Identification of the Etiology of Primary Aldosteronism with Adrenal Vein Sampling in Patients with Equivocal Computed Tomography and Magnetic Resonance Findings: Results in 104 Consecutive Cases

Abstract

The objectives of this study were to investigate the usefulness of adrenal vein sampling in identifying the etiology of primary aldosteronism (PA) in patients with equivocal CT and MR findings. Between 1990 and 1999, 104 referred hypertensive patients (45 women and 59 men, aged 49.6 +/- 11.6 yr) were diagnosed to have PA with inconclusive computed tomography scan and magnetic resonance results, based on established criteria. Adrenal vein sampling (AVS) for measurement of plasma aldosterone (A) and cortisol (C) levels was performed in all. Selectivity of AVS was assessed by the ratio between C levels in each adrenal vein and in the infrarenal inferior vena cava plasma (C(side)/C(IVC)). A receiver operator characteristics analysis was carried out to establish 1) the best AVS-derived index, 2) the degree of selectivity that could provide an accurate diagnosis, and 3) whether a correct diagnosis could be made from a unilaterally selective AVS. An aldosterone-producing adenoma (average diameter, 12.2 +/- 0.08 mm) was eventually diagnosed in 41 patients (39.4%) and was excluded in the rest. Adrenal vein rupture leading to partial adrenal loss occurred in 1 patient (0.9% complication rate). By assuming a cut-off value of C(side)/C(IVC) > or = 1.1, AVS was selective in 85.7% and 94.1% of cases on the right and left sides, respectively, and bilaterally in 80.6% of cases. Of all AVS-derived indexes, the A/C of one over the A/C contralateral side [(A/C)(side)/(A/C)(contralateral side)] furnished the best diagnostic accuracy. With a bilaterally selective AVS, a value of (A/C)(side)/(A/C)(contralateral side) > or = 2 provided a conclusive etiological diagnosis of PA in 79.7% of cases. At variance, no accurate diagnosis could be made from unilaterally selective AVS. AVS was feasible and safe in most PA patients with inconclusive computed tomography and magnetic resonance scans. When bilaterally selective (i.e. C(side)/C(IVC) > or = 1.1) a ratio of (A/C)(side)/(A/C)(control) > or = 2 provided the best compromise of sensitivity and false positive rate for lateralization of the etiology of PA.

Renal Damage in Primary Aldosteronism

“…This score estimates the individual probability of APA in each patient. Patients with an ARR Ն40 baseline or Ն30 after captopril and/or with an LDF score Ն0.50 underwent a saline infusion test (2 L of 0.9% NaCl solution in 4 hours), and, if necessary, an imaging test that was composed of a high-resolution computed tomography with 3-mm slices and/or magnetic resonance followed by adrenal vein sampling 23 or dexamethasone-suppressed adrenocortical scintigraphy.…”

Primary Hyperparathyroidism With Concurrent Primary Aldosteronism

“…Adrenal vein sampling, which was bilaterally selective, 7 evidenced a slightly predominant aldosterone production on the left side (lateralization index: 1.69). 8 …”

Small tumor size as favorable prognostic factor after adrenalectomy in Conn's adenoma

“…In all patients with confirmed PA, differentiation between an adrenal adenoma and idiopathic aldosteronism was obtained using computerized tomographic (CT) scan of the adrenal glands with 3 mm contiguous slices after administration of a non-ionic iodinated contrast agent (nZ37); or magnetic resonance imaging (MRI) in patients with iodine allergy or claustrophobia (nZ5), followed by adrenal vein sampling (AVS) for measurement of aldosterone and cortisol (nZ26); or dexamethasone-suppressed adrenal scintigraphy with I 131 cholesterol (nZ16). The correct cannulation of adrenal veins and lateralization of aldosterone hypersecretion were defined according to the criteria proposed by Rossi et al (26). Due to the lack of cannulation of adrenal veins, AVS was successfully repeated in eight patients.…”