LA Urolithiasis: Medical/Surgical Management and Complications Flashcards
what are the goals of medical versus surgical therapy? what do they include?
medical:
-stabilize patient
-dissolve existing calculi
-prevent formation of additional stones
-include: analgesics, antimicrobials, urine acidifers (tetanus prophylaxis!!)
surgical:
-urine drainage
-remove excess calculi
-re-establish urethral patency
-include: cystoscopy, urethrotomy/perineal urethrotomy (PU) in males, lithotripsy (mechanical, laser, shock wave)
management changes long term!
describe cystoliths in horses
- presenting complaint:
-typically hematuria mid or end stream, especially after exercise - clinical signs: hematuria, stranguria, oliguria, incontinence, urine scald, weight loss
- typically calcium carbonate, calcite (mineralized form)
-TI: soft, yellow, spiculated stones of CaCO3 crystals
-TII: <10% of calculi, smooth, rounded white (Ca, carbonate, P, Mg) - calculi most commonly in the bladder of the horse!!
- majority cases: males >8 years of age
describe considerations for surgery for uroliths in horses
- gen anesthesia or standing sedation
- perioperative analgesia: systemic and local (epidural)
- antimicrobials
- complications
- recurrence (especially if leave nidus behind (lithotripsy-punch until it shatters))
describe surgical approaches for removing bladder stones in horses
- mare lithotripsy, endoscopic bag removal
- gelding progressive urethral dilation via perineal urethotomy
- laparascopic removal: in standing horse; size limitations
- modified parainguinal approach: for larger stones, require general anesthesia
- pararectal cystotomy
describe what the bladder needs re: surgery
bladder requires water tight seal!
single layer closure recommended:
-achieves anatomic reconstruction
-accelerates healing
-obviates reduction in luminal diameter
-achieves water tight seal
potential complications:
1. incisional infection
2. dehiscence
3. difficult access
4. incision: mucosal defects heal in 5 days and full thickness defects heal in 14-21 days
5. cystolith removal tends to be incomplete :( lots of dust and debris can act as nidus for infection or future stone formation
describe potential surgical complications
- difficult exteriorization of bladder
- prolonged manipulation/bladder fatigue
- loss of stone architecture: incomplete removal
- tension in closure - can dehiss
describe follow-up care from cystotomy
- indwelling urinary catheter and abdominal drain
- broad spectrum antimicrobials (penicillin, gentamicin)
- anti-inflammatories: flunixin, IV lidocaine CRI
- IV fluid therapy
- serial metabolic panels
- serial abdominal ultrasounds
describe ultrasound for bladder stones in horses
a beneficial diagnostic!
renal and ureters: check them both
10% calculi at more than one location
how are larger calculi best removed?
through a parainguinal, caudal midline, or pararectal approach
-incisional infection or dehiscence and difficult accessa re known complications
what type of inflammation does urine cause?
nonseptic/sterile neutrophilic inflammation: because chemical irritant
-cell count: >5000 NC per ml
-specific gravity: >1.025 (hypersthenuric)
-total solids: >3.0 g/dL
describe urolithiasis in ruminants
- formation of stones within urinary tract
-leading cause of obstruction!! - very common due to dietary imbalances
- all species affected
- males predisposed: long urethra, small diameter urethra
- castrated males predisposed:
-urethral diameter is influence by testosterone, so if a pet goat, delay castration (the longer the better)!
compare and contract partial and complete obstruction in ruminants
partial:
-dribbling when urinating
-small, frequent urinations
-medial or surgical management
complete:
-no urine produced
-surgical EMERGENCY
describe early and late signs of urolithiasis in ruminants
early signs:
1. hematuria
2. dysuria
3. crystals on prepuce
4. dribbling
5. tail flagging
6. colic
late signs:
1. anorexia
2. depression
3. prepucial swelling
4. abdominal distension
5. recumbency
6. seizure activity
7. death
describe diagnostics for urolithiasis in ruminants
plain view radiographs helpful for radiopaque:
-calcium carbonate
-calcium oxalate
-silica
describe options for surgical management of obstruction in ruminants
- urethral process amputation:
-#1 place for obstruction in small ruminants
-no effect on future fertility in breeding males
-exteriorization is the hardest part! - bonnano-pre-pubic catheter
- perineal/ventral urethrostomy
- tube cystotomy +/- urethrotomy
- bladder marsupialization
- lithiotripsy