Figure 4 - uploaded by Ye-In Oh
Content may be subject to copyright.
Histopathology revealed an irregular region of papillary hyperplasia of the luminal transitional epithelium with luminal projections of stromal tissue and hyperplastic epithelium (A, asterisk). The epithelial components are welldifferentiated (B).
Source publication
An 8-month-old cat was presented with bilateral hydronephrosis. Bilateral ureteral obstructions were identified by diagnostic imaging and confirmed by necropsy. Histopathologic findings revealed polypoid transitional epithelial hyperplasia with chronic lymphoplasmacytic inflammation. This report documents congenital ureteral strictures as a cause o...
Citations
... Feline congenital ureteral obstructions have been reported relatively rarely and may result from a circumscribed narrowing of the ureteral lumen (3). In the veterinary medical literature, the feline congenital ureteral obstruction is reported in five studies (22)(23)(24)(25)(26), of which three cases underwent euthanasia, and no case dealt with multimodality imaging description in detail. ...
... Feline congenital ureteral obstruction without evidence of intraluminal obstruction has been rarely documented. To our knowledge, unilateral or bilateral congenital ureteral obstruction has been reported previously in five cats (22)(23)(24)(25)(26). Previous reports of considered feline congenital ureteral obstruction included one cat with bilateral ureteral fibrosis without evidence of an underlying cause (22); one cat wherein unilateral double ureteral stenosis without any clinical signs was incidentally discovered on US, although this was not confirmed by histopathology (23); one cat wherein necropsy with bilateral proximal ureteropelvic junction stenosis without fibrosis was confirmed (24); one cat wherein bilateral ureteral strictures with polypoid transitional epithelial hyperplasia and chronic lymphoplasmacytic inflammation were histopathologically revealed (25); and one cat wherein unilateral ureteral stenosis with a normal ureteral epithelium was histopathologically confirmed (26). ...
... Feline congenital ureteral obstruction without evidence of intraluminal obstruction has been rarely documented. To our knowledge, unilateral or bilateral congenital ureteral obstruction has been reported previously in five cats (22)(23)(24)(25)(26). Previous reports of considered feline congenital ureteral obstruction included one cat with bilateral ureteral fibrosis without evidence of an underlying cause (22); one cat wherein unilateral double ureteral stenosis without any clinical signs was incidentally discovered on US, although this was not confirmed by histopathology (23); one cat wherein necropsy with bilateral proximal ureteropelvic junction stenosis without fibrosis was confirmed (24); one cat wherein bilateral ureteral strictures with polypoid transitional epithelial hyperplasia and chronic lymphoplasmacytic inflammation were histopathologically revealed (25); and one cat wherein unilateral ureteral stenosis with a normal ureteral epithelium was histopathologically confirmed (26). The age of the five cats that were previously reported to be diagnosed with assumed congenital ureteral obstruction ranged from 4 months to 4 years, and this reported the youngest cat with congenital ureteral obstruction (22)(23)(24)(25)(26). ...
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.
... Serum biochemical results in diseased cats showed significant elevation of BUN and creatinine. These findings matched that of Lee et al. (2014) and Shipov and Segev (2013) as ureteral obstruction was a commonly recorded cause for acute uremia in cats. Another study described by Meldrum (2016) reviewed that decreased blood flow to the Hydronephrotic kidney resulted in decrease glomerular filtration and eventually acute kidney injury. ...
eline unilateral hydronephrosis is a critical disease in cat medicine. Twenty-six domestic cats from theteaching veterinary hospital and private clinics in Egypt were used in this study. For the diagnostic study, we examinedtwelve healthy cats and nine cats suffering from unilateral hydronephrosis. Diagnosis included physical examination,laboratory analysis, and ultrasonographical and radiographical examinations. In physical examinations of diseasedcases, the respiration rate was increased, anemia, pale mucous membrane, and pollakiuria. In hematological parameters,significant decrease in packed cell volume (PCV), hemoglobin concentration, and Red blood cells (RBCs) count,while white blood cells (WBCs) and absolute neutrophilic count were increased. Radiopaque renal calculi appearedradiologically in some cases. Ultrasonographically, an increase in the length of the kidney and severe enlargement withloss of architecture of renal parenchyma and also severely enlarged renal pelvises were gathered. For the anatomicalstudy, seven cases (two of them were in common with diagnostic examination) were dissected. Kidney were smoothunipapillated with the right kidney positioned more cranial than the left one. Radiologically, both kidneys mightappear mostly overlapping each other also the radiological length of the healthy kidney was 3 times the length of thesecond lumbar vertebra (L2) while the length of the hydronephrotic kidney reached 3.5 times the length of L2. Thenormal and hydronephrotic renal anatomical measurements were included. We concluded that not only the increasein kidney size indicated unilateral hydronephrosis but also loss of renal parenchymal architecture ultrasonographicallyand anatomically an increase in renal pelvis width in addition to significant changes in biochemical parameters.
(PDF) Diagnostic and Anatomical Studies on Unilateral Hydronephrosis in Domestic Cats. Available from: https://www.researchgate.net/publication/354412150_Diagnostic_and_Anatomical_Studies_on_Unilateral_Hydronephrosis_in_Domestic_Cats [accessed Jan 14 2023].
... solidified blood (DSB) calculi, and retroperitoneal fibrosis after a renal transplantation (Vanden et al. 2005;D'lppolito et al. 2006;Ragni and Fews 2008;D'Anjou et al. 2011;Zaid et al. 2011;Cohen et al. 2012;Foster and Pinkerton 2012;Lee et al. 2014;Selgas et al. 2014). Blood clots in the urinary tract are rare and may result from urinary tract calculi, infections, inflammation, neoplasia, trauma, clotting disorders, or idiopathic causes (Rawlings et al. 2003;DiBartola 2005;Vanden et al. 2005). ...
A seven-year-old male cat that was previously diagnosed with – and treated for – left hydronephrosis due to suspected idiopathic proteinaceous materials in the renal pelvis, presented with a short history of anorexia and vomiting. The abdominal ultrasound revealed bilateral hydronephrosis, and the intravenous pyelography showed a moderate amount of free fluid in the retroperitoneal space at 48 hours. After the nephrectomy, the gross examination of the right kidney revealed a very thin capsule with urine leakage, and the right renal pelvis showed small, black deposits. The histopathology of the right kidney revealed hydronephrosis with compression atrophy, necrosis of the renal cortex/medulla, and a moderate lymphoplasmacytic inflammation. The crystallographic analysis revealed that the black deposits were composed of 100% protein and no minerals. The cat was diagnosed with hydronephrosis and spontaneous renal rupture caused by proteinaceous pelvic materials, secondary to the idiopathic renal lymphoplasmacytic inflammation. In addition to revealing the possibility that immune-mediated renal disease can induce spontaneous renal rupture in cats, this case report demonstrates the utility of imaging for diagnosing and monitoring hydronephrosis, detecting urine leakage, and planning surgery.
... Strictures of the ureter are an interesting and increasingly reported cause of ureteral obstructions in cats (Leib et al. 1998, Kyles et al. 2005a, Berent 2011, Zaid et al. 2011, Berent et al. 2012, Foster & Pinkerton 2012, Horowitz et al. 2013, Belanger et al. 2014, Lee et al. 2014, Zotti et al. 2004. Three cases of congenital ureteral strictures have been reported in young cats, with two of those cases having histopathologic confirmation of the stricture obtained at necropsy (Leib et al. 1998, Lee et al. 2014). ...
... Strictures of the ureter are an interesting and increasingly reported cause of ureteral obstructions in cats (Leib et al. 1998, Kyles et al. 2005a, Berent 2011, Zaid et al. 2011, Berent et al. 2012, Foster & Pinkerton 2012, Horowitz et al. 2013, Belanger et al. 2014, Lee et al. 2014, Zotti et al. 2004. Three cases of congenital ureteral strictures have been reported in young cats, with two of those cases having histopathologic confirmation of the stricture obtained at necropsy (Leib et al. 1998, Lee et al. 2014). An additional young cat had progressive renal failure and hydronephrosis with bilateral UPJ stenosis confirmed at necropsy (Foster & Pinkerton 2012). ...
Feline ureteral obstructions are an increasingly recognised and challenging diagnostic and management problem. Many cats with ureteral obstructions are critically ill at the time of diagnosis, especially if there is dysfunction of the contralateral kidney. They may present with varying severities of acute kidney injury, electrolyte disturbances, and may have comorbidities such as heart disease that complicate perioperative and long‐term management. Medical management, which may consist of rehydration and restoration of intravascular volume with intravenous fluid therapy, osmotic diuresis, ureteral muscle relaxation, and antimicrobials for infection, is important in feline ureteral obstruction patients. Despite medical management, many cats with ureteral obstructions will require decompression of the obstructed kidney to relieve pressure‐nephropathy and restore urine flow. However, some cats may be too unstable for traditional medical management and require more emergent intervention to relieve the obstruction and address the life‐threatening sequelae to acute kidney injury, such as hyperkalaemia and fluid overload. Both surgical and interventional methods to address ureteral obstructions have been described in veterinary medicine, though debate continues as to the ideal approach.
We investigated the pathological characteristics of renal dysplasia with hydronephrosis and congenital ureteral stricture in two calves. Macroscopically, the affected kidneys were enlarged and the renal calyces were dilated and associated with ureteral strictures. Histopathologically, multifocal regions of mesenchyme were observed in the renal medulla. This mesenchyme was weakly eosinophilic with haematoxylin and eosin, blue with Alcian blue and pale blue with Masson's trichrome, and was immunopositive for vimentin and smooth muscle actin, consistent with persistent mesenchyme. There was asynchronous differentiation of the renal cortex characterized by immature glomeruli, immature tubules and arteriolar proliferation. Similar persistent mesenchyme was observed in the ureteral walls with ureteral stricture, and the ureteral musculature or smooth muscle bundles had a disorganized arrangement. Congenital ureteral stricture appeared to have caused ureteral obstruction and hydronephrosis. The lesions may represent a new phenotype of renal dysplasia with concomitant congenital ureteral stricture in Holstein-Friesian calves.
OBJECTIVE
To assess the usefulness of magnetic resonance urography (MRU) for the visualization of nondilated renal pelvises and ureters in dogs and to compare our findings for MRU versus CT urography (CTU).
ANIMALS
9 healthy Beagles.
PROCEDURES
Dogs underwent CTU, static-fluid MRU, and excretory MRU, with ≥ 7 days between procedures. Contrast medium was administered IV during CTU and excretory MRU, whereas urine in the urinary tract was an intrinsic contrast medium for static-fluid MRU. For each procedure, furosemide (1 mg/kg, IV) was administered, and reconstructed dorsal plane images were acquired 3 minutes (n = 2) and 7 minutes (2) later. Images were scored for visualization of those structures and for image quality, diameters of renal pelvises and ureters were measured, and results were compared across imaging techniques.
RESULTS
Excretory MRU and CTU allowed good visualization of the renal pelvises and ureters, whereas static-fluid MRU provided lower visualization of the ureters. Distention of the renal pelvises and ureters was good in excretory MRU and CTU. Distention of the ureters in static-fluid MRU was insufficient compared with that in CTU and excretory MRU. Distinct artifacts were not observed in CTU and excretory MRU images. Static-fluid MRU images had several mild motion artifacts.
CLINICAL RELEVANCE
Our findings indicated that excretory MRU with furosemide administration was useful for visualizing nondilated renal pelvises and ureters of dogs in the present study. When performing MRU for the evaluation of dogs without urinary tract dilation, excretory MRU may be more suitable than static-fluid MRU.
Feline ureteral obstruction can have several causes; however, ureterolithiasis has been increasing in occurrence. The restriction of urinary flow induced by the obstruction has harmful consequences to the body and can lead to acute renal failure. Calcium oxalate ureterolithiasis is reported in older cats, aged mean 12 years old. A case of bilateral ureteral obstruction in a 7-month-old mixed breed cat is described in this report. Imaging tests such as abdominal ultrasonography, radiography and excretory urography were performed to determine the diagnosis. The surgical procedure of bilateral ureterotomy was then performed, which allowed the improvement of the urinary flow of both kidneys and the resolution of clinical signs caused by uremia. The quantitative analysis of both uroliths revealed the composition of 100% monohydrate calcium oxalate. Calcium oxalate stones can also cause ureteral obstruction in young cats; although, are less common in this age. When conservative treatment fails, surgical intervention becomes necessary for the rapid return of renal function. To author’s knowledge this is the first report of a ureterolithiasis caused by calcium oxalate in a young cat.
Practical relevance
Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the urinary tract provides important information useful in the investigation of several conditions including ureteral obstruction and cystitis.
Clinical challenges
Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as lipid droplets in the bladder, and pathological changes can be challenging.
Aim
This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased renal pelvis, ureters and urinary bladder. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material. Ultrasound examination of the kidneys and perinephric space was discussed in an article published in May 2020.
Equipment
Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience.
Evidence base
Information provided in this article is drawn from the published literature and the author’s own clinical experience.
A 4-month-old, intact male, domestic longhair cat was admitted with a 2-month history of abdominal distention. Physical examination revealed a mild inspiratory distress and a large palpable intraabdominal mass, in an otherwise bright and alert cat. Abdominal ultrasonography revealed a large hypoechoic cystic structure compatible with hydronephrosis or a renal cyst. On exploratory celiotomy, hydronephrosis of the right kidney was documented and ureteronephrectomy was performed. Histopathology of the excised tissues revealed severe stenosis in the proximal ureteral lumen without evidence of obstructive material, a normal ureteral epithelium and severe atrophy of the renal cortex and medulla, supporting the diagnosis of congenital unilateral ureteral stenosis. The cat recovered uneventfully and 8 months later was in excellent clinical condition. Congenital ureteral stenosis with secondary hydronephrosis may occur rarely in cats and should be included in the differential diagnosis of progressive abdominal distention in young cats.
Feline obstructive ureteral disease will likely remain a common and frustrating cause of critical illness in cats for the foreseeable future. Since many cats are uraemic and cardiovascularly unstable secondary to obstructive nephropathy, prompt recognition using clinical intuition, blood work and diagnostic imaging is essential to make a timely diagnosis and decision about timing for intervention, if indicated. Multiple surgical and interventional procedures exist for the management of feline ureteral obstructions but there is no ideal technique and all currently available procedures carry risk of infection, re‐obstruction, urine leakage and the need for additional procedures in the future. Therefore, until clear, evidence‐based guideline exist, the decision about which ureteral procedure to perform in cats should be guided by nature of the obstruction, location, concurrent urolithiasis, infection and surgeon preference. In all likelihood, ureteral surgery, stents and ureteral bypass devices will continue to remain viable options and the decision about which procedure to use will be made on a case‐by‐case basis.
