Anesthetic considerations

Twenty-three million Americans, or 10% of the United States population, suffer from essential hypertension.1 About 20,000 persons, or 0.1 to 0.5% of hypertensive individuals, also have pheochromocytoma. This catecholamine-producing tumor arises from the chromaffin cells of the sympathoadrenal system. 2-4 It is a tumor which has no age or sex predilection, but seems to occur more often during the second and sixth decades of life.2,8'5 About 20% of the reported tumors have occurred in children, 39% of whom have had bilateral adrenal medulla tumors or multiple tumors occurring along the sympathetic axis. There seems to be a familial tendency in 5% of the cases and a somewhat greater incidence (from 5 to 20%) in patients with von Recklinghausen's neurofibromatosis, a cutaneous disease frequently involving bone, the central nervous system, and chromaffin tissue.2,4 The tumor was described as early as 1886, but it was not until 1912 that it was named pheochromocytoma, or "black celled tumor." During the 1920's Cesar Roux and Charles Mayo first successfully removed a pheochromocytoma. The clinical symptoms of this tumor were believed to be due to epinephrine. However, in 1949 and 1950 with the demonstration of the presence of norepinephrine in pheochromocytoma, it became apparent that the clinical manifestations were related at times to the secretion of norepinephrine as well as epinephrine.4 Pheochromocytoma may appear where any sympathetic nervous tissue exists, from the base of the brain to the pelvis. One just has to consider the preponderance of sympathetic ganglia to conceptualize the potential invasiveness of this disease. The sympathetic ganglia are arranged in three major groups. The first group is the paravertebral ganglia consisting of a chain of 22 ganglia on each side of the spinal cord connected to spinal nerves by white and grey rami. These ganglia are connected together, forming a sympathetic chain which extends from the base of the skull to the front of the coccyx. The second group is the prevertebral or collateral ganglia. These lie in the thorax, abdomen, and pelvis in relation to the aorta and its branches. The terminal (peripheral) ganglia, the third group, lie close to the organs innervated. These ganglia are associated with the bladder and rectum. The majority of pheochromocytoma tumors are found within the abdominal cavity, and there is an 80-90% proclivity for tumor growth in or near the adrenal gland, with the right adrenal