Basic LA Urinary Tract Sx

Question 1

What are the three most common urinary tract surgeries you perform?

Answer 1

Urolithiasis, patent urachus/infected umbilical remnant, ruptured bladder

Question 2

Urolithiasis occurs in what patterns in bovines?

Answer 2

Most common in steers; feedlot steers - multiple, range steers - single

Question 3

Where does urolithiasis most commonly occur?

Answer 3

Distal sigmoid flexure of the penis

Question 4

What are the signs of urolithiasis?

Answer 4

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

Question 5

What are the goals of treatment for urolithiasis?

Answer 5

Steers - salvage for market (perineal urethrostomy), epidural anesthesia, dissect down to penis and transact

Question 6

What is the pathophysiology of urolithiasis in small ruminants?

Answer 6

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

Question 7

What are calculi and what are common calculi found in pet goats and pigs?

Answer 7

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”

Question 8

Males that are affected by calculi are more predisposed to what? What part of the urinary tract predispose them to calculi?

Answer 8

Predisposed to urethral or bladder rupture; occurs d/t narrowed urethra (early castration and exogenous estrogens) and sigmoid flexure and vermiform appendage

Question 9

What factors are involved in forming calculi?

Answer 9

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

Question 10

What are the clinical signs of calculi in small ruminants?

Answer 10

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

Question 11

How does one diagnose urolithiasis?

Answer 11

Hx, through clinical exam, blood chem, elevated BUN, Crt, K, rads (plain and contrast), U/S

Question 12

What is your initial therapy for urolithiasis?

Answer 12

Massage or manipulation of the urethral process, exteriorization of the penis (diazepam), removal of urethral process, passage of catheter (urohydropulsion, traumatic)

Question 13

What does medical management of urolithiasis consist of?

Answer 13

Promotion of urethral relaxation (diazepam, ace, avoid xylazine - promotes dieresis), ammonium chloride (urinary acidifier), Walpoles solution (acidifying solution, pH 4.5 - high success rate)

Question 14

What does surgical management for urolithiasis involve?

Answer 14

Urethral process amputation (always), percutaneous catheter placement, tube cystotomy, bladder marsupialization, perineal urethrostomy

Question 15

Describe urethral process amputation

Answer 15

Should always be removed, sedation may be required (diazepam), put in a ‘sitting’ position, Allis tissue forceps are helpful, topical lidocaine, cut with scalpel

Question 16

Describe percutaneous catheter placement

Answer 16

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

Question 17

Describe a tube cystotomy

Answer 17

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

Question 18

What are common complications seen with tube cystotomies?

Answer 18

Blockage of the tube, failure of balloon, continued straining, premature removal of tube

Question 19

Describe bladder marsupialization

Answer 19

‘Permanent’ solution - after failed tube cystotomy, minimally invasive, two incision technique, approx 4 cm stoma is created, not rx for young/breeding goats

Question 20

What are potential complications of bladder marsupialization?

Answer 20

Cystitis, pyelonephritis, premature closure, bladder prolapse, urine scalding

Question 21

Describe a perineal urethrostomy

Answer 21

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

Question 22

Describe the incidence of urolithiasis in horses

Answer 22

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

Question 23

What are common procedures performed for urolithiasis in horses?

Answer 23

Subischial urethrostomy, lithotripsy, laparocystotomy

Question 24

Describe subischial urethrostomies

Answer 24

Epidural anesthesia, crush/remove stone with lithotrite, second intention healing

Question 25

What instrument is most commonly used to perform lithotripsies, since it is readily available?

Answer 25

Long regular slotted screw driver

Question 26

What are common causes of hematuria?

Answer 26

Cystic calculi (neck of bladder), urethral defects - ulcerated mucosa in proximal urethra - responds to subischial urethrostomy

Question 27

Describe patent urachuses

Answer 27

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

Question 28

What are two ways of managing a patent urachus?

Answer 28

Medical tx - silver nitrate cautery (avoid aggressive use); surgery - umbilical resection

Question 29

What do the urachus, umbilical arteries, and umbilical vein turn into after birth?

Answer 29

Urachus = scar at apex of bladder, umbilical arteries = round ligaments of the bladder, umbilical veins = falciform ligament

Question 30

What is omphalophlebitis and what are the causes and clinical presentation of it?

Answer 30

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

Question 31

What could cause a uroperitoneum?

Answer 31

Rupture of the bladder, urachus (internal) or ureter

Question 32

What are the signs of uroperitoneum? How might you diagnose this?

Answer 32

Hx and age (< 6d), gender (> males), depression, abd distension, abnormal urination; Dx: abdominocentesis, electrolytes (Blood and peritoneal fluid), US

Question 33

Excessive increases of what values in the peritoneal cavity vs. the blood are diagnostic for uroperitoneum?

Answer 33

Incr K and creatinine in peritoneal fluid (sodium in blood)

Question 34

What is the treatment for uroperitoneum?

Answer 34

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