Feline ureteral strictures: 10 cases (2007-2009)

Background: Feline ureteral obstructions have emerged as a common problem. Ureteral strictures rarely are reported as a cause and the predisposing factors and clinical course of this condition have not been described. Objectives: Evaluate cases of feline ureteral strictures and characterize historical features, clinical signs, diagnostic imaging, surgical and endoscopic findings, histopathology, treatment modalities, and short‐ and long‐term outcomes. Animals: Ten cats diagnosed with ureteral strictures based on compatible findings from at least 2 of the following: ultrasonography, ureteropyelography, surgical exploration, or histopathology. Methods: Retrospective study. Results: Median age, serum creatinine concentration, and size of the renal pelvis were 12 years, 3.7 mg/dL, and 11.75 mm, respectively. Six of 10 cats had hyperechoic periureteral tissue on ultrasound examination at the stricture site. Four cats had evidence of a circumcaval ureter at surgery. Eight cats had an intervention including ureteral stent placement (n = 6) and traditional surgery (n = 2). Seven of 8 cats had decreases in serum creatinine concentration and renal pelvic parameters preceding discharge and 6 had persistently improved results at their last examination. All patients survived to discharge. Median survival time was >294 days (range, 14 to >858 days) with 6/10 cats still alive. Conclusions and Clinical Importance: Ureteral strictures may occur in cats secondary to ureteral surgery, inflammation, a circumcaval ureter, impacted ureterolithiasis, or for unknown causes. With appropriate and timely intervention, the prognosis for long‐term survival is good. In addition to ureteral reimplantation or ureteronephrectomy, ureteral stenting or SC ureteral bypass may be considered as future therapeutic options.     

Intralesional corticosteroid injection in addition to endoscopic balloon dilation in a dog with benign oesophageal strictures

A three-year-old female spayed Golden retriever presented with a two-week history of regurgitation due to oesophageal stricture formation. Further diagnostics revealed two oesophageal strictures located at the thoracic inlet and caudal to the heart base, respectively. Endoscopic balloon dilation was performed four times at weekly intervals but recurrence of stricture formation was noted clinically within a few days after each procedure and was confirmed endoscopically. Finally, intralesional injection of triamcinolone acetonide was performed in combination with the fifth balloon dilation procedure. The dog recovered clinically and a final endoscopic examination performed 16 weeks after the injection did not reveal any evidence of oesophageal strictures.     

Asymptomatic double ureteral stricture in an 8-month-old Maine Coon cat: an imaging-based case report

Congenital ureteral strictures are rare both in human and veterinary medicine. While the diagnosis is generally made after a symptomatic or febrile urinary tract infection, we report here a case in which this condition represented an incidental finding during routine ultrasonography. To the best of the authors' knowledge imaging findings of a double monolateral ureteral stricture have not previously been reported.     

Recurrent single oesophageal stricture treated with a self-expanding stent in a cat

A 1-year-old, female spayed domestic shorthair cat was presented with a 4-week history of dysphagia and regurgitation soon after oral treatment with clindamycin. Fluoroscopic and endoscopic examinations confirmed the presence of a single cervical oesophageal stricture 4 cm caudal to the pharynx. A fluoroscopically and endoscopically guided balloon dilation was performed six times consecutively over a period of 3 weeks as reformation of the stricture appeared within 3-7 days. Feeding via percutaneous endoscopic gastrostomy-tube as long-term management of the condition was declined by the owner. A self-expanding metal oesophageal stent with the following dimension was subsequently implanted: fully open diameter 16 mm, length 30 mm. After stent implantation, the cat was fed on mashed canned food and did not show any clinical signs for 12 months. Twelve months post-implantation the cat was no longer able to eat even liquid food, became lethargic and the owner opted for euthanasia. On post-mortem examination the stent surfaces were overgrown by oesophageal mucosa by approximately 50%. Stent obstruction was detected and caused by swallowed hair which also seemed to have hampered mucosal integration in the distal part of the stent.     

Treatment of ureteral calculus obstruction with laser lithotripsy in an Atlantic bottlenose dolphin (Tursiops truncatus)

An adult female bottlenose dolphin (Tursiops truncatus) presented with acute anorexia secondary to progressive azotemia (blood urea nitrogen = 213 mg/dl, creatinine [Cr] = 9.5 mg/dl) and electrolyte abnormalities (K = 7.4 mEq/L). It was later diagnosed with postrenal obstruction secondary to bilaterally obstructing ureteral calculi seen on ultrasound. Treatment of the obstruction required two endoscopic procedures, cystoscopy for ureteral stent placement and ureteroscopy to perform intracorporeal lithotripsy on the obstructing calculi. Before the first procedure, the dolphin's azotemia was stabilized with aggressive fluid therapy, peritoneal dialysis, and treatment for acidosis. Diuresis subsequent to the fluid therapy enabled passage of the right obstructing urolith. For both endoscopic procedures, the dolphin was placed in left lateral recumbency due to the peritoneal dialysis catheter in the right retroperitoneal region. For the first procedure, a 12-French (Fr) flexible cystoscope was inserted retrograde into the bladder via the urethra, whereupon a calculus was seen obstructing the left ureteral orifice. A 4.8-Fr, 26-cm double-pigtail ureteral stent was placed up the left ureter to relieve the postrenal obstruction. Inadvertent proximal migration of the left ureteral stent occurred during the procedure. However, renal parameters (serum Cr = 5.8, K = 5.4) improved significantly by the next day. For the second procedure, 28 hr later, ureteroscopy was performed to treat the calculus and replace the existing stent with a longer stent. The left ureteral calculus was pulverized into tiny fragments by using a holmium:yttrium-aluminum-garnet laser inserted through a 6.9-Fr semirigid ureteroscope. The migrated stent was visualized in the distal left ureter and replaced with a 90-cm single-pigtail ureteral stent that was sutured exterior to the urogenital slit and removed 3 days later. Renal function normalized over the next several days, and the dolphin recovered over the next 2 mo.     

Conservative treatment of acquired oesophageal strictures by endoscopic‐guided balloon dilation in two horses

Oesophageal stricture is an uncommon condition in horses that results in an obstructive syndrome with regurgitation of food and possible aspiration pneumonia. Currently, in both human and small animal practice, one of the preferred treatment options for oesophageal strictures consists of pneumatic or hydrostatic balloon dilation. The aim of this article is to report 2 cases of severe oesophageal stricture in the horse, successfully treated with endoscopic‐guided hydrostatic balloon dilation.     

Bilateral hydronephrosis secondary to endometriosis managed by endoscopic ureteral stent placement in a captive Guinea baboon (Papio papio)

Spontaneous endometriosis is an estrogen-dependent, progressive and painful disease that affects a variety of nonhuman primates, including several species of baboons (Papio sp.). This case documents multimodal management of severe endometriosis in a captive female baboon within a zoological institution. An 18-yr-old, intact female Guinea baboon (Papio papio) was found to have an enlarged uterus. Fifteen months post ovariohysterctomy, scarring associated with endometrial tissue resulted in ureteral strictures, bilateral hydronephrosis, and azotemia. Cystoscopic placement of bilateral ureteral stents with fluoroscopy was performed and resulted in short-term clinical improvement. The animal's condition declined and euthanasia was elected 4 mo after ureteral stent placement. Severe endometriosis with secondary inflammation resulting in bilateral hydroureter and hydronephrosis, as well as concurrent cystitis, ureteritis, and pyelonephritis were confirmed at necropsy. Despite possible complications, ureteral stents can be considered a useful therapeutic option in patients with ureteral disease.     

Treatment of atresia ani type I by balloon dilatation in 5 kittens and one puppy

Atresia ani is the most common anorectal anomaly in small animals. In the present study, an anal stricture (atresia ani type I) in five 3 to 8 weeks old kittens and one 4 month old puppy was treated by balloon dilation. In 4 kittens and the puppy the stricture was eliminated permanently and without complications by a single intervention. Only the smallest kitten with the most severe stenosis developed a rectal fistula as a complication of repeated balloon dilation, which necessitated surgical correction. Balloon dilation proved to be an efficient therapeutic method for anal atresia type I, and can be recommended as the treatment of choice.     

Clinical Presentation and Outcome of Cats with Circumcaval Ureters Associated with a Ureteral Obstruction

Background

Circumcaval ureters (CU) are a rare embryological malformation resulting in ventral displacement of the caudal vena cava, which crosses the ureter, potentially causing a ureteral stricture.

Objectives

To evaluate cats with obstructed CU(s) and report the presenting signs, diagnostics, treatment(s), and outcomes. Cats with obstructed CU(s) were compared to ureterally obstructed cats without CU(s).

Animals

193 cats; 22 circumcaval obstructed (Group 1); 106 non‐circumcaval obstructed (Group 2); 65 non‐obstructed necropsy cases (Group 3).

Methods

Retrospective study, review of medical records for cats treated for benign ureteral obstructions from AMC and University of Pennsylvania between 2009 and 2013. Inclusion criteria: surgical treatment of benign ureteral obstruction, complete medical record including radiographic, ultrasonographic, biochemistry, and surgical findings.

Results

Seventeen percent (22/128) of obstructed cats had a CU (80% right‐sided) compared to 14% (9/65) non‐obstructed necropsy cats (89% right‐sided). Clinical presentation, radiographic findings, and creatinine were not statistically different between Groups 1 and 2. Strictures were a statistically more common (40%) cause of ureteral obstruction in Group 1 compared to Group 2 (17%) (P = .01). The MST for Groups 1 and 2 after ureteral decompression was 923 and 762 days, respectively (P = .62), with the MST for death secondary to kidney disease in both groups being >1,442 days. Re‐obstruction was the most common complication in Group 1 (24%) occurring more commonly in ureters of cats treated with a ureteral stent(s) (44%) compared to the subcutaneous ureteral bypass (SUB) device (8%) (P = .01).

Conclusions and Clinical Importance

Ureteral obstructions in cats with a CU(s) have a similar outcome to those cats with a ureteral obstruction and normal ureteral anatomy. Long‐term prognosis is good for benign ureteral obstructions treated with a double pigtail stent or a SUB device. The SUB device re‐obstructed less commonly than the ureteral stent, especially when a ureteral stricture was present.     

IMAGING DIAGNOSIS—RADIOGRAPHY AND ULTRASONOGRAPHY OF BILATERAL CONGENITAL URETEROVESICAL JUNCTION STENOSIS CAUSING HYDRONEPHROSIS AND HYDROURETER IN A FERRET (MUSTELA PUTORIUS FURO)

An 8‐month‐old neutered male ferret was presented for vaccination and preventive treatment for adrenal gland disease. Abdominal ultrasound revealed severe bilateral hydronephrosis and hydroureter. Excretory urography and negative contrast cystography showed bilateral ureterovesical junction stenosis. Positive retrograde cystography demonstrated right ureteral reflux. A subcutaneous ureteral bypass was placed in the left kidney; however, it had to be removed 3 months later due to an obstruction and persistent urinary tract infection. Bilateral ureteroneocystotomy was performed. Although congenital strictures are uncommon in veterinary patients, they should be included in the differential diagnosis in ferrets presenting with hydronephrosis and hydroureter of undetermined cause.     

Use of a biodegradable self-expanding stent in the management of a benign oesophageal stricture in a cat

An 11-year-old domestic shorthair cat presented with a six-week history of regurgitation following a dental procedure. Endoscopy identified a single oesophageal stricture in the cervical oesophagus. Stricture reformation occurred following endoscopic balloon catheter dilation on two occasions. Following a third balloon dilation a biodegradable polydioxanone self-expanding stent was placed across the stricture site. Following the implantation the cat was able to eat soft canned food orally without regurgitation. Fluoroscopic examination performed four months after placement indicated that the stent was no longer present and the cervical oesophagus was able to pass boluses of canned food with no signs of obstruction.     

Colonic seromuscular augmentation cystoplasty following subtotal cystectomy for treatment of bladder necrosis caused by bladder torsion in a dog

CASE DESCRIPTION: A 5-year-old Labrador Retriever was evaluated because of a 3-day history of lethargy, anorexia, vomiting, stranguria, and anuria after routine ovariohysterectomy. CLINICAL FINDINGS: On initial examination, signs of abdominal pain and enlargement of the urinary bladder were detected. Clinicopathologic abnormalities included leukocytosis, azotemia, and hyperkalemia. Radiography and surgical exploration of the abdomen revealed urinary bladder torsion at the level of the trigone; histologically, there was necrosis of 90% of the organ. TREATMENT AND OUTCOME: After excision of the necrotic wall of the urinary bladder (approx 0.5 cm cranial to the ureteral orifices), the remaining bladder stump was closed with a colonic seromuscular patch. Eleven weeks later, cystoscopy revealed an intramural ureteral stricture, for which treatment included a mucosal apposition neoureterocystostomy. Thirteen months after the first surgery, the dog developed pyelonephritis, which was successfully treated. By 3 months after subtotal cystectomy, the dog's urinary bladder was almost normal in size. Frequency of urination decreased from 3 to 4 urinations/h immediately after surgery to once every 3 hours after 2 months; approximately 4 months after the subtotal cystectomy, urination frequency was considered close to normal. CLINICAL RELEVANCE: Urinary bladder torsion is a surgical emergency in dogs. Ischemia of the urinary bladder wall may result from strangulation of the arterial and venous blood supply and from overdistension. Subtotal resection of the urinary bladder, preserving only the trigone area and the ureteral openings, and colonic seromuscular augmentation can be used to successfully treat urinary bladder torsion in dogs.     

Endoscopic balloon dilation of benign esophageal strictures in dogs and cats

Endoscopic balloon dilation of benign esophageal strictures was performed in 18 dogs and 10 cats with a median age of 4 years. Stricture formation was associated with a recent anesthetic episode in 18 patients. Regurgitation was the most common clinical sign and was present a median of 4 weeks before dilation. Most animals had a single stricture; median diameter was 5 mm, and median length was 1 cm. Esophagitis and mucosal fibrosis were detected in 9 patients each. Dilation was performed with progressively increasing diameter balloons, from 6 to 20 mm. After dilation, mucosal hemorrhage was mild to moderate in most patients. Esophageal perforation was the only serious complication and occurred in 1 patient. Postdilation therapy consisted of administration of cimetidine, metoclopramide, sucralfate, and prednisone in most animals. The median number of dilation procedures performed in each animal was 2, with a range of 1-5. The median interval between dilations was 13 days. Stricture diameter markedly increased with subsequent dilations. Median duration of follow-up was 131 weeks. A successful outcome occurred in 88% of patients, with most animals able to eat canned, mashed, or dry food without regurgitation. Mucosal fibrosis was associated with a better clinical response score, while increasing age was weakly associated with fewer dilations. The dilation protocol used in this group of animals was safe and efficacious.     

Intraluminal tracheal stenting for treatment of tracheal narrowing in three cats

OBJECTIVE: To describe the use of intraluminal tracheal stenting in 3 cats with either benign or malignant tracheal obstruction. STUDY DESIGN: Retrospective clinical study. ANIMALS: Three client-owned cats. METHODS: Medical records were reviewed and information regarding signalment, clinical signs, physical examination findings, diagnostic tests performed, treatment, outcome and follow-up were retrieved. Intraluminal tracheal stent placement was performed as previously described in the literature. RESULTS: Three cats received intraluminal tracheal stents for the treatment of tracheal obstruction due to 3 different underlying causes: stricture secondary to traumatic endotracheal intubation, stricture secondary to a previous tracheotomy, and neoplasia. Self-expanding metallic stents of varying sizes were placed, and all cats recovered uneventfully from the procedures. The cat with tracheal neoplasia was euthanized because of pulmonary metastatic disease 6 weeks post-stent placement. The two cats with tracheal obstructions secondary to benign strictures are currently 39 months and 32 weeks post-stent placement, respectively. No complications were noted during the post-stent period in any of the 3 cats. CONCLUSIONS: Intraluminal tracheal stenting was easily, safely, and rapidly performed without complications and resulted in immediate improvement in clinical signs in all three cases. None of the cats in this study developed significant stent-associated complications during the study period. CLINICAL RELEVANCE: Intraluminal tracheal stenting has the potential to be a viable option for the treatment of tracheal obstruction in cats and perhaps for similar disease processes in other veterinary patients.     

Ultrasonographic and histopathological features in 8 cats with fibrotic small intestinal stricture

Benign stricture is an uncommon cause of chronic small intestinal obstruction in the cat. The purpose of this retrospective case series was to describe the ultrasonographic features, histopathological findings, and clinical presentation in a group of cats with benign small intestinal stricture. Inclusion criteria were cats presenting during the period 2010‐2017, and that had ultrasonography and small intestinal stricture confirmed at surgery. For each cat, clinical data and ultrasonographic findings were retrieved from the medical record, and histopathology, where available, was reviewed. Eight cats met the inclusion criteria. The location of strictures was duodenum (1/8), mid‐ to distal jejunum (4/8), and ileum (3/8). Ultrasonographic findings included gastric distension (8/8) and generalized (3/8) or segmental (5/8) intestinal dilation consistent with mechanical obstruction. Ingesta did not propagate beyond the strictured segment. Wall thickening was mild to moderate (3‐6 mm). Normal wall layering was disrupted in all cats. Strictures were predominantly hypoechoic (7/8) and associated with hyperechoic peri‐intestinal mesentery (6/8). Annular strictures (5/8) were less than 15 mm in length whereas long‐segment strictures (3/8) were greater than 15 mm in length. Histopathology showed transmural disease with fibrosis and inflammation (8/8), often (6/8) extending into the bordering mesentery. The mucosa was the most severely affected layer and epithelial injury accompanied the mucosal fibrosis/inflammation. Clinical presentation reflected delayed diagnosis of chronic bowel obstruction with debilitation (8/8), marked weight loss (8/8), and prerenal azotemia (5/8). Benign fibrostenotic stricture should be considered a differential diagnosis in debilitated young cats presenting with chronic bowel disease and ultrasonographic features of intestinal obstruction.     

Ultrasound-guided percutaneous antegrade pyelography with computed tomography for the diagnosis of spontaneous partial ureteral rupture in a dog

A 10-year-old spayed female dalmatian dog developed acute vomiting and abdominal pain. Ultrasound examination of the abdomen showed right hydronephrosis and proximal ureter dilation with mild retroperitoneal free fluid. Computed tomography (CT) of the abdomen confirmed the ultrasonographic findings and revealed, additionally, a right ureteral stone. Spontaneus rupture of the right ureter was confirmed with CT post ultrasound-guided percutaneous antegrade pyelography. Pyeloureteral rupture and the presence of a ureteral stone were confirmed at surgery.     

Balloon dilation of oesophageal strictures in two horses

Oesophageal strictures in 2 horses with chronic recurrent oesophageal obstruction or choke was diagnosed by endoscopy and contrast radiography. Balloon dilation of the strictures was performed under endoscopic and fluoroscopic guidance. Follow‐up endoscopic and radiological examinations performed 6 weeks after the procedure showed clear dilation of the strictures. Both horses did not have any recurrence during follow‐up periods of 10 and 12 months.     

Use of a self-expanding metallic stent for the treatment of a urethral stricture in a young cat

A 4-month-old intact male domestic shorthair cat was evaluated for urinary outflow obstruction after several weeks of medical management for traumatic urethral rupture. Positive-contrast retrograde urethrography and anterograde cystoscopy performed 4 weeks after the initial urethral injury confirmed a stricture approximately 1cm distal to the bladder trigone at the site of the initial urethral tear. A self-expanding metallic urethral stent (SEMS) was placed under fluoroscopic guidance to relieve the urethral stricture and re-establish luminal patency. After stent placement, the cat was able to void urine normally with minimal urinary incontinence noted. This resolved several months post-stent placement. No known clinical complications persisted other than mild intermittent hematuria.     

Ureteral obstructions in dogs and cats: a review of traditional and new interventional diagnostic and therapeutic options

Objective – To describe and review both traditional and newer diagnostic and therapeutic options for canine and feline ureteral obstructions currently being performed clinically in veterinary medicine. Data Sources – A Medline search with no date restrictions was used for this review. Human Data Synthesis – The human literature would support the use of minimally invasive endourological techniques for the treatment of nearly all causes of ureteral obstructions, whenever possible. This typically includes extracorporeal shockwave lithotripsy, intracorporeal lithotripsy via retrograde ureteroscopy or antegrade percutaneous nephroureterolithotomy, ureteral stenting, percutaneous nephrostomy tube placement, and laparoscopic endopyelotomy. Typically open surgery is only suggested in cases of ureteral or gynecological malignancy when en bloc resection is considered a good option, or when various methods of endourological techniques have failed. Veterinary Data Synthesis – The veterinary literature is scarce on the use of interventional endourological techniques for the treatment of ureteral obstructions and has been growing over the last 5 years. The current literature reports the use of extracorporeal shockwave lithotripsy for ureteral stones, as well as the use of ureteral stents for the treatment of trigonal obstructive transitional cell carcinoma, ureterolithiasis, and ureteral strictures. Traditional surgical interventions, like ureterotomy, ureteronephrectomy, and ureteral reimplantation is more vastly reported and accepted. This review will focus on new clinical data using interventional endourological techniques for ureteral obstructions. Conclusions – Various treatment options for ureteral obstructions are now available for veterinary patients, and the trend away from traditional surgical techniques will hopefully be followed now that they are technically and clinically available for dogs and cats.