The excision of the gasserian ganglion (group of nerve cell bodies) of the trigeminal nerve.

The gasserian ganglion is a large ganglion, at the root of the trigeminal, or fifth cranial, nerve.

Trigeminal refers to the fifth pair of cranial nerves, which divide on each side of the head into three main branches distributed to the orbits, jaws, and parts of the mouth; trifacial.