Transsphenoidal Surgery for Acromegaly

Acromegaly is a hormonal disorder marked by the overproduction of growth hormone from the pituitary gland, even after the body has finished growing. The main culprit is often a noncancerous tumor (adenoma) in the pituitary gland that releases an excessive amount of growth hormone. This surplus hormone causes diverse symptoms, including enlarged hands and feet, excessive sweating, and other noticeable signs.

Transsphenoidal surgery is a common treatment option for acromegaly. During this procedure, the surgeon accesses the pituitary gland through the nose. By using specialized instruments and a microscope or endoscope, the surgeon removes the tumor causing the excess growth hormone production.

Transnasal transsphenoidal surgery is a common surgical procedure used for the removal of pituitary tumors. The technique involves a surgeon accessing the pituitary gland by inserting long surgical instruments through the nasal passages and sphenoid bone, giving the procedure its name.

This approach is widely used because it provides the most direct route to the pituitary gland, which is located at the base of the skull behind the nasal cavity. This method is also less invasive than traditional open surgery.

During transsphenoidal surgery, detailed visualization of the surgical field can be obtained using either a microscope or, more recently, an endoscope. In the endoscopic approach, a slender instrument called an endoscope, equipped with a tiny camera and light at its tip, is inserted through a nasal opening.

As the instruments probe further into the back of the nasal cavity, the sphenoid bone is encountered. Pieces of sphenoid bone are removed to reveal the pituitary gland and its tumor.

Transsphenoidal surgery is carried out by a surgical team comprised of a neurosurgeon and an ear, nose, and throat (ENT) surgeon who has specialized expertise in using the endoscope.

Like any medical procedure, transsphenoidal surgery carries inherent risks. General complications can include bleeding, infection, and adverse reactions to anesthesia and medications.

There are also specific risks associated with surgery on the pituitary gland, such as vision loss, damage to the normal functioning pituitary gland, hormonal changes, cerebrospinal fluid leakage through the nose, meningitis, and potential nasal deformity and bleeding.

After completion of the surgery, the patient is transferred to the recovery room, where their vital signs are closely monitored while regaining consciousness from anesthesia. Depending on the specific procedure, the patient might be directed to a regular room or the intensive care unit for further observation and monitoring.

It is not uncommon for a patient to experience nausea and headache after surgery. For those who have undergone transnasal transsphenoidal surgery, nasal congestion is a common occurrence.

The patient's care involves a multidisciplinary team that focuses on managing symptoms and ensuring that appropriate hormone levels are reached. Typically, within 1 or 2 days after the surgery, an imaging test is performed to assess the extent of removal.

If the patient remains stable and everything progresses well, they will be discharged from the hospital with detailed instructions. During the postoperative period, the endocrinology team plays a crucial role in overseeing the patient's care and ensuring optimal recovery.

If a pituitary tumor is not fully removed during surgery, if the tumor reappears, or if the surgeon determines that surgery is too risky for the patient, alternative treatment options such as radiation therapy or medications might be recommended to treat acromegaly. Radiation therapy is often administered in the form of stereotactic radiosurgery, which uses targeted radiation beams to shrink the pituitary tumor and stunt further growth.

Somatostatin analogs are a class of medications that work by mimicking the action of somatostatin, a natural hormone that inhibits the release of growth hormone and other hormones from the pituitary gland. Octreotide and lanreotide are usually given by injection, either subcutaneously (in the fatty tissue just under the skin) or intramuscularly (in the muscle) and are typically administered every 4 weeks.

Dopamine agonists are a class of medications that stimulate dopamine receptors. These medications suppress the production of growth hormone, although their exact mechanism of action is not known.

Cabergoline and bromocriptine are the dopamine agonists most commonly used for treating acromegaly. They are usually given orally and can be used alone or in combination with other medications, such as somatostatin analogs.

Growth hormone antagonists work by binding to growth hormone receptors and blocking growth hormone activity. Pegvisomant is usually given by injection and can be effective in reducing the symptoms of acromegaly, such as enlargement of the hands, feet, and facial features.

While these medications may help to alleviate symptoms, they cannot cure the tumor. Surgery remains the primary potentially curative option for removing the tumor and addressing the cause of the condition.

• Transsphenoidal surgery is a common treatment for acromegaly.
• It involves accessing the pituitary gland through the nasal passages.
• The main goal is to remove the tumor causing excess growth hormone production.
• After surgery, patients are monitored in the recovery room, and vital signs are closely observed.
• Depending on the case, patients will be taken to a regular room or the intensive care unit for further monitoring.
• Nausea, headache, and nasal congestion are common postoperative symptoms.

• Pituitary Network Association: Acromegaly
• The Pituitary Foundation [UK]: Acromegaly
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): Acromegaly
• National Health Service (NHS) [UK]: Acromegaly