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Lithotripsy 1127.e3

Video
Lithotripsy Available
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• Rare: urethral or bladder perforation (due
Difficulty level: ♦♦♦
to laser contact with the mucosa or to
Synonyms voiding urohydropulsion [VUH]), urethral
Electrohydraulic lithotripsy (EHL), laser litho- obstruction, indwelling urinary catheter for
tripsy (holmium-doped yttrium, aluminum, 1-5 days after the procedure, urinary tract
garnet [Ho:YAG] laser) infection
• Endoscope damage: probe activated within
Overview and Goal the endoscope
Fragmentation and removal of uroliths through • Precautions
natural orifices ○ Avoid activating laser against the mucosa
or closer than 1 mm, flush abundantly Procedures and Techniques
Indications while checking the bladder, and use rigid
Treatment of bladder and urethral uroliths in cystoscope in females whenever possible.
dogs and female cats ○ VUH the day after lithotripsy if remaining
fragments
Contraindications ○ Selection of candidates depends on sex, LITHOTRIPSY Endoscopic image demonstrates
two uroliths in the bladder of a dog. The probe is
Untreated bleeding diathesis size/shape/location of uroliths seen emerging from the bottom of the image and
■ Male dogs with urethral stones or two contacting the urolith on the right in preparation for
Equipment, Anesthesia or three bladder stones < 5-6 mm fragmentation.
• General anesthesia (stones can be brought into the urethra
• Epidural anesthesia can facilitate voiding for fragmentation, which facilitates
urohydropulsion by relaxing the urethra. fragment expulsion) • Stone analysis
• Endoscope: flexible ureteroscope (males and ■ Female dogs with urethral stones or • Five days (or longer if positive urine
small females), rigid cystoscope (females or one to five bladder stones < 1 cm culture) of broad-spectrum antibiotic (e.g.,
perineal access in male dogs) ■ Female cats with urethral stones or one amoxicillin)
• Sterile saline and 60-mL syringes to five bladder stones < 5-6 mm • Repeat lithotripsy and/or VUH to remove all
• Protective eyewear fragments (nidus for new uroliths) if needed.
• Ho:YAG laser or EHL probe Procedure
• Stone retrieval basket • Performing lithotripsy requires at least two Alternatives and Their
people (clinician and assistant). Relative Merits
Anticipated Time • Patients are placed under general anesthesia. • Lithotripsy is an excellent, minimally inva-
Varies (mean, 30 minutes). Depends on urolith Females are positioned in dorsal recumbency sive alternative to urethrotomy for urethral
location (longer in bladder than in urethra); sex and males in lateral recumbency (exception: stones.
of the patient (longer in males than in females); dorsal recumbency for perineal approach in • Cystotomy, a more invasive procedure,
number, size, and shape of the urolith (longer males). The vulva or prepuce is aseptically pre- allows the removal of bladder uroliths and
for multiple and/or large uroliths); visibility in pared. The cystoscope/ureteroscope is passed retropulsed urethroliths. Sutures can serve
the bladder (longer if hematuria) through the urethra. Saline is injected through as nidus for new stone formation.
the endoscope to distend the bladder and • A percutaneous cystolithotomy (PCCL)
Preparation: Important localize the urolith(s). In male dogs, perineal approach to bladder urolith removal can be
Checkpoints access can be used to pass the cystoscope. used in small patients when the endoscope is
• Urine culture and sensitivity 5 days before • The probe is passed through the working too large to pass through the urethra (male
the procedure and appropriate antibiotic channel of the scope until it contacts the dogs ≤ 5 kg, male cats) or there are multiple
therapy if needed urolith and is activated, applying laser energy or very large uroliths (cats and dogs).
• Coagulation profile (notably for dogs directly to the urolith (see Video). As soon as • Extracorporeal shock wave lithotripsy
of breeds predisposed to von Willebrand the urolith is fragmented (small enough to (ESWL) consists of fragmenting uroliths
disease) pass through the urethra), basket removal can by delivering external shock waves through
• Protective eyewear be attempted to remove the big fragments, a water bath or a specific fluid-filled cushion.
• Gauze squares over the eyes of the patient and VUH (saline) is performed to remove It has been very successful in fragmenting
(if using laser) the remaining smaller fragments from the nephroliths and ureteroliths in dogs but less
• Lateral abdominal radiograph before the urinary tract. successful for cystoliths and urethroliths.
procedure to check if stones are still present • The endoscope can then be reintroduced
and to measure and count them to check for remaining fragments, and Pearls
if needed, a new series of fragmentation, • Lithotripsy’s success depends on careful
Possible Complications and basket removal, and VUH can be performed. patient selection (sex, size of the patient,
Common Errors to Avoid Urolith fragments should be sent for culture number/size of uroliths, and presence of
• Most complications occur during or within and mineral analysis. hematuria)
24 hours of the procedure. • Basket removal or VUH allows removal of
• In dogs, minor complications related to Postprocedure remaining fragments.
cystoscopic-guided laser lithotripsy are • Analgesia (preferably opioids or nonsteroidal
reported in 13% (male) to 18% (female) antiinflammatory drugs [NSAIDs] if no renal SUGGESTED READING
of cases. compromise and well hydrated) Adams LG, et al: Use of laser lithotripsy for fragmen-
• Common: hematuria, stranguria usually • Radiographs or ultrasound to check for the tation of uroliths in dogs: 73 cases (2005-2006). J
self-limiting within 48 hours presence of uroliths/fragments Am Vet Med Assoc 232:1680-1682, 2008.

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