Table 4.
Variations in adrenal venous sampling protocols that could affect results and interpretations
| Advantages | Disadvantages | |
|---|---|---|
| Catheterization method | ||
| Sequential | Technically simpler | Could result in factitious lateralization, particularly when the time between 2 samplings is more than 15 minutes |
| Simultaneous | Helps minimize the difference due to sampling times between adrenal glands | Technically more involved |
| Sampling | ||
| Single adrenal venous sample | More convenient and less cost compared with multiple samples | Lacks precision and can result in misinterpretations owing to variability in aldosterone production |
| Multiple adrenal venous samples | Improves precision during AVS when calculating A/C ratio | Requires additional cost and time |
| Cosyntropin use | Enhances the selectivity index to increase confidence in successful adrenal vein cannulation Decreases the variability of aldosterone |
Can lower lateralization index and lateralization rates, leading to discordant interpretations, and may result in fewer patients diagnosed with lateralizing PA. Therefore, unstimulated data provide more reliable interpretations for lateralization |
| Confirmation of catheter placement | ||
| Cone-beam CT | Improves AVS success rate by confirming accurate catheterization, particularly to the right adrenal vein May reduce total radiation exposure during AVS |
Image degradation caused by several artifacts due to breath-hold or posture (patients are required to raise their arms above the head) Not available in all centers |
| Rapid intraprocedural cortisol assay | Improves AVS success rate by allowing biochemical confirmation of accurate catheterization during the procedure May reduce total radiation exposure during AVS |
May increase the procedural time (depending on the turnaround time for each laboratory) Not available at all centers and not validated |
| Standard cortisol assay | Available at nearly all AVS centers No additional cost |
Slow turnaround time |
Abbreviations: A/C, aldosterone-to-cortisol ratio; AVS, adrenal venous sampling; CT, computed tomography; PA, primary aldosteronism.