PAKISTAN
ENDOSCOPIC
SKULL BASE SURGERY CENTRE

What is transsphenoidal pituitary surgery?

Transsphenoidal literally means “through the sphenoid sinus.” It is a surgery performed through the nose and sphenoid sinus to remove pituitary tumors (Fig. 1). Transsphenoidal surgery can be performed with an endoscope, microscope, or both. It is often a team effort between neurosurgeons and ear, nose, and throat (ENT) surgeons.

Figure 1. A. Endoscopic transsphenoidal surgery is performed with less disruption to the nose to reach the sphenoid sinus and pituitary. B. The microscope technique removes a large portion of the septum to insert a retractor so that the surgeon can see to the sphenoid sinus and pituitary.

A traditional microscope technique uses a skin incision under the upper lip and removal of a large portion of the nasal septum so that the surgeon can directly see the sphenoid sinus area.

A minimally invasive technique, called endoscopic endonasal surgery, uses a small incision at the back of the nasal cavity and causes little disruption of the nasal tissues. The ENT surgeon works through the nostrils with a tiny camera and light called an endoscope. In both techniques, bony openings are made in the nasal septum, sphenoid sinus, and sella to reach the pituitary. Once the pituitary is exposed, the neurosurgeon removes the tumor.

Who is a candidate?

You may be a candidate for transsphenoidal surgery if you have a:

Pituitary adenoma: a tumor that grows from the pituitary gland; may be hormone-secreting or not.

Craniopharyngioma: a benign tumor that grows from cells near the pituitary stalk; may invade the third ventricle.

Rathke’s cleft cyst: a benign cyst, or fluid-filled sac, between the anterior and posterior lobes of the pituitary gland.

Meningioma: a tumor that grows from the meninges (dura), the membrane that surrounds the brain and spinal cord.

Chordoma: a malignant bone tumor that grows from the skull base.

If you have a prolactinoma or a small (<10mm) non-secretory tumor, surgery may not be required. These types of tumors respond well to medication or may be observed with periodic MRIs to watch for tumor growth.

Some tumors extend beyond the limits of the transsphenoidal approach. For these tumors, a more extensive craniotomy combined with skull base approaches may be needed.

Who performs the procedure?

A neurosurgeon performs transsphenoidal surgery often as a team with an ENT (ear, nose, and throat) surgeon who has specialized training in endoscopic sinus surgery. A team approach allows comprehensive care of both brain- and sinus-related issues before, during, and after surgery. Ask your surgeons about their training and experience.

SINCE LAST 16 YEARS PROF KHALID MAHMOOD NEUROSURGEON HAS PAIRED UP WITH PROF MUHAMMAD MUJEEB ENT SURGEON FOR SMOOTH EXECUTION OF ENDOSCOPIC BRAIN SURGERY THROUGH NOSE. THIS TEAM HAS PRESENTED THEIR WORK ON MANY CONFERENCES AND HAVE TO THEIR CREDIT MAXIMUM NUMBER OF SUCH SURGERIES IN PAKISTAN.

Step 1: Make an incision
The ENT surgeon inserts the endoscope in one nostril and advances it to the back of the nasal cavity. An endoscope is a thin, tube-like instrument with a light and a camera. Video from the camera is viewed on a monitor. The surgeon passes long instruments through the nostril while watching the monitor. A small portion of the nasal septum dividing the left and right nostril is removed. Using bone-biting instruments, the front wall of the sphenoid sinus is opened.

Figure 3. The endoscope is inserted through one nostril. A bony opening is made in the nasal septum (dotted line) and sphenoid sinus (green) to access the sella.

Step 2: Open the sella
At the back wall of the sphenoid sinus is the bone overlying the pituitary gland, called the sella. The thin bone of the sella is removed to expose the tough lining of the skull called the dura. The dura is opened to expose the tumor and pituitary gland.

Step 3: Remove the tumor
Through a small hole in the sella, the tumor is removed by the neurosurgeon in pieces with long grasping instruments (Fig. 4).

Figure 4. The surgeon passes instruments through the other nostril to remove the tumor.

The center of the tumor is cored out, allowing the tumor margins to fall inward so the surgeon can reach it. After all visible tumor is removed, the surgeon advances the endoscope into the sella to look and inspect for hidden tumor. Some tumors grow sideways into the cavernous sinus, a collection of veins. It may be difficult to completely remove this portion of the tumor without causing injury to the nerves and vessels. Any tumor left behind may be treated later with radiation.

Step 4: Obtain fat graft (optional)
After tumor is removed, the surgeon prepares to close the sella opening. If needed, a small (2cm) skin incision is made in the abdomen to obtain a small piece of fat. The fat graft is used to fill the empty space left by the tumor removal. The abdominal incision is closed with sutures.

Step 5: Close the sella opening
The hole in the sella floor is replaced with bone graft from the septum (Fig. 5). Synthetic graft material is sometimes used when there is no suitable piece of septum or the patient has had previous surgery. Biologic glue is applied over the graft in the sphenoid sinus. This glue allows healing and prevents leaking of cerebrospinal fluid (CSF) from the brain into the sinus and nasal cavity.

Figure 5. A fat graft is placed in the area where the tumor was removed. A cartilage graft is placed to close the hole in the sella. Biologic glue is applied over the area.

Soft, flexible splints may be placed in the nose along the septum to control bleeding and prevent swelling. The splints also prevent adhesions from forming that may lead to chronic nasal congestion.

What happens after surgery?

After surgery you will be taken to the recovery room, where vital signs are monitored as you awake from anesthesia. Then you’ll be transferred to a regular room or the intensive care unit (ICU) for observation and monitoring. You will be encouraged to get out of bed as soon as you are able (sitting in a chair, walking).

After surgery you may experience nasal congestion, nausea, and headache. Medication can control these symptoms. An endocrinologist may see you the day after surgery to check that the pituitary gland is producing appropriate levels of hormones. If it is not, hormone-replacement medications may be given. An MRI of the brain will be obtained the day after surgery. In 1 to 2 days, you’ll be released from the hospital and given discharge instructions.