Ch 115 ureters Flashcards

Question

ureterotomy

Answer 1

- There has been a move away from more traditional surgery due to high reported complication rate of urinary leakage, recurrent stricture and mortality of approx 20%. - More recent evidence appears to support interventional procedures of stents and SUBS that bypass the obstruction and allow acute decompression - Urine leakage (12%) - In dogs, ureterotomies that are left open will heal within 12 days if urine is evacuated from the abdomen - fibrosis and partial ureteral obstruction were shown to be more common in pigs if the ureter was allowed to heal by second intention

Answer 2

- defined as polyuria after relief of a urinary tract obstruction - clinically important because it can lead to dehydration and profound electrolyte and water disturbances if not managed appropriately - urine output >2 mL/kg/h - 2 studies: 71-88% cats develop POD - Results of the present study indicated that **high BUN, creatinine, phosphorus, and potassium** concentrations 24 hours before decompressive surgery in cats with ureteral obstruction were associated with longer and **more severe POD** following surgery. - Balsa 2019:

Answer 3

**ureterotomy, ureteral reimplantation, ureteronephrectomy, and at times renal transplantation** - Kyles et al reported 2 retrospective studies involving over 150 cats. - complications (over 30%) and the mortality rates ranged from 18% to over 30%, depending on the type of procedure performed - These studies not only included cats that had a ureterotomy or ureteral reimplantation, but also those that had renal transplantation or ureteronephrectomy procedures - Over 10% of cats that survived the these surgical complications required a second surgical procedure (30% subsequently euthanized or died for serial complications.) - small number had long-term imaging follow-up, and 40% of those that were followed had evidence of a recurrence of a ureteral obstruction

Answer 4

- ureteroneocystostomy with (6/12) or without (6/12 – 4 temporary) double pigtail catheter - survival: 11/12 survival to discharge - creatinine: decreased in all cases – not influenced by double pigtail catheter placement - complications: 2/12 without double pigtail → revision for uroabdomen - long-term complications more common with double pigtail (hematuria, pollkiuria, UTI)

Answer 5

Struvite and calcium oxalate | Approx 50% with ureteroliths had concomitant nephroliths or cystoliths

Answer 6

- ureterotomy or neoureterocystostomy are easily performed - double-pigtail ureteral stents (fluro guided) Lithotripsy - extracorporeal shockwave - In one study, successful treatment was reported in 6 of 7 dogs with ureteroliths, although 4 of 7 dogs required more than one retreatment. - All dogs had concurrent nephrolithiasis.

Answer 7

- Ureteral stent placement was performed endoscopically, surgically, or both, with fluoroscopic guidance. - follow up > 1,555 days, with 30 of 44 dogs alive at the time of last follow-up - post of infection 25% - Pavia 2018: Outcome of ureteral stent placement for treatment of benign ureteral obstruction in dogs: 44 cases (2010–2013) JAVMA

Answer 8

- no perioperative or procedure-related deaths - good short term results - long-term complication> mineralisation of six devices, four required exchange - MST >774days - Milligan 2020: Outcome of SUB placement for the treatment of benign ureteral obstruction in dogs: nine dogs and 12 renal units (2013 to 2017) JSAP

Answer 9

Benign fibroepithelial polyps DDx: leimyoma, TCC, sarcoma, MCT

Answer 10

- Secondary involvement of a ureter by tumors of the urinary bladder or a kidney is more commonly reported. - Ureteronephrectomy is usually performed when primary ureteral tumors do occur

Answer 11

Ureteropelvic junction | bilateral hydronephrosis and renal failure

Answer 12

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

Answer 13

Ureteral Injury Associated With Ovariohysterectomy - inadvertent ligation, transection, or resection or from obstruction secondary to ovarian, uterine, or vaginal granuloma formation. - Clinical signs associated with uremia (e.g., vomiting, lethargy) - signs are not immediately apparent (e.g., hydronephrosis) if there is unilateral obstruction blunt trauma - uroperitoneum - luid creatinine and potassium concentrations - Excretory urography or ct pyelography Tx - - ureteral reimplantation for mid to distal ureteral avulsions - ureteronephrectomy or ureteral ligation with SUB placement for proximal avulsions.

Answer 14

- ureterolithiasis, repeat ultrasonography is recommended immediately before surgery to confirm the location of all stones because calculi can migrate in either direction.42,92 - Intraoperative ultrasonography is sometimes required to confirm stone location or to confirm that all stones have been removed. - Ureterotomy or neoureterocystostomy in small dogs and cats requires magnification of the surgical site - Microvascular instruments and suture (7-0 to 10-0) are also required.

Answer 15

- urinary bladder is drained - - Larger ureteroliths (>2 to 3 mm) can often be visualized or palpated within the ureter. - Approximately 75% of cats have unilateral obstruction - left feline ureter often has a bend approx 3 cm distal to the kidney > common location for obstruction by ureteroliths. - - Visibility is improved cellulose surgical spears, Suction avoided to reduce ureteral edema - temporary stent during suturing > This prevents incorporation of the back wall and subsequent stricture. - Interrupted or continuous microvascular sutures (7-0 to 10-0 for cats, usually nylon) -

Answer 16

- - renal transplantation > the intravesical technique eliminated the formation of obstructive granulomas seen with the older technique - experimental dogs > renal technetium transit time increased for 2 to 4 days after intravesical reimplantation, returned to normal over 4 to 11 days after surgery in most cases

Answer 17

* Intravesicular - vental cystotomy performed to pull ureter from outside in and suture mucosa to mucosa after spatulating the ureter * Extravesicular - no cystotomy required, sutured to mucose with knows external Cats with contralateral nephrectomy had creatinine concentrations reduce more rapidly with extravesicular technique

Answer 18

* Renal descensus (shifting the kidney caudally) * Pexy apex of bladder to caudal pole of kidney * Pexy apex of bladder to iliopsoas muscle (psos cystopexy) * modified boari flap (Aronson 2018) * pelvicocystostomy using tube cystoplasty in a cat

Answer 19

* Similar rates of uroabdomen (15% reimplantation vs 16% ureterotomy) * Persistent obstruction more common after reimplantation (11% vs 3%)

Answer 20

- For intramural ureteral ectopia, a ventral cystotomy is performed - the ureteral and bladder mucosa are sutured together with 5-0 to 9-0 monofilament absorbable interrupted sutures - distal ureteral segment is then ligated

Answer 21

- disparity in ureteral luminal diameter between the dilated proximal and normal distal ureter, distal ureter is spatulated so that it matches the diameter of the proximal ureter - 3 to 4 weeks for coordinated peristalsis to return across the anastomosed ureter.32 - ureteral catheter is left in place. - fibrous tissue/stricture and leakage main cocnerns

Answer 22

Dilatation assoc with the distal ureter or ureteral orifice that occurs due to faulty embryonic development (Chwalla membrane fails to regress) - Orthotopic/intravesicular - Ureteral orifice in normal positionand entire ureterocoele is within the bladder - Ectopic - If any portion of ureterocoele is within the bladder neck or urethra - concurrent ectopic ureter > urinary incontinence Treatment: Resection of the ureterocoele (ureterocoelectomy) +/- neoureterocystostomy (if ectopic) - Endoscopic laser-ablation for the treatment of orthotopic and ectopic ureteroceles - poorer outcome if associated with ectopia

Answer 23

Skye terriers Golden retrievers Labs Huskies Newfies Bulldogs WHWT Fox terriers min and toy Poodles Females are 20x more likely

Answer 24

- In dogs > majority are intramural; they enter the bladder wall in the normal anatomic location and continue to travel submucosally - - In cats, uncommon in dogs, ureters may run completely separate from the bladder and urethra (extramural) until they empty into the distal urogenital system. - often associated with other urogenital abnormalities, including: > hydroureter > small, misshapen, or absent kidneys > vestibulovaginal abnormalities such as paramesonephric remnants.

Answer 25

- During urogenital development, the pronephros, mesonephros, and metanephros appear sequentially, with remnants of each possibly retained in the embryo. - In mammals, the pronephric duct persists as the mesonephric duct, which becomes vestigial in females but forms the deferent duct in males. - The ureter originates from the metanephric duct, a bud of the distal mesonephric duct. - Initially, both ducts share a common opening into the bladder, but as the bladder grows, they separate. - The mesonephric ducts shift caudally, opening on the dorsal urethral wall, while the ureters maintain their connection to the bladder.

Answer 26

- If the metanephric duct originates more cranially than normal on the mesonephric duct, the metanephric duct will not reach and establish an individual opening into the bladder - The metanephric duct will then be carried caudally with the mesonephric duct to open in the bladder neck or urethra of females or the deferent duct or urethra of males. - Most cases appear to terminate in the urethra of females and males

Answer 27

- - Continuous or intermittent incontinence when the animal is young - most animals produce a urine stream during conscious micturition - UTI reported in up to 83% of bitches presenting with EU, most E. coli RADS - traditionally relied on excretory urography±retrograde contrast studies - - significant discordance between radiographic and surgical findings, with only 78∙2% EUs being correctly identified - enema to empty the colon and fluoroscopy improves accuracy - Pneumocystography in conjunction with excretory urography may improve CT - remove superimposition of tissues - - Contrast dosage and acquisition times have also been defined - - CT has repeatedly been shown to have a high degree of accuracy + non invasive ultrasound - - determine if an ectopic ureter is present within the bladder neck or proximal urethra - evaluate the urinary bladder for the presence of ureteral “jets” - use ultrasound as an initial screening modality but this is a highly operator dependent cystoscopy - evaluation of the vagina, urethra, and urinary bladder - determining the exact location of ectopic orifices - 100% correlation between cystoscopic and surgical findings - can be surgically treated at the same time - disadvantage is the inability to examine the upper urinary tract

Answer 28

- 80% sensitivity and 100% specificity enema to empty the colon and fluoroscopy improves accuracy

Answer 29

- sensitivity 91-100% + specificity 100% 4D-CTEU showed a sensitivity and specificity of 97% and 94.6%, respectively

Answer 30

sensitivity 87.8% and specificity 86.7%.

Answer 31

Neoureterocystostomy (extramural) - End-to-side intravesicular or extravesicular - Side-to-side Cystoscopic guided laser ablation (intramural)

Answer 32

- Open surgery is only treatment option for extramural > ligation of the distal ureter and re-implantation - An adaptation in technique (three-stitch ureteroneocystostomy) based on evidence from the human literature, and compares favourably to previous techniques - higher complication rate reported: complications - hydroureter/hydronephrosis secondary to mucosal oedema, surgical trauma or stricture formation

Answer 33

- Persistence of urinary incontinence has been reported to occur in 42 to 71% of dogs after surgical interventions, including neoureterostomy, ureteral re-implantation and ureteronephrectomy - good to excellent outcome in 92.5% of dogs 1 month postop and in 81% of dogs at long-term outcome recurrence of incontinence was observed in 35%, most of these responding to adjuvant medical treatment - Major complications (11%) and included uroabdomen (3)

Answer 34

- Minor lower urinary tract complcations were more frequent after neoureterostomy (100%) compared to CLA (13%) - 1 major complication, only in neoureterostomy group Incontinence did not recur in any dog treated with CLA - Recurrence incontinence in 42% (5/12) of dogs treated with neoureterostomy; - The median duration of follow-up time was 38.9 months - 22/25 (88%) dogs achieved continence after correction of EU ± additional medical/surgical treatment Dekerle 2022

Answer 35

- only applicable for intramural EU - shown to be safe, with minimal risk of complications - - no significant complications were encountered in the treatment of 46 dogs (Smith et al. 2010, Berent et al. 2012). - This compares very favourably with reported major complication rates for surgical procedures of 4 to 11% - Evaluation of the efficacy restricted to comparison with historical surgical controls, due to the lack of any prospective comparative studies - - In study with longer follow-up (median 2.7 years), 14 of 30 female dogs had regained and maintained continence without the need for additional therapy - - Overall, 67.7% continent after CLA with or without adjunctive medical management. 17 dogs (54%) remained incontinent after CLA - Complete urinary continence achieved in 20/32 dogs (63%) with CLA alone. With addition of medical/surgical intervention > 72% Postprocedural neutering did not affect the continence score. risks of scarring and proliferative reaction that resulted in stranguria. Hoey 2021

Answer 36

* perforation, * haemorrhage * recanalization

Answer 37

- More accessible alternative to laser - 3/7 dogs were completely continent with CST-EU alone, 3 others became continent or were markedly improved with the addition of medications Jacobson 2022: Complications were minor, and only 3 dogs showed transient lower urinary tract sign

Answer 38

- Male dogs make up fewer than 15% of reported cases - success rate after surgical correction may be higher than females > This may be due to the longer urethral length in male dogs - In 5 case reports, all 5 were continent after ligation of the distal ureteral segment and neoureterocystostomy., or increased pressure within the prostatic urethra. Two of the dogs also had a ureterocele resected - 82% continence rate in a review of 16 male dogs treated with conventional surgery. Anders 2012 - 100% continence in 4 male dogs treated with cystoscopic-guided laser ablation (bilateral in 75%)

Answer 39

- minimally invasive treatment option has significantly reduced the morbidity and mortality - yet to improve and the long-term success continues to be in the region of 50 to 70% in females - continued incontinence likely have functional abnormalities of the bladder neck and urethra - for long-term outcome are broadly similar, suggesting that one technique is not superior to another - - another 7% to 28% of dogs becoming continent with a combination of surgery and treatment with drugs such as phenylpropanolamine that increase urethral tone. - - Recommend repeat cystoscopy – laser ablated, may result in ureteral openings that are not optimally positioned - - The importance of concurrent anomalies, their contribution to outcome, and whether they should be treated concurrently with ectopic ureters is unclear. - Preoperative urethral pressure profiling reported to be a potential useful tool in predicting postoperative incontinence (not been validated in a larger group of dogs

Answer 40

- Uncommon - In a review of 23 cases  no breed or gender predilection  21 of 23 cats were incontinent  13 cats unilateral  28 of 31 were extramural (unlike in dogs) - incontinent cats should be evaluated for ascending urinary tract infection. - most common correction is ureteral reimplantation, as long as hydronephrosis is not too severe. - The response to surgery may be better in cats than dogs; postoperative resolution of clinical signs was reported in 16 of 18 cats

Answer 41

Majority of cats are extramural

Answer 42

Retrospective surgical treatment of ectopic ureters in 12 cats Dx: ultrasound (8/10), CT (3/3) or cystoscopy (6/7). 66% extramural 8 ureteroneocystostomy, 1 neoureterostomy, 2 laser ablation, and 1 nephroureterostomy. postoperative complications: 6 short term > 1 revision. 2 long-term overall 66%, though major uncommon urinary incontinence > complete resolution in 11 cats (91%)

Answer 43

Study design: Retrospective cohort study. Animals: Thirty-five client-owned dogs The ability of CT to identify a normal and intra-or extramural ectopic ureters conclusively and correctly was 13/26 (50%) and 32/41(78%), respectively. CT did not accurately predict anatomy of ureters; CT findings may need confirmation by cystoscopy and possibly intraoperative fluoroscopy prior to determining if CLA is indicated or not.

Answer 44

– modified endoluminal stents for proximal ureteral obstruction - avoidance of irritation of UVJ and alterations to ureteral peristalsis, vesicorenal reflux the physical effect of intra-ureteral stent termination on the ureter at the stent end, is unknown. Intra-ureteral stent termination also precludes minimally invasive cystoscopic or fluoroscopic-guided removal,

Answer 45

Benign ureteral obstruction in 72 cats: medical management success 30% (31/103), partial 13% (13/103), and failure 57% (59/103) > 23% with uroliths, 50% pyonephrosis, and 50% with strictures Distal and smaller uroliths > significantly associated with success MST 1188 days success, 518 days partial success and 234 days failure positive urine culture 25% to 30% > may not represent SUB placement, because similar rates are reported without an implant and in cats with CKD which cats most benefit from medical vs surgery vs SUB placement is not clear with current literature.

Answer 46

Four cats received subcutaneous ureteral bypass (SUB) device placement and one had ureteral anastomosis over a stent Median follow-up time was 34 (min 28, max 58) months and renal function was normal in all cats at the last follow-up.

Answer 47

Retrospective. Extravesicular, two-layer, side-to-side ureteroneocystostomy in 10 cats with ureteral obstruction near the ureteropelvic junction (UPJ). Sx performed: renal descensus, ureterocystopexy, and nephrocystopexy Minor Perioperative complications: catheter dislodgement (3), transient pollakiuria (2), and dysuria (1 7/10 cats were alive without recurrent ureteral obstruction advantage > wider anastomosis and remaining very short ureter may have allowed spontaneous passage of small nephroliths

Answer 48

Study design: Experimental study. Animals: Twelve, adult, purpose-bred, cats. A simple NCT (n = 3) or bladder cuff NCT (n = 9) was performed in the right or left kidneys. All simple NCTs became obstructed after catheter removal. All bladder cuff NCTs were patent, and CT revealed contrast flow into the bladder Complete ureteral bypass was possible in cats using only native tissues.

Answer 49

Transmural migration of a subcutaneous ureteral bypass into the intestine in three cats CT scan could allow the migration to be identified Mechanism of the transmural migration > foreign body reaction from the SUB vs infection leading to adhesions and then a secondary foreign body reaction, cyanoacrylate glue could encourage adhesions Associated with UTI and acute onset of gastrointestinal signs

Answer 50

Direct renal pelvicocystostomy using tube cystoplasty in a cat stent and SUB failed due to rapid mineralisation. Cons > bacterial cystitis could easily progress to pyelonephritis. Pro’s > no artificial material and therefore no risk of mineralisation + provides a large-diameter and flexible tubelike structure for the calculi to pass through, as opposed to the small-diameter tubes.

Answer 51

8 incontinent female dogs with intramural ectopic ureters median procedure time: sx 105min (40-170), GA 118min (65-320) - 6/8 immediate improvement in continence; 3/7 (42.9%) long-term complete continence - additional 3/7 (42.9%) continent or improved with medication for USMI - complications: 3/7 transient LUT signs

Answer 52

No preoperative imaging characteristics or biochemical findings were found to be significantly associated with long-term serum creatinine concentrations

Answer 53

26% kidneys had renal pelvis mesurement <4mm; 74% >4mm - 8% <2mm - median renal pelvis diameter 6.6mm (1.1-37.0); ureteral diameter 3.2mm (0.0-11.0) - pathology: 70% secondary to stones, 21% positive culture - absence of dilatation does not rule out ureteral obstruction

Answer 54

age, sex, breed, housing, total calcium not associated - dry food → 15.9x more likely to develop ureteral obstruction

Answer 55

surgery: 17/25; CLA 8/25 - complications: 18/25 (72%) minor, 2/25 (8%) major - continence: 1-month post-oop continence in 20/25 (80%) - recurrence in 5/25 at median 24.9m with resposne to medical management - overall continence maintained median 66m in 22/25 (88%) with treatment - CLA → fewer complications and recurrence of incontinence - case numbers small and not equal

Answer 56

peritoneal/retro-peritoneal effusion rare: 4/25 short-term, 1/14 long-term - decreased renal pelvis width: short-term 2.4mm (0-7.0); long-term 1.7mm (0-3.5) - pre-op 11.7 (0.9-41) - all cats without complication → pelvic width ≤3.5mm at 3-months - complications: 16/27 (59.2%) overall – 9/27 (33%) non-obstructive 8/27 (29.6%) obstructive - renal pelvis size post-op often close to normal renal pelvis size

Answer 57

In total, 10 cats (8.5%) had a positive postoperative culture within 1 month postsurgery and 28 cats (23.7%) within 1 year postsurgery Perioperative hypothermia and preoperative positive culture were independent predictors of a postoperative positive culture and this should be taken into consideration when managing these cases. Positive postoperative culture rates were higher than have previously been reported.

Answer 58

complications: 19/24 (79.2%) overall - intra-op: 4/24 (16.7%) - ischemic encephalopathy, flluid overload, hyperkalemia - peri-op: 10/23 (43.5%) - device obstruction, UTI - post-op: short-term 9/18 (50%) long-term 14/16 (87.5%) - obstruction, UTI, sterile cystitis, pyelonephritis - risk factors: older cats → peri-op complications; increased Hct → short-term - survival: 19/24 (79.2%) survival to discharge – older cats less likely to survive complication rate was higher and the MST shorter than previously reported in cats undergoing SUB placement. Despite good short-term survival, the development of complications may necessitate regular and intensive control visits. Owners that consider SUB placement should be informed that follow-up can be strenuous and expensive

Answer 59

Long-term intramural ectopic ureters with cystoscopic-guided laser ablation Retrospective. 34 complications: urethral tear in 2/34 – managed conservatively - complete or near-complete continence in 26/32 (81%) with 3 dogs requiring additional tx (90%) - post-CLA neutering did not affect continence scores

Answer 60

95 cats with 130 SUB - survival: (89.5%) survival to discharge; MST 530d (7-1915) overall - survival associated with pre-op creatinine - complications: minor (19%), major (48%) - UTI: 27/85 (31.7%) 10% mortality and a high complication rate. Most complications were manageable, overall MST > 2 years antegrade pyelogram performed preop > proven to be 100% sensitive and specific in detecting obstructions Two cats > obstruction of the nephrostomy catheter by blood clots ( profuse haemorrhage intraop) Consider tissue plasminogen activator (TPA) infusion into the SUB prior to replacing the nephrostomy catheter SUB was removed if patency of both ureters.

Answer 61

Retrospective. 12 cats treated with ureteroneocystostomy. Ureteroneocystostomy with (6/12) or without (6/12 – 4 temporary) double pigtail catheter - survival: 11/12 92% survival to discharge * creatinine: decreased in all cases * complications: 2/12 without double pigtail → revision for uroabdomen * long-term complications more common with pigtail (hematuria, pollkiuria, UTI) * Seven cats MST 329 days (range, 8-1772) after surgery * none of the cats recurrent ureteral obstruction. * nephroliths were identified in 7 > no recurrence * The temporary ureteral catheter (instead of stent) > introduction in the ureter to urethra, allowing urination around the catheter

Answer 62

11/12 ureters previously stented → SUB for recurrent stricture, ureteritis, stent migration - no short-term worsening azotemia - complications: mineralisation of 6/9 → 4/6 exchanged UTI 5/9 – 5/5 pre-op hx of UTI

Answer 63

Fourteen female cats and five female dogs Five of seven animals with bilateral ureter injury presented with anuria. Three animals died or were euthanased without definitive surgery. Surgical repair included ureteroneocystostomy (eight cats, one dog), ureteronephrectomy (four cats, two dogs), subcutaneous ureteral bypass placement (three cats) and ureteral stent (one cat) (44%) that were discharged from the hospital experienced major complications requiring one or more additional surgeries. Overall outcome was excellent in 13 (68%), poor in 22% A key indicator of a ureteric injury is an animal failing to recover normally or becoming unwell shortly after ovariohysterectomy Ureteroneocystostomy is preferred to ureteronephrectomy to preserve renal function and is usually a requirement for bilateral ureteric injuries but carries a high complication rate resulting in additional surgery (and therefore costs), albeit often with an excellent final outcome All seven animals (100%) that had a major complication had undergone a neoureterostomy surgery

Answer 64

renal pelvis diameter: median pre-op 9mm (3-28mm); median post-op 3mm (2-23mm) - SUB abnormalities: 43/81 (53%) - stent obstruction, leakage, non-obstructive kinking loosened nephrostomy pig-tail loop - 54% ureters became patent, majority slightly dilated or irregular margins (chronic inflam)

Answer 65

A modified Boari flap can lead to long-term resolution of proximal ureteral obstruction in cats, without requiring stents or permanent implants

Ch 115 ureters Flashcards

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