Ureteral stents are thin catheters threaded into segments of the ureter that carry urine, produced by the kidney, either down into the bladder internally, or to an external collection system. Insertion is most often done through the skin (percutaneously); however, in the presence of kidney or ureteral stones, stenting is ideally done during cystoscopy.
Ureteral stenting may be placed on a long-term basis (months to years) in order to bypass ureteral obstruction. Short-term stenting (weeks to months) may be used as an adjunct to open surgical procedures of the urinary tract to provide a mold around which healing can occur, or to divert the urinary flow away from areas of leakage. Following balloon dilation or incision of ureteral strictures, placement of stents maintains the functionality of the ureters. Stents may also be used in the presence of kidney stones to manipulate or prevent stone migration prior to treatment, or to make the ureters more easily identifiable during difficult surgical procedures. Ureteral stents may be used in those with active kidney infection or with markedly diseased, intolerant bladders (e.g., damage from radiation therapy, bladder invasion by adjacent neoplasm).
The procedure should be thoroughly explained by a medical professional before it takes place. The patient will be asked to put on a hospital gown. If the procedure is performed with the aid of a cytoscope, the patient will assume a position that is typically used in a gynecological exam.
Stents must be periodically replaced to prevent fractures within the catheter wall, or buildup of encrustation. Stent replacement is recommended approximately every six months or more often in patients who form stones.
Normally, a ureteral stent assures the patient of a free flow of urine. Postoperatively, urine flow will be monitored to ensure the stent has not been dislodged or obstructed.
Serious complications of the procedure occur in approximately four percent of cases, with minor complications in another 10%. These may include:
- Bleeding. Usually minor and easily treated, occasionally requiring transfusion
- Catheter migration or dislodgement. May require readjustment with the fluoroscope in the Radiology Department
- Coiling of the stent within the ureter. May cause lower abdominal pain or flank pain on urination, urinary frequency, or blood in the urine
- Introduction or worsening of infection
- Penetration of adjacent organs (e.g., bowel, gallbladder, or lungs)
Schrier, Robert, and Carl Gottschalk. Diseases of the Kidney. Philadelphia: Little, Brown and Co., 1997.
Cystoscopy — Examination or treatment of the interior of the urinary bladder by looking through a special instrument with reflected light.
Stricture — An abnormal narrowing of a tube or passageway.
Ureter — The tube-like passageway in the body that carries urine from the kidney to the bladder.