Surgery for Cushing's Disease

Cushing's disease is a rare medical condition characterized by the excessive production of cortisol, a hormone that plays a crucial role in regulating various processes in the body.  

The condition arises when a non-cancerous tumor, known as an adenoma, develops in the pituitary gland, a small pea-sized gland located at the base of the brain. This tumor leads to the overproduction of adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce excessive amounts of cortisol, resulting in a range of symptoms and health problems.

The symptoms of Cushing's disease are diverse and can include weight gain, especially in the upper body and face, elevated blood pressure, thin and delicate skin, and various other manifestations. Fortunately, there are several treatment options available to manage or eliminate these symptoms. These treatment approaches may involve surgery, medications, or radiation therapy.

In this article, we will focus on the treatment of Cushing's disease through transsphenoidal surgery, a procedure used to remove the pituitary adenoma responsible for the excessive production of ACTH. The goal of this surgery is to normalize cortisol levels, alleviate symptoms, and potentially achieve remission.

The history of pituitary surgery dates back to the late 18th century when it was a complex procedure involving the temporary removal of a significant portion of the skull bone (craniotomy) to access the pituitary gland.

Today, the more minimally invasive transsphenoidal approach is widely used in pituitary surgery and involves accessing the pituitary tumor through the nasal passages.

It is often performed with the aid of an endoscope—a long, thin instrument with a light and camera—to enhance visualization of the intricate structures within the nasal passage.

Although a larger craniotomy may be used in more complex cases, the evolution of a more minimally invasive technique has greatly improved surgical outcomes in the field of pituitary surgery.

Surgery is the sole potentially curative treatment option for ACTH-secreting pituitary adenomas. In most cases, transsphenoidal surgery is the preferred approach. In contrast to a traditional craniotomy, transsphenoidal surgery will access the tumor through the nasal passages with the general steps below.

• Upon the patient's arrival in the operating room, general anesthesia is administered, and the patient is positioned on the operating table. The nose is carefully cleaned and prepared for access.
• A microscope or an endoscope, along with long surgical instruments, are passed through the nasal cavity. The surgeon carefully drills through the sphenoid bone at the skull base to reach the tumor.
• Beyond the sphenoid bone lies a protective tissue layer called the dura, which is meticulously cut to reveal the tumor and the pituitary gland.
• The tumor is then removed in pieces while preserving its surrounding structures. The primary objective is to completely excise the tumor, but if there is a high risk of damaging adjacent tissues, a portion of the tumor may be intentionally left behind.
• Once the tumor resection is complete, the surgeon ensures there is no active bleeding and proceeds to close each layer.
• The bone is typically replaced with either a piece of fat from the abdomen or the lining of the nasal mucosa, and/or a bone graft from the nasal septum.
• Nasal packing may be placed after the procedure to control bleeding. Your surgeon may instruct you to leave those in for several days.

The transsphenoidal approach can be performed in two ways. One method utilizes an operating microscope, enabling direct visualization of the operating area for tumor removal. The other approach involves the use of a long endoscopic camera, which is inserted through a small incision and provides a broader view.

In certain cases, a combination of both techniques may be employed, depending on the patient's unique characteristics and the tumor's specific features, as well as the surgeon's preference and training.

Compared to a traditional craniotomy, the transsphenoidal approach is less invasive, leaving no visible scar, and facilitates a faster recovery process. It is also effective, with symptom improvement or complete resolution occurring in approximately 80% to 85% of patients.

Prior to undergoing transsphenoidal surgery, blood tests will be performed to assess hormone levels, including cortisol. If you opt for surgery, the surgeon will provide a detailed explanation of the procedure, along with its associated risks and benefits.

You will be required to complete consent forms and other necessary paperwork. The medical team will review your medical history, allergies, current medications, prior response to anesthesia, and any previous surgeries.

Complication rates following transsphenoidal surgery are generally low, and potential issues may include cerebrospinal fluid leak, diabetes insipidus (causing excessive urination and thirst), and hormone deficits. Fortunately, these complications are often temporary. Most patients stay in the hospital for no more than 3 to 4 days.

After the surgery, you will be carefully monitored either in the intensive care unit (ICU) or a regular hospital ward. Patients with Cushing's disease are typically observed in the ICU to promptly address any symptoms of low cortisol levels, which can be life-threatening if left untreated. If nasal packing is present, antibiotics may be administered as a preventive measure.

• Surgery is often the first-line treatment for Cushing's disease.
• Transsphenoidal surgery is often the preferred treatment approach for Cushing's disease.
• Successful surgery can lead to symptom improvement or even complete resolution in approximately 80% to 85% of patients.
• In cases where surgery is not feasible or unsuccessful, alternative treatments like medication and radiation therapy may be considered.

• Endocrine Society
• Pituitary Foundation
• Urology Care Foundation
• National Adrenal Diseases Foundation