Obstructive struvite ureterolithiasis in 4-month-old intact male Bernese mountain dog.

A 4-month-old, 7 kg, intact male, Bernese mountain dog was presented for obstructive struvite ureterolithiasis. Multiple urethroliths, ureteroliths, and urocystoliths were present. Based on an abdominal ultrasound, there was severe left hydronephrosis and hydroureter from distal ureterolith obstruction, just proximal to the vesicoureteral junction. The dog was not azotemic. Successful treatment was accomplished via ventral cystotomy. Bladder wall culture revealed a methicillin-resistant Staphylococcus spp. No predisposing cause was identified. There are no known genetic predispositions in Bernese mountain dogs for struvite urolithiasis. The urinary tract infection resolved with surgical retrieval of the uroliths and antibiotic treatment. The dog remained clinically normal after the cystotomy but developed a subclinical urinary tract infection 4 mo post-operatively. Key clinical message: Urolithiasis is rare in pediatric veterinary patients. To the authors' knowledge, this is the first report of obstructive ureterolithiasis in a puppy. There is no known genetic predisposition for urolithiasis in Bernese mountain dogs.

Urétérolithiase obstructive à struvite chez un bouvier bernois mâle intact de 4 mois. Un bouvier bernois mâle intact de 4 mois, pesant 7 kg, a été présenté pour une urétérolithiase obstructive à struvite. De multiples urétrolithes, urétérolithes et urocystolithes étaient présents. Sur la base d'une échographie abdominale, il y avait une hydronéphrose gauche sévêre et un hydro-uretêre dû à une obstruction distale de l'urétérolithe, juste en amont de la jonction vésico-urétérale. Le chien n'était pas azotémique. Le succês du traitement a été obtenu par cystotomie ventrale. La culture de la paroi vésicale a révélé un Staphylococcus spp. résistant à la méticilline. Aucune cause prédisposante n'a été identifiée. Il n'y a pas de prédisposition génétique connue chez les bouviers bernois pour la lithiase urinaire à struvite. L'infection des voies urinaires s'est résolue avec l'extraction chirurgicale des urolithes et un traitement antibiotique. Le chien est resté cliniquement normal aprês la cystotomie mais a développé une infection subclinique des voies urinaires 4 mois aprês l'opération.Message clinique clé:La lithiase urinaire est rare chez les patients vétérinaires pédiatriques. À la connaissance des auteurs, il s'agit du premier rapport d'urétérolithiase obstructive chez un chiot. Il n'y a pas de prédisposition génétique connue pour la lithiase urinaire chez les bouviers bernois.(Traduit par Dr Serge Messier).

Risk factors and clinical relevance of positive urine cultures in cats with subcutaneous ureteral bypass.

BACKGROUND: The objective of the study was to report the incidence and risk factors associated with positive urine bacterial cultures as well as long-term outcome in cats with subcutaneous ureteral bypass (SUB) devices. RESULTS: Medical records of cats that underwent SUB device placement were retrospectively reviewed. Signalment of the cat, laterality of the ureteral obstruction, surgery, anesthesia and hospitalization duration, bacterial culture results and follow-up data were retrieved. Thirty-two cats met the inclusion criteria. Four cats (12.5%) had a positive intraoperative culture, with two of them being treated successfully. Ten cats out of 28 (35.7%) were documented with a positive urine culture during follow-up period, with a median time between discharge and identification of the first positive urine culture of 159 days (range 8-703 days). Bacteriuria resolved in 60% of cats (6/10). Escherichia coli was the most common organism, isolated in 4 out of 10 postoperative urine cultures. Overall, subclinical bacteriura was documented for 6 of 32 (18.8%) cats and 5 of 32 (15.6%) cats displayed clinicals signs suggestive of persistent UTI. One cat had subclinical bacteriuria. Three cats died during the follow-up period. There was a significant difference between negative and positive urine bacterial culture groups in median hospitalization duration (5 days versus 6 days, P = 0.022) and in median body condition score (5/9 versus 4/9, P = 0.03). Cats with a longer hospital stay and with a lower body condition score were more likely to have a positive urine culture during follow-up period. CONCLUSIONS: SUB device placement surgery is associated with complications such as chronic bacteriuria. Bacteriuria in our study resolved with appropriate antibiotic treatment in more than half of cats. Risk factors identified for positive urine culture were a longer hospitalization duration and a decreased body condition score.

Renal pelvic rupture, intrapelvic haematoma and retroperitoneal haemorrhage associated with obstructive ureterolithiasis in a cat.

A neutered female cat presented with a 9-day history of hyporexia and depression. The referring veterinarian had identified moderate non-regenerative anaemia, haematuria and suspected unilateral obstructive ureterolithiasis. Subsequent ultrasonography revealed moderate distension of the left renal pelvis with echogenic material, ureteral distension and ureterolithiasis. A partial ureteral obstruction was suspected. After 4 days of medical management, there was further distension of the renal pelvis with well-delineated echogenic material and an accumulation of perinephric fluid. A left nephroureterectomy was performed. Renal pelvic rupture with intrapelvic haematoma and retroperitoneal haemorrhage was confirmed by histopathology. Eighteen months following surgery, the cat remained clinically well with normal renal values.

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.

Use of a subcutaneous ureteral bypass device for treatment of benign ureteral obstruction in cats: 174 ureters in 134 cats (2009-2015).

OBJECTIVE To determine outcomes of subcutaneous ureteral bypass (SUB) device placement for treatment of benign ureteral obstruction in cats. DESIGN Retrospective case series. ANIMALS 134 cats with SUB devices placed in 174 obstructed ureters during 144 hospitalizations. PROCEDURES Medical records of cats that underwent SUB device placement for treatment of benign ureteral obstruction between 2009 and 2015 were reviewed. The SUB device was placed by use of fluoroscopic and surgical methods. Signalment, history, diagnostic imaging results, postprocedural results, duration of hospitalization, complications, and short- and long-term outcomes were recorded. RESULTS Ureteral obstructions were caused by ureterolithiasis (114/174 [65.5%]), stricture (28/174 [16.1%]), both ureterolithiasis and stricture (29/174 [16.7%]), or pyonephrosis (1/174 [0.6%]); in 2 (1.1%) cats, the cause was not recorded. Fifty-two of the 134 (39%) cats had bilateral ureteral obstruction. At admission, 127 (95%) cats were azotemic. Median serum creatinine concentrations at admission and 3 months after SUB device placement were 6.6 and 2.6 mg/dL, respectively. Median renal pelvis diameters before and after the procedure were 9.2 and 1.5 mm, respectively. Postsurgical complications included device occlusion with blood clots (14/172 [8.1%]), device leakage (6/172 [3.5%]), and kinking of the device tubing (8/174 [4.6%]). Cats survived to hospital discharge after 135 of the 144 (94%) hospital admissions. The most common long-term complication was catheter mineralization (40/165 [24.2%]), which was documented a median of 463 days after device placement. A high postoperative serum ionized calcium concentration was significantly associated with SUB device occlusion. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that SUB device placement may be a viable option for treatment of cats with benign ureteral obstruction.

Perioperative Occlusion of a Subcutaneous Ureteral Bypass Secondary to a Severe Pyonephrosis in a Birman Cat.

A subcutaneous ureteral bypass (SUB) was placed in a 10-year-old Birman cat for management of unilateral ureterolithiasis. Perioperative occlusion of the nephrostomy tube of the SUB device happened secondary to a severe pyonephrosis. Flushing of the system throught the subcutaneous shunting port was made with saline solution after clamping the urinary bladder catheter. Repetitive flushing of the device was performed daily for 3 days to be sure of the remanent patency of the catheter. Repetitive flushing of the SUB device is a successful renal-sparing treatment for pyonephrosis in a cat and may be considered as an effective treatment option for this condition.

Comparison between double-pigtail ureteral stents and ureteral bypass devices for treatment of ureterolithiasis in cats.

OBJECTIVE To compare the complication rates and outcomes in cats with ureteral obstruction treated by placement of double-pigtail ureteral stents or ureteral bypass (UB) devices. DESIGN Retrospective cohort study. ANIMALS Cats with unilateral or bilateral ureterolithiasis that received double-pigtail ureteral stents (30 stents in 27 cats; stent group) or UB devices (30 devices in 23 cats; UB group). PROCEDURES Medical records were reviewed to collect data on signalment, clinical signs, serum biochemical data, surgical procedure, duration of hospitalization, complications, and follow-up (≥ 6 months after placement) information. Outcomes were compared between device types. RESULTS Median durations of surgery and hospitalization were significantly longer in the stent versus UB group. Perioperative mortality rate was 18% (5/27) in the stent group and 13% (3/23) in the UB group. Median survival time was shorter in the stent versus UB group. Stent placement was associated with a greater risk of lower urinary tract-related signs, such as hematuria (52% [14/27]) and pollakiuria or stranguria (48% [13/27]). The risk of device occlusion was also greater in the stent (26% [7/27]) versus UB (4% [1/23]) group. The percentage of cats requiring additional procedures to treat complications was greater in the stent (44%; complications included uroabdomen, stent occlusion, and refractory cystitis) versus UB (9%; complications included UB occlusion and urethral obstruction) group. CONCLUSIONS AND CLINICAL RELEVANCE Although the benefits of stent placement in the treatment of ureteral obstruction in cats have been established, results suggested that cats treated with UB devices had a lower risk of complications and a longer survival time than those treated with double-pigtail ureteral stents.

Glomerular filtration rate determination by computed tomography in two pet rabbits with renal disease.

CASE DESCRIPTION A 3-year-old and a 7-year-old spayed female rabbit (Oryctolagus cuniculus) were evaluated because of digestive stasis associated with renal asymmetry. CLINICAL FINDINGS Neoplasia of the right kidney was diagnosed via cytologic analysis in the 3-year-old rabbit. Ureterolithiasis of the left kidney was diagnosed via abdominal ultrasonography in the 7-year-old rabbit. To evaluate whether unilateral nephrectomy was indicated, evaluation of glomerular filtration rate by dynamic CT (CT-GFR) was performed on both rabbits. On the basis of the functional and morphological CT-GFR results, radical nephrectomy was recommended for the rabbit with renal neoplasia whereas a more conservative approach was recommended for the other rabbit. TREATMENT AND OUTCOME The rabbit with renal neoplasia underwent radical nephrectomy without complication. The rabbit with ureterolithiasis underwent ureteral stent placement, and the renal pelvic dilatation resolved. Both rabbits maintained unremarkable serum urea and creatinine concentrations after surgery. CLINICAL RELEVANCE GFR is a highly useful and reliable variable for the evaluation of renal function but is difficult to assess with routine clinical laboratory tests. The CT-GFR technique described here was quickly performed, was technically suitable for rabbits, and provided clinically relevant information. Studies are required to establish reference values for CT-GFR in rabbits.

Rigid urethrocystoscopy via a percutaneous fluoroscopic-assisted perineal approach in male dogs: 19 cases (2005-2014).

OBJECTIVE To describe the technique and outcome for male dogs undergoing rigid urethrocystoscopy via a novel percutaneous, fluoroscopic-assisted perineal approach. DESIGN Retrospective case series. ANIMALS 19 client-owned male dogs. PROCEDURES Medical records of male dogs that underwent urethrocystoscopy via a percutaneous perineal approach for treatment of a variety of conditions from 2005 through 2014 were reviewed. Signalment, history, pertinent diagnostic imaging results, endourologic and postprocedure details, duration of hospitalization, complications, and outcome (short-term, < 1 month; long-term, ≥ 1 month) were recorded. After flexible urethrocystoscopy, direct percutaneous perineal needle puncture and guidewire placement by means of fluoroscopic guidance (with or without ultrasonography) allowed access to the urethral lumen. The perineal tract was subsequently serially dilated to accommodate a peel-away sheath and rigid endoscope. Rigid urethrocystoscopy was performed, and on completion of endourologic procedures, the access site was left to heal by second intention. RESULTS 19 male dogs successfully underwent 20 procedures. No intraoperative complications were reported. Short-term outcome was good (ie, mild perineal urine leakage) for 3 dogs and excellent (ie, no abnormalities with urination) for 16. Long-term outcome was excellent for the 17 dogs for which follow-up information was available. CONCLUSIONS AND CLINICAL RELEVANCE A percutaneous fluoroscopic-assisted perineal approach (with or without ultrasonography) allowed access to the pelvic urethra with no major complications in the present series of patients. This minimally invasive approach may be a valuable tool for endourologic procedures in male dogs.

[Subcutaneous ureteral bypass devices as a treatment option for bilateral ureteral obstruction in a cat with ureterolithiasis]. / Beidseitiger Einsatz eines subkutanen Ureter-Bypass bei einer Katze mit bilateraler Harnleiterobstruktion.

A 6-year-old female spayed Domestic Shorthair cat was presented with acute lethargy, dehydration, marked azotemia, metabolic acidosis, left-sided renomegaly, and bilateral hydronephrosis. Ureterolithiasis and ureteral obstruction were suspected based on further diagnostics including abdominal sonography. Medical treatment was not successful. Fluoroscopically guided antegrade pyelography confirmed the diagnosis of bilateral ureteral obstruction due to ureterolithiasis. Subcutaneous ureteral bypass (SUB) devices were placed bilaterally, followed by close patient monitoring. Frequent reassessment of patient parameters and blood work served to adjust the fluid needs of the patient and to ensure proper hydration, correction of azotemia at an appropriate rate, and cardiovascular stability. After significant improvement of all patient parameters within 5 days, the patient was discharged from the hospital. Treatment included a dietary change to reduce the risk of stone formation as well as a phosphorus binder. Clinical and clinicopathologic parameters were unchanged at the 1- and 4- and 7-month rechecks (consistent with IRIS CKD stage II-NP-AP0), and both SUB devices continued to provide unobstructed urine flow. Bilateral placement of subcutaneous ureteral bypass devices may be a safe and potentially effective treatment option for acute bilateral ureteral obstruction in cats with ureterolithiasis. Strict patient monitoring and patient-centered postoperative treatment decisions are crucial to successful treatment outcomes.

Estudo da ocorrência de litíase renal e ureteral em gatos com doença renal crônica / Study of nephrolithiasis and ureterolithiasis in cats with chronic kidney disease

Investigou-se a ocorrência de nefrolitíase e/ou ureterolitíase em 72 gatos portadores de doença renal crônica (DRC), classificados predominantemente no estágio II, segundo os critérios designados pela IRIS - International Renal Interest Society. Destes pacientes, 47 (65,27por cento) apresentaram litíase renal e ou ureteral. Não houve diferença estatística entre o grupo de estudo (DRC com cálculo) e o grupo controle (DRC sem cálculo) em relação à idade (p=0,274). Apesar disso, os pacientes portadores de nefrolitíase e/ou ureterolitíase apresentaram maiores indícios de lesão renal, caracterizados por diferenças estatisticamente relevantes da densidade urinária (p=0,013) e pelo menor tamanho dos rins direito (p=0,009) e esquerdo (p=0,048). Encontrou-se similaridade entre os grupos em relação a outros parâmetros, tais como as concentrações plasmáticas de cálcio total, cálcio ionizado, fósforo, sódio, potássio e paratormônio intacto (PTHi). Os valores das concentrações séricas de ureia e bicarbonato diferiram entre os grupos, com valores de p=0,039 e p=0,037, respectivamente. Além disso, foi mensurada a pressão arterial, que se manteve inalterada na comparação entre o grupo de estudo e o grupo controle. Os resultados obtidos reforçam a necessidade de acompanhamento ultrassonográfico de todos os pacientes portadores de DRC, mesmo daqueles assintomáticos ou em estágios iniciais da doença.

Nephrolithiasis and/or ureterolithiasis were investigated by means of ultrasonography in 72 cats with chronic kidney disease (CKD), predominantly classified in stage II, according to IRIS - International Renal Interest Society criteria. Of these patients, 47 (65.27 percent) had nephrolithiasis and/or ureterolithiasis. There was no statistical difference between the study group (CKD with calculi) and control group (CKD without calculi) regarding age (p=0.274). Nevertheless, patients with nephrolithiasis and/or ureterolithiasis had greater evidence of renal injury, characterized by statistically significant differences in the urinary density (p=0.013) and the smaller size of the right kidney (p=0.009) and left kidney (p=0.048), measured in the longitudinal plane. There were no difference between groups in the other parameters investigated such as plasmatic total calcium, ionized calcium, phosphorus, sodium, potassium and intact parathyroid hormone concentrations. The values of serum urea and bicarbonate differ between groups with p=0.039 and p=0.037, respectively. Furthermore, arterial blood pressure was measured, remaining unchanged between the groups. One can conclude that nephrolithiasis and/or ureterolithiasis are common findings in cats with CKD and these results reinforce the need to perform image investigation in cats with CKD even in the asymptomatic ones, or those in the early stages of the disease.

Indwelling double pigtail ureteral stent combined or not with surgery for feline ureterolithiasis: complications and outcome in 15 cases.

Ureteral obstruction secondary to ureterolithiasis in cats is a challenging situation. Ureteral stenting has recently been introduced to prevent complications that often occurred after ureterotomy or other invasive surgeries. The purpose of this study is to describe the stenting technique and perioperative difficulties, as well as long-term outcome and complications with ureteral stenting in 12 cats with ureteroliths. Fifteen 2.5 Fr soft double pigtail multi-fenestrated ureteral stents were placed in an anterograde fashion under open surgical approaches and with fluoroscopic guidance in 12 cats. Nine cats received a unilateral stent and three received bilateral stents. Ureterotomy or ureteral resection and end-to-end anastomosis were performed in three and four cases, respectively. In six cats, papillotomy was performed to facilitate dilatator and stent placement. All cats recovered well from the surgical procedure, except one cat, which died during the anaesthesia recovery period. Postoperative complications included dysuria (three cases, diagnosed at 15 days, 1 month and 3 months, respectively), urinary tract infection (one case, 1 month after surgery), stent migration requiring stent replacement (one case, 19 months after surgery) and stent obstruction requiring stent removal (three cases with previously end-to-end anastomosis between 2 and 8 months after surgery). Nine cats (75%) were alive at a mean follow-up of 453 ± 194 (123-720) days. The median survival time was >415 days. Stent placement appeared to be a valuable and safe option for treating ureteral obstruction in cats. However, periodic and long-term monitoring of stents is warranted.

Nephroliths and ureteroliths: a new stone age.

Nephroliths may obstruct the renal pelvis or ureter, predispose to pyelonephritis, or result in compressive injury of the renal parenchyma leading to progressive chronic kidney disease. Indications for removal of nephroliths in dogs include obstruction, recurrent infection, progressive nephrolith enlargement, presence of clinical signs (renal pain), and patients with nephroliths in a solitary functional kidney. The most common indication for removal of upper tract uroliths in cats is ureteral obstruction caused by ureteroliths. Nonobstructive nephroliths in cats are not usually treated unless they move into the ureter resulting in ureteral obstruction. The treatment approach to nephroliths and ureteroliths is different for dogs versus cats. Surgical removal of nephroliths or ureteroliths by nephrotomy and ureterotomy respectively is associated with potential for complications in more than 30% of cats treated by ureterotomy; therefore, minimally invasive options should also be considered. Extracorporeal shock wave lithotripsy (ESWL) treatment of nephroliths results in small "passable" stone fragments in most dogs, whereas ESWL does not work effectively in cats. Ureteral stents are effective for relief of ureteral obstruction by ureteroliths in both dogs and cats. Ureteral stents may be left in place long-term to relieve ureteral obstruction by ureteroliths. Post-operative morbidity and mortality are substantially lower for ureteral stent placement compared to open surgical ureterotomy in cats.

New alternatives for minimally invasive management of uroliths: nephroliths.

Urolithiasis is a common clinical problem in small animal veterinary patients. Management of upper urinary tract calculi can be particularly challenging in small animals, as traditional surgical removal can be associated with significant morbidity. In humans, minimally invasive treatment options have replaced traditional surgical removal in many cases. This article reviews the current literature on the various types of lithotripsy and some of the newer minimally invasive options available for management of nephrolithiasis in small animal veterinary patients. An article in the January 2013 issue addressed management of lower urinary tract uroliths; a future article will discuss current management strategies for ureteroliths.

New alternatives for minimally invasive management of uroliths: ureteroliths.

Ureterolithiasis is a serious clinical problem in small animal veterinary medicine, and management can be challenging and frustrating. Various traditional surgical treatment options exist but are associated with significant morbidity and mortality. In humans, minimally invasive treatment options have overtaken traditional surgical removal. This article reviews the current literature on the management of ureteral stone disease, including various types of lithotripsy, and discusses some of the newer minimally invasive options available for small animal veterinary patients. It is important to realize that much of the data in this article is only published in abstract form and is largely one institution's experience with these novel techniques. Articles on minimally invasive management of lower urinary tract uroliths and nephroliths were published in the January 2013 and February 2013 issues, respectively.

Postoperative mortality in cats after ureterolithotomy.

OBJECTIVE: To identify preoperative risk factors associated with mortality before discharge in cats having a single or multiple ureterotomy procedures to treat a ureteral obstruction. STUDY DESIGN: Case series. ANIMALS: Cats (n=47). METHODS: Data were obtained from the medical records (2002-2009) of cats that had undergone ureterolithotomy procedures. Multiple preoperative factors were evaluated for association of survival to discharge. RESULT: Survival to discharge after ureterolithotomy was 79% (37/47). Over 79% of cats were azotemic before surgery and 94% had chronic kidney disease changes at the time of ultrasonographic diagnosis. Six cats required an additional surgical procedure because of complications with ureterolithotomy. Overall prevalence of postoperative uroabdomen was 6% (3/47). On multivariate analysis, there were no preoperative variables significantly associated with survival to discharge. CONCLUSIONS: Ureterolithotomy in cats was associated with a 21% mortality rate before hospital discharge. No preoperative variables associated with mortality were identified; therefore, further studies are needed to identify more discriminating preoperative characteristics for mortality after ureterolithotomy in this population of cats.

(99m)Tc-DTPA diuretic renal scintigraphy in cats with nephroureterolithiasis.

The purpose of this study was to evaluate results of diuretic renal scintigraphy in 32 feline kidneys with nephroureterolithiasis and variable degrees of renal pelvis/ureteral dilation. Six kidneys showed a non-obstructive scintigraphic pattern, with a downward slope of time-activity curves (TAC) and a median excretion half-time of radiopharmaceutical (T((1/2))) of 6.09 (5.08-8.43) min. Eight kidneys showed an obstructive pattern, with a continuous rise of TAC and median T((1/2)) of -7.91 (-43.13-0.00) min. In one kidney with presumptive partial obstruction scintigraphic results were equivocal. Seventeen kidneys, most of which had an individual kidney glomerular filtration rate below 0.5ml/min/kg, had non-diagnostic studies. Diuretic renal scintigraphy may be a useful adjunct modality in the diagnosis of ureteral obstruction in some cats if renal function is maintained. However, the large number of non-diagnostic studies in animals with decreased renal function represents a clear limitation of the technique.