Transnasal Obliteration of the Eustachian Tube (ET) for Repair of Cerebrospinal Fluid Leak: A Report of Two Cases

Background Cerebrospinal fluid (CSF) leak after posterior fossa surgery is a well-known complication. At times the leak occurs via the obliterated middle ear into the ET and is very challenging to repair. Various approaches have been described for repair of CSF leak in lateral skull base defects and the transcanal route is more commonly used for obliteration of the ET. However, endoscopic transnasal access is also possible and we describe the technique in two patients with CSF leak following resection of a lateral skull base tumor. In both cases, the repair via a transnasal obliteration of the ET was successful after one attempt.

Case Descriptions The first case is a 28-year-old woman who underwent temporal resection of a right infratemporal fossa tumor with subsequent CSF leak from the right ET. She underwent nasal endoscopy with obliteration of the ET using Cymetra. This led to cessation of rhinorrhea over a 10-year follow-up period. The second case is a 31-year-old woman who developed CSF rhinorrhea after translabyrinthine removal of vestibular schwannoma. She also underwent nasal endoscopy to obliterate the ET using Surgicel, SurgiMend, and Gelfoam packing in addition to a posteriorly based inferior turbinate mucoperiosteal flap. A transoral approach was additionally used to allow for passage of suction Bovie during the case. She has remained free of rhinorrhea over a 16-month follow-up period.

Discussion Few cases of endonasal obliteration of the ET have been described in the literature, and in the reported cases, this method is reserved for recalcitrant cases of CSF rhinorrhea. At times, obliteration of the ET via the middle ear is difficult and may disrupt the repair of the defect. In this article, we present two successful cases of endonasal closure of the ET as an initial intervention. This approach offers quick, safe, and minimally invasive access to the eustachian tube, and it should be considered for initial repair and not only for recalcitrant cases of postoperative CSF rhinorrhea.