This is the second part of “Top 10 Things to Know About Adrenal Vein Sampling for Primary Hyperaldosteronism”. View the first part of the post  in this series about adrenal vein sampling here.

Primary hyperaldosteronism, or Conn’s syndrome, is due to overproduction of the very toxic hormone, aldosterone, from the adrenal glands. The disease can be due to a single tumor on one of the adrenal glands (left or right) or too much aldosterone from both adrenal glands.

Read about primary hyperaldosteronism, or Conn’s syndrome, here.

Adrenal vein sampling is an X-ray study to figure out

1. a) Does the patient have too much aldosterone production from one or both adrenal glands?
2. b) Which adrenal gland harbors the tumor, the left or right?

Adrenal vein sampling is recognized by Endocrine Society (U.S.) guidelines as the only reliable way to correctly diagnose the subtype of primary hyperaldosteronism. The Carling Adrenal Center in Tampa has the world’s best IR doctor and team to perform adrenal vein sampling.

Top 10 Things to Know About Adrenal Vein Sampling for Primary Hyperaldosteronism - Part II

6) The trickiest part of adrenal vein sampling is to obtain accurate samples from the right adrenal vein.

The reason adrenal vein sampling has been thought of as a tricky procedure is that sometimes it can be difficult to get accurate samples from the very short right adrenal vein. This is why you need the most experienced interventional radiologist to perform your study. The procedure requires both technical finesse and some patience. However, performed by a very experienced radiologist, the procedure can be done in minutes. When the radiologist puts the little catheter into the very small and short right adrenal vein, the problem is that the catheter can slip out and that it fails to measure the aldosterone level in the correct spot. Again, having the best technical interventional radiologist is very important.

Figure 1. Tiny catheters are placed through the femoral vein (groin) and into the inferior vena cava, and the left and right adrenal veins. Blood samples for measurements of aldosterone and cortisol (serves as control) are obtained. Adopted from reference Monticone S. et. al. Lancet Diabetes Endocrinol. 2015.

7) You need an experienced team and laboratory to run the test for aldosterone and cortisol when having adrenal vein sampling

You do need an excellent team to perform the adrenal vein sampling. Even if the interventional radiologist is very good, it is imperative that this procedure is done frequently and that there is a laboratory team that knows how to handle the specimens correctly to measure aldosterone and cortisol. Also, you do want very rapid turnaround times for the cortisol and aldosterone levels to be analyzed. This provides important feedback to the interventional radiologist and enables adrenal surgery during the same visit. Dr. Carling and Carling Adrenal Center is the only center in the world that can provide same visit adrenal vein sampling and curative adrenalectomy for primary hyperaldosteronism. The reason we can do this is that we do more of these cases than anywhere in the world and we have invested the time and effort in setting up a system and workflow that involves the best in surgery, radiology, and laboratory medicine.

Figure 2. Typical results from a positive adrenal vein sampling demonstrating an aldosterone-producing adrenal tumor in the left adrenal gland. The adrenal vein sampling results need to be interpreted by an expert. The first thing is to ensure that the study was performed correctly. The cortisol levels prove this. In this case you can see that the cortisol levels are >10x higher in both the right (563) and the left (407) adrenal vein, as compared to the inferior vena cava (IVC; 34). This confirms that the catheter was in the correct position when the blood samples were obtained. Next, you can see that the aldosterone level is significantly higher in the left adrenal vein (4751). The aldosterone levels are corrected for the cortisol concentration (A/C ratio). The aldosterone ratio of 102 indicates a dramatic overproduction from the left side. An aldosterone ratio (sometimes referred to as lateralization index) of >4 proves a tumor on one adrenal gland. This patient had a 17-minute Mini Back Scope Adrenalectomy (MBSA) and was completely cured of her Conn’s syndrome. She came off all her blood pressure medications and all potassium pills.

The best adrenal operation for primary hyperaldosteronism is the Mini Back Scope Adrenalectomy (MBSA). Read more about the MBSA surgery here.

8) Adrenal vein sampling is not without risks.

Adrenal vein sampling is not without risks. This is an invasive procedure. Again, the risk of complication is directly related to the experience and mastery of the interventional radiologist. The most common risks with the procedure are bleeding causing a hematoma, adrenal infarction, adrenal vein thrombosis and perforation (or rupture) of the adrenal vein. At the Carling Adrenal Center, we use very small amounts of contrast dye injection and have an extremely favorable safety profile. In fact, we have never had bleeding or injury to the adrenal veins during this procedure. But because there are some (although very low in our hands) risks associated with the procedure, it is important that adrenal vein sampling is performed only in patients who truly need it. This is where the expertise of an adrenal surgeon and the team is very important to identify the patients that truly benefit from the procedure. You and your doctor need to find the best center not only for your adrenal surgery but also for adrenal vein sampling.

9) Even if the adrenal vein sampling demonstrates that there is no obvious tumor on one of the adrenal glands, surgery still can be the best option

In the ideal scenario the adrenal vein sampling demonstrates significantly higher aldosterone production from one of the two adrenal glands (Figure 2 describes an ideal case). This makes surgery and adrenalectomy curative in nature. If there is overproduction of aldosterone from both adrenal glands, surgery still may be a very favorable option as opposed to just treating the patient with blood pressure pills for life. There is emerging data that the combination of adrenal surgery and maximal medical therapy is better than just treating the patient with blood pressure medications. Surgery not only improves the blood pressure and potassium levels, but liberates the patients of debilitating symptoms, and improves the quality of life. Surgery can be particularly helpful in patients who are on several blood pressure medications, respond poorly to blood pressure medication or have developed resistance to blood pressure medications. Sometimes performing bilateral partial adrenalectomy may be the best option in patients with Conn’s syndrome due to aldosterone overproduction coming from both adrenal glands, when medical treatment is failing.

Read more about partial (cortex-sparing) adrenalectomy here.

10) An allergy to contrast dye is a contraindication to adrenal vein sampling

Adrenal vein sampling is very safe. However, some patients have an allergy to intravenous iodinated contrast dye. This is the same contrast dye used in CT scans. Severe reactions to iodinated contrast media is very rare (about 1/10,000 or 0.01%). Sometimes patients can be pre-treated with steroids, and antihistamines if they have had previous problems with contrast media. However, if you have had a serious reaction (swelling, erythema, low blood pressure, anaphylactic shock, raising heart rate, and wheezing) to contrast media, avoiding adrenal vein sampling may be the best option. In this case, it is preferable to let the CT scan (without contrast) guide the plan for adrenalectomy instead of adrenal vein sampling.

This is the second part of “Top 10 Things to Know About Adrenal Vein Sampling for Primary Hyperaldosteronism”. View the first part of the post  in this series about adrenal vein sampling here.

Reference:

• Monticone S, Viola A, Rossato D, Veglio F, Reincke M, Gomez-Sanchez C, Mulatero P. Adrenal vein sampling in primary aldosteronism: towards a standardised protocol. Lancet Diabetes Endocrinol. 2015 Apr;3(4):296-303. PMID: 24831990. https://pubmed.ncbi.nlm.nih.gov/24831990/

Additional Resources: 

Learn more about the Carling Adrenal Center

Learn more about Dr. Tobias Carling

Learn more about our sister surgeons at the Norman Parathyroid Center, Clayman Thyroid Center and Scarless Thyroid Surgery Center