During canal wall up mastoidectomy for cholesteatoma, the surgeon drills the facial recess (posterior tympanotomy) to access the middle ear from behind. Which structures form the medial and lateral boundaries of this recess?

• A Facial nerve medially, chorda tympani laterally ✓
• B Sigmoid sinus medially, facial nerve laterally
• C Chorda tympani medially, incus buttress laterally
• D Facial nerve medially, external auditory canal skin laterally

Explanation

The facial recess is bounded medially by the descending (mastoid) segment of the facial nerve, laterally by the chorda tympani nerve, and superiorly by the incus buttress (short process of incus). It provides direct access to the oval window niche and mesotympanum without removing the posterior canal wall. The sigmoid sinus forms the posterior limit of the mastoidectomy itself, not the recess boundary.

Reference: Cummings Otolaryngology: Head and Neck Surgery, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.