Removal of Dominant Adrenal Lateralized by Glucagon-Stimulated Adrenal Venous Sampling Alleviates Hypertension in Bilateral Pheochromocytoma

Abstract

Abstract:In bilateral pheochromocytoma, localization of the dominant adrenal is challenging but highly important since the removal of dominant side can markedly improve cardiovascular outcomes. To demonstrate the usefulness of glucagon-stimulated BAVS (bilateral adrenal venous sampling) in determining the dominant adrenal to be removed, the authors reviewed records of patients who underwent BAVS with glucagon stimulation from 1997-2010. Nineteen out of 44 patients were diagnosed with bilateral pheochromocytoma. Mean age at diagnosis was 33 ± 14 years. Duration of hypertension was 5 ± 6 years with highest systolic BP (blood pressure) of 186 ± 30 mmHg and diastolic BP of 113 ± 18 mmHg. Headache (68%) is the most common symptom followed by paroxysmal hypertension (58%). Majority were taking  3 anti-hypertensive drugs. On glucagon-stimulated BAVS, 63% had right adrenal dominance. Three patients, who were hypertensive for 1, 6 and 12 years, underwent removal of the dominant adrenal. On follow-up (mean period = 36 months), there was marked improvement in BP control [pre-op vs. post-op: (systolic) 160-240 mmHg vs. 120-150 mmHg; (diastolic) 90-110 mmHg vs. 70-90 mmHg] and reduction in number of anti-hypertensive medications (from 3-5 to 2 classes of drugs). BAVS with glucagon stimulation is a valuable tool in the identification of the dominant adrenal to be removed in patients with bilateral pheochromocytoma to alleviate chronic hypertension.