Internal Medicine

Laser Lithotripsy of Canine Bladder and Urethral Stones

About Laser Lithotripsy

Lithotripsy

Candidates

Laser lithotripsy is equally as successful as traditional surgery for removing stones from female dogs. The main benefit of lithotripsy is the procedure is completed without an incision which typically results in a faster recovery time for the patient.

To date, the VTH Small Animal Internal Medicine team has achieved a 100% success rate in removing stones from the urethra of male dogs. However, the typical success rate for removing bladder stones from male dogs is less than females. This is due to the smaller size of the male urethra and more complex urethral shape. As such, some dogs are not considered good candidates for laser lithotripsy, including:

  1. Male dogs < 15 pounds, because the endoscope may be too large to traverse the urethra
  2. Male dogs with more than 2 bladder stones >5 mm in diameter (depending on the size of the dog)
  3. Female dogs in which the entire bladder is full of stones >5 mm in diameter
  4. Dogs with uncontrolled UTI - once infection is controlled, lithotripsy can be considered.

Procedure

The length of the lithotripsy procedure is dependent on stone size and number and patient size. A visit to our hospital for this procedure will proceed as follows:

  1. The patient is evaluated on day 1.
  2. Lithotripsy is performed on day 2. Dogs with urethral obstruction will have laser lithotripsy performed more expeditiously.
  3. The patient is recovered and discharged when appropriate, which results in a 2 day, 1-2 night hospital stay.

The lithotripsy procedure includes the following steps:

  1. The patient undergoes general anesthesia and rigid (female) or flexible (female or male) cystoscopy is performed.
  2. A laser fiber is passed through the endoscope, placed in contact with the stone, and Holmium:YAG laser energy is then applied causing fragmentation.
  3. The procedure is repeated until all stone fragments are small enough to be extracted via endoscopic baskets or voiding urohydropulsion.

Efficacy

Calcium oxalate, struvite, urate, and cystine stones are all susceptible to laser lithotripsy.

Risks

Thermal injury to the bladder/urethral mucosa is possible but risk is minimal as the laser energy only penetrates <1 mm. Urinary tract penetration with the laser fiber or cystoscope is rare, but possible. Urethral edema with subsequent stranguria or obstruction is possible. The inherent risk of anesthesia is present.

Endoscopic Laser Lithotripsy Images & Video

Urolith

This is a video of endoscopic laser lithotripsy of the bladder stone. The red light indicates where the tip of the laser fiber is. Once the laser is activated you can see the stone breaks apart with fragments flying by the endscope.