What is a stent?
Ureteral stents are soft, hollow, plastic tubes placed temporarily into the ureter to allow drainage around a stone or or to speed healing after a stone surgery.
When are they needed?
Stents are used for various reasons in patients with kidney stones. They may be placed in patients to help reduce pain from a stone, when infection is present to allow drainage, or when a stone is preventing a kidney from working adequately. Stents are also commonly placed after surgeries for stones, as in ureteroscopy, to allow healing and prevent swelling of the ureter.
How is a stent placed?
Stents are placed during surgery by sliding them over a soft “guidewire” which is placed up the ureter, which is the tube draining the kidney. See a video below of a stent being placed.
How is a stent removed?
Stents can be removed in two different ways. Sometimes, a string is left attached to the end of the stent. This string is allowed to come out of the patient’s urethra, the tube where he or she urinates. The string can be used to pull on the stent and remove it. In cases where a string is not left attached, a small camera called a cystoscope is inserted into the patient’s urethra after numbing medication has usually been administered. The cystoscope is then advanced into the bladder and the stent is grasped with an instrument and removed. See our post on stent removal for a video and more details.
How long can a stent stay in?
In general, most stents should only remain in for no longer than 3 or so months. If a stent is left in too long, it can form stones directly on it, making removal difficult.
What are the symptoms of having a stent?
While some patients with stents have minimal discomfort related to them, other patients will report symptoms that can range from being annoying to being severe enough that the stent has to be removed. These symptoms can include:
- Sensation of needing to urinate
- Seeing blood in the urine
- Bladder spasms
- Burning sensation during urination
- Pain in the back during urination or when moving
- Pain in the bladder
Is there anything that can help reduce the discomfort of a stent?
Different medications may be given to help reduce the discomfort of a stent. The most effective appears to be those from the alpha blocker class of medications including tamsulosin (Flomax) and Alfuzosin (Uroxatral). Other types of medications commonly given for stent discomfort, such as oxybutynin (Ditropan) or phenazopyridine (Pyridium), do not appear to be successful at reducing stent related discomfort in placebo controlled studies. Traditional pain medications are also less successful at reducing stent discomfort.
Hasn’t anyone come up with a better stent?
Research into improving stent designs will hopefully reduce the discomfort associated with them. Innovative stent designs currently being tested include stents embedded with medications to reduce discomfort and stents that dissolve by themselves.