Adrenal Venous Sampling for the Diagnosis of Hyperaldosteronism
Vascular and Interventional Radiology
- Notify the /mmunology lab that we will be bringing blood samples for in about 1-2 hours.
- Start Cosyntropin infusion at 40ug, (0.04mg)/hr, 30 minutes before adrenal vein catheterization and continue throughout the procedure. If 0.25mg of cosyntropin is diluted in 100cc of NS or dextrose the concentration is 0.0025mg/cc, and the infusion rate is 16cc/hr.
- Blood is obtained simultaneously from both the adrenal veins and the IVC below the renal veins and assayed for aldosterone and cortisol concentration. Make sure all tubes are properly labeled and marked: Right, Left, IVC. Deliver blood specimens to the Lab. Have them run stat cortisol levels to verify the adrenal veins have been sampled.
- Discontinue the cosyntropin drip. Hold the patient in the post procedural area. Do Not remove the vascular sheaths until the Immunology Lab verifies that the samples have been collected properly. Restart the ACTH and resample if necessary.
- Interpretation:
Mean adrenal/IVC cortisol ratio: Right-32.1/1Â Â Â Left-21.9/1
Mean Right to Left Cortisol gradient: 1.6/1Â Â Â (range 0.5-9.6)
Cortisol-corrected lateralization ratio:
Unilateral source > 4.0/1
Overlap zone 3-4/1
Bilateral zone < 3.0/1
Possible sites of sampling:
Left adrenal     Right adrenal           IVC,           supra-renal IVC,        infra-renal IVC
Left renal        Right renal
Reference: Phechromocytoma and Primary Aldosteronism: Diagnostic Approaches. Endocrinology and Metabolism Clinics of NA. 1997;26(4):801-927
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Frequently Asked Questions
What is adrenal vein sampling used for?
Adrenal vein sampling is a diagnostic procedure used to determine the source of excess aldosterone production in patients suspected of having hyperaldosteronism. It helps differentiate between unilateral (one-sided) and bilateral (both sides) adrenal gland involvement, which is crucial for deciding the appropriate treatment approach, such as surgical removal of an adrenal gland or medical management.
How is the adrenal vein sampling procedure performed?
The procedure involves inserting a catheter through a large vein, typically in the groin, and guiding it to the adrenal veins. Blood samples are collected simultaneously from both adrenal veins and the inferior vena cava (IVC) to measure aldosterone and cortisol levels. This helps in assessing the function of each adrenal gland. The procedure requires careful coordination with labs for immediate processing and verification of sample integrity.
What is the role of cosyntropin in adrenal vein sampling?
Cosyntropin, a synthetic form of adrenocorticotropic hormone (ACTH), is infused to stimulate the adrenal glands during the procedure. This ensures optimal hormone secretion, which enhances the accuracy of the sampling by stabilizing cortisol production. The infusion starts 30 minutes before catheterization and continues throughout the procedure to maintain consistent hormone levels.
Why are cortisol levels measured during adrenal vein sampling?
Cortisol levels are measured to confirm successful sampling of the adrenal veins. High cortisol concentrations indicate that the samples are from the adrenal vein, not a nearby vessel. This verification is crucial for interpreting aldosterone results accurately, as it ensures the correct anatomical source of the blood samples.
What does a cortisol-corrected lateralization ratio indicate?
The cortisol-corrected lateralization ratio helps determine if aldosterone production is coming predominantly from one adrenal gland. A ratio greater than 4:1 suggests unilateral aldosterone excess, which may warrant surgical intervention. Ratios between 3:1 and 4:1 fall into an overlap zone, while ratios below 3:1 indicate bilateral production, which is typically managed medically.
What are potential complications of adrenal vein sampling?
Though generally safe, adrenal vein sampling can have complications such as bleeding, hematoma formation, or vascular damage due to catheter insertion. There is also a risk of adrenal vein rupture. These risks are minimized by performing the procedure in specialized centers with experienced interventional radiologists.
How long does it take to get results from adrenal vein sampling?
Results from adrenal vein sampling can be available within hours if processed as a priority, but it might take a few days for complete interpretation. Quick processing of cortisol levels is crucial to verify sample collection quality, while aldosterone measurements may take longer to analyze.