kidney stone stent is simply one of many treatment options which can be considered for kidney stones. If a doctor recommends a stent for a patient, the doctor should be able to estimate how long the stent will be left in, and he or she should articulate a plan for the removal of the stent.
When a kidney stone stent is placed, the patient may be given a general or a local anesthetic, depending on the situation. A cystoscope is inserted into the urinary tract to allow the doctor, commonly a urologist, to see, and the stent is carefully threaded into the ureter and left in place. Coils or J-shaped hooks at either end of the stent keep it place so that it cannot drift once it has been inserted. As a general rule, a kidney stone stent can be left in place for up to six weeks, at which point it will need to be removed.
Commonly, a stent is inserted when it appears possible that a patient will pass a kidney stone, with a little help. The stent helps urine drain from the kidneys to the bladder, clearing any obstructions and hopefully bringing stones along with it. Stents may also be inserted after cystoscopy or surgical removal of a kidney stone to ensure that urine drains properly for a few days or weeks while the ureter gets a chance to heal. If the stent is left in too long, it can develop deposits of material which could lead to infection or obstruction of the ureter.
One of the most important things to know about a kidney stone stent is that it can be extremely painful. This varies, depending on the patient, but many people report a tugging or pulling sensation, and a constant need to urinate. The stent can become painful or irritating during exercise sessions or early in the morning, and certain body positions may be intolerable with a stent in place because they place too much strain on the stent. Some patients have expressed unhappiness because they were not adequately warned about the difficulties involved in wearing a stent, and it is important to address specific concerns such as exercise routines with a doctor before a kidney stone stent is placed.
During stent removal, the patient is usually placed under a local anesthetic while the doctor visualizes the area and gently removes the stent. Patients may experience some pain and soreness for several days after a kidney stone stent is removed, as their ureters heal.
Can You Pass a Kidney Stone With a Stent In?
A stent is comprised of a thin, flexible plastic tube measuring from 10 to 15 inches. When it is placed, it causes the ureter, the passageway between the kidney and the bladder, to become larger, as the stent itself is 1/4" in diameter. This opening not only unblocks obstructions but creates a route for stones or stone fragments to pass through.
However, while it is ideal for a kidney stone to pass once a stent is in place, it's more common that the stone won't pass. If the patient doesn't pass a stone after placement, the stent still allows larger access for surgery so the removal procedure is less traumatic for the patient.
How Long Does a Stent Stay In for Kidney Stones?
Generally, a stent for kidney stones should stay in for no longer than a couple of weeks but can be in for as short a period as a few days. If the time needs to be prolonged, the stent will need to be removed and replaced. This is due to the buildup that occurs on the stent during its time in the ureter.
Permanent removal of a stent can be done as an in-office procedure. After determining the stent is no longer needed through either X-ray or ultrasound, the physician inserts a cystoscope from the urethra into the bladder. The cystoscope is equipped with small clamps that latch onto the stent so it can be carefully pulled out.
What Happens After Kidney Stone Removal and Stent Placement?
After a stone is removed, the doctor may opt to put a stent in place to prevent post-operative swelling from blocking the flow of urine. As well, there may be additional stone fragments that need to pass from the kidney.
In most cases, you should be able to return home the same day as your surgery. Your doctor may advise you to drink plenty of water following the procedure to ensure proper bladder function.
The stent placed in the ureter is temporary. Following the removal of stones, the physician determines the exact length of time the stent should be left in place. Generally, if the stones were small to medium in size, it should be no longer than a couple of weeks.
While the stent is in place, the patient should expect to experience some discomfort, though it should be less significant than the discomfort experienced when the stone was present. Side effects vary on a patient-to-patient basis but may include:
- Back pain
- Pelvic pain
- The feeling of needing to urinate
- Pain during urination
- Passing small amounts of blood in the urine
In addition to the presence of the tubing, some patients who have stents for just a few days may also have a string in place that provides for easy removal.
What Complications May Occur During Stent Placement?
Some patients may experience complications once a stent is in place. Aside from the common side effects already mentioned, the tube could also become broken or dislodged. As with any operative medical procedure, there is also a risk for an infection.
While the placement of stents is generally safe, to prevent these types of complications the doctor may place physical restrictions on the patient for the first week. The patient may also be advised to abstain from sexual activities during the first week.
It's important to keep in mind that the complications that can arise from stent placement don't compare to the complications that can occur if a kidney stone is left in place. A ureteral obstruction created by a stone can quickly become a life-threatening situation.