Sometimes it is possible, and preferable, to remove the adrenal tumor without removing the entire gland. This is called partial adrenal surgery. Removing only part of the adrenal gland is a much more advanced operation and should be reserved only for the most expert adrenal surgeons. The goal is to leave some normal adrenal tissue behind so that the patient can avoid adrenal insufficiency (not enough adrenal hormones leading to the requirement to take hormone supplements). 

When is Partial Adrenal Surgery Best?

Imagine if you had already one adrenal gland removed and now you develop another tumor on the other side.

• What would you do?
• What adrenal surgery operation should you have?
• Can you have a partial (also known as adrenal-sparing) adrenalectomy?
• What adrenal surgeon can get you cured and at the same time preserve adrenal hormone function, so you don’t need to be dependent on hormone supplements such as prednisone the rest of your life?

Let me introduce you to a recent patient of mine. She is 69 years old from the western part of United States. She has a condition called Multiple Endocrine Neoplasia Type 2 (MEN2), where she has an inherited mutation in a gene called RET. This makes her genetically predisposed to develop pheochromocytomas. In fact, she had undergone a right adrenalectomy at a western US hospital in 2007. She no longer has a right adrenal gland. Now, she has developed another pheochromocytoma, but this time on the left adrenal gland. To learn about pheochromocytoma, please go here: https://www.adrenal.com/pheochromocytoma/overview

Figure 1. A CT scan demonstrating the left pheochromocytoma (16 mm) in this patient who already had her right adrenal gland removed. Arrow indicates old clips from the previous operation.

Let us review her recent CT scan in this short video.

The patient was a perfect candidate for a partial adrenalectomy through the mini back scope adrenalectomy (MBSA) approach. Read more about the mini back scope adrenalectomy (MBSA) here.

Figure 2. Gross pathology of the pheochromocytoma, bisected. The patient underwent a partial (adrenal-sparing) adrenalectomy. The arrow points out the larger pheochromocytoma and, in fact, she had a smaller 5 mm tumor as well. The operation lasted 21 minutes, and the patient has excellent adrenal cortisol production, and is being weaned off steroids.

When is a Partial Adrenalectomy Appropriate?

For optimal results, there are five crucially important concepts the patient needs to understand about the partial adrenalectomy. The ability to perform partial adrenal surgery is dependent on:

1. The tumor type: Is it producing hormones, and if so, which ones?
2. The risk of it being cancerous (malignant)
3. The size of the tumor, as well as its relationship to the adrenal vein, surrounding organ and other structures such as the inferior vena cava (IVC).
4. Whether there is sufficient tissue available to save (the tumor is not too big and the blood supply to the remaining adrenal tissue can be preserved).
5. Whether the surgeon is expert enough to know how to do this more technically challenging operation. Very few surgeons have ever performed several partial adrenal operations.

The key to successful partial adrenalectomy is to preserve sufficient normal adrenal cortex tissue (at least 30% of one adrenal gland; or 15% of both glands) and at the same time not compromising the surgical resection margin (i.e., potentially spilling tumor cells which may lead to recurrence). Important: non-cancerous adrenal tumors, pheochromocytomas and cancerous adrenal tumors can all grow back (so-called "recurrence") if not resected accurately. Thus, partial, adrenal-sparing surgery should only be attempted by the most skilled and experienced adrenal surgeons. Unless your adrenal surgeon performs adrenal surgery every week and partial adrenalectomy regularly, he or she is better off not offering this more advanced operation.

Who is a Good Candidate for a Partial Adrenalectomy?

Typically, over 90% of patients who are thought to be good candidates for partial adrenalectomy (based on preoperative imaging) will be able to undergo it. It is very important to consider the below mentioned 5 concepts to determine the ability to perform partial adrenalectomy:

1. What type of tumor the patient has?
2. The risk of cancer
3. The size of the tumor, as well as its relationship to the adrenal vein, and other structures such as the inferior vena cava (IVC).
4. Whether there is sufficient tissue available to save (the tumor is not too big, and the blood supply to the remaining adrenal tissue can be saved).
5. Whether the surgeon is skilled enough to do this more technically challenging operation.

Importantly, in about 10% of cases, the surgeon can find something during the operation that may indicate that a partial adrenalectomy is the wrong operation. An experienced surgeon will not compromise the surgical resection margin and put the patient at risk of the disease coming back. This is where experience and excellent surgical judgment play a huge role.

What About Patients Who Need Bilateral (both) Adrenal Glands Removed?

In cases where partial adrenalectomy is performed for bilateral adrenal tumors, the large majority of patients (roughly three quarters to more than 90% in the published studies discussed below) do not require life-long steroid supplementation (prednisone, hydrocortisone, etc). This means that most patients undergoing partial bilateral adrenalectomy can be saved from developing long-term adrenal insufficiency. In some cases, with bilateral tumors, the correct operation would be to completely resect the entire adrenal gland on one side and then perform a partial resection on the other side. However, this has to be individualized in each scenario. Similarly, the best option may be to resect one tumor (often the larger one), and then perform the surgery on the other side at a subsequent operation. Experience and excellent surgical judgment play a huge role, as well as tailoring the treatment to the individual patient’s needs. The key to prevent adrenal insufficiency is to save at least 30% of one gland, or a total of 15% of both adrenal glands.

As I mentioned, the 69-year-old female patient has a condition called Multiple Endocrine Neoplasia Type 2 (MEN2) where she has an inherited mutation in a gene called RET. In addition to pheochromocytoma, the disease predisposes to tumors of the thyroid and parathyroid glands as well. In fact, the day after the partial adrenalectomy via the mini back scope adrenalectomy (MBSA) approach, she underwent a total thyroidectomy by my partner Dr. Gary Clayman.

Learn more about thyroid tumors, thyroid cancer, thyroid surgery, the Clayman Thyroid Center and Dr. Clayman here.

Learn more about parathyroid tumors and hyperparathyroidism here.

What does the Scientific Literature say about Partial (Adrenal-Sparing) Adrenal Surgery (Adrenalectomy)?

Two large studies analyzed the outcomes of partial (adrenal-sparing) adrenal surgery (adrenalectomy) in patients with adrenal tumors. The first study included patients with a variety of tumors including 106 Conn's adenomas (primary aldosteronism), 83 pheochromocytomas, 76 Cushing's adenomas (hypercortisolism), and 60 nonfunctioning tumors. One hundred of the 325 operations (31%) were partial adrenalectomies. In all of them, biochemical cure was obtained. In 14/15 (93%) who underwent bilateral surgery, the adrenocortical function was preserved, meaning they did not need to take life-long steroid supplementation. Local recurrence (meaning the tumor grew back) did not occur in any cases.

The second study was focused on patients (like our patient in the clinical vignette) with bilateral pheochromocytomas treated with either total or adrenal-sparing adrenalectomies (the study uses the term “cortical-sparing”). Primary adrenal insufficiency occurred in all patients treated with total adrenalectomy but only in 23.5% of patients treated with adrenal-sparing adrenalectomy. The trade-off is that about 13% of the patients who had successful adrenal-sparing surgery later developed another pheochromocytoma in the remaining adrenal tissue, which is why lifelong follow-up is needed. The authors concluded that: “Cortical-sparing adrenalectomy should be considered in all patients with hereditary pheochromocytoma.”

References:

Walz MK, et. al. Partial versus total adrenalectomy by the posterior retroperitoneoscopic approach: early and long-term results of 325 consecutive procedures in primary adrenal neoplasias. World J Surg. 2004 Dec;28(12):1323-9.

Neumann HPH, et. al. International Bilateral-Pheochromocytoma-Registry Group. Comparison of Pheochromocytoma-Specific Morbidity and Mortality Among Adults With Bilateral Pheochromocytomas Undergoing Total Adrenalectomy vs Cortical-Sparing Adrenalectomy. JAMA Netw Open. 2019 Aug 2;2(8):e198898.