Case of the Month at Metropolitan Veterinary Consultants

Tara is a 12 year old spayed female golden retriever. Her past pertinent history consisted of previous splenectomy following an acute hemoabdomen approximately 3 years ago. Histopathology of the spleen demonstrated hemangiopericytoma. The rest of the workup at that time did not demonstrate any metastatic disease, but there was ongoing suspicion about the initial histopathologic diagosis. She had been relatively well over that time.

She was referred to Metropolitan Veterinary Consultants at the Veterinary Referral Center of New Hampshire following an acute onset of weakness, lethargy, and partial anorexia.

On physical examination she was quiet but responsive. She was febrile with a respiratory rate of 45 and a heart rate of ~80-90bpm. Her mucous membranes were pale with a CRT=2seconds. There was no murmur heard on thoracic auscultation but heart sounds were moderately muffled on both sides. The lungs had mild bilateral bronchovesicular noises and moderate bilateral pleural friction rubs. Pulses were synchronous and fair in quality. The abdomen was slightly distended but there was no palpable mass or ballotable fluid wave. The rest of the physical exam was unremarkable.

Review of radiographs sent by the referring veterinarian demonstrated mild to moderate globoid cardiomegaly with a slight increase on the right side. Lungs demonstrated mild perihilar pulmonary edema and very mild bilateral pleural effusions.

Clinical pathology demonstrated a relatively normal biochemical profile. A CBC demonstrated an inflammatory leukogram with a total white count of 27K and no cellular atypia. The PCV was 27% and was poorly regenerative with mild microcytosis and polychromasia, consistent with anemia of chronic disease. Platelet count, PT and PTT were normal.

Abdominal ultrasound revealed no discernable fluid or evidence of metastatic disease in any solid parenchymal organ. The liver had mild increase in portal vein size and the overall the liver was slightly hypoechoic. Echocardiography revealed moderate pericardial effusion with marked thickening and hyperechogenicity of the pericardium.

Immediately following incision into the pericardium, Tara became much more hemodynamically stable and the surgery was completed routinely. A thoracostomy tube was placed for 24 hours post operatively and she was discharged at the end of the first post operative day.

This case demonstrates the tremendous utility of minimally invasive thoracic surgery even in palliative cases. Clearly, Tara is not likely to have an extended period of survival. However, with a limited surgical intervention, and a short hospital stay, and the marked symptomatic benefit of the procedure, this was an excellent option for this patient and these clients.

The right ventricle and atrium were mildly dilated, and systolic function was decreased with a low ejection fraction and fractional shortening. There was a suspicious focus on the right atrial appendage but given the relatively smaller amount of pericardial fluid seen, it was not clear whether this was indeed a mass.

Given the history however, a tentative diagnosis of a malignant pericardial effusion with secondary pericardial tamponade was made. A decision was made to stabilize the dog with digoxin, enalapril, furosemide, and antibiotics pending a thoracoscopic pericardectomy.

Initially, Tara stabilized well. Twenty four hours prior to surgery she destabilized and became profoundly weak and recumbent. Following induction with propofol and maintenance with isoflurane she was taken to surgery. A ventral paraxyphoid approach to the thorax was undertaken using VATS (video assisted thoracoscopic surgical) technique. A partial pericardectomy was performed.