Endoscopic Endonasal Surgery (EES)

Medically reviewed by Yaron A. Moshel, MD, PhD ·Last reviewed: January 2, 2026 ·4 min read

Fellowship-trained skull base surgeons • 12 hospital affiliations across New Jersey

In short

Endoscopic endonasal surgery (EES) is a minimally invasive skull base approach that reaches the pituitary gland and anterior skull base through the natural nasal passages using a high-definition endoscope. Performed collaboratively by fellowship-trained skull base neurosurgeons and specialized ENT surgeons, EES allows many pituitary tumors and selected skull base lesions to be removed without an external incision or brain retraction. This approach has become the standard treatment for most pituitary adenomas and is also used for selected craniopharyngiomas, clival chordomas, Rathke’s cleft cysts, cerebrospinal fluid (CSF) leaks, and other anterior skull base lesions.

Key takeaways

Endoscopic endonasal surgery reaches the pituitary gland and anterior skull base through the natural nasal passages—without an external incision or brain retraction.
The procedure is performed collaboratively by fellowship-trained skull base neurosurgeons and specialized ENT surgeons using a high-definition endoscope and microsurgical instruments.
The angled endoscope provides panoramic visualization around corners, allowing excellent visualization of the surgical field.
Intraoperative neuronavigation, endoscopy, and other advanced technologies help maximize safe tumor removal while protecting nearby critical structures.
Most patients return home within 2 to 3 days after pituitary surgery, although more extensive skull base procedures may require a longer hospital stay.

ENDOSCOPIC ENDONASAL SURGERY AT A GLANCE

Approach	Through the natural nasal passages without an external incision
Anesthesia	General anesthesia
Surgery time	Approximately 2 to 4 hours for most pituitary adenomas; longer for complex skull base procedures
Hospital stay	Typically 2 to 3 nights for pituitary adenomas; longer for more extensive skull base surgery
Conditions treated	Pituitary adenomas, craniopharyngiomas, clival chordomas, Rathke's cleft cysts, selected anterior skull base meningiomas, and CSF leaks
Team approach	Collaborative surgery performed by fellowship-trained skull base neurosurgeons and specialized ENT surgeons
Endocrine follow-up	Endocrinology follow-up is required after pituitary surgery to monitor hormone function

Timing and stay vary by patient and complexity. Your surgeon will confirm what to expect in your case.

How endoscopic endonasal surgery works

The pituitary gland sits at the base of the skull directly behind the nasal passages, making it accessible through a natural surgical corridor. Using a high-definition endoscope and specialized microsurgical instruments, surgeons can reach the pituitary gland and many anterior skull base lesions without making an external incision or retracting the brain.

At Atlantic Brain and Spine, endoscopic endonasal surgery is performed collaboratively by fellowship-trained skull base neurosurgeons and specialized ENT surgeons with expertise in endoscopic skull base surgery. Depending on the diagnosis, endocrinologists, neuroradiologists, neuro-ophthalmologists, radiation oncologists, and other specialists may also participate in treatment planning and long-term follow-up.

Every case is individually evaluated to determine whether an endoscopic endonasal approach offers the safest and most effective treatment.

Common Conditions Treated

Endoscopic endonasal surgery is most commonly performed for pituitary adenomas, but it is also used to treat a growing range of skull base tumors and other conditions located beneath the brain. The approach is selected when it provides the safest, least disruptive path to the lesion while minimizing manipulation of the brain and surrounding neurovascular structures.

Pituitary adenomas — The most common indication for endoscopic endonasal surgery. These benign tumors may secrete excess hormones (functioning adenomas) or grow large enough to compress surrounding structures, including the optic nerves (macroadenomas).

Prolactinomas — Often managed medically; surgery is considered when medication is ineffective or not tolerated.
Growth hormone (GH)-secreting adenomas — Cause acromegaly.
ACTH-secreting adenomas — Cause Cushing’s disease.
Non-functioning adenomas — Often present with vision changes, headaches, or pituitary dysfunction as they enlarge.

Other common indications include craniopharyngiomas, clival chordomas, Rathke cleft cysts, selected anterior skull base meningiomas, and cerebrospinal fluid (CSF) leaks. Not every skull base tumor is best treated through an endoscopic endonasal approach, and the multidisciplinary Skull Base Program determines the safest surgical approach for each patient. Compared with older microscopic techniques, endoscopic endonasal surgery provides improved visualization and, in appropriately selected patients, may improve tumor removal, hormonal remission, and visual outcomes.

Benefits and risks

Potential benefits

No external incision, no visible scar, no brain retraction
HD endoscopic visualization superior to older microscopic transsphenoidal technique
Rapid recovery -- most patients home within 2 to 3 days
High rates of tumor removal and hormonal remission for appropriately selected adenomas

Possible risks

CSF leak from the skull base opening -- repaired intraoperatively; rarely requires lumbar drain
Diabetes insipidus (temporary or permanent excessive urination from pituitary stalk manipulation) -- monitored in hospital
Hypopituitarism (hormonal deficiency) -- requires lifelong hormone replacement in some patients
Nasal congestion and crusting during the 4 to 6 week healing period

Your surgeon will review the benefits and risks specific to your diagnosis during your consultation.

What recovery looks like

Recovery after endoscopic endonasal surgery depends on the condition being treated and the extent of surgery. Most patients undergoing pituitary surgery recover more quickly than patients undergoing traditional open skull base procedures.

Days 1 to 3 Hospital stay of approximately 2 to 3 nights for pituitary surgery. Hormone levels, sodium levels, urine output, neurological function, and vision are monitored closely.
Weeks 1 to 2 Nasal saline irrigations begin. Avoid nose blowing, heavy lifting, bending, and strenuous activity while the surgical corridor heals. Endocrinology follow-up and laboratory testing are performed as needed.
Weeks 2 to 6 ENT follow-up for nasal healing and debridement as needed. Most patients gradually return to normal daily activities during this period.
6 weeks to 3 months Follow-up MRI evaluates the extent of resection. Endocrinology follow-up continues to monitor hormone function, with additional treatment determined by the underlying diagnosis and pathology.

Frequently asked questions

Will my sense of smell be affected?

Some temporary reduction in smell is common during the 4 to 6 week nasal healing period. Permanent loss of smell is uncommon with modern endoscopic techniques that preserve the olfactory mucosa.

Is endoscopic surgery better than older microscopic pituitary surgery?

For many patients, yes—but not every patient requires an endoscopic approach. Compared with traditional microscopic transsphenoidal surgery, endoscopic endonasal surgery provides a wider field of view, improved visualization around corners, and better access to larger or more complex tumors. However, the best surgical approach depends on the location, size, and characteristics of the tumor, as well as the surgeon’s experience. Your skull base team will recommend the approach that offers the safest and most effective treatment for your specific condition.

What happens if the pituitary tumor grows back?

Residual or recurrent pituitary tumor can be treated with a second endoscopic procedure, stereotactic radiosurgery (CyberKnife or Gamma Knife), or medical therapy depending on the tumor type. Annual surveillance MRI is important for detecting recurrence early.

Will I need hormone replacement after surgery?

This depends on pre-operative hormonal function and the extent of surgical manipulation. All patients have endocrinological follow-up after pituitary surgery, with hormone replacement started if deficiencies are identified.

This page is for general education and does not replace medical advice. Treatment decisions should be made with a qualified neurosurgeon based on your individual diagnosis and imaging. To discuss your options, call Atlantic Brain and Spine Brain Tumor Care at 973.993.7100 or request a consultation.

Endoscopic Skull Base Specialists at Atlantic Brain and Spine

Your care is provided by Atlantic Brain and Spine's multidisciplinary skull base team, including fellowship-trained skull base neurosurgeons who collaborate closely with specialized ENT surgeons for complex endoscopic skull base procedures.