The development of ventricular fibrillation as a complication of pericardiectomy in 16 dogs.

OBJECTIVE: To describe the clinical characteristics, perioperative protocols, and outcomes in dogs diagnosed with ventricular fibrillation (VF) while undergoing pericardiectomy. STUDY DESIGN: Retrospective, multi-institutional study. ANIMALS: Sixteen client-owned dogs. METHODS: Cases were accrued through a listserve request posted to 3 subspecialty veterinary societies. Dogs were included if they developed VF during a pericardiectomy performed through an open or thoracoscopic approach. Data collected included signalment, history and physical examination, surgical approach, histopathology, treatment, and outcome. RESULTS: Indications for pericardiectomy included idiopathic chylothorax (n = 7), neoplasia (4), idiopathic pericardial effusion (4), and foreign body granuloma (1). Surgical approaches included thoracoscopy (12), intercostal thoracotomy (3) and median sternotomy (1). Electrosurgical devices were used to complete at least part of the pericardiectomy in 15 of 16 dogs. Ventricular fibrillation appeared to be initiated during electrosurgical use in 8/15 dogs. However, in 5/15 dogs it was not obviously associated with electrosurgical use. In 3/16 dogs the timing of initiation of VF was unclear. In 7/16 dogs, cardiac arrhythmias were noted prior to the development of VF. Fourteen of 16 dogs died from intraoperative VF. CONCLUSION: In most dogs ventricular fibrillation was a fatal complication of pericardiectomy. Ventricular fibrillation might be associated with the use of electrosurgical devices and cardiac manipulation during pericardiectomy although a causal link could not be established from the data in this study. CLINICAL SIGNIFICANCE: Surgeons must be aware of the risk of VF during pericardial surgery. Electrosurgery might need to be used judiciously during pericardiectomy, particularly in dogs exhibiting cardiac arrythmias.

Influence of interlocking thread screws to repair simulated adult canine humeral condylar fractures.

OBJECTIVE: To determine the influence of interlocking screw threads on the biomechanical properties of repaired canine humeral condylar fractures. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: Thirty-six humeral condyles. METHODS: Simulated fractures of the lateral aspect of the humeral condyle were stabilized by a 3.5 mm interlocking thread screw (ITS) or 3.5 mm buttress thread screw placed in lag (BTS-L) or positional fashion (BTS-P) and axially loaded at a walk, trot, 2-mm displacement, and failure cycles. Compact flute drill bits (CFBs) were used for ITS constructs and standard flute drill bits (SFB) for BTS constructs. The effects of bit type on drilling parameters and screw type on screw insertion properties and fragment stability were assessed. RESULTS: CFB produced a 6°C greater temperature increase (p = .042) and required 20 N higher torque (p = .003) than SFB. Insertional torque was greater for ITS than BTS-P (p = .001) and BTS-L (p = .001). Condylar fragment rotation at failure was lower in ITS (lsmean ± SE, 8.3° ± 1.9°) than BTS-L constructs (14.5° ± 2.3°, p = .011). ITS resisted greater loads (1503 ± 105 N) than BTS-P (1189 ± 99 N, p = .038) but not BTS-L (1249 ± 123 N, p = .121) constructs. CONCLUSION: Biomechanical performance of constructs was improved with ITS rather than BTS fixation. CLINICAL SIGNIFICANCE: ITS can be considered for stabilization of humeral condylar fractures in adult dogs.

Biopsy of an intracardiac paraganglioma in a dog using a fluoroscopically guided endovascular technique.

A 10-year-old female spayed mixed breed dog was evaluated for diarrhea and vomiting. Diagnostic imaging demonstrated the presence of an intracardiac mass. A modified Seldinger technique was used to access the right jugular vein, and an endomyocardial biopsy forceps was introduced through a sheath to obtain several biopsies. Histopathology and immunohistochemistry demonstrated a paraganglioma. The dog underwent 1 fraction of radiotherapy and l-asparaginase chemotherapy and was discharged. The dog developed a pulmonary thromboembolism 2 days after radiotherapy and chemotherapy, and the owner elected humane euthanasia. Although long-term assessment of treatment response was unable to be performed, this novel diagnostic option could be considered for similar cases due to success in obtaining a histopathologic diagnosis, which is essential in developing a disease-specific treatment plan. This report also describes the use of radiotherapy for primary treatment of an intracardiac neoplasm, which can be a consideration in the future.

Perioperative morbidity and mortality in dogs with invasive adrenal neoplasms treated by adrenalectomy and cavotomy.

OBJECTIVE: To report the morbidity and mortality associated with adrenalectomy with cavotomy for resection of invasive adrenal neoplasms in dogs and evaluate risk factors for perioperative outcomes. STUDY DESIGN: Retrospective study. ANIMALS: Forty-five client-owned dogs. METHODS: Dogs that underwent open adrenalectomy with cavotomy for resection of adrenal masses with tumor thrombus extending into the vena cava were included. Clinicopathologic data were harvested from medical records. Selected clinical, imaging, and operative variables were statistically evaluated as risk factors for packed red blood cell transfusion, nephrectomy, perioperative death, and overall survival. RESULTS: Thirty-six of 45 masses were pheochromocytomas, 7 were adrenocortical carcinomas, and 2 were unknown type. Caval thrombus terminated prehepatically in 21 of 45 dogs and extended beyond the porta hepatis but terminated prediaphragmatically (intrahepatic prediaphragmatic location) in 15 dogs and thrombi extended postdiaphragmatically in 5 dogs. Thirty-four (76%) dogs were discharged from the hospital, and 11 (24%) dogs died or were euthanized prior to discharge. Median overall survival time for all 45 dogs was 547 days (95%CI 146-710). Bodyweight, tumor type, and size and extent of caval thrombus did not affect survival to discharge, but postdiaphragmatic (rather than prediaphragmatic) thrombus termination was associated with a greater risk of death. CONCLUSION: Long-term survival was common in dogs that survived the perioperative period. Postdiaphragmatic thrombus extension affected the prognosis for overall survival. CLINICAL SIGNIFICANCE: Findings of this study help to stratify operative risk in dogs with adrenal neoplasia and caval invasion.

Apocrine gland anal sac adenocarcinoma with perineural metastasis in a cat.

CASE SUMMARY: A 15-year-old female spayed domestic shorthair cat was presented for hyporexia and acute development of L4-Cd myelopathy (urinary incontinence, pelvic limb paresis with hyporeflexia and absent tail tone). Humane euthanasia was elected owing to the rapid neurological deterioration and necropsy was performed. Post-mortem examination identified a right-sided anal sac mass and medial iliac lymphadenopathy. No gross lesions were evident in the cauda equina or peripheral nerves. Histopathology and immunohistochemistry utilizing wide-spectrum cytokeratin confirmed apocrine gland carcinoma of the anal sac with lymph node, peripheral nerve and cauda equina metastasis. RELEVANCE AND NOVEL INFORMATION: This is the first report of feline anal sac adenocarcinoma metastasizing to perineural tissue. In addition, it provides a novel differential diagnosis for L4-Cd myelopathy and urinary incontinence in a cat.