gms | German Medical Science

Objective: Microsurgical resection of sphenoorbital meningeomas yields unique surgical challenges due to the proximity and involvement of various neurovascular structures. Intraoperative identification of important bony landmarks (optic canal, SOF, Vidian canal, carotid canal) and resection control by intraoperative CT (iCT) and iCT-based image guidance could potentially facilitate radical tumor removal.

Methods: In a consecutive series of 57 sphenoorbital meningeomas (32 primary, 15 residual, 10 recurrent), the impact of iCT-imaging and image guidance used in the last 31 cases (group A) on surgical morbidity, residual tumor volume and revision rate was assessed, with the initial 26 patients operated on using conventional image guidance without intraoperative imaging serving as reference (group B).

Results: Patient mean age (54 vs. 57 y) and gender (f: 64% vs. 61%), tumor location and growth pattern (primary vs. residual or recurrent), mean tumor volume (46.8 ml vs. 43.6 ml), presenting symptoms (proptosis, visual acuity and field deficits), and incidence of preoperative neurological deficits did not differ between groups. In 28 patients of group A (24 patients of group B), surgical removal involved extensive sphenoid wing resection, orbitotomy, removal of ACP and drilling of the optic canal. In 9 patients of group A (29%) and 8 patients of group B (31%), tumor was removed from the cavernous sinus. Leading symptoms of visual acuity and field impairment improved significantly in 21 patients of group A (68%) and 17 of group B (65%). Permanent non-visual morbidity was 9.7% in group A and 11.5% in group B (n.s.). Complete tumor removal according to postoperative MRI was achieved in 13 patients of group A (42%) vs. 9 patients in group B (35%; p < .05). In 5 of 13 individuals of group A scheduled for complete tumor removal, residual tumor (intraosseous in 3 and intraorbital in 2 cases) was detected by iCT. Orbital titanium mesh reconstruction was readjusted due to suboptimal positioning in another 2 individuals of group A, amounting to a total of 7 primary revisions based on iCT findings in group A (22%). Three secondary revisions (11%) for residual tumor were performed in group B, but none in group A.

Conclusions: Intraoperative assessment of tumor removal and orbital reconstruction by iCT may facilitate radical tumor removal in selected cases and thus reduce the incidence of secondary revisions in the surgical treatment of sphenoorbital meningeomas.