During FESS for chronic rhinosinusitis, the surgeon identifies the uncinate process and plans to create an uncinectomy. Which landmark structure is immediately lateral to the uncinate process and at greatest risk of inadvertent entry?
- A Lamina papyracea (medial orbital wall) ✓
- B Nasolacrimal duct
- C Anterior ethmoidal artery
- D Skull base (fovea ethmoidalis)
Correct answer: A. Lamina papyracea (medial orbital wall)
Explanation
The lamina papyracea forms the lateral boundary of the ethmoid labyrinth and is immediately lateral to the uncinate process. During uncinectomy, particularly if the uncinate is laterally displaced or the dissection is carried too laterally, the lamina papyracea can be breached causing orbital fat herniation or injury to the medial rectus. The nasolacrimal duct is anterior and medial to the uncinate. The anterior ethmoidal artery and fovea ethmoidalis are roof structures at risk during ethmoidectomy, not uncinectomy.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.