Identification of the right adrenal vein opening using intraoperative 4D-CT angiography from the right adrenal artery in adrenal vein sampling: A case report.

Primary aldosteronism is the most common cause of secondary hypertension. Adrenal vein sampling (AVS) is a diagnostic procedure to determine whether aldosterone hypersecretion is unilateral or bilateral, and thereby guide the choice of adrenalectomy or pharmacotherapy as the appropriate treatment. However, during AVS, it is challenging to cannulate the right adrenal vein (RAV) owing to its anatomical variability and poor visibility on preoperative CT. This case report describes the successful use of intraoperative 4D-CT angiography from the right adrenal artery to identify the RAV opening, which was invisible on preoperative contrast-enhanced CT. The patient, a woman in her 40s with primary aldosteronism and a right adrenal nodule, underwent 4D-CT because the RAV could not be located by conventional preoperative CT. The intraoperative 4D-CT clearly visualized the RAV and contrast material ascending along the right wall of the inferior vena cava. These images were then fused onto live fluoroscopy to guide a catheter into the RAV. The AVS indicated bilateral aldosterone hypersecretion, and the patient was managed pharmacologically. Intraoperative 4D-CT angiography from the right adrenal artery can increase the success rate of AVS, especially in difficult cases where the RAV is invisible on preoperative CT.