Diagnostic utility of ultrasonography for detection of the cause and location of ureteral obstruction in cats: 71 cases (2010-2016).

OBJECTIVE To assess the utility of ultrasonography to detect the cause and location of ureteral obstruction in cats and to identify factors associated with agreement between ultrasonographic and surgical findings. STUDY DESIGN Retrospective case series. ANIMALS 71 cats. PROCEDURES Medical records were searched to identify cats that had ureteral obstruction diagnosed ultrasonographically and that subsequently underwent exploratory laparotomy. Patient signalment, ultrasonographic findings, interventions performed, and surgical findings were recorded. Cause and location of ureteral obstruction as assessed by ultrasonography were compared with surgical findings. Sensitivity, specificity, and positive predictive value of ultrasonography for detection of ureteroliths and strictures were calculated. Statistical analysis was performed to identify factors associated with agreement between ultrasonographic and surgical findings. RESULTS There was significant, moderate agreement between ultrasonographic and surgical findings for the cause and location of ureteral obstruction. Signalment variables, ureter affected (left vs right), and presence of retroperitoneal effusion were not associated with this agreement. Sensitivity was 98% and 44%, specificity was 96% and 98%, and positive predictive value was 98% and 88% for detection of ureteroliths and strictures, respectively, by ultrasonography. CONCLUSIONS AND CLINICAL RELEVANCE Ultrasonography was highly sensitive for detection of ureteroliths that caused ureteral obstruction but was considerably less sensitive for detection of ureteral strictures in the study population. Future prospective studies are needed to determine the role of advanced imaging in assessing cats with ureteral abnormalities. (J Am Vet Med Assoc 2019;254:710-715).

Use of a modified Boari flap for the treatment of a proximal ureteral obstruction in a cat.

OBJECTIVE: To describe the use and long term outcome of a novel surgical technique developed to treat a proximal ureteral obstruction in a cat. STUDY DESIGN: Case report. ANIMALS: A 3-year-old female spayed Russian blue cat. METHODS: A 3-year-old female spayed Russian blue cat presented with a fever, decreased appetite, vomiting, and abdominal discomfort. A proximal left ureteral obstruction was noted on ultrasonographic examination. No filling defect was noted on antegrade pyelography. Due to the proximal location of the obstruction, a modification of a Boari flap was performed. In the current technique, the ureter was cut proximal to the level of obstruction, and the distal ureter was resected. A flap was created on the ventral surface of the bladder, the cut end of the ureter was pulled through the flap, and a ureteroneocystostomy was performed. The bladder was closed in a simple interrupted pattern. RESULTS: At re-evaluation 2 and 4 weeks after surgery, azotemia had resolved. According to ultrasonography, the ureteroneocystostomy site appeared to be healing, and pelvic dilation had resolved. One year later, the cat continued to do well, with no lower urinary tract signs and no abnormality noted on blood tests or ultrasonography. CONCLUSION: The tubularized bladder flap originally described by Boari was modified to create a tension-free ureteroneocystostomy, without complication. This technique relied on surrounding native tissues and resulted in long-term resolution of the ureteral obstruction. CLINICAL SIGNIFICANCE: A modified Boari flap can lead to long-term resolution of proximal ureteral obstruction in cats, without requiring stents or permanent implants.

Perioperative morbidity and outcome of esophageal surgery in dogs and cats: 72 cases (1993-2013).

OBJECTIVE To evaluate perioperative morbidity and outcome in dogs and cats undergoing esophageal surgery. DESIGN Retrospective case series. ANIMALS 63 client-owned dogs and 9 client-owned cats. PROCEDURES Medical records of dogs and cats that underwent esophageal surgery were reviewed for information on signalment, history, results of preoperative diagnostic testing, condition treated, details of surgery, intraoperative complications, and postoperative complications. Long-term follow-up data were obtained via veterinarian and client telephone conversations. The relationship between complications and survival to hospital discharge was evaluated by means of regression analysis. RESULTS The most common indication for surgical intervention was an esophageal foreign body in dogs (50/63 [79%]) and esophageal stricture in cats (3/9). Complications were documented in 54% (34/63) of dogs and 3 of 9 cats. The most common immediate postoperative complications were respiratory in nature (9 dogs, 1 cat). Partial esophagectomy and resection with anastomosis were significantly associated with the development of immediate postoperative complications in dogs. The most common delayed postoperative complications were persistent regurgitation (7 dogs) and esophageal stricture formation (3 dogs, 1 cat). For dogs, a mass lesion and increasing lesion size were significantly associated with the development of delayed postoperative complications. Six dogs (10%) and 1 cat died or were euthanized prior to discharge, and pneumomediastinum and leukopenia were negative prognostic factors for dogs being discharged from the hospital. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study suggested that the short-term prognosis for dogs and cats that survive surgery for treatment of esophageal lesions is favorable, with 90% of patients discharged from the hospital (57/63 dogs; 8/9 cats). However, dogs treated for more extensive esophageal lesions as well as those undergoing esophagectomy or resection and anastomosis were more likely to develop postoperative complications.

Outcomes of ureteral surgery and ureteral stenting in cats: 117 cases (2006-2014).

OBJECTIVE: To evaluate and compare outcomes in cats following ureteral surgery or ureteral stent placement. DESIGN: Retrospective case series. ANIMALS: 117 cats. PROCEDURES: Data regarding signalment, history, concurrent disease, clinical signs, clinicopathologic tests, surgical procedures, and perioperative complications (including death) were recorded. Follow-up data, including presence of signs of chronic lower urinary tract disease, chronic urinary tract infection, reobstruction, and death, if applicable, were obtained by records review or telephone contact with owners. Variables of interest were compared statistically between cats treated with and without stent placement. Kaplan-Meier analysis and Cox regression were performed to assess differences in survival time between cats with and without ureteral stents. RESULTS: Perioperative complications referable to the urinary tract were identified in 6 of 43 (14%) cats that had ≥ 1 ureteral stent placed and 2 of 74 (3%) cats that underwent ureteral surgery without stenting. Perioperative mortality rates were similar between cats with (4/43 [9%]) and without (6/74 [8%]) stents. After surgery, signs of chronic lower urinary tract disease and chronic urinary tract infection were significantly more common among cats with than cats without stents. Nineteen of 87 (22%) cats with follow-up information available had recurrent obstruction; incidence of reobstruction did not differ between cats with and without stents. Median survival time did not differ between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: The potential for signs of chronic lower urinary tract disease and chronic infection, particularly among cats that receive ureteral stents, warrants appropriate client counseling. Judicious long-term follow-up for detection of reobstruction is recommended.

Perioperative morbidity and long-term outcome of unilateral nephrectomy in feline kidney donors: 141 cases (1998-2013).

OBJECTIVE To evaluate the outcome associated with unilateral nephrectomy in feline kidney donors. DESIGN Retrospective case series. ANIMALS 141 cats. PROCEDURES Medical records of cats that underwent nephrectomy for renal donation were reviewed for information on signalment, date of renal donation, results of blood and urine analyses, infectious disease history, anesthetic protocols, intra- and postoperative complications, and postoperative analgesic protocols. Long-term follow-up data were obtained via client telephone interview and review of referring veterinarian medical records. RESULTS All donors were healthy young adult cats with a median age of 1.5 years (range, 0.8 to 2 years). No cats died or were euthanized during the perioperative period. Intraoperative complications occurred in 2 cats, and postoperative complications occurred in 17. Median time from nephrectomy to hospital discharge was 3.6 days (range, 2 to 8 days). Long-term follow-up information was available for 99 cats, with a median interval between nephrectomy and follow-up of 10 years (range, 0.25 to 15 years). Six cats had a history of urinary tract disease including stable chronic kidney disease (n = 3), acute kidney injury (2), and cystitis (1). Nine cats were dead at follow-up; death was attributed to chronic renal failure in 2 and acute ureteral obstruction in 4. CONCLUSIONS AND CLINICAL RELEVANCE Feline donor nephrectomy had an acceptably low perioperative morbidity in this series. Most cats (84%) for which follow-up information was available had no associated long-term effects. However, a small subset (7%) developed renal insufficiency or died of urinary tract disease.

Diagnostic Accuracy of Ultrasound to Predict the Location of Solitary Hepatic Masses in Dogs.

OBJECTIVE: To determine the sensitivity, specificity, and predictive value of ultrasonography for localizing hepatic masses in dogs and to identify patient factors associated with diagnostic accuracy. STUDY DESIGN: Retrospective cross-sectional study. ANIMALS: Client-owned dogs (n = 137). METHODS: Medical records of dogs diagnosed with a solitary hepatic mass on abdominal ultrasound and confirmed by laparotomy or laparoscopy were reviewed. Location of the mass predicted by ultrasound was compared to mass location identified at surgery. Ultrasound exams were performed by or under the supervision of a board certified radiologist. Sensitivity, specificity, and positive predictive values were calculated. Patient factors associated with accurate localization were identified using logistic regression. RESULTS: Ultrasound correctly localized liver masses in 71/137 dogs (51.8%). The sensitivity of ultrasound localization was 55% for left and right division masses and 29% for central division masses. The specificity was 98% for left division masses, 87% for central division masses, and 89% for right division masses. Correct localization was 3.2 times more likely when the mass arose from the right or left division compared to the central division (odds ratio [OR] 3.2; 95% confidence intervals [CI] 1.1, 9.0; P = .030). Correct localization was significantly less likely when diffuse or multifocal hepatic disease was present (OR 0.32; 95% CI 0.15, 0.70; P = .004). CONCLUSION: Ultrasound was specific but not sensitive for localizing hepatic masses, and localization accuracy was influenced by mass location and the presence of concurrent liver pathology. These findings should be taken into consideration by veterinary surgeons using ultrasound examination to guide patient treatment and surgical planning.

Advances in Laparoscopic Surgery.

Recently, a new platform of abdominal access, called single-port surgery, has emerged in human and veterinary laparoscopy. The single-port platform enables all laparoscopic instruments, including the telescope, to pass individually through the same abdominal incision. Recently, there have been several published reports documenting the efficacy and safety of single-port procedures in veterinary patients. This article discusses the common single-port devices and instrumentation, as well as procedures now routinely offered in veterinary minimally invasive surgery.

End-to-end ureteral anastomosis and double-pigtail ureteral stent placement for treatment of iatrogenic ureteral trauma in two dogs.

CASE DESCRIPTION: A 6-month-old spayed female Soft-Coated Wheaten Terrier and 8-month-old spayed female Shih Tzu were referred because of complications related to inadvertent ureteral ligation and transection during recent ovariohysterectomy. CLINICAL FINDINGS: The Soft-Coated Wheaten Terrier had a 2-day history of stranguria and polyuria that began after ovariohysterectomy. Initial examination findings were unremarkable with the exception of high rectal temperature. The Shih Tzu had a 10-day history of pyrexia, vomiting, diarrhea, and stranguria that began after ovariohysterectomy. On examination, the dog had signs of depression; clinicopathologic tests revealed hypoalbuminemia, neutrophilia, lymphocytosis, and monocytosis. Abdominal ultrasonography was performed for both dogs, revealing severe unilateral pyelectasia and hydroureter (proximal portion). TREATMENT AND OUTCOME: Both dogs underwent exploratory celiotomy; ureteral ligation and transection was confirmed. Ventral cystotomy was performed to allow retrograde placement of a double-pigtail ureteral stent into the affected ureter and renal pelvis. End-to-end ureteral anastomosis was performed over the stent with the aid of an operating microscope. Stent position was confirmed via fluoroscopy, and incisions were closed routinely. Dogs continued to have intermittent signs of stranguria until stent removal via cystoscopy 6 or 7 weeks after surgery. Ultrasonographic examination of the urogenital tract was performed 2 or 4 months after surgery, revealing resolution of pyelectasia and hydroureter. CLINICAL RELEVANCE: The surgical technique used provided a viable option for preserving renal function in dogs with focal, iatrogenic ureteral trauma. Use of a ureteral stent facilitated ureteral anastomosis and minimized postoperative complications.

Thoracoscopic-assisted pulmonary surgery for partial and complete lung lobectomy in dogs and cats: 11 cases (2008-2013).

OBJECTIVE: To describe the use of thoracoscopic-assisted pulmonary surgery (TAPS) for partial and complete lung lobectomy in small animal patients and to evaluate short-term outcome. DESIGN: Retrospective case series. ANIMALS: 11 client-owned dogs and cats. Procedures-Medical records of dogs and cats that underwent a partial or complete TAPS lung lobectomy were reviewed. All patients underwent general anesthesia and were positioned in lateral recumbency with the affected hemithorax uppermost. One-lung ventilation was not implemented in any patient. For initial exploration, a 5- to 10-mm incision was made for insertion of a 30° telescope approximately 5 to 7 rib spaces away from the site of the pulmonary lesion in the dorsal third of the thorax. All subsequent incision placements were case dependent and determined by the location of the lesion to be resected. Following lesion localization, a 2- to 7-cm minithoracotomy incision was made with direct thoracoscopic visualization without the use of rigid rib retractors. In 10 of 11 patients, a 360° wound retraction device was placed at the minithoracotomy site prior to exteriorization and resection of the affected lung. Lymph nodes were inspected intraoperatively, but biopsies were not performed; incisions were closed routinely, and a thoracostomy tube was placed in all patients. RESULTS: 3 cats and 8 dogs underwent successful partial (5) or complete (6) TAPS lung lobectomy over a 5-year period (2008 through 2013). Median surgery time was 92.7 minutes (range, 77 to 150 minutes). Thoracostomy tubes were removed a median of 22.3 hours after surgery (range, 18 to 36 hours). The median time to discharge was 3.1 days (range, 1 to 6 days). No intraoperative complications were encountered. All patients were discharged from the hospital, with 9 of 11 patients alive 6 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study suggested that lung lobectomy by means of TAPS can be successfully performed in dogs and cats. When compared with total thoracoscopic surgery, TAPS may offer a more technically feasible approach from both a surgical and anesthetic standpoint, because it provides the benefits of minimally invasive thoracic surgery without the necessity of 1-lung ventilation.

Retroperitoneal fibrosis in feline renal transplant recipients: 29 cases (1998-2011).

OBJECTIVE: To evaluate features, treatment, and prognosis associated with retroperitoneal fibrosis that developed after renal transplantation in cats. DESIGN: Retrospective case series. ANIMALS: 29 cats. PROCEDURES: Medical records of cats that developed retroperitoneal fibrosis after renal transplantation at the College of Veterinary Medicine, University of Pennsylvania, between 1998 and 2011 were reviewed for signalment, date of transplantation, age, results of urine and blood analyses, blood pressure at the time of diagnosis, infectious disease and medication anamneses, anesthetic protocols, and intraoperative complications. RESULTS: Of 138 transplant recipients, 29 (21%) developed clinically important retroperitoneal fibrosis. Nineteen (66%) were male, and median age at the time of renal transplantation was 8 years (range, 4 to 13 years). Median number of days after transplantation to diagnosis of retroperitoneal fibrosis was 62 (range, 4 to 730 days; mean, 125 days). The most common clinical signs were lethargy and anorexia. All affected cats were azotemic (BUN concentration > 32 mg/dL; creatinine concentration > 2.0 mg/dL) and anemic (PCV < 35%) at the time of retroperitoneal fibrosis diagnosis, although cats were nonazotemic at the time of discharge following transplantation, and anemia was less pronounced. Twenty-five cats successfully underwent surgical ureterolysis in which scar tissue was dissected away from the allograft ureter to relieve extraluminal compression. Retroperitoneal fibrosis recurred in 6 (22%) cats a median of 180 days (range, 8 to 343 days) following the original diagnosis and was treated successfully by repeated ureterolysis. CONCLUSIONS AND CLINICAL RELEVANCE: Retroperitoneal fibrosis occurred in a substantial percentage of feline renal transplant recipients and should be considered a differential diagnosis in any feline renal transplant recipient with clinicopathologic findings, imaging abnormalities, or signs suggestive of obstructive uropathy.

Potentiation of regulatory volume decrease by a p2-like receptor and arachidonic acid in american alligator erythrocytes.

This study examined the role of a P2 receptor and arachidonic acid (AA) in regulatory volume decrease (RVD) by American alligator red blood cells (RBCs). Osmotic fragility was determined optically, mean cell volume was measured by electronic sizing, and changes in intracellular Ca(2+) concentration were visualized using fluorescence microscopy. Gadolinium (50 µM), hexokinase (2.5 U/ml), and suramin (100 µM) increased osmotic fragility, blocked volume recovery after hypotonic shock, and prevented a rise in intracellular Ca(2+) that normally occurs during cell swelling. The P2X antagonists PPADS (50 µM) and TNP-ATP (10 µM) also increased fragility and inhibited volume recovery. In contrast, ATPγS (10 µM), α,ß-methylene-ATP (50 µM) and Bz-ATP (50 µM) had the opposite effect, whereas 2-methylthio-ATP (50 µM) and UTP (10 µM) had no effect. In addition, the phospholipase A(2) (PLA(2)) inhibitors ONO-RS-082 (10 µM), chlorpromazine (10 µM), and isotetrandrine (10 µM) increased osmotic fragility and blocked volume recovery, whereas AA (10 µM) and its nonhydrolyzable analog eicosatetraynoic acid (ETYA, 10 µM) had the reverse effect. Further, AA (10 µM), but not ATPγS (10 µM), prevented the inhibitory effect of a low Ca(2+)-EGTA Ringer on RVD, whereas both AA (10 µM) and ATPγS (10 µM) caused cell shrinkage under isosmotic conditions. In conclusion, our results are consistent with the presence of a P2-like receptor whose activation stimulated RVD. In addition, AA also was important for volume recovery.

Regulatory volume response following hypotonic stress in Atlantic salmon erythrocytes.

The purpose of this study was to examine regulatory volume decrease (RVD) in Atlantic salmon red blood cells (RBCs). Osmotic fragility was determined optically, mean cell volume was measured electronically, and changes in intracellular Ca(2+) concentration were visualized using fluorescence microscopy and fluo-4-AM. Cells displayed an increase in osmotic fragility and an inhibition of volume recovery following hypotonic shock when they were exposed to a high taurine Ringer or when placed in a high K(+) medium. Interestingly, RVD in cells from fish collected during the summer depended more on taurine efflux, whereas fall cells relied more on the loss of K(+). In addition, RVD in fall cells was prevented with the K(+) channel inhibitor quinine, whereas the ionophore gramicidin decreased osmotic fragility and potentiated volume recovery. Further, hypotonic shock (0.5X Ringer) for both summer and fall cells caused an increase in cytosolic Ca(2+), which resulted from influx of this ion because it was not observed when extracellular Ca(2+) was chelated with EGTA (10 nM free Ca(2+)). Cells exposed to a low Ca(2+) hypotonic Ringer also had a greater osmotic fragility and failed to recover from hypotonic swelling. Finally, inhibition of phospholipase A(2) with ONO-RS-082 blocked volume recovery. In conclusion, Atlantic salmon RBCs displayed volume decrease in response to hypotonic shock, which depended on a swelling-induced influx of Ca(2+) and an increase in the efflux of K(+) and taurine.

Cardiac troponin-I concentrations in dogs with bradyarrhythmias before and after artificial pacing.

OBJECTIVES: To quantify cardiac troponin-I (cTnI) concentration in dogs with symptomatic bradyarrhythmias before and after artificial pacing and to correlate cTnI concentration with diagnosis, echocardiographic parameters, serology, and outcome. ANIMALS, MATERIALS AND METHODS: Medical records from the University of Pennsylvania from 2006 to 2009 were reviewed, and 14 dogs with cTnI assay results before and after pacemaker were identified. The ECG diagnosis included complete atrioventricular block (AVB), sick sinus syndrome, 2nd degree AVB, and atrial standstill. Serology, presence of premature beats, echocardiographic measurements, and pacing modality were recorded. RESULTS: Mean cTnI concentration was elevated both pre- and post-pacing, and was significantly higher pre-pacing vs. post-pacing. Post-pacing cTnI concentration in 9 of 14 dogs (64%) remained above the reference range. Four dogs yielded high serum titers for Bartonella spp. Four dogs with markedly increased cTnI concentration had progressive left ventricular enlargement and myocardial failure as compared to pre-pacing examination. CONCLUSIONS: Elevated cTnI concentration suggests that cardiac injury persists after artificial pacing in dogs with bradyarrhythmias. Myocarditis secondary to Bartonella spp. or other causes may be an important cause of AVB in dogs. Prospective studies investigating the correlation of cTnI to potential etiology and development of post-pacing LV dysfunction and outcome are needed.