Clinical Context
Pituitary adenomas are the third most common intracranial tumor, affecting up to 20% of the population based on autopsy studies, though most remain clinically silent. Symptomatic adenomas cause problems through hormone hypersecretion (acromegaly, Cushing’s disease, prolactinoma, TSH-secreting adenoma) or mass effect (visual field defects from optic chiasm compression, headache, hypopituitarism from stalk/gland compression).
Transsphenoidal surgery—approaching the pituitary through the nasal passages and sphenoid sinus—has been the standard surgical approach for decades. Two technical variations have evolved: traditional microscopic surgery using an operating microscope for visualization, and newer pure endoscopic surgery using a rigid endoscope. The endoscope-assisted microscopic approach combines both technologies, using the microscope as the primary visualization with the endoscope for supplementary views.
The pure endoscopic approach offers panoramic visualization, angled viewing of hidden recesses, and potentially better illumination of the surgical field. However, it requires bimanual surgery with the scope held by an assistant or mechanical holder, potentially limiting instrument manipulation. This randomized trial directly compared the two approaches to determine if pure endoscopy offers meaningful advantages.
PICO Summary
Population: Patients with pituitary adenomas requiring transsphenoidal surgical resection.
Intervention: Pure endoscopic transsphenoidal surgery, using the endoscope as the sole visualization tool.
Comparison: Endoscope-assisted microscopic transsphenoidal surgery, using the operating microscope as primary visualization with endoscopic assistance.
Outcome: Pure endoscopic surgery achieved higher rates of surgical goal completion and better preservation of anterior pituitary function compared to the microscopic approach. Long-term radiological, endocrinological, rhinological, and ophthalmological outcomes were similar between groups.
Clinical Pearls
1. Visualization Translates to Completeness: The endoscope’s panoramic view and ability to look around corners likely explains the higher surgical goal achievement. Residual tumor in hidden recesses (cavernous sinus invasion, suprasellar extension) may be better visualized and resected with angled endoscopy.
2. Pituitary Function Preservation: Better anterior pituitary function preservation with endoscopy is clinically significant—hypopituitarism requires lifelong hormone replacement and monitoring. Enhanced visualization may allow more precise tumor removal while sparing normal gland tissue.
3. Equivalent Long-Term Outcomes: While immediate surgical goals differed, long-term outcomes (tumor control, hormonal normalization, visual improvement, nasal function) were similar. This suggests that the microscopic approach, while perhaps achieving less complete initial resection, doesn’t result in worse ultimate outcomes—possibly due to adjuvant treatments for residual disease.
4. Learning Curve Consideration: Pure endoscopic surgery requires different skills (hand-eye coordination with screen viewing, bimanual technique) than microscopic surgery. Surgeon experience with each technique affects outcomes, and the optimal approach depends partly on surgical training and institutional expertise.
Practical Application
For patients referred for pituitary adenoma surgery, inquire about institutional expertise with endoscopic versus microscopic approaches. Centers with established endoscopic programs may offer advantages in surgical completeness and pituitary function preservation, though outcomes also depend heavily on surgical volume and experience.
For functioning adenomas (acromegaly, Cushing’s disease) where complete tumor removal determines biochemical remission, the potential for better surgical goal achievement with endoscopy may be particularly valuable. For non-functioning adenomas primarily causing mass effect, either approach may be acceptable if visual improvement is the main goal.
Discuss with patients that newer endoscopic techniques may offer benefits in complete resection and gland preservation, while acknowledging that long-term outcomes appear similar and the optimal approach depends on surgeon expertise and tumor characteristics.
Broader Evidence Context
The shift toward pure endoscopic pituitary surgery has been driven largely by observational studies and case series rather than randomized trials. This prospective randomized comparison provides higher-quality evidence supporting endoscopic advantages. Meta-analyses have shown trends favoring endoscopy for gross total resection rates and complication profiles, though most included studies were retrospective.
Study Limitations
Single-center study limits generalizability to other settings and surgeons. The definition of “surgical goal achievement” wasn’t specified in detail. Tumor characteristics (size, invasion, functional status) that might modify the technique comparison weren’t described. Long-term follow-up duration wasn’t specified. Surgeon experience with each technique could influence outcomes.
Bottom Line
Pure endoscopic transsphenoidal surgery achieves higher surgical goal completion rates and better anterior pituitary function preservation compared to endoscope-assisted microscopic surgery for pituitary adenomas. Long-term outcomes are similar, but the immediate surgical advantages of endoscopy support its adoption where surgical expertise is available.
Source: Eördögh M, et al. “Comparison of Endoscopic and Endoscope-Assisted Microscopic Transsphenoidal Surgery for Pituitary Adenoma Resection: A Prospective Randomized Study.” Read article
