Basic LA Urinary Tract Sx Flashcards
What are the three most common urinary tract surgeries you perform?
Urolithiasis, patent urachus/infected umbilical remnant, ruptured bladder
Urolithiasis occurs in what patterns in bovines?
Most common in steers; feedlot steers - multiple, range steers - single
Where does urolithiasis most commonly occur?
Distal sigmoid flexure of the penis
What are the signs of urolithiasis?
If it’s urethral obstruction - abd pain, distended bladder (per rectal); if it’s ruptured urethra - distended bladder (per rectal), ventral swelling (sheath, abd), cellulitis, uremic smell; ruptured bladder - no abd pain, symmetric abd distension, bladder full but not empty (per rectal), elevated BUN, acidotic
What are the goals of treatment for urolithiasis?
Steers - salvage for market (perineal urethrostomy), epidural anesthesia, dissect down to penis and transact
What is the pathophysiology of urolithiasis in small ruminants?
Typically a sporadic metabolic dz that can be caused by environmental, dietary, metabolic, and improper husbandry; primarily male ruminants; tx with surgery but can reobstruct
What are calculi and what are common calculi found in pet goats and pigs?
Calculi = mineral or mucoprotein aggregates causing direct traumatic lesion or obstruction of the urinary tract; struvite (mag ammonium phosphate), apatite (Ca P), struvite and apatite (high grain based diets), Ca carbonate (legumes), Ca oxalate, Silicate (western US and Canada), struvite and apatite tend to be sandy where as Ca carbonate tends to be true “stones”
Males that are affected by calculi are more predisposed to what? What part of the urinary tract predispose them to calculi?
Predisposed to urethral or bladder rupture; occurs d/t narrowed urethra (early castration and exogenous estrogens) and sigmoid flexure and vermiform appendage
What factors are involved in forming calculi?
High urine pH = major factor - alkaline urine allows struvite, apatite, and Ca carbonite uroliths to form; silicate or Ca oxalate may not be affected by pH; hydration, desquamated epithelial cells common, mucoproteins, cystitis and infection
What are the clinical signs of calculi in small ruminants?
Early signs: restlessness or anxiety, tail twitching; Progressive: excessive focalization, stretching/arched back, forceful urination, reduced urine flow, bloody urine, crystals on preputial hairs; Advanced: swelling/pain of urethra, ventral edema, sudden cessation of C/S, abd distension, anorexic, depression, weakness, death
How does one diagnose urolithiasis?
Hx, through clinical exam, blood chem, elevated BUN, Crt, K, rads (plain and contrast), U/S
What is your initial therapy for urolithiasis?
Massage or manipulation of the urethral process, exteriorization of the penis (diazepam), removal of urethral process, passage of catheter (urohydropulsion, traumatic)
What does medical management of urolithiasis consist of?
Promotion of urethral relaxation (diazepam, ace, avoid xylazine - promotes dieresis), ammonium chloride (urinary acidifier), Walpoles solution (acidifying solution, pH 4.5 - high success rate)
What does surgical management for urolithiasis involve?
Urethral process amputation (always), percutaneous catheter placement, tube cystotomy, bladder marsupialization, perineal urethrostomy
Describe urethral process amputation
Should always be removed, sedation may be required (diazepam), put in a ‘sitting’ position, Allis tissue forceps are helpful, topical lidocaine, cut with scalpel
Describe percutaneous catheter placement
Option for stabilization overnight or even cheap version of a tube cystotomy, pigtail catheters (lock in place), sedate w/ diazepam, local anesthesia, U/S guidance, suture in place and give abx/NSAIDs
Describe a tube cystotomy
Most commonly performed surgical procedure for urolithiasis, allows the urethra to ‘rest’ - can allow complete recovery and tube removal in a few months, allow to administer urinary acidifiers to help dissolve any remaining stones following sx, temporary diversion, must change diet also
What are common complications seen with tube cystotomies?
Blockage of the tube, failure of balloon, continued straining, premature removal of tube
Describe bladder marsupialization
‘Permanent’ solution - after failed tube cystotomy, minimally invasive, two incision technique, approx 4 cm stoma is created, not rx for young/breeding goats
What are potential complications of bladder marsupialization?
Cystitis, pyelonephritis, premature closure, bladder prolapse, urine scalding
Describe a perineal urethrostomy
As a general rule, this has been used as a salvage procedure for ruminants; high rate of stricture, newer technique = incision ventral to anus, penile body freed from ischium, urethral mucosa spatulated —> incr success rates
Describe the incidence of urolithiasis in horses
Males more common, usually at neck of bladder, chronic cystitis, C/S: incontinence, dysuria, pollakuria, polyuria, he matures, and stranguria, staining, scalding, recurrent colic, stilted hindquarter gait, weight loss, usually Ca carbonate; rectal exam typically diagnostic
What are common procedures performed for urolithiasis in horses?
Subischial urethrostomy, lithotripsy, laparocystotomy
Describe subischial urethrostomies
Epidural anesthesia, crush/remove stone with lithotrite, second intention healing
What instrument is most commonly used to perform lithotripsies, since it is readily available?
Long regular slotted screw driver
What are common causes of hematuria?
Cystic calculi (neck of bladder), urethral defects - ulcerated mucosa in proximal urethra - responds to subischial urethrostomy
Describe patent urachuses
Urachus carries urine from bladder to allantois - persists in foals for weeks postpartum, closes after birth so no urine passes thru; can stay patent w/ or w/o omphalophlebitis (not life-threatening); can resolve w/o tx
What are two ways of managing a patent urachus?
Medical tx - silver nitrate cautery (avoid aggressive use); surgery - umbilical resection
What do the urachus, umbilical arteries, and umbilical vein turn into after birth?
Urachus = scar at apex of bladder, umbilical arteries = round ligaments of the bladder, umbilical veins = falciform ligament
What is omphalophlebitis and what are the causes and clinical presentation of it?
Infected umbilical remnants; C/S: septicemia, fever, swollen (septic) joints - seen in first 4 weeks; Causes = overzealous iodine application; use US if umbilicus is not hot and swollen
What could cause a uroperitoneum?
Rupture of the bladder, urachus (internal) or ureter
What are the signs of uroperitoneum? How might you diagnose this?
Hx and age (< 6d), gender (> males), depression, abd distension, abnormal urination; Dx: abdominocentesis, electrolytes (Blood and peritoneal fluid), US
Excessive increases of what values in the peritoneal cavity vs. the blood are diagnostic for uroperitoneum?
Incr K and creatinine in peritoneal fluid (sodium in blood)
What is the treatment for uroperitoneum?
Fluid therapy (incr Na, Cl, decr K), 0.9% NaCl, dextrose, crystalline insulin, sodium bicarbonate if acidotic; anesthesia and surgery - treat hyperkalemia, preoperative drainage, repair defects
