Lateralizing Asymmetry of Adrenal Imaging and Adrenal Vein Sampling in Patients With Primary Aldosteronism

Norio Wada; Yui Shibayama; Takashi Yoneda; Takuyuki Katabami; Isao Kurihara; Mika Tsuiki; Takamasa Ichijo; Yoshihiro Ogawa; Junji Kawashima; Masakatsu Sone; Takanobu Yoshimoto; Yuichi Matsuda; Megumi Fujita; Hiroki Kobayashi; Kouichi Tamura; Kohei Kamemura; Michio Otsuki; Shintaro Okamura; Mitsuhide Naruse; JPAS/JRAS Study Group

Disclosures

J Endo Soc. 2019;3(7):1393-1402. 

In This Article

Abstract and Introduction

Abstract

Context: In patients with primary aldosteronism (PA), it remains unclear whether aldosterone-producing adenomas are likely to develop in the left or right adrenal gland.

Objective: To investigate left-right differences of PA laterality diagnoses via CT imaging and adrenal vein sampling (AVS).

Design: Retrospective, observational study.

Patients: From the Japan Primary Aldosteronism Study, 1493 patients with PA were enrolled who underwent CT and ACTH-stimulated AVS.

Measurements: Left or right adrenal nodular lesion distribution and laterality observed on CT scans and from AVS were noted.

Results: Both on CT scans and AVS, unilateral results were observed more frequently on the left side than on the right side (25.1% vs 15.4% and 17.3% vs 13.5%, respectively; P < 0.01for both diagnostic techniques). There was no significant difference in the concordance rate for CT and AVS between patients with left and right unilateral nodular lesions observed on CT scans (44.1% and 50.9%, respectively; P = 0.15). In patients with nodules <20 mm, the concordance rate was significantly greater on the right side than the left side (45.8% vs 56.4%; P= 0.03). In patients with bilateral results of AVS, unilateral nodular lesions were detected more frequently on the left side than the right side (17.8% vs 9.4%; P < 0.01).

Conclusion: These results suggest aldosterone-producing adenomas and nonfunctioning tumors are more likely to develop on the left side in patients with PA and that misdiagnosis of CT-based lateralization may occur more frequently on the left side.

Introduction

Primary aldosteronism (PA) is characterized by autonomous hypersecretion of aldosterone and is the most common cause of secondary hypertension, accounting for either 6% or 8% of all hypertensive patients.[1] Patients with PA are at a higher risk of cardiovascular morbidity than those with essential hypertension.[2] The two common PA subtypes, aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism, must be diagnosed correctly, because the former condition requires an adrenalectomy, whereas the latter is treated by medication.[2]

Two modalities of lateralization diagnosis—adrenal imaging, including CT and MRI, and adrenal vein sampling (AVS)—are commonly used to determine the localization of unilateral aldosterone production in patients with PA. It is well known that there are often discrepancies between the imaging diagnosis including CT and MRI and the lateralization diagnosis of AVS.[3–5] Reports[3–5] have discussed unilateral or bilateral diagnoses, although they did not consider whether the unilateral lesions were located on the left or right side. Recently, a few reports discussed left-right differences in laterality diagnosed using both imaging and AVS.[6,7] However, those studies either had a small sample size[6] or did not use a unified diagnostic imaging modality.[7]

In theory, adrenal tumors are considered to occur equally on the left or right side. However, several studies focusing on other objectives have suggested a potential lateralizing asymmetry with a greater prevalence of left-sided adrenal tumors.[8–10] Recently, Hao et al.,[11] using the data from a large cohort study, investigated left-right differences in incidentally discovered adrenal adenomas, excluding functioning tumors. They found adrenal adenomas were more prevalent on the left side than the right side. In the current study, we investigated left-right differences determined from CT imaging and AVS, using the data from a large cohort of a multicentric collaborative study for PA, the Japan Primary Aldosterone Study (JPAS).

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