A stent is a tube-like structure used to prop open a body conduit. Some of the most common types of stents are coronary and vascular stents. These are placed in major blood vessels to aid in blood flow. Ureteral and urethral stents are two other types. These are placed in the ureter and the urethra, respectively.
A coronary stent is probably the most common type of stent. These are often used during angioplasty surgeries to hold open an artery. Coronary stents are typically inserted through a small incision in the arm, leg, or groin. With the help of internal imaging, a catheter is threaded through a major vein into a the coronary artery that needs stenting. A balloon on the end of the catheter is then inflated, which causes the stent to expand.
A few types of stents also are used for coronary stenting. A metal mesh stent is one of the most common. Some even contain drugs, which are slowly released into the patient's body. Scientists also have developed a stent designed to be absorbed by the body over time.
Other major blood vessels throughout the body may also need stenting. This is usually done to help treat or prevent an aneurysm. For example, a stent will usually be placed in the abdominal aorta in the case of an abdominal aortic aneurysm.
There are two ureters in the human body, which drain urine from the kidneys to the bladder. A ureteral stent is usually put in place to help keep this passageway open so urine can pass into the bladder. Obstructions of the ureters can cause serious complications, so patients with a kidney stone may have these types of stents put in. These may also be put in patients who have a tumor pressing against the ureter, clamping it shut.
The urethra is the passageway in the body that leads from the bladder to the outside of the body. This tube is necessary to rid the body of urine. Urethral stents are used to help keep the urethra open. These are usually only used in male patients when their prostates become enlarged.
There are two types of urethral stents. Temporary urethral stents are placed for a short amount of time, then removed. These can usually be put in place in doctors' offices. Permanent urethral stents, on the other hand, are usually placed during a surgical procedure, and they are meant to be left in the urethra.