Combined Endonasal and Transcranial Resection of Complex Skull Base Chordomas and Chondrosarcomas: A Multi-Corridor Strategy

Background: Chordomas and chondrosarcomas of the skull base are formidable lesions; their often insidious growth allows them to reach significant sizes, with involvement of the internal carotid arteries and cranial nerves and extensive erosion and deformity of the surrounding bone. Recent technological advances and a greater understanding of the anatomical relations of the ventral skull have enabled endoscopic techniques to be applied to the resection of these tumors with great success. Nonetheless, these lesions can present involvement of multiple compartments of the cranial base, thus demanding a combination of endonasal and transcranial approaches to permit a thorough removal.

Objective: Describe a series of patients harboring extensive skull base chordomas and chondrosarcomas in which a combination of endonasal and transcranial approaches was employed to allow maximal resection.

Methods: All pertinent records of chordomas and chondrosarcomas resected through a combination of endonasal endoscopic (EEA) and transcranial approaches were reviewed. Operative and pathology reports, pre and postoperative imaging and follow-up data were analyzed.

Results: Analysis of the senior authors' (DMP, RLC) database yielded 7 cases in which combined approaches were employed, 5 chordomas and 2 chondrosarcomas (4 females, 3 males, mean age 37.7 years). Surgical strategy was employed as follows: 1) EEA + Far lateral approach + EEA; 2) EEA + middle fossa approach + EEA; 3) EEA + bilateral transcondylar approach with fusion + EEA; 4) EEA + middle fossa approach + EEA; 5) EEA + transoral approach + retrosigmoid approach; 6) EEA + cranio-orbito-zygomatic approach; 7) EEA + EEA + infratemporal fossa approach. Combination of these approaches yielded gross total resection in all cases; all patients were referred for adjuvant proton beam therapy. Follow-up was lost in 2 patients; the remaining 5 have been free of recurrence since the end of their therapy (mean follow-up 12 months).

Conclusion: Despite the local aggressiveness of skull base chordomas and chondrosarcomas, through meticulous surgical planning and strategy, even large lesions can be thoroughly resected with minimal morbidity. A combination of various endonasal modules and tailored transcranial skull base techniques can yield optimal results in these challenging cases.