Presentation
Perforated left ear drum. ENT surgeon can see vascular mass in the middle ear cleft.
Patient Data
Vascular channel (arrows) arising from the proximal carotid canal entering the middle ear cleft in the region of the cochlear promontory and stapes then passing adjacent to the facial nerve canal to enter its own canal (parallel to the 7th canal) passing forward to the middle cranial fossa where it becomes the middle meningeal artery.
Case Discussion
The stapedial artery is an embryological vessel arising from the primitive second aortic arch that divides into a dorsal branch (the future middle meningeal artery) and a ventral division (future maxillary and mandibular arteries). These divisions link with branches developing from the external carotid artery during the third fetal month causing the stapedial artery to regress.
If the stapedial artery persists in postnatal life, the middle meningeal artery arises from it thus the foramen spinosum (normally containing the middle meningeal) is absent.
The vessel is important to recognize as it can be confused on examination with vascular tumors such as tympanic paraganglioma. It should not be biopsied as it will bleed profusely.