Ureteroscopy
The word ureteroscopy literally means to scope, or look inside of the ureter. The ureter is the tube that connects the kidney to the bladder. It varies in length and size from individual to individual, but is generally about 20-25centimeters in length, and about 5 millimeters across.
The indications for ureteroscopy may include certain ureteral stones, or kidney stones, obstruction from an unknown cause, or hematuria (blood coming from one ureter, seen at cystoscopy). Lesions inside the collecting system of the kidney present another indication for ureteroscopy.
The most common indication is for kidney stones. In these cases, the stone has usually dropped out of the kidney into the ureter, and has become impacted, or stuck, on its way down towards the bladder. If the stone is seen well on x-ray, your physician may suggest that ESWL (shock wave lithotripsy) be done. If the situation is such that the lithotripter is not available, or the stone cannot be seen on x-ray, or has failed fragmentation with ESWL, the ureteroscope is the next logical instrument to use.
Depending on the location and size of the stone, the ureteroscope used may be rigid, or flexible. In order to pass the scope, general anesthesia is required. Cystoscopy is the first step, during which a small guide wire is passed into the ureter. This flexible wire allows for coaxial access to the ureter, as well as to insure that the risk of perforation is kept to a minimum. A second, safety wire is usually passed at the same time. This wire is used as a back up to the first, as well as to help with stent placement, which usually follows the procedure.
With the guide wires in place, a decision as to the necessity for ureteral dilation can be made. Balloons or other dilating instruments will make the lower part of the ureter large enough to accommodate the scope. The lower portion of the ureter is usually smaller in diameter, because it is wrapped in the same muscle that wraps the bladder. This is why most stones get hung up, at this point, known as the uretero-vesical-junction.
After dilation of the ureter, the scope is passed, and the ureter is visualized. If the purpose for the procedure is to treat a stone, the scope will be advanced to the level of the stone, at which time a holmium laser fiber will be passed. If the stone is large, or if there is a tumor or other lesion in the ureter that needs to be addressed, the surgeon will often pass a ureteral sheath to protect the entire length of the ureter. Once the laser fiber is in place the stone can be broken up under direct vision. Depending on the number, location and size of the fragments, they are either left in place to pass on their own, or pulled out with a stone basket.
In cases where the indication for ureteroscopy is for a process other than stone, the same basic steps are taken in order to gain access to the ureter. In some cases of small stones or lesions lying within the kidney, the procedure is also the same.
The urologic literature is full of articles debating the use of stents after ureteroscopy. These small "double-J" or "pigtail" tubes are very soft and flexible. They allow for urine to pass through the ureter that has been traumatized by the scopes. The downside of having a stent in place is the urgency and frequency of urination that usually accompanies their placement. In cases where no dilation is required, the stent can be left out. The trade off is the possibility of severe back pain due to the swelling of the ureter, preventing the normal passage of urine. In some instances, patients without stents initially, will have to have them placed later, to decrease the pain. It is our practice philosophy to generally leave a stent after all of the simplest ureteroscopy cases.
With a stent in place, urgency and frequency of urination are the rule, as is some bleeding. There may also be back pain when the individual voids. All of this will subside over time, with the stent, in place. The symptoms will usually abate very quickly once the stent is removed. On occasion, we will give our patients medication to help quell some of these symptoms before they start. Please talk to your physician at the time of the procedure.
The stent is usually removed anywhere from 48 hours to 4 weeks after the procedure. The length of time it is left in place is determined by the procedure, its difficulty, and surgeon preference. Some surgeons will leave a string on the stent (dangler), which allows the stent to be removed without looking back into the bladder. In instances where there is no dangler, the stent can usually be removed under local anesthesia in the office.
All of our physicians at the Urologic Surgeons of Washington have years of experience with these procedures and will be happy to answer any questions not addressed in this paper.