Surgery of tumors of the skull base spreading into the orbit and accessory nasal sinuses
(Burdenko Research Neurosurgical Institute of the Russian Academy of Medical Science, Moscow, Russia)
Treatment of tumors of the skull base, spreading into the orbit and accessory nasal sinuses, is a complex problem. Involvement of the above
structures is a cause of difficulties, arising during neoplasm removal. As a rule, a volume of surgical interventions in such tumors is a zone of interest of neurosurgeons,
rhinosurgeons and ophthalmosurgeons. The results of it is inefficiency of operations and ungrounded widening of a notion "inoperable tumor".
Case reports of 91 patients, aged 12-87, were analyzed. They had benign tumors of the skull base, spreading to the orbit and accessory
nasal sinuses. The majority of tumors was represented by meningiomas (67 cases). According to the classification, worked out by us, all the patients were subdivided
into 6 groups:
- A tumor affects the ethmoidal sinus, anterior cranial fossa, medial segments of one or both orbits, sphenoidal sinus, median segments of one or both maxillary sinuses, nasal cavity and nasopharynx - 12 patients.
- Limited tumors in the area of the orbit roof and its medial wall, spreading mainly into the orbit, ethmoidal sinus and partially into anterior cranial fossa - 6 patients.
- A tumor affects one of the orbits and spreads into anterior and middle cranial fossae, upper segments of the maxillary sinus and the infratemporal fossa - 11 patients.
- A tumor affects a region of temporal, infratemporal, pterygopalatine fossae, spreading along the skull base into inferiorlateral segments of the maxillary sinus - 15 patients.
- Tumors with signs of four preceding types - 41 patient.
- Tumors of the skull base, spreading into the orbit and accessory nasal sinuses and accompanied by other neoplasms of the brain and skull base - 6 patients.
A choice of a surgical approach is dependent on the following factors:
- Tumor localization and spread.
- Interrelations with nerves, major vessels, brain tissue, orbit structures, mucous membrane of paranasal sinuses, the nasopharynx.
- Sources of blood supply and a tumor vascular net.
- Bone changes.
- A somatic state of a patient.
- Availability of special instruments.
- Special surgical skills.