- 1. When discussing the option of surgery to remove uroliths from the lower urinary tract, clients should be informed that
even in the hands of experienced surgeons, there is a risk that not all uroliths will be removed. Therefore, appropriate radiographs
will be evaluated following surgery. Clients also should be informed of the consequences of incomplete removal of uroliths,
and the benefits and risks of therapeutic strategies available to manage this complication.
- 2. Uroliths often migrate to lower portions of the urinary tract. Therefore, if several days have elapsed between the date
of diagnostic radiography and/or ultrasonography and the date of surgery scheduled to remove the uroliths, the number and
location of stones should be re-evaluated by appropriate imaging methods just prior to surgery.
- 3. Appropriate caution should be taken to remove all uroliths from the bladder lumen, bladder neck and urethra. When possible,
the number of uroliths removed from the lower urinary tract should be compared with the number of uroliths detected by radiography,
ultrasonography or via cystoscopy. Uroliths may be removed with the aid of spoons, forceps, gauze sponges or suction devices.
The lumen of the bladder and bladder neck should be explored with a finger to detect remaining uroliths.
In addition, the bladder lumen should be flushed with an isotonic solution to remove subvisual uroliths. Uroliths that have
passed into the urethral lumen may be flushed back into the bladder lumen by injecting appropriate quantities of physiological
saline through a catheter placed in the external urethral orifice. The external urethral orifice should be occluded around
the catheter to facilitate flushing of the urethroliths back into the bladder lumen. If the distal urethra is not occluded,
fluid may flow around small urethroliths without moving them into the bladder lumen. This will result in incomplete removal
If retrograde flushing techniques are used to flush urethroliths into the bladder with the aid of a catheter inserted into
the distal urethral orifice, appropriate caution must be used to minimize retrograde flushing of bacteria that normally colonize
the mucosa of the distal urethra and genital tract into the urinary bladder and surgical site. Inserting a flexible catheter
through its lumen via the urinary bladder also may enhance patency of the urethra. Injection of an isotonic solution through
the catheter may force uroliths out of the distal urethral orifice. In some cases, it may be of value to check for uroliths
by digital palpation of the urethra per rectum. Appropriate precaution should be used to avoid contamination of the surgical
- 4. Especially when multiple uroliths are detected prior to cystotomy, re-evaluate the urinary tract radiographically immediately
following surgery. Immediate detection of uroliths that were inadvertently left in the urinary tract is of great importance.
If they obstruct the urethra before the cystotomy incision heals, life-threatening complications may develop.
If uroliths remaining in the lower urinary tract following surgery are first detected by radiography or ultrasonography several
weeks following surgery, it may be erroneously assumed that the patient is highly predisposed to recurrent urolithiasis.
Dr. Osborne, a diplomate of the American College of Veterinary Internal Medicine, is professor of medicine in the Department
of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota.
Dr. Lulich, a diplomate of the American College of Veterinary Internal Medicine, is a professor in the Department of Small
Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota.