Comparison of sequential versus simultaneous methods of adrenal venous sampling

PURPOSE: To compare two methods of adrenal venous sampling (AVS) in preoperative localization of adrenal lesions in primary hyperaldosteronism. MATERIALS AND METHODS: Twenty-one patients (13 men, eight women) underwent selective adrenal venous sampling between July 2001 and May 2003. One of the 21 patients underwent repeat AVS, for a total of 22 procedures. In half the procedures (n = 11), simultaneous bilateral adrenal venous catheterization and sampling was performed before and after intraprocedural adrenocorticotropic hormone (ACTH) administration; in the remaining half (n = 11), sequential catheterization of the left and right adrenal veins was performed during continuous ACTH infusion 1 hour before and throughout AVS. Chart review provided procedural data, including sampling intervals and aldosterone/cortisol ratios. Patient records provided clinical data, including blood pressure, serum aldosterone levels, and computed tomography and magnetic resonance imaging findings. Surgical pathology reports confirmed unilateral disease but were not applicable to bilateral disease. RESULTS: Selective AVS was completed successfully in 21 of 22 procedures (95%); the unsuccessful sampling was repeated successfully. Disease lateralized in 13 of 22 cases. Simultaneous bilateral AVS localized unilateral disease in seven of eight cases (88%) and was nondiagnostic in one case (13%), with cases confirmed by surgical pathology reports. Sequential bilateral AVS localized unilateral disease in four of four cases (100%) confirmed by surgical pathology reports, with one lost to follow-up. Bilateral disease was diagnosed in six of 22 cases: two of 11 by simultaneous AVS and four of 11 by sequential AVS. Three of 22 cases demonstrated borderline hormone levels that failed to meet the diagnostic threshold for recommended adrenalectomy. Mean elapsed time between acquisition of right and left samples did not differ between simultaneous and sequential AVS (P = .09). Baseline (prestimulation) sampling did not contribute unique diagnostic information in any case and provided contradictory or confounding information in three of 11 simultaneous AVS procedures (27%). CONCLUSIONS: Sequential bilateral catheterization does not compromise the reliability of time-sensitive AVS. Both simultaneous and sequential AVS are adequate studies; however, obtaining baseline prestimulation samples during simultaneous AVS is unnecessary and increases the cost of the procedure.