Aural complications of foramen ovale procedures for trigeminal neuralgia: anatomical study and literature review.

Aim: A case of Eustachian tube dysfunction following percutaneous balloon compression (PBC) of the trigeminal ganglion led us to investigate aural complications of PBC and similar procedures. We aimed to clarify both the physiological effects of compression of the trigeminal ganglion on aural function and the possibility of puncture of the Eustachian tube during placement of the needle.

Methods: We reviewed the anatomy of the Eustachian tube in relation to the foramen ovale and the aural structures supplied by the trigeminal nerve through cadaveric study. Following CT scanning, neuronavigation was used to guide a needle into Meckel's cave of a cadaver. Dissection was subsequently carried out with the needle in-situ to assess the proximity of the needle to the Eustachian tube and other structures. A literature review of aural complications of foramen ovale procedures using Ovid Medline, PubMed, and Google Scholar databases was undertaken.

Results: Our literature review summarises the relationship of the Eustachian tube to the foramen ovale, the nerve supply of aural structures from the trigeminal nerve and examines previously reported post-operative aural complications. From our anatomical study, at its closest point, the needle was 7 mm from the Eustachian tube.

Conclusion: The trigeminal nerve supplies both the tensor tympani and tensor veli palatini muscles and percutaneous procedures may, therefore, lead to aural symptoms. Also, the path of the needle is close to the Eustachian tube and can be punctured during these procedures. The authors recommend discussing aural complications during consent for these procedures.