A transsphenoidal hypophysectomy is a specialized, minimally invasive surgical procedure used to access and remove all or part of the pituitary gland. The term “transsphenoidal” describes the surgical path: navigating through the nasal passages and the air-filled cavity behind the nose, called the sphenoid sinus, to reach the base of the skull where the pituitary gland is located.
This technique is favored because it avoids the need for a large incision in the skull, known as a craniotomy. Utilizing the natural openings of the nasal cavity reduces visible scarring, minimizes disruption to brain tissue, and generally leads to a shorter hospital stay and faster recovery time. The primary purpose of this surgery is to remove abnormal growths, most commonly non-cancerous tumors, from the pituitary gland.
Conditions Requiring Transsphenoidal Hypophysectomy
The surgery is primarily performed to treat pituitary adenomas, which are benign tumors growing from the pituitary gland’s cells. These tumors are classified based on whether they secrete excess hormones (functioning tumors) or do not (non-functioning tumors). Both types of tumors can cause significant health problems.
Functioning adenomas produce an overabundance of specific hormones, leading to distinct endocrine disorders. For example, a tumor secreting too much Adrenocorticotropic Hormone (ACTH) results in Cushing’s Disease, characterized by excessive cortisol production. Tumors that release too much Growth Hormone (GH) cause Acromegaly in adults, involving abnormal growth and metabolic changes.
Non-functioning tumors do not produce excess hormones, but their growth can still cause problems due to their location. As they expand, they can compress surrounding structures, including the optic nerves, potentially leading to vision loss. They can also press on healthy pituitary tissue, causing a deficiency in normal hormone production, known as hypopituitarism. The transsphenoidal route is the preferred method for removing most adenomas because it provides direct access to the sella turcica, the bony pocket where the pituitary gland sits.
How the Procedure is Performed
The surgical approach is conducted by a team that includes a neurosurgeon and an ear, nose, and throat (ENT) surgeon. The patient is placed under general anesthesia, and the procedure begins with the surgeon inserting instruments into one or both nostrils. The surgery is commonly performed using an endoscope, a thin tube equipped with a camera and light, which provides a magnified, high-definition view of the surgical field on a monitor.
The surgeon carefully navigates the endoscope through the nasal cavity, past the nasal septum, and into the sphenoid sinus. Image guidance systems, which use real-time imaging like fluoroscopy or pre-operative scans, are often used to ensure precise navigation. Once the sphenoid sinus is reached, a small opening is created in the posterior wall of the sinus, which is the bone covering the sella turcica.
After the bony opening is made, the membrane covering the pituitary gland is opened, allowing the neurosurgeon to visualize and access the tumor. Specialized, long, delicate instruments are used to carefully remove the tumor, often in small fragments, while working to preserve the surrounding healthy pituitary tissue. For larger or more complex tumors, a traditional microscopic approach may be used, which involves a slightly different initial entry but follows the same core pathway to the gland.
The final stage of the operation involves sealing the surgical site to prevent leakage of cerebrospinal fluid (CSF), the clear fluid surrounding the brain. The surgeon typically uses a patch of tissue, such as a small piece of fat harvested from the patient’s abdomen or thigh, or a synthetic sealant to close the opening in the sella. The instruments are then withdrawn.
Initial Recovery and Hospital Care
Following the surgery, patients are closely monitored, often spending the first few hours in a recovery or intensive care unit. The typical hospital stay after a transsphenoidal hypophysectomy is relatively short, usually lasting between three and five days. Immediate post-operative monitoring focuses on checking for early complications.
A primary concern during the initial recovery period is monitoring for a cerebrospinal fluid (CSF) leak, which manifests as clear fluid dripping from the nose. Patients are also monitored for changes in fluid balance and urine output, as temporary hormone deficiencies can lead to a condition called diabetes insipidus. Blood tests are performed frequently to check the body’s sodium and electrolyte levels, which are controlled by the pituitary gland’s hormones.
Patients commonly experience temporary nasal congestion, a headache, or some nasal discharge and crusting for the first few weeks. To aid healing and prevent complications, several restrictions are put in place immediately after surgery. Patients are instructed to avoid actions that create pressure that could disrupt the surgical seal:
- Blowing their nose
- Coughing vigorously
- Drinking through a straw for up to four weeks
- Strenuous activity, heavy lifting, or straining during bowel movements
Long-Term Hormone Management
The pituitary gland controls the production of hormones by the thyroid, adrenal, and gonadal glands. Because the surgery involves working directly on or near the pituitary gland, the function of these interconnected endocrine systems must be carefully evaluated long-term. Post-operative endocrine testing is essential to determine if the removal of the tumor has affected the production of normal pituitary hormones.
Deficiencies in hormone production, known as hypopituitarism, can be temporary or permanent. A common and potentially serious deficiency is in ACTH, which requires replacement with adrenal steroids like hydrocortisone. Patients may also need to take thyroid hormone replacement, sex hormones like estrogen or testosterone, or desmopressin for diabetes insipidus, which helps regulate water balance.
Lifelong follow-up with an endocrinologist is necessary to manage and adjust these hormone replacement therapies. Even if hormone levels are initially normal, they must be reassessed regularly, as recovery or decline in function can occur over time, sometimes taking up to a year. The goal of this long-term management is to restore the body’s hormonal balance and maintain overall quality of life.