Bronchoscopically delivered microwave ablation in an in vivo porcine lung model.

BACKGROUND: Percutaneous microwave ablation is clinically used for inoperable lung tumour treatment. Delivery of microwave ablation applicators to tumour sites within lung parenchyma under virtual bronchoscopy guidance may enable ablation with reduced risk of pneumothorax, providing a minimally invasive treatment of early-stage tumours, which are increasingly detected with computed tomography (CT) screening. The objective of this study was to integrate a custom microwave ablation platform, incorporating a flexible applicator, with a clinically established virtual bronchoscopy guidance system, and to assess technical feasibility for safely creating localised thermal ablations in porcine lungs in vivo. METHODS: Pre-ablation CTs of normal pigs were acquired to create a virtual model of the lungs, including airways and significant blood vessels. Virtual bronchoscopy-guided microwave ablation procedures were performed with 24-32 W power (at the applicator distal tip) delivered for 5-10 mins. A total of eight ablations were performed in three pigs. Post-treatment CT images were acquired to assess the extent of damage and ablation zones were further evaluated with viability stains and histopathologic analysis. RESULTS: The flexible microwave applicators were delivered to ablation sites within lung parenchyma 5-24 mm from the airway wall via a tunnel created under virtual bronchoscopy guidance. No pneumothorax or significant airway bleeding was observed. The ablation short axis observed on gross pathology ranged 16.5-23.5 mm and 14-26 mm on CT imaging. CONCLUSION: We have demonstrated the technical feasibility for safely delivering microwave ablation in the lung parenchyma under virtual bronchoscopic guidance in an in vivo porcine lung model.

CD4 and CD8 double-negative immunophenotype of thymoma-associated lymphocytes in a dog.

Persistent small-cell lymphocytosis in dogs with a concurrent mediastinal mass has been associated with both thymoma and small-cell lymphoma. In thymomas, neoplastic thymic epithelial cells induce overproduction and release of polyclonal lymphocytes, whereas thymic lymphoma results in thymic effacement by a clonal expansion of neoplastic lymphocytes and subsequent leukemic phase of lymphoma. Flow cytometry has been used to differentiate these 2 entities by immunophenotyping mediastinal mass aspirates. It has been reported that cases with mediastinal masses in which ≥ 10% of the associated small-cell lymphocytes were double positive for CD4 and CD8 were thymomas, whereas masses associated with < 10% were suggestive of lymphoma. We report a unique case of thymoma-associated lymphocytosis lacking the classic CD4+CD8+ immunophenotype. Our findings suggest that there may be more diversity in the thymoma-associated lymphocyte immunophenotype than has been identified previously; immunophenotyping alone might not be sufficient to differentiate thymic small-cell lymphoma from thymoma-associated lymphocytosis. In dogs with mediastinal masses and peripheral lymphocytosis, employing a variety of testing modalities to avoid misdiagnosis is prudent. These modalities include cytologic and/or histologic evaluation, immunophenotyping, and clonality assessment.

Extruded gallbladder mucoceles have characteristic ultrasonographic features and extensive migratory capacity in dogs.

Limited information is available on the ultrasonographic characteristics of extruded gallbladder mucoceles. The objective of this retrospective case series study was to describe the ultrasonographic features of extruded gallbladder mucoceles in a group of dogs. Medical records of four veterinary centers were searched between June 2010 and January 2018 for all dogs with a suspected extruded gallbladder mucocele based on abdominal ultrasound. Seven client-owned dogs met the inclusion criteria. All seven dogs had a discrete, heteroechoic, multilayered, stellate, or striated mass within the peritoneal cavity. Blood flow was not present in these structures. Four of these structures were identified in the caudal abdomen. In five cases, the gallbladder lumen was filled with material similar in appearance to the free-floating peritoneal mass. Four cases were confirmed surgically and one case was confirmed at necropsy. Histopathology of the gallbladder wall was evaluated in all surgical cases and analysis of the free-floating material was performed in one of the four cases. Extruded gallbladder mucoceles have common imaging characteristics that may be helpful in establishing a presumptive diagnosis. Additionally, these structures may have extensive migratory capacity. The results of the study justify the recommendation for exploration of the entire abdomen during cholecystectomy for gallbladder mucocele removal.

COMPUTED TOMOGRAPHIC FINDINGS IN 24 DOGS WITH LIPOSARCOMA.

Computed tomography (CT) continues to become more widely available for assessment of tumors in dogs, yet there are no studies describing the CT appearance of canine liposarcomas. In this retrospective, multicenter study, CT images of dogs with histologically confirmed liposarcomas were reviewed for size, location, attenuation, contrast enhancement, border definition, internal homogeneity, local infiltration, and mineralization. A total of 24 dogs with 26 liposarcomas were sampled. Mean attenuation was +15.2 (SD = 22.3) Hounsfield units (HU) with a range of -36 to +47.5 HU based on representative regions of interest. Twenty tumors (77%) contained focal areas of fat attenuation. All masses enhanced with contrast medium administration, which is distinct from what has been reported previously in infiltrative lipomas. Other CT features associated with canine liposarcomas included heterogeneous internal attenuation (81%) and lack of a clearly defined capsule (38%) suggesting infiltration of local structures. Six tumors (23%) had foci of mineralization. Findings from the current study indicated that liposarcoma should be considered as a differential diagnosis for mixed-attenuation, contrast-enhancing masses in dogs that contain at least one focus of fat attenuation on precontrast images; however, presence of foci of fat attenuation was not a necessary finding for the diagnosis of canine liposarcoma.

Evaluation of an overlapping pubic and ischiatic osteotomy for the improvement of acetabular ventroversion in dogs: an ex vivo study.

OBJECTIVES: To assess the potential of a new single-session surgical procedure, the overlapping pubic and ischiatic osteotomy (OPIO) for modification of bilateral hip conformation. We hypothesized that OPIO would be simple to perform with currently available surgical equipment, through a single surgical approach, with minimal potential morbidity, and that it would allow adequate simultaneous bilateral improvement of coxofemoral joint conformation in patients at risk of canine hip dysplasia. METHODS: The OPIO procedure was performed in the pelves of five large breed canine cadavers. Computed tomography images of each cadaver were compared by measurement of the dorsal acetabular rim angle (DARA), acetabular angle (AA), dorso-ventral sacroiliac ratio (SR), and pubic inlet area before and after OPIO. RESULTS: Coxofemoral joint conformation was improved after OPIO. Postoperative DARA was significantly decreased (mean: -5.09°) and AA was significantly increased (mean: 3.54°) after OPIO. The SR was not significantly different after OPIO, indicating minimal impact on the sacro-illiac joints by the procedure. Pubic inlet dimensions and area were significantly decreased after OPIO, but the overall effect on pelvic inlet area was clinically insignificant. CLINICAL SIGNIFICANCE: An OPIO allows some improvement of coxofemoral joint conformation in canine cadavers.

Anicteric gallbladder rupture in dogs: 5 cases (2007-2013).

OBJECTIVE: To describe clinical, laboratory, and surgical findings in dogs with confirmed gallbladder rupture and in which serum total bilirubin concentration was within reference limits. DESIGN: Retrospective case series. ANIMALS: 5 dogs. PROCEDURES: Medical records were searched to identify dogs with gallbladder rupture that underwent treatment at the Kansas State University Veterinary Health Center from November 2007 through November 2013. Dogs were included if they had undergone abdominal ultrasonography, serum total bilirubin concentration was ≤ 0.4 mg/dL, and abdominal exploratory surgery confirmed the presence of gallbladder upture. RESULTS: An exploratory celotomy was performed in all dogs because of ultrasonographic findings of mild to marked abdominal effusion and either an unidentifiable gallbladder (n = 1 dog) or a distended gallbladder with a suspected gallbladder mucocele (4 dogs). Serum total bilirubin concentration was within reference limits (median, 0.2 mg/dL; range, 0.1 to 0.4 mg/dL; reference range, 0.1 to 0.4 mg/dL) in all dogs before surgery. In 1 dog, bile acids concentrations in serum and in peritoneal fluid were compared and the results (48 µmol/L and 1,070 µmol/L, respectively) were supportive of the diagnosis of gallbladder rupture. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that even when serum total bilirubin concentration is within reference limits, gallbladder rupture should be considered in dogs with acute signs of abdominal pain when a mucocele is suspected on abdominal imaging and free abdominal fluid is present. Results suggested that a comparison of serum to peritoneal fluid bile acids concentrations may provide additional support for a diagnosis of gallbladder rupture.

Pre-operative fibrous osteodystrophy and severe, refractory, post-operative hypocalcemia following parathyroidectomy in a dog.

A 13-year-old dog exhibited dramatic, radiographic osteopenia consistent with fibrous osteodystrophy secondary to primary hyperparathyroidism. Following parathyroidectomy, the dog developed severe, prolonged hypocalcemia, but was successfully treated and discharged 32 d after surgery. A variety of factors may have contributed to this dog's hypocalcemia including hypoparathyroidism and hungry bone syndrome.

Ostéodystrophie fibreuse préopératoire et hypocalcémie grave, réfractaire postopératoire après une parathyroïdectomie chez un chien. Un chien âgé de 13 ans a manifesté une ostéopénie radiographique dramatique conforme à une ostéodystrophie fibreuse secondaire à un hyperparathyroïdisme primaire. Après une parathyroïdectomie, le chien a développé une hypocalcémie grave et prolongée, mais il a été traité avec succès et a reçu son congé 32 jours après la chirurgie. Divers facteurs peuvent avoir contribué à l'hypocalcémie de ce chien, y compris l'hypoparathyroïdisme et l'hypocalcémie par avidité osseuse.(Traduit par Isabelle Vallières).

Emphysematous cystitis and pyelonephritis in a nondiabetic dog and a diabetic cat.

Emphysematous cystitis (EC) and emphysematous pyelonephritis (EPN) are the result of infection of the urinary bladder and kidneys by gas-producing microorganisms. Those infections are most often reported in diabetic patients and rarely occur concurrently. This article describes two cases of concurrent EC and EPN, one in a nondiabetic dog and the other in a diabetic cat. The use of diagnostic imaging is necessary in the diagnosis of emphysematous infections. Both radiography and ultrasonography were used in the diagnosis of EC and EPN in the patients described in this report.

Radiographic and histopathologic characteristics of pulmonary fibrosis in nine cats.

Pulmonary fibrosis is a progressive fatal interstitial lung disease that is often idiopathic, occurs in multiple species, and may be caused by a number of inciting factors. The purpose of this retrospective, multicenter study was to describe the radiographic and histopathologic characteristics of idiopathic and induced pulmonary fibrosis in a group of cats. Cats with thoracic radiographs and histopathologically confirmed pulmonary fibrosis were recruited using the American College of Veterinary Radiology list serve. A board-certified veterinary radiologist and diagnostic imaging intern reviewed radiographs and recorded characteristics by consensus. Findings from additional imaging modalities were also recorded when available. All histopathology samples were re-reviewed by a veterinary pathology resident. A total of nine cats met inclusion criteria. All patients had a broad range of radiographic characteristics that included broncho-interstitial pattern, alveolar pattern, pulmonary masses, pulmonary bullae, pleural effusion, and cardiomegaly. Cats with available echocardiographic studies had characteristics that included right ventricular dilation and hypertrophy and pulmonary arterial hypertension interpreted to be secondary to primary lung disease. Cats with available CT studies had characteristics that included focally increased soft tissue attenuation, masses, and ventral consolidation that exhibited no improvement with dorsal versus ventral recumbency. Histopathology showed pulmonary fibrosis, type II pneumocyte hyperplasia, and smooth muscle hypertrophy in all patients. Epithelial metaplasia was present only in one patient. Findings from the current study indicated that cats with pulmonary fibrosis have highly variable radiographic characteristics and that these characteristics may mimic other diseases such as asthma, pneumonia, pulmonary edema, or neoplasia.

Carotid artery pseudoaneurysm in a cat.

UNLABELLED: CLINICAL SUMMARY: A 4-month-old female intact domestic shorthair cat presented to Kansas State University Veterinary Medical Teaching Hospital for investigation of a large, firmly adhered mass in the left mid-cervical region that developed after phlebotomy performed at the referring veterinarian's clinic. Ultrasound examination of the mass revealed a cystic structure in communication with the left carotid artery, with bidirectional blood flow through the area. A diagnosis of pseudoaneurysm secondary to accidental needle penetration of the carotid artery during jugular venepuncture was made. OUTCOME: Strict cage rest and pain management resulted in complete resolution of clinical and ultrasonographic signs in this cat.

Comparison of three-view thoracic radiography and computed tomography for detection of pulmonary nodules in dogs with neoplasia.

OBJECTIVE: To compare the detection of pulmonary nodules by use of 3-view thoracic radiography and CT in dogs with confirmed neoplasia. DESIGN: Prospective case series. ANIMALS: 33 dogs of various breeds. PROCEDURES: 3 interpreters independently evaluated 3-view thoracic radiography images. The location and size of pulmonary nodules were recorded. Computed tomographic scans of the thorax were obtained and evaluated by a single interpreter. The location, size, margin, internal architecture, and density of pulmonary nodules were recorded. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for thoracic radiography (with CT as the gold standard). RESULTS: 21 of 33 (64%) dogs had pulmonary nodules or masses detected on CT. Of the dogs that had positive CT findings, 17 of 21 (81%) had pulmonary nodules or masses detected on radiographs by at least 1 interpreter. Sensitivity of radiography ranged from 71% to 95%, and specificity ranged from 67% to 92%. Radiography had a positive predictive value of 83% to 94% and a negative predictive value of 65% to 89%. The 4 dogs that were negative for nodules on thoracic radiography but positive on CT were all large-breed to giant-breed dogs with osteosarcoma. CONCLUSIONS AND CLINICAL RELEVANCE: CT was more sensitive than radiography for detection of pulmonary nodules. This was particularly evident in large-breed to giant-breed dogs. Thoracic CT is recommended in large-breed to giant-breed dogs with osteosarcoma if the detection of pulmonary nodules will change treatment.

Ultrasound of the gastrointestinal tract.

Sonographic scanning techniques of the gastrointestinal tract are presented. Normal anatomy and ultrasound appearance of the stomach, small intestine, and large intestine are discussed, followed by the ultrasound appearance of gastrointestinal inflammation, neoplastic disease, and obstruction.

Comparison of digitized and direct viewed (analog) radiographic images for detection of pulmonary nodules.

The purpose of this study was to compare direct (analog) viewing of thoracic radiographs with digitized images obtained with a radiographic scanner and seven digital cameras for detection of pulmonary nodules. Direct viewing of the analog radiographs was significantly better than all digitized methods (P<0.01). Significant variations exist between the radiographic scanner and the digital cameras. The scanner (Kodak LS75) was significantly better than the Kodak DC 4800 and the Sony DSC-707 cameras (P<0.05). The Nikon 995, Canon EOS-D30, and Ricoh i500 were significantly better than the Sony DSC-707 (P<0.05). There was no significant difference between the Kodak DC 3800, Kodak DC 4800, and the Sony DSC-707. For pairwise comparison of raters (when evaluating the radiographs individually compared with the consensus), the raters matched the consensus rating from 85% to 92% with no significant difference between raters.

Subclinical intestinal duplication in a cat.

An abdominal mass was identified upon palpation of the abdomen in a normal, asymptomatic, 1-year-old female domestic shorthair cat presented for elective ovariohysterectomy. Radiographic and ultrasound examinations demonstrated a well-circumscribed caudal abdominal mass. Ultrasound guided needle aspiration cytology was consistent with an accumulation of squamous epithelial cells. The mass was associated with the jejunum and was excised via resection anastomosis of the intestinal segment after ovariohysterectomy. Histologic examination provided the diagnosis of an intestinal duplication lined with epithelium typical of that in the esophagus. The cat recovered without complications.

Feline polycystic kidney disease is linked to the PKD1 region.

Autosomal dominant polycystic kidney disease (ADPKD) is a commonly inherited disorder (1/1000) in humans characterized by fluid-filled cysts in the kidneys. Defects in the PKD genes, PKD1 and PKD2, cause 85% and 15% of human ADPKD cases, respectively. Mutations in the PKHD1 gene cause autosomal recessive PKD (ARPKD). Mutations in several genes, including Nek8, cause PKD in mice. Although PKD affects 38% of Persian cats worldwide, making it the most prominent inherited feline disease, a causative gene has not been identified. Feline PKD is an autosomal dominant disease with clinical presentations similar to human ADPKD. Forty-three microsatellites were chosen from the feline genetic maps based on known homology with human chromosomal regions containing the PKD1, PKD2, PKHD1, and Nek8 genes. Linkage analysis using seven Persian cat pedigrees segregating for PKD has shown significant linkage and no recombinants (Z=5.83, theta=0) between the PKD disease phenotype and marker FCA476, which is within 10 cR of the feline PKD1 gene on Chromosome E3. This suggests that the PKD1 gene or another gene within this region may cause feline PKD. Further investigation into the cause of PKD will be valuable for feline health and provide insights into human ADPKD.

Low-field magnetic resonance imaging of bone marrow in the lumbar spine, pelvis, and femur in the adult dog.

The purpose of this study was to describe the appearance of normal bone marrow in seven adult dogs using low-field (0.3T) magnetic resonance (MR) imaging. The areas imaged included the lumbar spine, pelvis, and femur. T1-weighted, fast spin-echo T2-weighted, and short tau (T1) inversion recovery (STIR) sequences were obtained at all locations. Histopathology was performed on sections from the sixth lumbar vertebral body, the wing of the ilium, and the femur (head and neck, mid-diaphysis, and condyle) for evaluation of cellularity and fat content. The lumbar spine and pelvic marrow MR images were similar in all dogs. The lumbar vertebral bone marrow was uniform, intermediate signal intensity, and isointense to muscle on all sequences. There was variation between dogs in the bone marrow distribution with MR imaging of the femur. In the proximal and mid-diaphysis of the femur there was patchy high-signal intensity on T1- and T2-weighted images, and hypointense foci on the STIR images. The distal femoral metaphysis had a variable pattern ranging from intermediate-to-high signal on T1- and T2-weighted images and intermediate-to-low signal on STIR images. The femoral condyles were uniformly high signal on T1- and T2-weighted images and hypointense on STIR images. Histopathologically there was a normal variation in the bone marrow cellularity. The marrow was normocellular (25-75% cellularity) for all sites examined except the femoral condyles, which were hypocellular (<25% cellularity).

Feline polycystic kidney disease mutation identified in PKD1.

Autosomal dominant polycystic kidney disease (ADPKD) is a commonly inherited disorder in humans that causes the formation of fluid-filled renal cysts, often leading to renal failure. PKD1 mutations cause 85% of ADPKD. Feline PKD is autosomal dominant and has clinical presentations similar to humans. PKD affects approximately 38% of Persian cats worldwide, which is approximately 6% of cats, making it the most prominent inherited feline disease. Previous analyses have shown significant linkage between the PKD phenotype and microsatellite markers linked to the feline homolog for PKD1. In this report, the feline PKD1 gene was scanned for causative mutations and a C>A transversion was identified at c.10063 (human ref NM_000296) in exon 29, resulting in a stop mutation at position 3284, which suggests a loss of approximately 25% of the C-terminus of the protein. The same mutation has not been identified in humans, although similar regions of the protein are truncated. The C>A transversion has been identified in the heterozygous state in 48 affected cats examined, including 41 Persians, a Siamese, and several other breeds that have been known to outcross with Persians. In addition, the mutation is segregating concordantly in all available PKD families. No unaffected cats have been identified with the mutation. No homozygous cats have been identified, supporting the suggestion that the mutation is embryonic lethal. These data suggest that the stop mutation causes feline PKD, providing a test to identify cats that will develop PKD and demonstrating that the domestic cat is an ideal model for human PKD.

Intravesical instillation of dilute formalin for the treatment of severe hemorrhagic emphysematous cystitis in a diabetic dog.

Intravesical formalin is a known treatment for control of hemorrhagic cystitis caused by multiple etiologies in humans and dogs. This case report documents the successful use of intravesical formalin for the treatment of severe hemorrhagic cystitis that occurred secondary to emphysematous cystitis in a diabetic dog. In addition, a review of emphysematous cystitis and the use of intravesical formalin in human and veterinary medicine is discussed. Formalin instillation into the urinary bladder is an option for life-threatening, refractory cases of hemorrhagic cystitis; but clinicians must be familiar with the proper technique and be aware of potential complications prior to its use.

Glomerulocystic kidney disease in a kitten.

A 4-month-old 1-kg female Siamese-Manx cross kitten was evaluated because of renomegaly and renal failure. Ultrasonography and cytologic examination of a renal aspirate failed to provide an antemortem diagnosis. Histologic lesions included diffuse cystic dilatation of all tubules and Bowman's spaces in the renal cortex and occasional small glomerular tufts; the lesions were similar to those of glomerulocystic kidney disease of humans. Glomerulocystic kidney disease is a rare cause of early-onset renal failure, but should be considered when renomegaly is detected, cysts are not detected in the kidney by ultrasonography, and cytologic examination of a renal aspirate is nondiagnostic.