Tentorial meningiomas: operative nuances and perioperative management dilemmas

Acta Neurochir (2009) 151:1037–1051.DOI 10.1007/s00701-009-0421-3

Tentorial meningiomas (TM), comprising approximately 3–6% of all intracranial meningiomas, are complex entities with an intricate relationship to surrounding structures and require multiple surgical approaches. In the present study, the rationale for deciding the approaches for TMs and the perioperative management dilemmas were evaluated.
Methods  Thirty-seven patients (28 primary [supratentorial (2), infratentorial (20) and both (6)] and nine complex [cerebellopontine (CP) angle (5) and petroclival (4)] TM) underwent surgery using the occipital transtentorial, supracerebellar infratentorial, subtemporal transtentorial, bioccipital suboccipital, midline suboccipital, retrosigmoid, and combined pre and retrosigmoid approaches. The extent of excision was categorized according to Simpson’s grade.
Results  Simpson’s grade of excision was I in six, II in 11, III in nine and IV in 11 patients, respectively. Follow-up assessment (2 months to 9 years) in 27 patients (72.9%) showed that 23 patients returned to their previous activity level with either no or minimal symptoms, three returned to previous activity level with major cranial nerve palsy, and one patient required permanent assistance. One patient had recurrence and four others underwent resurgery for residual tumor. Two patients with petroclival lesions died due to aspiration pneumonitis and meningitis, respectively; one with CP angle TM presented in a poor general condition and expired following emergency ventriculoperitoneal shunt and subsequent definite surgery. Pseudomeningocele, cerebrospinal fluid leak, and cranial nerve palsy were the major morbidities.
Conclusions  Classifying TM into medial and lateral, supra and infratentorial groups helps in deciding an appropriate and safe approach. Meticulously preserving venous sinuses is important since the risk of venous infarction cannot be predicted even with radiological good venous collaterization and apparent venous sinus blockade by tumor. Laterally situated tumors carry a better prognosis when compared to the medially situated ones. Leaving a small residual tumor in an effort to preserve important neurovascular structures does not obviate the expectation of a good long-term prognosis with minimal morbidity and low recurrence rates.