Endoscopic Transsphenoidal Resection of Pituitary and Anterior Skull Base Tumours

What is Transsphenoidal Pituitary and Anterior Skull Base Surgery?

Endoscopic transsphenoidal resection of a pituitary tumour is a minimally invasive neurosurgical procedure performed to remove pituitary adenomas and other sellar region tumours through the nose and sphenoid sinus — without any external incision.  This approach allows the neurosurgeon to access the pituitary region and brain without retracting the brain. It is now the standard surgical approach for the vast majority of pituitary tumours.

The pituitary gland sits in a bony pocket at the base of the skull called the sella turcica. By navigating a high-definition endoscope through the nasal passages including the sphenoid sinus, the surgeon can gain direct access to the pituitary gland and its tumour from below — entirely avoiding the brain.

One Brain and Spine's neurosurgeons have established a highly skill skull base team in collaboration with an ENT skull base surgeon.  Our skull base team has pioneered the approach in Victoria and have continued to evolve the technique utilising new technologies for the betterment of the patient undergoing surgery.  This team approach optimises both the nasal approach and the intracranial resection.

What Conditions Are Treated?

• Non-functioning pituitary macroadenomas — compressing the optic chiasm or causing hypopituitarism
• Growth Hormone (GH) secreting adenomas causing acromegaly
• Adrenocorticotrophin Hormone (ACTH) secreting adenomas causing Cushing's disease
• Prolactinomas not responding to medical therapy
• Thyroid Stimulating Hormone (TSH) secreting adenomas resulting in thyrotoxicosis
• Craniopharyngioma — selected cases
• Rathke's cleft cyst
• Meningiomas situated along the anterior skull base 

Preoperative Preparation

MRI with dedicated pituitary protocol is the key imaging investigation. Endocrine review and a full pituitary hormone profile are obtained preoperatively. Formal visual field testing documents any optic chiasm compression. An ENT skull base surgeon is involved in planning the nasal approach. Blood thinners are ceased before surgery.

What Happens During Transsphenoidal Surgery?

The procedure is performed under general anaesthesia. A high-definition endoscope is introduced through one nostril and the nasal pair passages opened up to create a binostril approach. The sphenoid sinus (air sinus at the back of the nose) is entered and its posterior wall (the floor of the sella) is opened with a high-speed drill. The dura of the sella is incised and the pituitary tumour is identified and carefully removed using curettes, ring curettes, and micro-instruments under continuous endoscopic visualisation.

In non-functioning macroadenomas, the goal is maximal resection of the tumour with decompression of the optic chiasm and surrounding structures.  This may not be possible if the tumour has grown into the cavernous sinus (pocket of vascular space with veins and arteries that also allow passage of some cranial nerves).  In these situations, maximal safe resection may be the goal.

In functioning adenomas (Cushing's, acromegaly), the tumour is often small (microadenoma) and requires meticulous dissection to identify and selectively remove it while preserving the surrounding normal pituitary gland. 

Once the tumour is removed, the sella is reconstructed with localised nasal tissue (mucosa, septal flaps) and fibrin glue to prevent CSF leak. The sphenoid sinus is packed with dissolvable packing. No external sutures are required and nothing will need to be removed from the nasal passages on the ward. 

Surgery will typically around 1 to 2 hours.

Extended Transsphenoidal Approaches

For larger tumours with significant suprasellar extension or lateral extension into the cavernous sinuses, and/or tumours emanating from the anterior skull base, extended endoscopic skull base approaches may be used, allowing wider access to the skull base without craniotomy.  This approach will be particularly utilised for non-pituitary tumours of the anterior skull base such as meningiomas.

Recovery After Transsphenoidal Surgery

Hospital Stay

There is little pain following surgery and most patients will want to go home around day 2.  You will however stay for 5 days as the endocrinologist will want to measure your hormone levels over this period.  As part of the testing you wil be on a strict fluid balance chart which means the nursing staff will be recording every ml of fluid you drink, and that you pass.

In certain situations you will have further post-operative imaging in the form of an MRI within the first few days however this is not routine.

Nasal Symptoms

Nasal congestion, crusting, and mild epistaxis are expected in the first weeks following the nasal approach. This is particularly so if there has been an extended approach.

Nasal saline irrigation is used to keep the nasal passages clear. Complete nasal recovery typically takes 4 to 6 weeks and you will be assess post-operative by the ENT surgeon in his rooms.

Activity Guidelines

• No nose blowing for 4 to 6 weeks — risk of CSF leak and pneumocephalus
• No heavy lifting for 4 to 6 weeks
• Driving — typically 2 to 3 weeks
• Return to office work — typically 2 to 4 weeks
• Return to physical work — 4 to 6 weeks
• No contact sports for 3 months

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Endocrine Recovery and Monitoring

Endocrine function is closely monitored postoperatively. Hormone replacement therapy may be required for deficiencies identified preoperatively or arising after surgery. For functioning adenomas, serum hormone levels are measured in the days after surgery to assess biochemical remission. Long-term endocrinological follow-up is essential.

Visual Recovery

When surgery is performed for optic chiasm compression, visual field improvement is typically rapid — most patients notice improvement within days to weeks of surgery as the chiasm decompresses. The degree of visual recovery depends on the severity and duration of compression before surgery.

Outcomes of Transsphenoidal Pituitary Surgery

Transsphenoidal surgery at One Brain and Spine achieves complete total resection in approximately 90-95% of non-functioning macroadenomas and biochemical remission in 80–90% of adenomas causing Cushing's disease or acromegaly. These success rates are significantly higher than other centers due to the sub-speciality training and experience of the One Brain and Spine skull base team.

Visual improvement following chiasm decompression occurs in approximately 80% of patients with preoperative visual field deficits. Complication rates are low with experienced teams.

Risks and Complications

General Anaesthetic Risks

Standard risks of general anaesthesia, discussed by the anaesthetist preoperatively.

Transsphenoidal-Specific Risks

• CSF leak — intraoperative or postoperative; occurs in approximately 1-2%; usually managed conservatively with lumbar drain or reoperation if persistent; presents as constant clear nasal fluid
• Diabetes insipidus (excessive urine output resulting in dehydration) — transient in up to 10%, permanent in approximately 1–2%; due to effects on the posterior pituitary or stalk following decompression
• Hypopituitarism (5%) — new hormone deficiencies from damage to normal pituitary tissue as it re-expands following decompression; may require lifelong replacement
• Meningitis (<1%) — from contamination of CSF; very rare with prophylactic antibiotics
• Vascular injury — carotid artery injury is the most feared complication; very rare in experienced hands.  One Brain and Spine neurosurgeons have a 0% rate of vascular injury
• Nasal complications — septal perforation, sinusitis, epistaxis; uncommon with careful technique
• Incomplete resection — tumour remnant may require reoperation or radiotherapy.  This is particularly so with tumours invading the cavernous sinus or giant (>4cm) tumours.  It is likely this will have been discussed with you prior to your procedure.