Pterion Prep CraniPro VUMC Case Prep
2026-06-27

Case Prep: Pituitary Adenoma — Endoscopic Endonasal Transsphenoidal Approach

Case / Approach Snapshot

One-Liner

[Age]yo [M/F] with a [size] cm [functioning/non-functioning] pituitary [micro/macro]adenoma presenting with [visual loss/headaches/endocrinopathy/apoplexy] planned for endoscopic endonasal transsphenoidal resection.

Figures, Imaging & Video

🎥 Operative videos & resources

CNS Video Library

🧭 Operative approach: Endoscopic endonasal approach — detailed corridor setup, step-by-step technique & figures

Copyrighted operative figures/videos are linked, not copied. Embedded figures below are public-domain or CC-BY; see media-sources.md and CREDITS.md.

Pituitary macroadenoma — preoperative and intraoperative contrast coronal T1 MRI showing residual tumor at the sellar diaphragm and cavernous sinus

Macroadenoma with cavernous-sinus / suprasellar extension; intraoperative MRI detecting residual tumor (arrows). Source: Celtikci et al., Front Oncol 2021;11:733838, Fig 1. CC BY 4.0.

Endoscopic endonasal side-firing intraoperative ultrasound — parasellar anatomy with adenoma and the cavernous segment of the internal carotid artery

Intraoperative ultrasound during endonasal resection localizing the cavernous ICA and tumor margin. Source: Baker et al., Front Oncol 2022;12:1043697, Fig 1. CC BY 4.0.

High-Yield Literature

Curated Image Set

Open-access figures are embedded from PubMed Central articles and kept unique to this guide.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Figure 1 Figure 1. Anterior pituitary lobe function over time. The diagram depicts the non-continuous development of anterior pituitary lobe function over time. Source: Comparison of endoscopic and endoscope-assisted microscopic transsphenoidal surgery for pituitary adenoma resection: a prospective randomized study — Frontiers in Endocrinology 2025; CC BY.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Figure 2 Figure 2. Achievement of overall well-being over time. The diagram depicts the non-continuous time point when symptom-free well-being was achieved. The values are in %. Source: Comparison of endoscopic and endoscope-assisted microscopic transsphenoidal surgery for pituitary adenoma resection: a prospective randomized study — Frontiers in Endocrinology 2025; CC BY.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Figure 3 Figure 3. Achievement of rhinological well-being over time. The diagram depicts the non-continuous time point when symptom-free well-being was achieved. The values are in %. Source: Comparison of endoscopic and endoscope-assisted microscopic transsphenoidal surgery for pituitary adenoma resection: a prospective randomized study — Frontiers in Endocrinology 2025; CC BY.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Figure 4 Figure 4. Mental and physical scores of SF-36 over time. E, endoscopic group; M, microsurgical group; MCS, mental component summary score; PCS, physical component summary score; continuous line,… Source: Comparison of endoscopic and endoscope-assisted microscopic transsphenoidal surgery for pituitary adenoma resection: a prospective randomized study — Frontiers in Endocrinology 2025; CC BY.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Fig. 1 Fig. 1. Examples of endonasal anatomical variations that required surgical correction. a Coronal CT-scan with a left bullous middle turbinate, b left endonasal bullous middle turbinate, c left… Source: Variations of endonasal anatomy: relevance for the endoscopic endonasal transsphenoidal approach — Acta Neurochirurgica 2010; CC BY-NC.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Fig. 1 Fig. 1. An endoscopic view showing essential intra-sphenoidal anatomy. Internal Carotid arteries (ICA), a right-sided pituitary microadenoma (yellow) Source: HOW I DO IT: Cushing’s disease—selective adenomectomy via an endoscopic transsphenoidal approach — Acta Neurochirurgica 2024; CC BY.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Fig. 2 Fig. 2. Axial MRI T2 demonstrates a right-sided pituitary gland enlargement correlating to the pituitary microadenoma Source: HOW I DO IT: Cushing’s disease—selective adenomectomy via an endoscopic transsphenoidal approach — Acta Neurochirurgica 2024; CC BY.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Fig. 3 Fig. 3. Coronal T1 + GAD demonstrating the disproportionately enlarged right pituitary gland - microadenoma (yellow arrow), normal pituitary gland (blue arrow), and the internal carotid arteries… Source: HOW I DO IT: Cushing’s disease—selective adenomectomy via an endoscopic transsphenoidal approach — Acta Neurochirurgica 2024; CC BY.

Pituitary Adenoma Endoscopic Endonasal Transsphenoidal Approach — Fig. 4 Fig. 4. T1 Sagittal + GAD demonstrating the pituitary microadenoma (yellow arrow) and normal pituitary gland (blue arrow). The conchal sphenoidal sinus can be appreciated Source: HOW I DO IT: Cushing’s disease—selective adenomectomy via an endoscopic transsphenoidal approach — Acta Neurochirurgica 2024; CC BY.

History of Present Illness

Past Medical History

Imaging Review

MRI Sella (Thin-cut, T1, T1+Gad, T2, Coronal and Sagittal)

CT Sella / Sinuses

CTA (if large or vascular tumor)

Labs — Endocrine Workup

Pre-op Endocrine Considerations

Neurological Examination

Visual

Cranial Nerves

Endocrine Exam

Surgical Planning

Case Logistics, OR Needs & Orders

Diagnosis & Indication

Position

Approach: Endoscopic Endonasal Transsphenoidal

Critical Anatomy & Structures at Risk

  1. Internal carotid arteries — bilateral, lateral to sella in cavernous sinus; carotid prominences in sphenoid sinus
  2. Optic chiasm — superior to tumor; decompression is the goal
  3. Optic nerves — in optic canals, superolateral
  4. Normal pituitary gland — compressed by tumor; must identify and preserve
  5. Pituitary stalk — connects hypothalamus to gland; injury causes DI
  6. Cavernous sinus contents — CN III, IV, V1, V2, VI
  7. Sphenopalatine artery / posterior septal artery — blood supply to nasoseptal flap; preserve pedicle
  8. Diaphragma sellae — may descend into sella intraoperatively (marks complete suprasellar decompression)
  9. Arachnoid membrane — intact arachnoid = no CSF leak; if violated, must repair

Equipment & Instrumentation

Monitoring

Anesthesia Considerations

Potential Complications & Contingencies

  1. CSF leak — most common complication; nasoseptal flap closure, possible lumbar drain
  2. Diabetes insipidus (DI) — from stalk/posterior pituitary injury; monitor UOP, Na q4-6h; treat with DDAVP if UOP > 300 mL/hr with rising Na
  3. SIADH — delayed (typically days 5-10); monitor Na closely after discharge
  4. Hypopituitarism — new anterior pituitary deficits; check AM cortisol POD1
  5. ICA injury — catastrophic; pack and emergent angiography/endovascular treatment
  6. Visual worsening — from hematoma in sella or aggressive packing; emergent CT/MRI and return to OR
  7. Meningitis — monitor for fever, stiff neck; CSF leak is a risk factor
  8. Epistaxis — usually from sphenopalatine artery branch; may need repacking or embolization
  9. Incomplete resection — if cavernous sinus invasion (Knosp 3-4); plan for adjuvant SRS

Operative Note Template

Preoperative Diagnosis: [Non-functioning / GH-secreting / ACTH-secreting / prolactin-secreting] pituitary macroadenoma with [chiasmal compression / cavernous sinus invasion (Knosp ___)]

Postoperative Diagnosis: Same (pending final pathology and immunohistochemistry)

Procedure: Endoscopic endonasal transsphenoidal resection of pituitary adenoma

Surgeon: Co-surgeon (ENT): Assistant: Anesthesia: General endotracheal anesthesia

EBL: Fluids: Specimens: Pituitary adenoma (sent for permanent pathology, immunohistochemistry, Ki-67) Drains: [None / Lumbar drain] Complications: None Implants: None

Indications: The patient is a [age]yo [M/F] with a [size] cm [type] pituitary macroadenoma. Preoperative MRI demonstrated [findings including suprasellar extension, chiasmal compression, cavernous sinus involvement]. The patient presented with [visual field deficit / endocrinopathy / mass effect]. Formal visual field testing showed [findings]. Endocrine workup demonstrated [findings]. After discussion of risks, benefits, and alternatives, the patient elected to proceed with endoscopic endonasal transsphenoidal resection.

Description of Procedure: [Standard opening — anesthesia, positioning]

The patient was positioned supine with the head slightly extended in a [Mayfield clamp / horseshoe headrest]. [Electromagnetic navigation was registered and accuracy confirmed.] [A lumbar drain was placed.] The nose was prepared with oxymetazoline-soaked pledgets bilaterally. A time-out was performed.

Nasal phase: The endoscope was introduced into the [right] nasal cavity. The middle turbinate was identified and out-fractured laterally. A nasoseptal flap was harvested on the [right] side, based on the posterior septal artery, and stored in the nasopharynx. A posterior septectomy was performed to create a binostril corridor. The bilateral sphenoid ostia were identified at the level of the superior turbinates. A wide sphenoidotomy was performed, removing the rostrum of the sphenoid and connecting both ostia.

Sphenoid phase: The sphenoid sinus was entered and the septations were removed. The key landmarks were identified: sellar floor centrally, bilateral carotid prominences laterally, opticocarotid recesses superolaterally, and the clivus inferiorly. [Navigation confirmed anatomy.] The sellar floor was opened with a [high-speed drill / Kerrison rongeurs] and the opening was enlarged laterally to the medial edges of the cavernous sinuses and superiorly to the tuberculum sellae.

Sellar phase: The sellar dura was coagulated and opened in a cruciate fashion. [The tumor was immediately encountered and was noted to be soft/firm, gray/white/hemorrhagic.] Tumor removal was performed systematically using ring curettes, suction, and angled endoscopes. The inferior and lateral components were removed first, followed by the superior component. [With 30-degree endoscope visualization, the suprasellar component was observed to descend into the sella and was progressively removed.] The normal pituitary gland was identified [superiorly/posteriorly/laterally] and carefully preserved. [The diaphragma sellae was observed to descend into the sella, indicating complete suprasellar decompression.]

[For Knosp 3-4: The medial wall of the cavernous sinus was opened and tumor within the cavernous sinus was debulked. The ICA was identified with micro-Doppler and direct visualization, and all manipulation was kept medial to the artery.]

Intraoperative assessment: [An intraoperative CSF leak was / was not identified. Navigation confirmed extent of resection.]

Closure: Hemostasis was achieved with [Surgicel/Floseal]. The sella was packed with [Gelfoam / abdominal fat graft]. [An inlay collagen matrix graft was placed, followed by the nasoseptal flap to cover the entire bony defect. Fibrin glue was applied. / No CSF leak was noted, and the sella was packed with Gelfoam.] [Nasal packing was placed bilaterally.] A throat pack was removed. [The lumbar drain was clamped.]

Postoperative: The patient was awakened from anesthesia, extubated, and found to be neurologically intact. The patient was transferred to the neurosurgical ICU for monitoring.

Postoperative Plan

Chief-Level Case Review

Use these as the senior-level mental model for Pituitary Adenoma — Endoscopic Endonasal Transsphenoidal Approach:

Common Pimp Questions

Use these to pressure-test preparation for Pituitary Adenoma — Endoscopic Endonasal Transsphenoidal Approach:

  1. What is the surgical goal: gross-total, maximal safe, decompression, diagnosis, or cytoreduction?
  2. What eloquent cortex, tract, cranial nerve, vessel, or sinus defines the stopping point?
  3. What adjunct changes the case: navigation, mapping, 5-ALA, ultrasound, endoscope, ICG, or neuromonitoring?
  4. What is the edema, steroid, seizure, DVT, and postop imaging plan?
  5. What complication would you check for first in PACU based on this lesion location?

Attending Preference Variables

Items that commonly vary by surgeon or institution: