Ureteroscopy is a common urological procedure which refers to looking up the ureter (the small tube-like structure that drains the kidney to the bladder) with a small lighted scope. The procedure is nearly always done under general anesthesia. Ureteroscopy may be performed with a semi-rigid scope when only the ureter is visualized. When endoscopy of the inner parts of the kidney (renal pelvis and calyces) is needed then a flexible scope is required. As technology over the years has improved, the size of the scopes has been greatly reduced making the procedure much less traumatic to the ureter and kidney. The lense-system and fiber optics of the scopes have also been vastly improved making the light and focus much better. Ureteroscopy is used to diagnose pathology of the ureters and inner kidney, to treat problems like ureteral strictures, and to perform lithotripsy with urinary stone removal.
Lithotripsy with urinary stone removal
A common and effective means to treat ureteral stones and small kidney stones is through ureteroscopy. When the stones are less than about 4 mm, then a stone basket or flexible grasping instrument may be placed through the ureteroscope and used to engage the stone and remove it without dilating the ureter or breaking the stone(lithotripsy). When stones are larger than 4-5 mm then the ureter may be gently dilated by placing a ureteral access sheath into the ureter to the level of the stone under fluoroscopy, and then lithotripsy performed. The best means to perform lithotripsy through the ureteroscope is with Neodymium Holmium laser energy (NdHo). A small quartz fiber is placed through the scope and extended to very near the stone to be broken. The settings on the laser-generating unit are adjusted to the appropriate levels for the stone, which depend on the size, location, and stone makeup. The surgeon then activates the laser in small short bursts until the stone is fragmented into small pieces that can then be removed through the access sheath. Once all stones are removed, then the sheath is removed, and a small flexible stent is usually placed into the ureter. The ureteral stent will internally by-pass ureteral swelling, which is usually present for about 5 days after ureteroscopy through the dilating sheath. This allows the urine to flow easily from the kidney to the bladder and protects the kidney from obstruction. A 6-week follow-up ultrasound of the kidney is then recommended to assure that there is good drainage and no ureteral injury.
What can I expect after my ureteroscopic lithotripsy?
Since cystoscopy is necessary to access the ureter, then some voiding discomfort in the urethra and bladder is common for a few days. If the stone removed was small and did not require ureteral dilation or placement of an access sheath, then recovery should be quick and with little or no ureteral or kidney discomfort. On the other hand, if the stone required a sheath to be placed and a stent was left in place, then there will be potential for ureteral stent pain. Ureteral stents have been in common use since they were developed in the mid-1970s. They are made of soft surgical hydrophilic plastics and developed to minimize an inflammatory response from the ureteral lining and bladder. They have a soft J-shape on each end to keep them from migrating up or down the ureter (double-J stent). They are placed over a soft hydrophilic guidewire under fluoroscopy at the time of ureteroscopy and extend from the bladder to the renal pelvis (inner kidney). Sometimes a small monofilament string is left attached to the bladder end, which extends out the urethra – it is taped to the thigh and then used to remove the stent in about 5 days. At other times office cystoscopy is needed to remove the stent when its purpose is no longer needed. There is a lot of variability regarding voiding symptoms from the stent. Many patients will have little or no awareness that it is present, while a small number of patients have extreme urgency and frequency with dysuria (voiding pain). The average patient has mild flank pain when the bladder is full, mild to moderate dysuria, and frequent urination until the stent is removed. Drinking extra water and lying down is helpful.
When should I call the doctor’s office after ureteroscopy?
- Fever more than 100 degrees Fahrenheit
- Blood in the urine which is bright red or clotting
- Substantial flank pain that is not helped by voiding or lying down
- If the stent on a string is accidentally removed
- Be sure to make arrangements for stent removal, if you have one