As regards the inner ear, the endolymphatic duct ends in a closed saccus, imbedded in the dura mater of the cranial cavity.
However, one of the products that was discussed was composed of human dura mater.
Iatrogenic CJD is very rare and most cases have resulted from hGH treatment or human dura mater grafts.
In the image below, the dark ruler is showing the dura mater still adhering to the inside of the cranial cavity.
The outside is a tough, fibrous covering called the dura mater.