Endoscopic Transnasal Transsphenoidal Pituitary Surgery

Endoscopic surgery is performed through the nose to remove tumors from the pituitary gland and skull base. In this minimally invasive surgery, the surgeon works through the nostrils with a tiny endoscope camera and light to remove tumors with long instruments. Pituitary tumors can cause hormone problems and vision loss. Tumor removal often reverses vision problems and restores normal hormone balance.

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.

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.

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.

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.

You will have an office visit with a neurosurgeon, ENT surgeon, and endocrinologist before surgery. A consult with an ophthalmologist may be necessary if you have vision problems. During the office visit, the surgeon will explain the procedure, its risks and benefits, and answer any questions. Next, you will sign consent forms and complete paperwork to inform the surgeon about your medical history (i.e., allergies, medicines, bleeding history, anesthesia reactions, previous surgeries).

Discuss all medications (prescription, over-the-counter, and herbal supplements) you are taking with your health care provider. Some medications need to be continued or stopped the day of surgery. Presurgical tests (e.g., blood test, electrocardiogram) may need to be done several days before surgery. Consult your primary care physician about stopping certain medications and ensure you are cleared for surgery.

Stop taking all non-steroidal anti-inflammatory medicines (ibuprofen, naproxen, etc.) and blood thinners (Coumadin, Plavix, aspirin, etc.) 7 days before surgery. Stop using nicotine and drinking alcohol 1 week before and 2 weeks after surgery to avoid bleeding and healing problems.

You may be asked to wash your skin with Hibiclens (CHG) or Dial soap before surgery. It kills bacteria and reduces surgical site infections. (Avoid getting CHG in eyes, ears, nose or genital areas.)

Morning of surgery

• No food, drink, gum or candy.
• Shower using antibacterial soap. Dress in freshly washed, loose-fitting clothing.
• Wear flat-heeled shoes with closed backs.
• If you have instructions to take regular medication the morning of surgery, do so with small sips of water.
• Remove make-up, hairpins, contacts, body piercings, nail polish, etc.
• Leave all valuables and jewelry at home (including wedding bands).
• Bring a list of medications with dosages and the times of day usually taken.
• Bring a list of allergies to medication or foods.

Patients are admitted to the hospital the morning of surgery. The nurse will explain the preoperative process and discuss any questions you may have. An anesthesiologist will talk with you to explain the effects of anesthesia and its risks.

There are 6 steps of the procedure, which generally takes 2 to 3 hours.

Step 1: prepare the patient
You will lie on the operating table and be given general anesthesia. Once you are asleep, your nose is prepped with antibiotic and antiseptic solution.

An image-guidance system may be placed on your head (Fig. 2). This device is like a global positioning system (GPS) and helps the surgeon navigate through the nose using a 3D “map” created from your CT or MRI scans.

Step 2: 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 

Step 3: 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 4: remove the tumor
Through a small hole in the sella, the tumor is removed by the neurosurgeon in pieces with long grasping instruments

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.

At some hospitals, surgery can be performed in a special OR room equipped with an intraoperative MRI scanner. The patient can undergo an MRI during surgery. This gives the surgeon real-time images of the patient’s brain to know exactly how much tumor has been removed before ending the procedure. This technology enables more complete tumor removal and may reduce the need for a second operation [1].

Step 5: 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 6: 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.