Surgical treatment of pheochromocytoma: technique, complications, and results in six dogs.

Six dogs were diagnosed with pheochromocytoma and staged according to the World Health Organization's system for tumor classification. Two dogs had benign tumors (T1, N0, M0) and four dogs had malignant tumors (T2, N0, M1 or T3, N0, M0). All dogs had adrenalectomy, two dogs had concurrent nephrectomy, and three dogs had concurrent resection of a tumor thrombus from the vena cava. Anesthetic complications occurred in five dogs, including wide variations in heart rate (four dogs), blood pressure (five dogs), and cardiac arrhythmias (one dog). One dog died 12 hours after surgery from partial dehiscence of the suture line and hemorrhage from the vena cava, and one dog died 6 days after surgery during general anesthesia for treatment of laryngeal paralysis. Four dogs survived from 3 to 23 months (median, 15 months). One dog remained hypertensive after surgery. Benign and malignant pheochromocytomas seem to be amenable to surgical resection.