Ch 115 - Ureters Flashcards
What % of felines have circumcaval ureters?
- Right 30.6%
- Left 1.3%
- Bilateral 3.3%
7% have a double cava
List the layers or the ureter
- Outer adventitial layer
- Central muscular layer
- Inner mucosal layer (lamina propria and transitional epithelium)
What is the response in terms of ureteral pressure in response to acute ligation?
Ureteral pressures increase and peak by 5 hours and then lessen but remain elevated for 12-24hr
What is the response of renal blood flow after acute ureteral ligation?
- 24hr - 40% of normal
- 2 weeks - 20% of normal
Results in a decreased GFR and a compensatory increased GFR in the contralateral kidney
What cellular response is seen in response to acute ureteral ligation?
- Influx of macrophages and T-lymphocytes
- Macrocyte proteolytic enzymes and cytokines resilt in fibroblast recruitment and activation
- Interstitial fibrosis or glomerulosclerosis
What is the expected return of GFR after ureteral obstruction in previouslt healthy kidneys?
- 1 week obstruction - 65% of normal GFR over 5wk
- 2 week obstruction - 46% of normal over 4m
Slight, moderate and severe fibrosis occurs over 1, 2 and 3 weeks respectively
List important points to discuss with the owner in a cat with ureteral obstruction
- Cannot predict how long the obstruction has been presetn and how well the cat will recover
- Most have some degree of chronic interstitial nephritis which will progress despite surgery
- If azotaemic with unilateral obstruction, cat has bilateral kidney disease
- Significant risk of complications - overall mortality 18-21%
List options for surgical management of ureteral obstruction
- Ureteral resection with reimplantation
- Ureterotomy
- Double-pigtail ureteral stent
- SUB
- Ureteral resection and anastomosis
- Lithotripsy
What % of cats need removal or replacement of a double pigtail stent?
27% - stent occlusion or dysuria
List complications associated with a SUB
- Urolith occlusion 13%
- Occlusion with blood clot under 3%
- Kinking 3%
- Urine leakage - rare
- Infection
- Migration into intestines
What is the % of reported urine leakage after a ureterotomy?
6-12%
May heal on its own with draining from an abdominal or nephrostomy drain
What are the most common ureteroliths in dogs?
- Struvite and calcium oxalate
What is the most common primary ureteral neoplasia in dogs?
Benign fibroepithelial polyps
DDx: leimyoma, TCC, sarcoma, MCT
Where are congenital ureteral strictures most commonly located?
Ureteropelvic junction
What is a urinoma?
What is the treatment?
A collection of urine within the retroperitoneal space that causes fat necrosis and subsequent reactive fibrosis
Tx: ureteronephrectomy with ablation or omentalisation of the urinoma cavity