Subtotal petrosectomy in the treatment of cerebrospinal fluid fistulae of the lateral skull base

Abstract

Cerebrospinal fluid (CSF) fistulae almost invariably lead to meningitis, even in the absence of other clinically obvious sequelae of the fistula such as a CSF fluid leak. The only effective means of reducing the risk of meningitis is surgical closure of the fistula. If surgery is to be recommended to patients with CSF fistulae even if they are currently asymptomatic, the morbidity of the procedure must be a principal determinant of the chosen technique. Recovery after the extracranial approach to a CSF fistula is much more rapid than after an intracranial procedure. The extracranial route is also free of the long-term risk of epilepsy which accompanies a craniotomy. The principal disadvantage of the lateral extracranial approach, failure of treatment, has been largely eliminated following studies into the obliteration of simple bony cavities using free adipose grafts. This paper describes our use of the extracranial approach to closure of CSF fistulae of the lateral skull base.

Massive Cerebrospinal Fluid Leak of the Temporal Bone

“…Rhinorrhea, otorrhea, or middle ear effusion could, in certain cases, camouflage CSF leakage [6, 13, 27]. …”

“…High-resolution noncontrast CT (HRCT) is considered the best initial diagnostic study. HRCT usually identifies any bony defects of the temporal bone but might not demonstrate the site of the dural tear [2, 13, 18, 27]. …”

“…Magnetic resonance imaging is able to distinguish isolated temporal bone CSF leakage from middle ear/mastoid encephalocele because the CSF signal is usually bright on T-2 weighted images, and the encephalocele appears contiguous with the brain [1, 2, 13, 18, 26]. Arachnoid cysts are isointense while neoplastic, hemorrhagic, or inflammatory cysts are hyperintense in comparison to CSF on T-1 sequences [13, 28]. …”

“…Subtotal petrosectomy with obliteration of the middle ear cleft seems to be an efficient solution for stubborn CSF otorrhea [2, 12, 13, 15, 29, 30]. Kronenberg et al [18] asserted that in 44% of cases CSF leakage was through the internal auditory canal, making it advisable to extend the subtotal petrosectomy technique to the inner ear and the internal auditory canal in order to seal any possible leakage from this point.…”

“…To treat the massive CSF leak, equine pericardium grafts were used to repair the posterior fossa dural defect and a subtotal petrosectomy [9–13] with blind sac closure of the external auditory canal, closure of the Eustachian tube, and obliteration of the middle ear and petrous bone was performed using abdominal fat.…”