Eustachian tube obliteration in translabyrinthine vestibular schwannoma excision: cerebrospinal fluid rhinorrhea and middle ear status.

OBJECTIVES

To assess the incidence of cerebrospinal fluid (CSF) rhinorrhea by systematic eustachian tube (ET) obliteration at the time of a translabyrinthine vestibular schwannoma (VS) excision and to evaluate its effect on the middle ear and on the tympanic membrane and if it is well tolerated by patients.

STUDY

DESIGN

Retrospective study.

SETTING

Tertiary care centre.

PATIENTS: Group 1 (57 patients) and group 2 (87 patients) underwent translabyrinthine VS excision with and without systematic ET obliteration, respectively.

MAIN OUTCOME MEASURES: Petrous apex pneumatization level and postoperative CSF leak were evaluated. Group 1 patients had a late postoperative otologic examination, tympanometric test, Valsalva manoeuvre, and ear symptom evaluation.

RESULTS

There were six cases of CSF rhinorrhea in group 2, whereas no cases were observed in group 1 (p  =  .043), despite its larger tumour grade (p  =  .002). In group 2, CSF rhinorrhea was absent at pneumatization level 1. Three of six CSF rhinorrhea cases developed meningitis. None of the 27 tested patients of group 1 demonstrated a tympanic membrane retraction or a positive Valsalva manoeuvre. Tympanometry showed a type A curve (2 patients), a type As curve (14 patients), and a type B curve (11 patients). Air volumes and air pressures of the operated ears were lower than those of the nonoperated ears (p < .001).

CONCLUSION

Patients of group 1 tolerated the procedure well, with preserved tympanic membrane compliance. Bidirectional air exchange throughout a normal middle ear mucosa explains this fact. We recommend obliteration of both the petrous apex cells and ET in all cases of petrous apex pneumatization levels 2 to 4.