Pituitary Tumours

Pituitary tumours have an estimated prevalence of somewhere between 15-22.5%, with clinically relevant pituitary adenomas occurring in 1/1000 individuals worldwide.

The clinical manifestations of pituitary adenomas are extremely broad, with emerging data clearly defining the impact of hormonal and neurological  sequelae of many tumours impacting quality of life and  life expectancy.

Although many pituitary tumours do not need treatment there are others that require surgical removal. This is usually because they are growing and are causing compression of some important structures, or in other cases where the hormones being secreted can have significant medical and physiological effects.

Endoscopic pituitary surgery, also called transsphenoidal endoscopic surgery, is the most common surgery used to remove pituitary tumors. The pituitary gland is located at the bottom of your brain and above the inside of your nose. It is responsible for regulating most of your body’s hormones.

Endoscopic pituitary surgery is done with an endoscope. An endoscope is a thin, rigid tube that has a microscope, light, and camera built into it, and it’s usually inserted through the nose. The camera allows us to watch a magnified version of your tumour whilst we resect it from the surrounding structures.

St Vincent’s Hospital was the first Hospital in Australia to perform the removal of a pituitary tumour. This was performed by Sir Victor Horsely in 1952. Since that time St Vincent’s has been at the forefront of skull base surgery, where we are now striving to be a Centre of Excellence for Pituitary Tumour Management. We perform more pituitary surgeries than any other Hospital in NSW and have a dedicated team managing pituitary disorders.

THE TEAM

Management and removal of pituitary tumours requires a dedicated Endoscopic Skull Base Team. The team includes Neurosurgery, ENT, Endocrinologists, Neuroradiologists, Neuro-ophthalmologists, Experienced Nursing Staff (Thetares and Wards) and Neuro-oncologists. We are fortunate to have a World class team at St Vincent’s Hospital which includes:

A/Prof Winder undertook a dedicated Skull Base and Pituitary Fellowship in Seattle, Washington. He was fortunate enough to be able to work alongside some World Experts in the field, operating on over 15-20 pituitary tumours per week. He has completed the world renowned Pittsburgh Endoscopic Skull Base Course, enabling a minimally invasive approach to complex skull base lesions such as pituitary tumours.  Since returning to Australia in 2010, A/Prof Winder has been actively involved in helping further the skull base team at St Vincent’s Hospital. The Pituitary Service now offered at St Vincent’s offers a dedicated Pituitary Team, that encompasses diagnosis, management and research through a Multidiciplinary team. The service is aimed at the Centre of Excellence for the management of Pituitary Services and has been able to institute the Sydney Collaborative Pituitary Meetings.

ENT (Ear, Nose and Throat Surgeons). The ENT surgeon performs the approach to the pituitary gland with the use of the endoscope. We are fortunate to have a World recognized neuro-rhinologist, Associate Professor Richard Harvey, who is an expert in the field. We have been working together as a team for over 7 years, attaining the highest possible clinical results.

ENDOCRINOLOGISTS

The specialists of hormonal management are the principal managers of hormone regulation. They are intricately involved in diagnosis, peri-operative management and subsequent post operative management of pituitary tumour patients. We are extremely lucky to have experts in the field and include:

• Dr Anne McCormack
• Assoc Profesor Jerry Greenfield
• Dr Andrew Weissberger
• Dr Kathy Samaras
• Dr Daniel Chen

NEURORADIOLOGISTS, NEURO-ONCOLOGISTS , NEURO-OPHTHALMOLOGISTS.

These members of the team are an essential part of the management and assessment when treating pituitary tumours. All members are part of the Multi-disciplinary team and are integrally involved in the overall management of any of our patients treated for a pituitary tumour.

REASONS FOR ENDOSCOPIC PITUITARY SURGERY

Endoscopic pituitary surgery is done to remove certain types of tumors that start to grow in your pituitary gland:

• Hormone-secreting tumors.These growths secrete chemical messengers that travel through the blood.
• Nonhormone-secreting tumors. These growths, also called non functioning adenomas (NFA) are removed by surgery because as they increase in size they may cause headache and visual disturbances.
• Cancerous tumors.These growths may be treated with a combination of surgery, cancer drugs (chemotherapy) and radiation treatment.

RISKS OF ENDOSCOPIC PITUITARY SURGERY

Endoscopic pituitary surgery is a VERY safe type of surgery, but all surgical procedures carry some risk for reaction to anesthesia, bleeding, and infection. Risks and complications that may occur with this type of surgery also include:

• CSF rhinorrhea. CSF, or cerebrospinal fluid, is the fluid that surrounds the brain, and it may leak from the nose after surgery. In some cases, another surgery may be needed to repair this leak. In our series (all cases performed), this is less than 3%.
• This is a type of infection occurring in the membrane lining the brain and spinal cord that can occur after surgery. It is more common if the CSF leaks.
• Damage to normal parts of the pituitary gland.Damage to areas of the pituitary that secrete hormones may require hormone replacement after surgery.
• Diabetes insipidus.Damage to a part of the pituitary gland that helps control urination may lead to frequent urination and thirst. This may occur early or be delayed and is relatively easily managed once confirmed.
• Severe bleeding.Heavy and persistent bleeding into the brain or from the nose may occur if a large blood vessel is damaged during surgery. This is extremely rare.
• Visual problems.The nerves that supply vision are close to the area of the pituitary gland can be damaged. The estimated risk is in the order of 1/1000.

There may be other risks, depending on your specific medical condition. Be sure to discuss any concerns with Dr Winder before the procedure.

BEFORE ENDOSCOPIC PITUITARY SURGERY

You will likely have seen and endocrinology specialist for an evaluation before surgery. Endocrinologists are the medical specialists that deal with glands and hormones. You may also have your vision checked before surgery.

Endoscopic pituitary surgery is usually done under general anesthesia, so you will be asked to stop eating and drinking after midnight on the night before surgery. You may need to stop taking some types of medications that may increase bleeding during surgery. Don’t take any over-the-counter medications before surgery without telling your doctor. You may have several blood tests, an ECG, and a chest X-ray. These will all be checked before surgery and you will need to be examined by the doctor who gives anesthesia.

You will be asked to have an MRI or CT prior to surgery so that we can perform stereotactic navigation at the time of surgery. This enables us to be very accurate with the exposure, aimed at minimizing any complications.

DURING ENDOSCOPIC PITUITARY SURGERY

The actual surgery may take a few hours.

Dr Harvey will place the endoscope through the nose. A mucosal flap is usually raised which will be placed over the site of tumour removal at completion

• The endoscope is advanced until the bony wall of the sphenoid sinus is found at the back of the nose.
• The sphenoid sinus is opened and the scope is passed through to the back wall of the sinus.
• An opening is made in the back wall of the sinus allowing a wide exposure of the pituitary fossa.
• When the pituitary area is entered, Dr Winder removes the pituitary tumor aiming for macroscopic clearance and preservation of the normal gland.
• When all parts of the tumour that can be reached have been removed, the endoscope is removed. The mucosal flap is placed over the site of tumour removal allowing a very robust vascular flap to be developed. Small Silastic splints are placed along the septum and are sutured in place. These allow mucosal recovery and will be removed by Dr Harvey in his rooms at the 3 week follow up appointment.

AFTER ENDOSCOPIC SURGERY

You may need to stay in the hospital for several days. During this time, nurses will help you with any dressings and bathroom needs. A catheter is in place and will normally be removed at Day 2. You will be able to return to a normal diet as long as you are taking fluids well. You will be encouraged to get out of bed and walk as soon as you are able. While in the hospital, you will be asked to help your nurses keep track of the amount of fluids you drink and your urine output to evaluate pituitary function.

You will be on intra-venous antibiotics whilst in hospital and will be on an oral course of antibiotics for a period of 2 weeks in total

Aftercare at home may include:

• Pain medication to control headaches, the most common complaint after surgery
• Restricted activities – no lifting or straining until cleared by your surgeons
• Follow-up visits with your endocrinologist and surgeons
• Repeat MRI (3 months)
• Visual testing

It is important to let your surgeons know about:

• Any headache that doesn’t go away with medication
• Nausea and vomiting
• Fever
• Balance difficulty or significant lethargy