A Craniozygomatic Approach Combined with Midfacial Degloving for a Large Skull Base Meningioma

Introduction: Large primary middle cranial fossa tumors that extend into the spheno-ethmoido-clival regions and infratemporal fossa often require combined approaches that may be performed at the same sitting or in staged procedures. We applied a low pterional approach with zygomatic arch osteotomy combined with a midfacial degloving to a large, predominantly right-sided skull base meningioma that threatened contralateral vision. This unique surgical approach was used to successfully debulk a massive meningioma originating from the right sphenoid wing and expanding medially toward the cavernous sinus and pituitary fossa, anteriorly into the sphenoid and ethmoid sinuses and right orbital apex, and inferiorly into the right infratemporal fossa and maxillary antrum.

Case Report: We present a case of a 32-year-old right-handed Asian woman who as a child had been treated successfully for acute lymphoblastic leukemia with a combination of chemotherapy and craniospinal irradiation. In 2003, she presented with a 2-year history of progressive headaches, which had been persistent in nature and particularly worse prior to her menstrual period. An MRI scan showed a large lesion in the right temporal lobe extending medially into the cavernous sinus surrounding the internal carotid and cranial nerves II–VI, with some pituitary impingement. There was further extension into the right posterior ethmoids and infratemporal fossa. Biopsy confirmed a histopathological diagnosis of a meningioma that was progesterone receptor positive. Clinical examination showed no focal neurology with normal visual fields, and there was no evidence of pituitary dysfunction. Initially, surgery and radiotherapy were considered inappropriate due to the significant associated comorbidity. Gradual disease progression over the following 4 years resulted in right-eye proptosis, optic atrophy, divergent squint, and visual acuity limited to hand movements only. She also developed paresthesia in the right maxillary and mandibular trigeminal branches. Serial MRIs showed progressive compression of the orbital apex and encroachment of the optic chiasm. Conservative treatment with antiprogesterone and octreotide was initiated but was not effective. Recent deterioration in the visual acuity of her left eye prompted surgical intervention, and a combined approach debulking procedure was performed jointly with neurosurgery and ENT expertise. The patient made an uneventful postoperative recovery with good residual function.

Discussion: The craniozygomatic approach, using a bicoronal flap to gain adequate exposure and cranial access obtained via a low pterional craniotomy, provided excellent access to the anterior and middle cranial fossa. Complete extirpation of the intracranial component of the tumor was achieved, leading to adequate decompression of the II and III cranial nerves. Zygomatic arch osteotomies provided further access to the infratemporal fossa. Midfacial degloving gave excellent exposure to the midfacial skeleton allowing us to resect all tumor in the ethmoids and sphenoid as well as debulking tumor in the infratemporal fossa. Although lesions located in this region can be treated via other radical approaches, we felt this combined approach provided optimal decompression while minimizing operative morbidity. We feel this technique is one that should be considered in the armamentarium of a skull base surgeon.