Surgical management of meningiomas involving the optic nerve sheath.

OBJECT: The management of optic nerve sheath meningiomas (ONSMs) remains controversial but includes surgery, radiotherapy, and plain observation. Surgery is often thought to result in postoperative blindness. The authors report on a large series of patients surgically treated for ONSM, with an emphasis on the visual outcome. METHODS: Seventy-three patients with ONSMs who had undergone surgery between 1991 and 2002 were retrospectively analyzed. The standard surgical approach consisted of pterional craniotomy, intradural (54 patients) or extradural (10 patients) unroofing of the optic canal, or a combined procedure (seven patients). Thirty-two tumors demonstrated extension through the optic canal. Twenty-nine tumors reached the chiasm or contralateral side. Patients with intraorbital flat tumors should undergo radiotherapy instead of surgery. Those with a large intraorbital mass and no useful vision should undergo surgery. Tumors extending intracranially through the optic canal are amenable to decompression of the optic canal and resection of the intracranial portion. The follow-up period was a mean 45.4 months (range 6-144 months). Ten patients underwent postoperative radiotherapy. Visual acuity was not significantly influenced by surgery but did become worse with a longer duration of preoperative symptoms and a longer follow-up period. A tumor location in the optic canal was another negative factor. Radiotherapy preserved vision in five of 10 cases. CONCLUSIONS: The loss of vision in patients with ONSM is only a matter of time. In patients with good vision the role of radiotherapy becomes more important. Surgery is recommended for intracranial tumors to prevent contralateral extension.

Surgical treatment of orbital cavernomas.

BACKGROUND: There are numerous descriptions for the operative techniques applied in orbital lesions. We present a systematic overview of the surgical approaches, as determined by the location and extension of orbital cavernomas. METHODS: In our study, 37 patients (12 m, 25 f, aged 21-74 years, mean 51.22 years) underwent surgical removal of their orbital cavernoma at our clinic between 1988 and 2002. RESULTS: In ten cases the cavernoma was located in the lateral part of the intraconal space and a lateral orbitotomy was performed. Nine cavernomas were located more inferiorly and a transconjunctival approach was used. Seven cavernomas involving the optic canal, orbital apex and superior orbital fissure were operated on via an ipsilateral intradural approach. Four cavernomas of the superior orbital fissure or of the laterobasal intraconal space were approached extradurally. In one patient, a combined extra- intradural pterional operation was performed. Four patients with a lesion located medially in the posterior intraconal space were operated on via a contralateral pterional approach. One superior, medial, intraconal cavernoma was approached supraorbitally. In one cavernoma with direct contact to the sinus a transantral approach was used. The postoperative visual acuity improved in 14 of 19 cases with visual impairment, but in none with primary visual loss. Proptosis resolved completely in 21 of 27 patients. Ocular motility recovered in four of six patients, two patients with involvement of the superior orbital fissure presented with new oculomotor palsy postoperatively. CONCLUSIONS: The location of the cavernoma determines the recommended surgical approach. Because of their tendency to lead to irreversible loss of visual acuity due to the mass effect, we favor early surgery after the onset of symptoms.