A ureteral stent is a thin tube inserted via a surgical procedure into one of the ureters for the purpose of draining urine from the kidney to the bladder. Stenting is primarily necessary when there is an obstruction found in one of the ureters, but it also can be used as a tool to aid surgical procedures in that area of the body. The composition of the ureteral stent is dependent upon the patient's anatomy, the type of urinary procedure being performed, and how long the stent will be necessary. Insertion of the stent requires a device known as a cystoscope; a guide wire often aids in placement in the body. Removal can be achieved through cystoscopy or via a thread attached to certain stents.
Under normal circumstances, each of the kidneys in the human body is attached to a ureter — a pair of long narrow tubes that facilitate the transfer of urine to the bladder. When ureters become obstructed, a ureteral stent may be required to perform the function of the ureters. Reasons for obstruction can include kidney ailments, such as stones, tumors, swelling, infection, or blood clots. In some cases, a ureteral stent may be inserted to aid in other urinary surgical procedures by acting as a mold to allow healing in the area, to stop kidney stone movement, or to prevent urine leakage into a problem area.
Depending upon the specifics of the medical procedure, the size and shape of a ureteral stent may vary. Stents are generally between 5 inches (about 12.7 cm) and 12 inches (about 30.5 cm) in length with a diameter of less than .2 inches (about 5 mm). If the stent is expected to be temporary, it generally is open-ended. More permanent stents may have to be coiled at one or both ends.
The general method for insertion of a stent requires a cystoscope, which is inserted into the bladder and allows the surgeon a view of the ureter that needs stenting. Normally, a guide wire is then inserted into that ureter, over which the stent is moved into place. At that point, the cystoscope and guide wire are removed. Another possibility is to have it placed directly into the ureter, where the stent is poked through the skin and into the kidney.
Cystoscopy often is used to remove a stent once it is no longer required. Some stents come with a thread attached, which extends out of the body. These types of stents may be removed by using the thread to pull it out.