A transsphenoidal hypophysectomy is a specialized, minimally invasive surgical procedure designed to access and treat conditions of the pituitary gland. This pea-sized gland is located at the base of the brain, nestled within a bony structure called the sella turcica. The term “hypophysectomy” refers to the removal of all or part of the pituitary gland, also known as the hypophysis. The “transsphenoidal” part of the name describes the specific route the surgeon uses to reach this deep-seated gland. This technique avoids the need for a traditional open craniotomy, which involves opening the skull.
Purpose of the Procedure
The main reason for performing a transsphenoidal hypophysectomy is the removal of pituitary tumors, which are overwhelmingly benign growths called adenomas. These adenomas cause problems either by physically pressing on nearby structures or by inappropriately producing hormones. For instance, a growing tumor can compress the adjacent optic nerves, leading to vision loss.
Many pituitary tumors are “functioning tumors” that secrete excess hormones, causing specific endocrine disorders. Examples include the overproduction of growth hormone (acromegaly) or too much adrenocorticotropic hormone (Cushing’s disease). Removing these tumors restores the body’s normal hormone balance and alleviates related symptoms.
Other growths, called “non-functioning tumors,” require removal if they grow large enough to cause symptoms like headaches or vision impairment. The surgery aims to relieve this pressure and preserve the function of the remaining healthy pituitary tissue.
How the Surgery is Performed
The transsphenoidal approach accesses the pituitary gland through the nasal passages and the sphenoid sinus. The sphenoid sinus is an air-filled cavity situated behind the nose, providing a direct corridor to the sella turcica where the pituitary gland resides. This method is significantly less invasive than traditional open brain surgery.
The procedure is commonly performed using an endoscopic technique. A thin tube equipped with a camera and light, called an endoscope, is inserted through one nostril, providing a magnified view of the surgical field. A specialized team, often including a neurosurgeon and an ear, nose, and throat (ENT) surgeon, collaborates on the procedure.
The surgeon navigates the endoscope through the nasal cavity and creates an opening in the back wall of the sphenoid sinus. Once inside, the surgeon identifies the sella turcica, the bony cup encasing the pituitary gland. A small opening is then made through the bone and the dura mater (the membrane covering the brain) to expose the tumor.
Specialized instruments are passed alongside the endoscope to meticulously remove the tumor tissue. The goal is to remove the entire tumor while minimizing trauma to the surrounding healthy pituitary gland, carotid arteries, and optic nerves. If the tumor is large, it may be removed in smaller pieces.
After removal, the surgeon reconstructs the surgical site to prevent cerebrospinal fluid (CSF) leakage. This reconstruction often involves using a small piece of tissue, fat, or synthetic material to seal the opening in the sella. Since the procedure uses the body’s natural openings, it leaves no visible external incisions.
Post-Operative Care and Recovery
Following the transsphenoidal hypophysectomy, patients typically spend two to four days in the hospital for observation. Initial recovery involves managing short-term discomfort, such as mild headaches and nasal congestion, with prescribed medications. Some bloody or mucous discharge from the nose is common for the first week or two.
Immediate post-operative care focuses on monitoring fluid balance and hormone levels. Since the pituitary gland regulates many hormones, surgical manipulation can temporarily affect its function. Nurses track urine output and blood sodium levels to check for water balance issues, such as diabetes insipidus.
Patients may temporarily receive corticosteroid replacement therapy, such as hydrocortisone, to support the adrenal axis. This therapy is often continued after surgery to manage potential stress and reduced pituitary function. An endocrinologist works closely with the surgical team to manage any hormone deficiencies.
Upon discharge, patients must avoid strenuous activities, heavy lifting (over 10 pounds), and actions that increase pressure in the head, such as blowing the nose forcefully, for several weeks. Full recovery and a return to normal activity levels usually take between four and eight weeks. Long-term follow-up with an endocrinologist is necessary, as some patients require permanent hormone replacement therapy (HRT).
Potential Complications and Monitoring
While transsphenoidal hypophysectomy is a safe procedure, the location of the pituitary gland presents specific risks. One common complication is a cerebrospinal fluid (CSF) leak, where the clear fluid surrounding the brain drains into the nasal cavity. This requires prompt intervention to prevent infection.
Another complication is temporary or permanent endocrine dysfunction, particularly central diabetes insipidus (DI). DI results from damage to the posterior pituitary gland, causing a deficiency of antidiuretic hormone (ADH) that leads to excessive urination and thirst. While often transient, permanent DI requires treatment with synthetic ADH analogues like desmopressin.
Rarely, damage to surrounding structures can occur, including injury to the carotid arteries or optic nerves, potentially leading to vision loss. Endocrine monitoring is necessary for many months after surgery to ensure the pituitary-adrenal, thyroid, and gonadal axes are functioning correctly.
Ongoing follow-up includes periodic magnetic resonance imaging (MRI) scans, typically three months after the procedure and then at regular intervals. These scans assess the surgical site, confirm the extent of tumor removal, and monitor for any signs of recurrence.