Development of a Free Latissimus Dorsi Muscle Flap in Cats

Anatomic and experimental evaluation of the feline latissimus dorsi muscle was performed to assess its potential use as a free muscle flap. In the anatomic study, nonselective angiography of the subscapular artery was performed in nine heparinized feline cadavers. The muscle dimensions and vascular anatomy of the dissected latissimus dorsi muscle were recorded. In the experimental study four cats underwent heterotopic transplantation of a partial latissimus dorsi flap, and three cats underwent orthotopic transplantation of a complete latissimus dorsi flap. The mean length and width of the latissimus dorsi muscle was 19.0 and 5.4 cm, respectively. The dominant vascular pedicle was the thoracodorsal artery and vein. The average length and diameter of the thoracodorsal artery was 2.7 cm and 0.6 mm, respectively. Minor vascular pedicles were provided by branches of the intercostal arteries. Numerous choke anastomoses existed between the two pedicle systems. Viability of muscle flaps based on subjective evaluation, angiography, and histopathology, was 66% and 100% in the heterotopic and orthotopic studies, respectively. Flap failure seemed to be caused by both arterial and venous thrombosis. The latissimus dorsi muscle flap met criteria required for application in microvascular reconstruction. The vascular pattern was appropriate and consistent. Donor site morbidity was low, whereas surgical accessibility was high. The muscle satisfied the physical criteria of a free flap. Long-term anastomotic patency and flap viability was shown.     

EFFECT OF METHYLCELLULOSE ON UPPER GASTROINTESTINAL QUALITY IN DOGS

This study was performed to evaluate and optimize a small bowel contrast technique using barium and methylcellulose in dogs. Ten healthy dogs underwent both a conventional upper gastrointestinal study that used only barium and a modified study that used barium and methylcellulose. The control group received 10 mL/kg of 40% barium suspension. Experimental groups were divided into three subgroups given 15 mL/kg of different viscosities (low, moderate, and high viscosity) of 0.5% methylcellulose after 4 mL/kg of 40% barium suspension. Compared with the control group, dogs receiving methylcellulose had higher-quality upper gastrointestinal studies. Moderate viscosity of methylcellulose was superior to the other methylcellulose groups. In conclusion, the use of methylcellulose is a simple and effective method for improving the image quality in an upper GI examination.     

Hepatic myelolipoma incarcerated in a peritoneopericardial diaphragmatic hernia in a cat

Hepatic myelolipoma incarcerated in a peritoneopericardial diaphragmatic hernia was diagnosed in an 11-year-old, desexed female Persian cat. The cat was initially referred for investigation of tachypnoea and dyspnoea. Peritoneopericardial diaphragmatic hernia is a common incidental finding in cats and is usually asymptomatic. Myelolipoma is an extremely rare benign tumour, composed of extramedullary haematopoietic cells and adipose tissue. Myelolipomas are hypothesised to result from metaplastic alteration, rather than a neoplastic process, although this theory cannot be substantiated. The present case is only the fourth report of such an unusual occurrence in cats and displays significant differences to previous reports. Hepatic entrapment and burgeoning of the mass within the pericardial sac resulted in cardiac tamponade and overt signs of right-sided cardiac failure. Surgical intervention was successful and despite concerns regarding the cat's clinical presentation and the gross appearance of the lesion(s), a good long-term outcome is anticipated.     

Effects of high and low inspired fractions of oxygen on horse erythrocyte membrane properties, blood viscosity and muscle oxygenation during anaesthesia

ObjectivesTo evaluate whether a period of hyperoxia or after a period of hypoxia produced changes attributable to reactive oxygen species in anaesthetized horses.Study designProspective randomized experimental study.AnimalsSix healthy (ASA I) geldings, aged 4.5–9.5 years and weighing 510–640 kg^?1.MethodsAfter 30 minutes breathing air as carrier gas for isoflurane, horses were assigned randomly to breathe air as carrier gas (CG0.21) or oxygen as carrier gas (CG1.00) for a further 90 minutes. After an interval of 1 month each horse was re-anaesthetized with the other carrier gas for the 90 minute test period. Ventilation was controlled throughout anaesthesia. Arterial blood was sampled to measure gas tensions, lactate, cholesterol, vitamin E, 4-hydroxy-alkenals, 8-epi-PGF_2α, half haemolysis time, half erythrolysis time, and erythrocyte membrane fluidity. Muscle blood flow and oxygenation were evaluated by near infrared spectroscopy and coloured Doppler.ResultsAfter the first 30 minutes horses were hypoxemic. Subsequently the CG1.00 group became hyperoxaemic (PaO₂～240 mmHg) whereas the CG0.21 group remained hypoxaemic (PaO₂～60 mmHg) and had increased lactate concentration. No significant changes in vitamin E, 4-hydroxy-alkenals, or 8-epi-PGF_2α concentrations were detected. During the 90 minute test period the CG0.21 group had increased resistance to free-radical-mediated lysis in erythrocytes, whereas the CG1.00 group had slightly decreased resistance of whole blood to haemolysis. CG0.21 induced a progressive muscle deoxygenation whereas CG1.00 induced an increase in muscle oxygen saturation followed by progressive deoxygenation towards baseline.Conclusions and clinical relevanceDuring isoflurane anaesthesia in horses, the hyperoxia induced by changing from air to oxygen induced minimal damage from reactive oxygen species. Using air as the carrier gas decreased skeletal muscle oxygenation compared with using oxygen.     

Efficacy and Toxicity of Doxorubicin/Cyclophosphamide Maintenance Therapy in Dogs with Multicentric Lymphosarcoma

Doxorubicin/cyclophosphamide were evaluated as maintenance drugs for dogs with multicentric lymphosarcoma (n = 28). Median remission time of all dogs was 173 days. Remission duration was shorter, however, in dogs with stage IV/V disease, in dogs with pretreatment hypoalbuminemia, and in dogs that had received glucocorticoids before initiation of chemotherapy (P less than 0.04). Nineteen dogs were evaluable for toxicity. Dose-limiting gastrointestinal toxicosis was observed in three dogs, neutropenia was observed in three dogs, and cardiomyopathy was observed in three dogs. The doxorubicin/cyclophosphamide protocol described in this report is safe and effective in treating canine multicentric lymphosarcoma. Clinical stage, pretreatment steroid therapy, and hypoalbuminemia are prognostic factors for response to this protocol.