Predictive factors of the postoperative proptosis recovery in surgery of spheno-orbital meningiomas

Abstract

Objective: This study aimed to identify factors affecting proptosis recovery in spheno-orbital meningioma (SOM) surgery and assess functional and oncological outcomes.

Methods: Data from 32 consecutive SOM surgery cases (2002-2021) were analyzed. Clinical, radiological, operative, and oncological parameters were examined. Proptosis was assessed using the exophthalmos index (EI) on MRI or CT scans. Statistical analyses were performed to identify predictive factors for proptosis recovery.

Results: Proptosis improved in 75% of patients post-surgery (EI decreased from 1.28 ± 0.16 to 1.20 ± 0.13, p = 0.048). Patients with stable or worsened EI had higher body mass index (28.5 ± 7.9 vs. 24.1 ± 4.7, p = 0.18), Simpson grade (IV 75% vs. 65%, p = 0.24), and middle sphenoid wing epicenter involvement (63% vs. 38%, p = 0.12), but no significant factors were associated with unfavorable exophthalmos outcomes. The improvement group had higher en plaque morphology, infratemporal fossa invasion, and radiation treatment for cavernous sinus residual tumor (88% vs. 75%, p = 0.25; 51% vs. 25%, p = 0.42; 41% vs. 25%, p = 0.42, respectively), but without statistical significance. Visual acuity remained stable in 78%, improved in 13%, and worsened in 9% during follow-up. Surgery had a positive impact on preoperative oculomotor nerve dysfunction in 3 of 4 patients (75%). Postoperative oculomotor nerve dysfunction was observed in 25%, of which 75% fully recovered. This occurrence was significantly associated with irradiation of an orbital tumor residue (p = 0.04). New postoperative trigeminal hypoesthesia was observed in 47%, of which 73% recovered. All SOMs were classified as WHO grade 1, and complementary treatments achieved oncological control, requiring gamma-knife radiosurgery in 53% and standard radiotherapy in 6%.

Conclusions: Surgery effectively improves proptosis in SOM, though complete resolution is rare. The absence of predictive factors suggests multifactorial causes, including body mass index and tumor resection grade. Postoperative oculomotor nerve dysfunction and trigeminal hypoesthesia are common but often recover. Gamma-knife radiosurgery maintains long-term oncological control for evolving tumor residue.

Keywords: Exophtalmos; Meningioma; Proptosis; Spheno-orbital meningioma; Sphenoid bone.