Predictive Factors and the Effect of Phenoxybenzamine on Outcome in Dogs Undergoing Adrenalectomy for Pheochromocytoma

49-month survival following caval venectomy without nephrectomy in a dog with a pheochromocytoma

An 11 yr old spayed female Labrador retriever was diagnosed with a right adrenal tumor. At surgery, adhesions to the right kidney were dissected, allowing the right kidney to be preserved. The tumor showed extensive invasion into the suprarenal vena cava. It was felt that thrombus removal via venotomy could not be performed. Instead, the vena cava was ligated caudal to the liver and cranial to the right renal vein. The neoplastic gland was then excised en bloc together with the portion of the invaded caudal vena cava. Hind limb edema had developed preoperatively and increased transiently in the first days postoperatively. The animal was discharged 6 days postoperatively with no other clinical disorders, and hind limb edema resolved over time. Histopathology identified a pheochromocytoma. The dog died 49 mo later. A neoplastic thrombus of the vena cava may require venotomy to allow thrombus removal. Occasionally, removal of the thrombus by venotomy may prove impossible. In such a situation, en bloc removal of the concerned portion of the vena cava may be performed with a good long-term outcome provided that gradual occlusion of the vena cava by the thrombus has allowed time for collateral circulation to develop.

Metabolic complications of endocrine surgery in companion animals

Metabolic complications of endocrine surgery occur commonly and precautions should be taken to avoid potentially life-threatening situations and to lessen expense associated with a more extended hospital stay. Common complications of endocrine surgery as well as prevention strategies will be reviewed for pancreatic, parathyroid, and adrenal surgery.

Endocrine hypertension in small animals

Hypertension is classified as idiopathic or secondary. In animals with idiopathic hypertension, persistently elevated blood pressure is not caused by an identifiable underlying or predisposing disease. Until recently, more than 95% of cases of hypertension in humans were diagnosed as idiopathic. New studies have shown, however, a much higher prevalence of secondary causes, such as primary hyperaldosteronism. In dogs and cats, secondary hypertension is the most prevalent form and is subclassified into renal and endocrine hypertension. This review focuses on the most common causes of endocrine hypertension in dogs and cats.