Endocrine Abstracts

Background: The current recommendation on the use of venous sampling is reserved for difficult cases of small pheochromocytoma. Bilateral adrenal venous sampling (BAVS) with glucagon stimulation has been reported to be safe and useful in the early diagnosis of the disease. For bilateral lesions, localization can be challenging but highly important since the removal of the dominant side can markedly improve fatal cardiovascular outcomes as a consequence of chronic hypertension.

Objective: To demonstrate the usefulness of glucagon-stimulated BAVS in determining the dominant adrenal to be removed.

Methodology: This is a cross-sectional study wherein records of patients who underwent BAVS with glucagon stimulation from 1997–2010 were reviewed.

Results: Of the 46 patients who underwent BAVS with glucagon stimulation, 19 were diagnosed with bilateral pheochromocytoma. The mean age at diagnosis was 33±14 years. The mean duration of hypertension was 5±6 years with an average highest systolic blood pressure (BP) of 186±30 mmHg and diastolic BP of 113±18 mmHg. Headache (68%) is the most common symptom followed by paroxysmal hypertension (58%), palpitation (42%), and flushing (37%).Majority were taking three or more anti-hypertensive drugs. On glucagon-stimulated BAVS, 63% had right adrenal dominance. The mean epinephrine and norepinephrine levels on the dominant side were 24,506±30710 pg/ml and 8,642±13,395 pg/ml, respectively. The mean ratio of the dominant versus nondominant adrenal for epinephrine and norepinephrine were 3.62 and 4.13, respectively. Three patients underwent unilateral adrenalectomy. On follow-up, there was marked improvement in BP and reduction of anti-hypertensive medications.

Conclusion: 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.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.