Association between Lateral Skull Base Thickness and Surgical Outcomes in Spontaneous CSF Otorrhea

Otolaryngol Head Neck Surg. 2016 Apr;154(4):707-14. doi: 10.1177/0194599816628528. Epub 2016 Feb 23.


Objectives: (1) Correlate skull base thickness with perioperative outcomes for spontaneous cerebrospinal fluid (CSF) otorrhea. (2) Augment perioperative counseling of patients with abnormally thin skull bases.

Study design: Case series with chart review.

Setting: Tertiary center. Patients with spontaneous CSF otorrhea have thin skull bases. This is associated with obesity and/or idiopathic intracranial hypertension. The influence of skull base thinning on perioperative outcomes is unknown.

Subjects and methods: A retrospective review was conducted from 2004 to 2014. Forty-eight cases of spontaneous CSF otorrhea met the inclusion criteria of primary surgery by the senior authors: preoperative dedicated temporal bone computed tomography, absence of other leak etiologies, and follow-up >6 months. Patients were stratified into thin (<0.9 mm) and thick (>0.9 mm) groups based on computed tomography measures of their tegmen. Primary outcomes measures were as follows: postoperative meningitis, recurrent leak, second site leak (contralateral ear/anterior fossa), and permanent shunt placement. Hearing outcomes were not assessed in this study.

Results: Thirty and 15 patients composed the thin and thick groups, respectively. Both the incidence (P < .0001) and the rate (P = .005) of adverse outcomes were significantly higher in the thin group. Only 2 patients in the thick group experienced an adverse outcome. Eleven patients underwent multiple procedures for spontaneous leaks. The recurrence rate was 14.5%. All but 1 recurrence occurred in the thin group.

Conclusions: An abnormally thin tegmen was significantly associated with adverse perioperative outcomes in cases of spontaneous CSF otorrhea. A thick skull base and the presence of an encephalocele may be protective against recurrence. The effect of untreated intracranial hypertension on the results is unknown.

Keywords: CSF leak; dehiscence; idiopathic intracranial hypertension; obesity; spontaneous; tegmen.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cerebrospinal Fluid Otorrhea / diagnostic imaging*
  • Cerebrospinal Fluid Otorrhea / surgery*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Postoperative Complications
  • Retrospective Studies
  • Skull Base / diagnostic imaging*
  • Skull Base / surgery*
  • Tomography, X-Ray Computed
  • Treatment Outcome