Author(s)

Nimesh Patel¹, Kyung J. Cho^2*

¹University of Michigan Medical School, Ann Arbor, MI, USA.
²Department of Radiology, Division of Vascular & Interventional Radiology, University of Michigan Health System, Ann Arbor, MI, USA.

We report on a 15-year-old male with 4-year history of hypertension and retroperitoneal masses referred to Interventional Radiology to evaluate the nature of the persistent masses and renal artery stenosis. Angiographic evaluation began with CO₂aortogram during which the patient had a hypertensive response with bradycardia and arrhythmia to the intra-aortic injection of CO₂. His hypertension, bradycardia, and arrhythmia responded to an intravenous nitroglycerin drip without administration of alpha or beta blockers. Due to this response and neovascularity of the mass, selective venous sampling of catecholamines and renin was performed which confirmed functioning paragangliomas and hemodynamically significant stenosis of left accessory renal artery, respectively. This is the first known case of hypertensive response to CO₂ aortography in a patient with unsuspected functioning paragangliomas. We propose that patients with known or suspected diagnosis of catecholamine-secreting tumors undergoing CO₂ angiography should be considered for pre-procedural treatment with alpha and beta blockage or have the appropriate medication on hand with close monitoring in the event of hypertensive response.

CO₂, Aortography, Paraganglioma, Caval Venous Sampling, Renal Artery Stenosis

Patel, N. and Cho, K. (2015) Transient Hypertensive Response to CO₂ Aortography in a Patient with Pheochromocytoma. Open Journal of Radiology, 5, 1-7. doi: 10.4236/ojrad.2015.51001.