Clinical presentation and outcome of cats with circumcaval ureters associated with a ureteral obstruction

Extravesicular, two-layer, side-to-side ureteroneocystostomy combined with tension-relieving techniques for feline proximal ureteral obstruction: A retrospective study

OBJECTIVE

To describe the surgical technique for extravesicular, two-layer, side-to-side ureteroneocystostomy combined with tension-relieving techniques (ETSUTT) for feline proximal ureteral obstruction and report clinical outcomes.

STUDY DESIGN

Retrospective case series.

ANIMALS

Ten privately-owned cats with ureteral obstruction near the ureteropelvic junction (UPJ).

METHODS

Medical records were retrospectively reviewed for cats with ureteral obstruction close to the UPJ that underwent ETSUTT (2018-2021). The ETSUTT procedure consisted of a modified extravesicular technique (two-layer, side-to-side ureteroneocystostomy) and tension-relieving techniques (renal descensus, ureterocystopexy, and nephrocystopexy).

RESULTS

All cats survived through discharge. In all cats, postoperative blood urea nitrogen and creatinine concentrations were decreased, compared with preoperative concentrations. Perioperative complications included ureteral catheter dislodgement (3), transient pollakiuria (2), and dysuria (1), but no specific treatments were required. Urinary tract infection was observed postoperatively in three of the 10 cats. The median follow-up was 648 days (min-max: 86-1229 days). Seven of the 10 cats were alive without recurrent ureteral obstruction at the end of this retrospective study.

CONCLUSION

The ETSUTT procedure was successfully performed without major complications in cats with ureteral obstruction occurring near the UPJ. Use of ETSUTT provided a fair-to-good, long-term prognosis in cats that were otherwise difficult to manage.

CLINICAL SIGNIFICANCE

This novel procedure, ETSUTT, was feasible, safe, and could be a viable treatment option for feline proximal ureteral obstruction, including the UPJ, especially for obstructions caused by stricture.

Antegrade CT pyelography of right retrocaval ureter causing ureteral stenosis and ureterohydronephrosis in an exotic shorthair cat: A case report

Retrocaval ureter is a rarely reported congenital malformation of the caudal vena cava in veterinary medicine. In this report, a 2-year-old exotic shorthair cat weighing 3.4 kg was presented for depression and loss of appetite. Laboratory findings was unremarkable. Abdominal radiography revealed right renomegaly, and ultrasonography suggested right ureterohydronephrosis. Right retrocaval ureter was recognized by computed tomography. An antegrade pyelography was performed to identify the localization of obstruction and whether obstruction was complete or partial. Complete right ureteral stenosis was confirmed through right antegrade pyelography on computed tomography. The cat underwent right nephroureteroectomy and recovered well after surgery. This is the first report of successful diagnosis and treatment of retrocaval ureter in a cat with significant clinical and imaging signs, using ultrasonographically guided percutaneous antegrade pyelography and multimodal imaging such as radiography, ultrasonography, and computed tomography.

Computed tomographic appearance of transcaval ureter in two dogs and three cats: A novel CVC congenital malformation

Transcaval ureter is a rarely reported human congenital malformation of the prerenal segment of the inferior vena cava (IVC) not yet reported in veterinary medicine. The objective of this multicenter retrospective case series study was to describe the computed tomography (CT) features of transcaval ureters in dogs and cats. Patients referring to pre- and post-contrast CT exams of the abdomen and presenting this abnormality were retrospectively included. Multiple qualitative features were described for each ureteral abnormality detected. Three cats and two dogs with transcaval ureter were identified consisting of a segmental duplication of the CVC at the prerenal level creating a vascular ring through which the ureter extended, identified as a double-barrel gun sign. The malformation was divided into two types according to the symmetry of the caval branches and location in relation to the aorta, namely, type I symmetrical branches and right-lateral to the aorta, and type II asymmetrically branches and right-dorsal to the aorta. In one case, the malformation was associated with hydroureter and mild pyelectasis. In three cases, the anomaly was incidental and, in the remaining two cases, the clinical significance was uncertain. This is the first study describing the presence of transcaval ureter in dogs and cats. CT was a suitable method for the diagnosis of transcaval and a focal double-barrel gun sign of the CVC is proposed as the hallmark feature of this anomaly. The clinical relevance of this congenital vascular malformation is unclear and needs to be further investigated.

Transmural migration of a subcutaneous ureteral bypass into the intestine in three cats

Subcutaneous ureteral bypass™ is a device placed in cats with ureteral obstruction. The most common complications include system occlusion, urinary tract infection and sterile cystitis. In this case series, we describe three cats with subcutaneous ureteral bypass devices placed where transmural migration of subcutaneous ureteral bypass catheters into the small intestine resulted in gastrointestinal signs, urinary infection and subcutaneous ureteral bypass occlusion. The system was changed in one case and removed in the other two. In all cases, an intestinal resection and anastomosis was performed. All cats had a good medium-term outcome, and urinary infection persisted in the case for which the subcutaneous ureteral bypass system was changed. Transmural migration of the device should be ​considered in cats with subcutaneous ureteral bypass presenting with persistent urinary tract infection, gastrointestinal signs or device obstruction, even if imaging studies such as ultrasound or contrast studies do not demonstrate any abnormalities.

Case Report: Imaging Features and Successful Management of Ureteral Stenosis in a Kitten With Bilateral Atypical Papillary Transitional Mucosal Hyperplasia

A 3-month-old cat weighing 2.62 kg was brought to the VIP Animal Medical Center with vomiting, diarrhea, anorexia, and depression. Laboratory findings confirmed azotemia with elevated blood urea nitrogen (BUN) (168.9 mg/dl) and creatinine (5.9 mg/dl) and symmetric dimethylarginine (SDMA) (86 μg/dl). Abdominal radiography revealed bilateral renomegaly. Ultrasonography revealed bilateral hydronephrosis and left partial and right complete ureteral obstructions with bilateral focal irregular and circumferential thickenings at ureters. Reduction of bilateral renal function was confirmed through excretory urography on computed tomography. The cat underwent subcutaneous ureteral bypass surgery on the left kidney, right nephrectomy, and bilateral ureterectomy. Histopathology of bilateral ureteral irregular and circumferential thickening revealed bilateral atypical papillary transitional mucosal hyperplasia. Three days after surgery, the left hydronephrosis resolved, and azotemia was almost resolved. This is the first report of successful management of ureteral stenosis with congenital papillary transitional mucosal hyperplasia in a kitten using multimodality imaging.

Comparison of nonenhanced computed tomography and ultrasonography for detection of ureteral calculi in cats: A prospective study

BACKGROUND

Radiographs and ultrasound (US) are the primary imaging modalities used to assess ureteral calculi in cats. Reports describing the use of nonenhanced computed tomography (CT) are scarce.

HYPOTHESIS/OBJECTIVES

To compare US and nonenhanced CT for detection, number and localization of ureteral calculi in cats.

ANIMALS

Fifty-one cats with at least 1 ureteral calculus, and 101 ureters.

METHODS

Prospective case series. All cats underwent an US followed by a nonenhanced CT. Cats were included in the study if at least 1 ureteral calculus was diagnosed on either modality. Number of calculi and their localization (proximal, middle, and distal) were recorded on both modalities. Pelvic dilatation and maximal ureteral diameter were recorded with US.

RESULTS

More calculi were detected by nonenhanced CT (126) compared to US (90), regardless of localization (P < .001). More ureters were affected on nonenhanced CT (70) compared to US (57; P < .001). The number of calculi detected was significantly different between US and nonenhanced CT in the proximal (P = .02) and distal ureteral region (P < .001). Bilateral calculi were more frequent with nonenhanced CT (19 cats) compared to US (9 cats; P < .001). A pelvic size superior to 5 mm and a maximal ureteral diameter value superior to 3 mm were always associated with ureteral calculi.

CONCLUSIONS AND CLINICAL IMPORTANCE

Computed tomography is an emerging imaging modality in cats with a suspected ureteral obstruction. Combination of CT and US can be beneficial for case management.

Surgical treatment of retroiliac ectopic ureters with secondary hydronephrosis and hydroureter in a dog

CASE DESCRIPTION

An 8-month-old 41.2-kg (90.6-lb) sexually intact male Dogue de Bordeaux with urinary incontinence and signs of nausea was referred for further evaluation and treatment of bilateral hydronephrosis, hydroureter, and ectopic ureters.

CLINICAL FINDINGS

Clinicopathologic analyses revealed urine specific gravity and serum concentrations of urea nitrogen and creatinine within reference limits. Abdominal ultrasonography and CT revealed unilateral abdominal cryptorchidism, ureters that bilaterally passed dorsal to and appeared compressed by the external iliac arteries (retroiliac ureters), and bilateral hydronephrosis, hydroureter, and ectopic ureters. On CT, minimal uptake of contrast medium by the right kidney indicated either a lack of renal function or ureteral obstruction.

TREATMENT AND OUTCOME

The dog underwent exploratory laparotomy, right ureteronephrectomy, left neoureterocystostomy, bilateral castration, and incisional gastropexy without complication and was discharged 2 days postoperatively. Eleven days after surgery, the dog had improved but continued urinary incontinence, improved left hydronephrosis and hydroureter, and serum concentrations of urea nitrogen and creatinine within reference limits. At 24 months after surgery, the dog was reportedly clinically normal, other than having persistent urinary incontinence.

CLINICAL RELEVANCE

To our knowledge, this was the first report of a dog with retroiliac ureters and compression-induced ureteral obstruction with secondary hydroureter and hydronephrosis. Retroiliac ureters should be considered as a differential diagnosis in young dogs with ureteral obstruction. Our findings indicated that a good outcome was possible for a dog with retroiliac ureters treated surgically; however, the presence of additional congenital anomalies should be considered and may alter the prognosis in dogs with retroiliac ureters.

Use of tissue plasminogen activator to alleviate postoperative subcutaneous ureteral bypass obstruction secondary to blood clot in seven cats

CASE SERIES SUMMARY

Seven cats were found to have postoperative subcutaneous ureteral bypass (SUB) occlusion secondary to blood clot formation. An increase in serum creatinine led to imaging and clot detection in all but one case. Alteplase, a tissue plasminogen activator, was infused into the SUB via the port in four cats, intravesicularly via a transurethral urinary catheter in one cat, and by both routes in two cats. Patency of the SUB was re-established in all cats within 2 days. No short- or long-term complications directly attributed to alteplase administration were observed.

RELEVANCE AND NOVEL INFORMATION

The results of this case series suggest that alteplase infusion via either the SUB port and/or a transurethral catheter should be considered prior to surgical intervention for the treatment of postoperative SUB occlusion secondary to a blood clot.

Survival and complications in cats treated with subcutaneous ureteral bypass

OBJECTIVES

To report the complications and factors affecting outcome for cats following placement of a subcutaneous ureteral bypass (SUB™).

MATERIALS AND METHODS

In this retrospective study, complications, the presence of a urinary tract infection and survival time were recorded following subctutaneous ureteral bypass placement. Factors affecting survival time were assessed using a Kaplan Meier curve and log rank test.

RESULTS

Ninety-five cats had 130 subcutaneous ureteral bypasses placed. Ten cats did not survive to discharge. Forty cats died or were euthanised after discharge (42%); the median survival time of these cats was 530 days (range 7 to 1915). Minor complications occurred in 18 cats (19%) and major complications occurred in 46 cats (48%), the majority of which were after hospital discharge. Twenty-seven cats were diagnosed with a urinary tract infection (UTI) post-operatively. A significant association between long-term survival and creatinine at presentation was identified. The median survival time for cats presenting with creatinine concentration ≥440 μmol/L (International Renal Interest Society stage acute kidney injury (AKI) 4 and 5) was 530 days (95% CI 273-787 days), compared to a median survival time of 949 days (95% CI 655-1243 days; Log Rank P=0.024) for those cats presenting with creatinine <440 μmol/L (International Renal Interest Society stage AKI 1-3).

CLINICAL SIGNIFICANCE

In this population of cats, subcutaneous ureteral bypass placement was associated with an approximately 10% in-hospital mortality and a high complication rate. Most complications were manageable, resulting in an overall median survival time of over 2 years.

Placement of ureteral stents in three rabbits for the treatment of obstructive ureterolithiasis

Management of ureteral obstruction with stenting is often associated with a lower rate of complications than ureterotomy in domestic carnivores, but this treatment has not been previously evaluated in rabbits. Three rabbits (7, 6 and 10 years old) were diagnosed with unilateral obstructive ureterolithiasis associated with hydronephrosis and hydroureter on abdominal ultrasound. Decreased overall renal function was confirmed in all three cases. Ureteral stents were placed retrogradely via cystotomy without complication in two cases and anterogradely via nephrostomy in the third case. Survival after stent placement was 30, 3 and 8 months, with encrustation of the stent and re-obstruction occurring 18, 1 and 6 months after stent placement in successive cases. Ureteral stenting can be considered for short-term management of ureterolithiasis in rabbits to improve renal function and maintain quality of life. Ultrasound or radiographic monitoring is recommended to detect encrustation of the stent. Studies comparing ureteral stenting to ureterotomy in rabbits are needed to determine the effectiveness of these techniques.

Complications and clinical utility of ultrasonographically guided pyelocentesis and antegrade pyelography in cats and dogs: 49 cases (2007-2015)

OBJECTIVE

To describe the diagnostic utility and clinical safety of ultrasonographically guided percutaneous pyelocentesis and antegrade pyelography in cats and dogs.

DESIGN

Retrospective case series.

ANIMALS

39 cats and 10 dogs with 55 affected kidneys.

PROCEDURES

Medical records were reviewed to identify cats and dogs that underwent ultrasonographically guided pyelocentesis and antegrade pyelography between June 1, 2007, and December 31, 2015. Data collected included procedure descriptions; results of diagnostic imaging, urine cytologic evaluation, and bacterial culture; and evidence of complications. Animals were assigned to the pyelocentesis group (underwent only pyelocentesis) or to the antegrade pyelography group (underwent pyelocentesis followed immediately by pyelography).

RESULTS

The diagnostic rate for pyelography was 94% (31/33; 95% confidence interval [CI], 80.4% to 98.9%). The total, minor, and major complication rates for both treatment groups combined were 25% (95% CI, 15.8% to 38.3%), 24% (95% CI, 14.4% to 36.3%), and 2% (95% CI, 0.09% to 9.6%), respectively. Performing bacterial culture of urine obtained by pyelocentesis did not provide an advantage over performing bacterial culture of urine obtained from the lower urinary tract.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings indicated that ultrasonographically guided pyelocentesis and antegrade pyelography were well-tolerated techniques for investigating upper urinary tract disease in cats and dogs and that pyelography had a higher diagnostic rate than previously reported; therefore, pyelography should be considered for identification of mechanical and functional ureteral patency abnormalities in cats and dogs.

Computed tomographic appearance of circumcaval and circumuterine ureter in a cat

BACKGROUND

Circumcaval ureter is a rare congenital anomaly resulting from the persistence of embryonic venous system. This anomaly is characterized by running of affected ureter around caudal vena cava (CVC).

CASE PRESENTATION

In this report, circumcaval ureter was found in a 2-year-old female cat attending as normal sample group in another research. This cat passed all health checkup protocols before computed tomography (CT) was performed.

CONCLUSION

The contrast-enhanced computed tomographic (cCT) images clearly revealed the dislocation of the right ureter that course around CVC and uterine body. This is the first report of feline circumcaval concurrent with circumuterine ureter detected by cCT.

Diagnostic imaging observations in cats treated with the subcutaneous ureteral bypass system

OBJECTIVES

To describe pre- and post-operative ultrasonographic and fluoroscopic findings, including any abnormalities, in cats treated for ureteral obstruction with a subcutaneous ureteral bypass system.

METHODS

Retrospective review of imaging findings in cats with ureteral obstruction that had surgery to place the first version of the bypass system and at least one follow-up ultrasound or fluoroscopic study. Pre- and post-operative renal pelvic diameter on ultrasound, fluoroscopic appearance of the bypass system and any related abnormality were recorded.

RESULTS

Eighty-one cats were included (47 unilateral, 34 bilateral bypass systems). Median preoperative renal pelvic diameter was 9 mm (range 3 to 28 mm) and median renal pelvic diameter at the first postoperative ultrasound was 3 mm (range 2 to 23 mm). The median number of postoperative imaging studies was two (range 1 to 8) and the median follow-up period after surgery was 205 days (range 1 to 1378 days). Bypass system abnormalities were identified postoperatively in 43 (53%) cats, including nephrostomy or cystostomy catheter blockage due to an undetermined cause or kinking of the catheter, nephrostomy or cystostomy catheter leakage, non-obstructive kinking of the catheter and loose nephrostomy pig-tail loop. Many abnormalities required repeat surgery, but others were managed conservatively. Fifty-four percent of obstructed ureters became patent after bypass placement, although the majority remained slightly dilated or had irregular margins compatible with chronic inflammation.

CLINICAL SIGNIFICANCE

Bypass abnormalities, mainly tube blockage, occurred frequently in cats treated for ureteral obstruction. Ultrasonography and fluoroscopy were useful for postoperative examination, including documenting renewed ureteral patency and investigation of suspected abnormalities.

Bilateral Pyelonephritis in a Cat with Multiple Urinary Malformations Including Ureteral Pseudodiverticulosis

Ureteral pseudodiverticulosis is an unusual acquired abnormality in humans and dogs. This report describes the first feline case of ureteral pseudodiverticulosis, associated with right retrocaval ureter and malposition of the uretero-vesical junctions, in the context of pyelonephritis. The coexistence of pseudodiverticulosis with other urinary abnormalities suggested that this lesion should be considered in other patients with urinary pathology.

CT variants of the caudal vena cava in 121 small breed dogs

Computed tomography is increasingly used as a treatment planning method in canine patients with diseases of the retroperitoneum, however, published information on normal variations in the caudal vena cava (CVC) are currently lacking. The objectives of this retrospective descriptive study were to characterize CVC variants using CT angiography in a sample of small breed dogs and localize the CVC bifurcations for each variant. Inclusion criteria were small breed dogs (weight ≤ 15) that underwent contrast-enhanced CT scans of the CVC, abdominal aorta, and CVC tributaries. A total of 121 small breed dogs were sampled. Four right-sided and one left-sided CVC variations were identified: normal (88/121, 72.7%), caudal-partial split (17/121, 14.0%), partial duplication (8/121, 6.6%), complete duplication (7/121, 5.8%), and left-sidedness (1/121, 0.8%). The mean lumbar vertebral levels of the CVC bifurcation were L6.39 ± 0.41, L5.70 ± 0.35, L4.39 ± 0.42, L2.74 ± 0.38, and L6.4 in the normal, caudal-partial split, partial duplication, complete duplication, and left-sidedness types, respectively. The location of the CVC bifurcation, the relationship between the aortic trifurcation and the CVC bifurcation, and the location of the bilateral deep circumflex iliac veins with respect to the CVC bifurcation were significantly different among the right-sided types (P ≤ .001). Bilateral deep circumflex iliac veins joined to the ipsilateral common iliac veins and the CVC in the caudal-partial split and duplication types, respectively. The results of this study indicated that canine CVC variants may be frequent and should be considered during surgery or diagnostic imaging of the retroperitoneum.

Therapeutic use of tetrasodium ethylenediaminetetraacetic acid solution for treatment of subcutaneous ureteral bypass device mineralization in cats

Background

Subcutaneous ureteral bypass (SUB) device placement is an increasingly popular treatment option for decompression of ureteral obstruction in cats. Mineralization occlusion of the device occurs in a minority of cases but is the most common complication.

Objective

To evaluate a 2% tetrasodium ethylenediaminetetraacetic acid (tEDTA) solution for treatment of mineralization occlusion in cats with SUBs.

Animals

Six client‐owned cats (8 obstructed devices).

Methods

Case series. Each cat was found to have device occlusion based on a combination of ultrasound examination, SUB irrigation, and failure to identify another cause of device obstruction. Each SUB was drained, irrigated using sterile saline, and infused with 1‐2 mL of 2% tEDTA solution. Success was defined as normalization of flow during subsequent ultrasound visualization while irrigating. The volume and frequency of tEDTA instillations, time to achieve device patency, follow‐up biochemical and ultrasound findings, and future reobstruction events were recorded.

Results

Resolution of mineralization was documented in all 8 SUBs. Reobstruction events occurred in 2 cats, all of which resolved after additional tEDTA infusions, but 1 cat ultimately required device exchange at 356 days from the first tEDTA infusion. In 1 cat, a single infusion was prematurely discontinued because of persistent pelvic dilatation after 1.25 mL of tEDTA had been instilled. No complications were observed.

Conclusions and Clinical Importance

Tetrasodium EDTA infusions can be safely considered as a treatment option for mineralized SUB devices in cats. This solution was easily infused, well tolerated, and avoided the need for SUB device exchange in the majority of cats in which it was used.

Subcutaneous ureteral bypass for treatment of bilateral ureteral obstruction in a cat with retroperitoneal paraganglioma

CASE DESCRIPTION A 7-year-old female domestic shorthair cat was referred for evaluation of azotemia and unilateral hydronephrosis. CLINICAL FINDINGS Abdominal ultrasonography revealed right-sided hydronephrosis and dilation of the proximal aspect of the ureter; the left kidney was small with irregular margins. A highly vascular, irregular retroperitoneal mass, not clearly associated with the ureteral obstruction, was also visualized. Surgical exploration confirmed a retroperitoneal mass involving the caudal mesenteric artery and both ureters, with hydroureter on the right side. TREATMENT AND OUTCOME A subcutaneous ureteral bypass (SUB) device was surgically implanted to treat right ureteral obstruction, and the mass was biopsied. Shortly after surgery, progressive azotemia and hyperkalemia were detected; ultrasonographic examination revealed left-sided hydronephrosis and hydroureter, which was suspected secondary to inflammation of the mass causing a left-sided ureteral obstruction. A second surgery was performed to place an SUB device for the left kidney and remove the retroperitoneal mass; both ureters were ligated at the mid- and distal aspects and then transected and removed with the mass. A neuroendocrine paraganglioma was identified by histopathologic evaluation of the mass. Hydronephrosis improved (right kidney) or resolved (left kidney) after surgery, and azotemia improved. Chemotherapeutic intervention was declined. Markers of renal function were static during the 14-month follow-up period. At the last follow-up evaluation, the patient was reportedly doing well, and both SUB devices were patent. CLINICAL RELEVANCE This was the first report of retroperitoneal paraganglioma in a domestic cat causing bilateral ureteral obstruction. Bilateral SUB device placement enabled en bloc mass resection and provided long-term relief of ureteral obstruction.

Type II retrocaval ureter causing hydronephrosis in a cat: case report

ABSTRACT Retrocaval ureter (RU) is an abnormal embryonic development of the caudal vena cava (CVC) that leads the ureter to be entrapped dorsal to the CVC. In most cases there is no clinical impact; however, it can cause hydronephrosis. We report a rare case of type II symptomatic retrocaval ureter in a feline treated with nephroureterectomy. A 4-year-old, intact male, mixed breed cat was submitted to abdominal ultrasound and severe right hydronephrosis was diagnosed, with no signs of obstruction. We performed an exploratory celiotomy, in which a displacement of the right ureter dorsal to the CVC was observed. The animal was treated with ureteronephrectomy and recovered well. No intraluminal cause was found, and a urethral catheter could be easily inserted across the ureter length. The real clinical relevance of the RU is unknown, since it is a common find in post-mortem examination without kidney impact and, when significant, is often associated to other causes of ureteral obstructions, such as calculi and strictures. Additionally, in humans, type II RU seldom develops obstruction and hydronephrosis. In our case, due to absence of other causes of obstruction, probably mechanical compression of the CVC against the psoas muscle caused the hydronephrosis.

Use of a subcutaneous ureteral bypass device for treatment of bilateral proximal ureteral injury in a 9-month-old cat

Case summary

A 9-month-old male domestic longhair cat presented following iatrogenic ureteral trauma after an attempted laparoscopic ovariectomy. Prior to identifying that the cat was male, both ureters were transected approximately 4 mm from the renal pelves. Initial management involved a left-sided Boari flap neoureterocystostomy, cystonephropexy and right ureteronephrectomy. Thirty-six hours later, the cat developed uroabdomen due to leakage from the neoureterocystostomy site. At a tertiary referral institution, the ureter was reconstructed via end-to-end anastomosis and a left-sided subcutaneous ureteral bypass (SUB) device was placed in the event the anastomosis failed. Five weeks after SUB placement, the cat was dysuric and stranguric. A urine culture was negative and clinical signs were attributed to sterile cystitis secondary to device placement. Blood urea nitrogen (BUN) was 22 mg/dl and creatinine was 1.2 mg/dl. Contrast pyelography confirmed device patency, but no contrast was identified through the ureteral anastomosis. At 12 months, BUN and creatinine were 1.5 mg/dl and 25 mg/dl, respectively, and a subclinical urinary tract infection was identified (Enterococcus faecalis). Antibiotic therapy was not prescribed in order to prevent multidrug resistance. At 42 months, BUN was 38 mg/dl and creatinine was 2.0 mg/dl. The cat had occasional and intermittent signs of pollakiuria and stranguria but was otherwise doing well.

Relevance and novel information

To our knowledge, this is the first case report to describe the use of a SUB device for management of traumatic proximal ureteral injury in a cat with one kidney. The case outcome provides valuable information about the direct effect of the SUB device and the presence of chronic Enterococcus species infection on long-term renal function.

Treatment of pyonephrosis with a subcutaneous ureteral bypass device in four cats

CASE DESCRIPTION 4 cats were examined because of ureteral obstruction. CLINICAL FINDINGS Clinical and clinicopathologic abnormalities were nonspecific and included anorexia, lethargy, weight loss, anemia, leukocytosis, neutrophilia, lymphopenia, and azotemia. A diagnosis of pyonephrosis was made in all cats. The presence of bacteriuria was confirmed by means of urinalysis in 2 cats, bacterial culture of a urine sample obtained by means of preoperative cystocentesis in 2 cats, and bacterial culture of samples obtained from the renal pelvis intraoperatively in 3 cats. Ureteral obstruction was caused by a urolith in 3 cats; ureteral stricture associated with a circumcaval ureter was identified in 1 cat. TREATMENT AND OUTCOME All 4 cats underwent renal pelvis lavage and placement of a subcutaneous ureteral bypass (SUB) device for treatment of obstructive pyonephrosis. Postoperatively, the cystostomy tube became occluded with purulent material in 1 cat, requiring exchange. The procedure was successful in relieving the obstruction and pyonephrosis in all cats. Three of 4 cats had documented resolution of urinary tract infection. One cat had persistent bacteriuria without clinical signs 1 month after SUB device placement. CLINICAL RELEVANCE Results of this small series suggested that renal pelvis lavage with placement of an SUB device may be a treatment option for cats with obstructive pyonephrosis.

Outcome of ureteral stent placement for treatment of benign ureteral obstruction in dogs: 44 cases (2010-2013)

OBJECTIVE To describe the technique and short- and long-term outcomes for dogs undergoing double-pigtail ureteral stent placement for treatment of benign ureteral obstruction. DESIGN Retrospective case series. ANIMALS 44 dogs (57 ureters). PROCEDURES Medical records of dogs that underwent ureteral stenting for treatment of benign ureteral obstruction between 2010 and 2013 were reviewed. Signal-ment, history, pertinent diagnostic imaging results, endourologic and post-procedural details, duration of hospitalization, complications, and outcome (short term, 7 to 30 days; long term, > 30 days) were recorded. Ureteral stent placement was performed endoscopically, surgically, or both, with fluoroscopic guidance. RESULTS 57 ureters (44 dogs) underwent stenting because of obstructive ureterolithiasis (n = 48 [84%]), stricture (5 [9%]), or both (4 [7%]). Endoscopic or surgical techniques were successful for stent placement in 45 of 55 and 12 of 12 ureters (34/42 and 10/10 dogs), respectively. Median hospitalization time was 1 day. Median creatinine concentration was 2 mg/dL prior to stenting and 1.3 mg/dL 3 months after the procedure. Urinary tract infections were present in 26 of 44 (59%) dogs prior to stenting and in 11 of 43 dogs (26%) after stenting. One of the 44 (2%) dogs died after undergoing stenting, but the cause of death was not related to the procedure. Median follow-up time was 1,158 days (range, 3 to > 1,555 days), with 30 of 44 dogs alive at the time of last follow-up. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ureteral stenting may be a viable option for first-line treatment of dogs with benign ureteral obstruction. However, patients should be monitored for urinary tract infection following stenting.

Treatment of congenital distal ureteral orifice stenosis by endoscopic laser ablation in dogs: 16 cases (2010-2014)

OBJECTIVE To determine characteristics of and outcomes for dogs with congenital distal ureteral orifice stenosis (CDUOS) treated by cystoscopic-guided laser ablation (CLA). DESIGN Retrospective case series. ANIMALS 16 client-owned dogs with CDUOS treated by CLA at 2 veterinary hospitals between 2010 and 2014. PROCEDURES Medical records were reviewed and data collected regarding clinical findings, imaging results, surgery characteristics, treatment, and outcome. Follow-up information was collected from dog owners and referring veterinarians via standardized interview. RESULTS Dogs included 10 males and 6 females; median age was 11.5 months (range, 4 to 112 months). Labrador Retriever (n = 6; 3 males) was the most common breed. Intramural ectopic ureteral openings were identified at the site of stenosis in 15 dogs (18/20 stenotic ureteral openings). Treatment with CLA to enlarge and relocate the stenotic opening was successful in all dogs. Median duration of anesthesia and hospitalization was 105 minutes and 24 hours, respectively. No complications were noted. Fourteen dogs remained alive (2 lost to follow-up) during a median follow-up period of 14.5 months. Owners of 11 of 13 dogs reported improvement in their dog's quality of life after CLA. The treated ureteral orifice remained patent in the 2 dogs that were reimaged. CONCLUSIONS AND CLINICAL RELEVANCE CDUOS should be considered as a differential diagnosis for dogs with idiopathic distal ureteral obstruction, particularly young male Labrador Retrievers, and was most often associated with an intramural ectopic ureter in this study. Treatment with CLA was safe and effective for opening the ureteral orifice.

Interventional Radiology and Interventional Endoscopy in Treatment of Nephroureteral Disease in the Dog and Cat

Interventional endoscopy and interventional radiology have led to the development of minimally invasive techniques for management of kidney and ureteral diseases in the dog and cat including idiopathic renal hematuria, ureteral obstruction, and ectopic ureters. Sclerotherapy is a renal-sparing chemical cauterization technique used in cases of idiopathic renal hematuria. Diagnosis of ureteral obstruction is challenging in some cases based on ultrasound alone and antegrade pyelography should be considered. Treatment options for obstructions include nephrostomy tubes, ureteral stents, and subcutaneous ureteral bypass devices. Treatment with cystoscopic-guided laser ablation provides similar outcomes to surgery in dogs with intramural ectopic ureters.

Ultrasound evaluation of the renal pelvis in cats with ureteral obstruction treated with a subcutaneous ureteral bypass: a retrospective study of 27 cases (2010–2015)

Objectives

The objective of the study was to measure the preoperative and postoperative renal pelvic size and describe the ultrasound findings following successful decompression of a ureteral obstruction using the subcutaneous ureteral bypass (SUB) device in cats.

Methods

This retrospective study assessed the measurement of the renal pelvis of 27 cats with unilateral (n = 21) or bilateral (n = 6) ureteral obstruction before (pre-t0) and after placement of a SUB during short- (before t0 + 3 months) and long-term (after t0 + 3 months) follow-up. Several qualitative ultrasound parameters were recorded for each cat. At both intervals, the last ultrasound examination was used for qualitative criteria and the mean pelvic size was recorded. The complications observed during follow-up were divided into obstructive and non-obstructive.

Results

No qualitative ultrasound parameter was statistically significant. The presence of retroperitoneal or peritoneal effusion was rarely seen (n = 4/25 during the short term and n = 1/14 during the long term). Hyperechogenicity of the perirenal adipose tissue decreased in the long term. A statistically significant decrease in the width of the renal pelvis was noted in the short- (2.4 mm, range 0–7.0 mm) and long-term (1.7 mm, range 0–3.5 mm) follow-ups compared with the preoperative value (11.7 mm, range 0.9–41 mm). Three months following SUB placement, each cat without an obstructive complication had a pelvic width ⩽3.5 mm.

Conclusions and relevance

Renal pelvic distension is at least partially reversible when ureteral obstruction is treated by placement of a SUB. Ultrasound monitoring is a useful tool to detect obstructive complications.

Placement of subcutaneous ureteral bypasses without fluoroscopic guidance in cats with ureteral obstruction: 19 cases (2014-2016)

Objectives The purpose of this study was to describe the perioperative and postoperative complications as well as short-term and long-term outcomes in cats with ureteral obstructions treated by placement of a subcutaneous ureteral bypass (SUB) device without imaging control. The second objective of this study was to compare cats treated by SUB device with cats treated by traditional surgical intervention. Methods Data were obtained retrospectively from the medical records (2014-2016) of cats that underwent SUB placement (SUB cats) and cats that underwent traditional ureteral surgery (C cats). Results Nineteen SUB devices were placed without fluoroscopic, radiographic or ultrasonographic guidance in 13 cats. Fifteen traditional interventions (ureterotomy and neoureterocystostomy) were performed in 11 cats. Successful placement of the SUB device was achieved in all cats with only one major intraoperative complication (kinking of the kidney catheter) and one minor intraoperative complication (misplacement of the kidney catheter). Eleven SUB cats recovered from the surgical procedure; two SUB cats and three C cats died during the anaesthesia recovery period. Postoperative SUB complications included anaemia (n = 2), urinary tract infection (UTI) (n = 4), non-infectious cystitis (n = 5) and SUB device obstruction (n = 1). Postoperative traditional surgery complications included anaemia (n = 7), UTIs (n = 6), non-infectious cystitis (n = 1), re-obstruction (n = 4) and ureteral stricture (n = 1). Median postoperative duration of hospitalisation (3 days) was significantly shorter for SUB cats than for C cats ( P = 0.013). Ten SUB cats (76.9%) and four C cats (40%) were still alive at a median follow-up of 225 days and 260 days, respectively. Owners were completely (90%) or mostly (10%) satisfied with the SUB device placement. Conclusions and relevance SUB device placement appears to be an effective and safe option for treating ureteral obstruction in cats, and this study has shown that fluoroscopic guidance is not essential in all cases.

ACVIM Small Animal Consensus Recommendations on the Treatment and Prevention of Uroliths in Dogs and Cats

In an age of advancing endoscopic and lithotripsy technologies, the management of urolithiasis poses a unique opportunity to advance compassionate veterinary care, not only for patients with urolithiasis but for those with other urinary diseases as well. The following are consensus-derived, research and experience-supported, patient-centered recommendations for the treatment and prevention of uroliths in dogs and cats utilizing contemporary strategies. Ultimately, we hope that these recommendations will serve as a foundation for ongoing and future clinical research and inspiration for innovative problem solving.

Nephroureteral Obstructions: The Use of Stents and Ureteral Bypass Systems for Renal Decompression

Canine and feline nephroureteral obstruction is a complex disease process that can be challenging to treat. Although the availability of various imaging modalities allows for a straightforward diagnosis to be made in most cases, the decision-making process for when a case should be taken to surgery and the optimal treatment modality that should be used for renal decompression remains controversial. In the following discussion, an overview of the perioperative management of cases with nephroureterolithiasis and nephroureteral obstruction is reviewed, with particular focus on the use of renal decompressive procedures, such as ureteral stenting and subcutaneous ureteral bypass system placement.

Renal pelvic and ureteral ultrasonographic characteristics of cats with chronic kidney disease in comparison with normal cats, and cats with pyelonephritis or ureteral obstruction

Objectives

The objective was to describe ultrasonographic characteristics of cats with stable chronic kidney disease (CKD) and determine if these were significantly different from cats with pyelonephritis (Pyelo) and ureteral obstruction (UO), to aid in clinical assessment during uremic crisis.

Methods

Sixty-six cats with stable CKD were prospectively enrolled, as well as normal control cats (n = 10), cats with a clinical diagnosis of Pyelo (n = 13) and cats with UO confirmed by surgical resolution (n = 11). Renal ultrasound was performed and routine still images and cine loops were obtained. Analysis included degree of pelvic dilation, and presence and degree of ureteral dilation. Measurements were compared between groups using non-parametric one-way ANOVA with Dunn’s post-hoc analysis.

Results

In total, 66.6% of CKD cats had measurable renal pelvic dilation compared with 30.0% of normal cats, 84.6% of Pyelo cats and 100% of UO cats. There was no statistically significant difference in renal pelvic widths between CKD cats and normal cats, or CKD cats and Pyelo cats. On almost all measurement categories, UO cats had significantly greater renal pelvic widths compared with CKD cats and normal cats ( P <0.05) but not Pyelo cats. Six percent of stable CKD cats had measurable proximal ureteral dilation on one or both sides vs 46.2% of Pyelo cats and 81.8% of UO cats. There was no statistically significant difference in proximal ureteral width between normal and CKD cats, or between Pyelo and UO cats. There was a statistically significant difference in proximal ureteral width between CKD and Pyelo cats, CKD and UO cats, normal and UO cats, and normal and Pyelo cats.

Conclusions and relevance

No significant difference in renal pelvic widths between CKD cats and Pyelo cats was seen. These data suggest CKD cats should have a baseline ultrasonography performed so that abnormalities documented during a uremic crisis can be better interpreted.

Advances in Urinary Tract Endoscopy

The use of endoscopy in veterinary medicine has become the mainstay of diagnosis and treatment in the subspecialty of small animal urology over the past decade. This subspecialty is termed endourology. With the common incidence of urinary tract obstructions, stones disease, renal disease, and urothelial malignancies, combined with the recognized invasiveness and morbidity associated with traditional surgical techniques, the use of endoscopic-assisted alternatives using interventional endoscopic techniques has become appealing to both owners and clinicians. This article provides a brief overview of some of the most common urologic procedures being performed in veterinary medicine.

Interventional urology: endourology in small animal veterinary medicine

The use of novel image-guided techniques in veterinary medicine has become more widespread, especially in urologic diseases. With the common incidence of urinary tract obstructions, stones disease, renal disease, and urothelial malignancies, combined with the recognized invasiveness and morbidity associated with traditional surgical techniques, the use of minimally invasive alternatives using interventional radiology and interventional endoscopy techniques has become incredibly appealing to owners and clinicians. This article provides a brief overview of some of the most common procedures done in endourology in veterinary medicine to date, providing as much evidence-based medicine as possible when comparing with traditional surgical alternatives.