Outcomes and Technique for Palliative Orbital and Optic Nerve Decompression

Background The anterior cranial base comprises a complex region of vital anatomy. Due to the relationship of the orbit to the sinonasal cavity, endonasal approaches to the medial orbit are well described. While typically used for decompression of Graves' ophthalmopathy, the clinical outcomes in patients undergoing palliative orbital or optic nerve decompression for tumor extension or invasion are not well described.

Methods Consecutive patients undergoing palliative (without curative intent) endoscopic orbital and/or optic nerve decompression over a 3-month period were reviewed. Clinical history, disease pathology, visual symptoms, surgical approach, and visual/clinical outcomes were reviewed. Patients underwent endoscopic medial orbital decompression and optic nerve decompression when indicated. If there was significant orbital invasion, patients underwent transcaruncular orbitotomy in conjunction with the endoscopic decompression. For these patients, the orbitotomy was performed first, and cottonoids were left along the periorbita or medial rectus to protect orbital contents during the endoscopic approach. Surgical navigation was used in all cases to assist in identification of the optic nerve.

Results Eight patients underwent endoscopic decompression during the 3-month period with four patients using a combined orbitotomy approach. Disease pathologies included sinonasal melanoma (three patients), SMARCB-1 deficient sinonasal carcinoma (one patient), small cell neuroendocrine carcinoma (one patient), metastatic squamous cell carcinoma (one patient), polyostotic fibrous dysplasia (one patient), and fronto-orbital meningioma (one patient). In four of eight patients, the affected eye was the only functional eye. There were no complications. Vision improved (resolution of diplopia or improved visual acuity) in five of eight (62%) patients with resolution of diplopia in one patient and improved acuity in four others. In the four monocular patients, operative interventions were aggressively pursued following any clinical or radiographic signs of orbital or optic impingement. Fifty percent of these patients had some improvement in acuity. Continued treatment varied widely and includes immunotherapy, neoadjuvant chemotherapy, external beam radiation, and observation.

Conclusion The efficacy of palliative endoscopic orbital and optic nerve decompression for skull base neoplasms has not been well described. In our study, 62% of patients demonstrated some improvement in vision. A transcaruncular approach with cottonoid placement to protect the orbital contents followed by aggressive endoscopic decompression has proven to be a safe and effective technique in our experience. Due to the highly diverse nature of disease pathologies and treatment requirements, long-term outcomes will require further studies.