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

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

• Does the patient have too much aldosterone production from one or both adrenal glands?
  
  
• Which adrenal gland harbors the tumor, the left or right?

This blog post is very comprehensive and thus is split up in two parts. This is part one and you will find a link to part two at the bottom of this post.

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

Adrenal vein sampling is an interventional radiology study performed by radiologists trained specifically in performing invasive procedures using catheters. Adrenal vein sampling is used in patients with primary hyperaldosteronism (Conn’s syndrome) when the adrenal CT scan does not show a tumor (the tumor is too small to be detected on a CT or MRI scan) or in patients who have adrenal tumors on both the right and the left side. Through small catheters, blood samples are obtained from each adrenal vein and the inferior vena cava. In experienced centers, the bilateral adrenal veins are catheterized and sampled with a technical success rate exceeding 90%. Technical success is directly associated with operator experience. You want the best possible interventional radiologist to perform your adrenal vein sampling. The Carling Adrenal Center in Tampa has a highly experienced IR doctor and team to perform adrenal vein sampling. Adrenal vein sampling is recognized by Endocrine Society (U.S.) guidelines as the standard test for telling one-sided from two-sided primary hyperaldosteronism. It is an invasive and technically difficult procedure, however, and not every patient needs it (see point 2 below).

A positive adrenal vein sampling enables curative adrenal surgery for primary hyperaldosteronism (Conn’s syndrome). In our view, the best adrenal operation is the Mini Back Scope Adrenalectomy (MBSA). Read more about the MBSA surgery here.

1) You need to find the most experienced interventional radiologist to perform your adrenal vein sampling

Similar to adrenal surgery, performing adrenal vein sampling is both an art and science. There is a very strong correlation between the expertise and experience of the interventional radiologist and the results of adrenal vein sampling. The most expert centers for adrenal vein sampling have a technical success rate exceeding 90%. The technical success is directly related to the operator experience. Your job and the job of your doctors are to find the most experienced interventional radiologist to perform your procedure. An expert interventional radiologist has a much higher success rate, lower complication rates and can perform the procedure much faster than somebody who is not an expert. There are very few experts performing adrenal vein sampling in the United States. If you have primary hyperaldosteronism and need adrenal vein sampling, it is definitely worth traveling to an expert center for it. Every week we see cases where the patient has had an adrenal vein sampling for Conn’s syndrome performed erroneously and the results become meaningless. Even worse, we sometimes see patients who have suffered major complications with bleeding, hematomas, and rupture of the adrenal veins. You do want to travel for your adrenal vein sampling. Most hospitals, including many large university hospitals, perform adrenal vein sampling only occasionally. At the Carling Adrenal Center in Tampa, we have an experienced interventional radiology team that performs adrenal vein sampling all the time.

In selected patients, it is feasible to come in for adrenal vein sampling and then have curative adrenalectomy during the same trip, although this requires several days in the Tampa area because of the time it takes the laboratory to run the aldosterone tests.

Figure 1. Adrenal vein sampling is performed by an interventional radiologist in an interventional radiology (IR) suite. These types of doctors are radiologists with special training in using X-rays and performing procedures with tiny catheters.

2) Not all patients with primary hyperaldosteronism (Conn’s Syndrome) need adrenal vein sampling

Not all patients with primary hyperaldosteronism need adrenal vein sampling. Patients with severe primary hyperaldosteronism who have an obvious tumor on one side on a high-quality CT scan, and a completely normal adrenal gland on the other side, can often go straight to curative adrenalectomy and skip this step. At the other end, patients with mild primary hyperaldosteronism often have disease in both adrenal glands and respond well to spironolactone and similar drugs; they usually need neither adrenal vein sampling nor surgery. Adrenal vein sampling has its greatest value in patients with moderate or severe disease whose CT scan shows no tumor or is unclear, and it can help patients with tumors on both sides when removal of only one adrenal gland is planned. The decision is individualized, and it also takes into account where you live (access to expert adrenal vein sampling) and your own preference.

What do I do if I am unsure if I need adrenal vein sampling, or not? After you have had your CT scan of your adrenal glands, you can always contact the Carling Adrenal Center and we will be happy to evaluate your case and your CT scan and determine whether or not you need adrenal vein sampling. If you need to have the procedure, in selected patients we can perform both the adrenal vein sampling and the surgery during the same trip; this requires several days in the Tampa area. For nearly all patients with primary hyperaldosteronism who have surgery, our preferred operation is the Mini Back Scope Adrenalectomy (MBSA).



Figure 2. 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

3) Adrenal vein sampling should not be performed for patients with Cushing’s syndrome (cortisol-producing tumors) or pheochromocytoma (adrenaline-producing)

Adrenal vein sampling is only used in patients who have primary hyperaldosteronism (Conn’s syndrome). We see no role for adrenal vein sampling in patients who have cortisol-producing tumors causing Cushing’s syndrome or adrenaline-producing tumors (pheochromocytoma). If your doctor wants to send you for adrenal vein sampling and you have any of these conditions, do let us know. We would be happy to speak to your doctor. Alternatively, print out this page and show it to your doctor. Adrenal vein sampling is only helpful for aldosterone-producing tumors. It should not be performed for Cushing’s syndrome and pheochromocytoma. It is true that adrenal vein sampling has been scientifically evaluated in Cushing’s syndrome due to adrenal tumors on both adrenal glands, and some doctors use it to find the more active side when removing one whole gland is the only operation on offer. However, we do not recommend it; in our experience patients with tumors on both adrenal glands are much better off having partial (adrenal-sparing) adrenalectomy, dealing with both adrenal glands.

Read more about Cushing’s syndrome here.

4) Having a specific adrenal-protocol pre-procedure CT scan prior to adrenal vein sampling improves the results and success rate

It is very important to have a specific adrenal-protocol CT scan prior to adrenal vein sampling since it improves the technical success rate dramatically. The reason for this is that the CT scan gives very detailed anatomical information about the tiny adrenal veins, specifically the right adrenal vein. The CT scan guides the interventional radiologist during the procedure and allows him to accurately identify the tiny vessels. Dr. Carling and his radiology colleagues at the Carling Adrenal Center have developed a very specific pre-procedure CT scan protocol that dramatically improves the success rate of adrenal vein sampling. If your center does not offer an adrenal protocol pre-procedure CT scan in preparation of your adrenal vein sampling, chances are the success rate is lower and you should consider going elsewhere. Remember, this is a procedure that you should strongly consider travelling for. There are few centers that have extensive experience performing adrenal vein sampling for primary hyperaldosteronism (Conn’s syndrome).

5) Do not let your doctor just treat you with blood pressure pills because he or she cannot find a center to perform adrenal vein sampling.

This may be the most important thing every patient with primary hyperaldosteronism needs to understand. Every single week, we talk to patients that have been told that they are just going to be treated with blood pressure pills for their primary hyperaldosteronism for the rest of their lives. Their doctor does not know what to do next, how to find someone to perform adrenal vein sampling, and they have given up. They settle for treating the patient just with blood pressure pills. For a patient who could be cured by surgery, we believe this is the wrong advice. Many doctors are not familiar with primary hyperaldosteronism and with when adrenal vein sampling should be performed. Other doctors are afraid to send patients for adrenal vein sampling or do not even know who to send the patient to. The path of least resistance is to just treat the patient with blood pressure pills. Compared with people who have ordinary high blood pressure of the same severity, patients with primary hyperaldosteronism have about 2.5 to 4 times the risk of stroke, 2.6 to 6.5 times the risk of heart attack, and 3.2 to 12 times the risk of atrial fibrillation (a heart arrhythmia). Patients die prematurely from primary hyperaldosteronism. Medication (spironolactone, eplerenone) is a good treatment for mild disease and for disease coming from both adrenal glands. But when the cause is a tumor in one adrenal gland, putting patients on pills is akin to putting a Band-Aid on a major bleeding artery. It is not going to fix the underlying problem. The underlying problem is the tumor that produces too much aldosterone, and the disease cannot be cured until that tumor is removed. Treating the disease with pills does not remove the tumor, it just treats the symptoms. If you have moderate or severe primary hyperaldosteronism and your CT scan shows no tumor at all, or shows tumors on both adrenals, do not accept a lifetime of pills simply because nobody nearby performs adrenal vein sampling. This is exactly the situation in which adrenal vein sampling has its greatest value. It has a good chance of identifying disease that can be cured or greatly improved with surgery (adrenalectomy). And if your CT scan shows a clear tumor on one side with a normal gland on the other, you may not need adrenal vein sampling at all (see point 2).

Continue reading the second part of “Top 10 Things to Know About Adrenal Vein Sampling for Primary Hyperaldosteronism” 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