A ureteral stent is a small, temporary, and flexible tube placed inside the body’s urinary system to ensure the free flow of urine from the kidney to the bladder. When this natural pathway becomes blocked, the stent acts as a bypass, preventing urine backup into the kidney, which could otherwise lead to swelling and potential damage. This intervention is designed to be a temporary solution, maintaining kidney function until the underlying medical issue can be definitively treated.
Anatomy and Design of the Ureteral Stent
The stent itself is a hollow tube, typically made from a flexible polymer like silicone or polyurethane, though metallic stents are sometimes used for longer-term placement. Its design is engineered for secure placement within the urinary tract, often measuring between 10 to 15 inches in length. The most common type is known as a “double-J” or “pigtail” stent because of the characteristic J-shaped curves at both ends.
One curved end is designed to coil within the kidney’s urine-collecting area, while the other rests inside the bladder. These curled ends anchor the stent in place, preventing migration. The stent’s tube also features multiple small openings along its length, which allow urine to drain both through the center of the tube and along its exterior, maximizing drainage efficiency.
Primary Reasons for Stent Placement
The most frequent medical reason for placing a ureteral stent is to relieve an obstruction that is blocking urine flow. Kidney stones are the single most common cause of this blockage, where a stone lodged in the ureter prevents urine from passing, causing severe pain and swelling in the kidney.
A stent is also routinely placed following surgical procedures on the kidney or ureter, such as ureteroscopy for stone removal. Post-surgical swelling and inflammation can temporarily narrow the ureter, and the stent holds the passage open, allowing the tissue to heal without forming scar tissue. Less commonly, stents are used to manage ureteral narrowing caused by external compression from tumors, scar tissue from conditions like endometriosis, or to protect the ureter during other treatments like chemotherapy or radiation.
What to Expect While the Stent is in Place
While the stent is a helpful medical device, its presence can cause noticeable side effects. Many patients experience an increased and often sudden urge to urinate, which is caused by the stent irritating the bladder lining. This bladder irritation may also lead to discomfort or a burning sensation during urination, known as dysuria.
The stent can also cause pain, which is typically felt in the lower abdomen, groin, or the flank (the area on the side and back near the kidney). This flank pain is often more pronounced immediately after urinating, as the bladder’s contraction causes the urine to momentarily reflux, or flow backward, up the stent to the kidney. It is also common to see blood in the urine, known as hematuria, especially after physical activity.
Insertion and Removal
Insertion of the stent is typically performed under sedation or general anesthesia using a cystoscope, a small camera inserted through the urethra into the bladder. The removal process is generally much simpler and often occurs in an outpatient setting, sometimes with just a local anesthetic. If the stent has a removal string attached, the doctor simply pulls the string; otherwise, a flexible scope is used to grasp and remove the stent from the bladder.