Surgical Strategy for Skull Base Chordomas : Transnasal Midline Approach or Transcranial Lateral Approach

Abstract

Objective: The clinical management paradigm of skull base chordomas is still challenging. Surgical resection plays an important role of affecting the prognosis. Endonasal endoscopic approach (EEA) has gradually become the preferred surgical approach in most cases, but traditional transcranial surgery cannot be completely replaced. This study presents a comparison of the results of the two surgical strategies and a summary of the treatment algorithms for skull base chordomas.

Methods: We retrospectively analyzed the surgical outcomes and follow-up data of 48 patients with skull base chordomas diagnosed pathologically who received transnasal midline approaches (TMA) and transcranial lateral approaches (TLA) from 2010 to 2020.

Results: Among the 48 patients, 36 cases were adopted TMA and 12 cases were performed with TLA. In terms of gross total resection (GTR) rate, 27.8% in TMA and 16.7% in TLA and with EEA alone it was increased to 38.9%, while 29.7% in primary surgery. In TMA, the cerebrospinal fluid (CSF) leak remains the most common complication (13 cases, 36.1%), other main complications included death, cranial nerve palsy, hypopituitarism, all the comparisons were no statistical significance. The Karnofsky Performance Scale scores in TMA were all better than those in TLA at different time, and the overall survival (OS) and recurrence free survival/progression free survival was just the reverse.

Conclusion: The EEA for skull base chordomas resection has improved the GTR rate, but transcranial approach is still an alternative approach. It is necessary to select an appropriate surgical approach based on the location and the pattern of tumor growth in order to obtain the best surgical outcomes.

Keywords: Chordoma, skull base; Craniotomy; Endoscopy; Surgical outcome.

Fig. 1.

The KPS scores and p-values in two groups at different period of time. TLA : transcranial lateral approaches, TMA : transnasal midline approaches, KPS : Karnofsky Performance Scale.

Fig. 2.

Kaplan-Meier analysis of TMA and TLA for cumulative survival (A) and cumulative RFS/PFS (B). TLA : transcranial lateral approaches, TMA : transnasal midline approaches, RFS/PFS : recurrence free survival/progression free survival.

Fig. 3.

Preoperative sagittal (A), coronal (B), and axial (C) magnetic resonance imaging (MRI) scans revealed a large tumor was located on sellar, sphenoid sinus and clivus areas with bilateral cavernous sinus and carotid artery involvement. Postoperative MRI (D-F) showed a subtotal resection was accomplished.

Fig. 4.

Preoperative sagittal (A), coronal (B), and axial (C) magnetic resonance imaging (MRI) scans revealed the tumor is located on the right side of the lower clivus, compressing the medulla. Postoperative MRI (D-F) indicated complete removal of tumor.

Fig. 5.

Preoperative sagittal (A), coronal (B), and axial (C) magnetic resonance imaging (MRI) scans revealed a huge mass extending from the upperclivus to the craniocervical junction with medulla, left temporal lobe and infratemporal fossa involvement. Postoperative MRI (D-F) displayed subtotal resection of tumor with residual in lower-clivus.

Fig. 6.

Schematic diagram of skull base: the shadow area represents the midline area of the skull base roughly, with the boundary from rostral to caudal is the median orbital wall, lateral wall of the cavernous sinus, jugular tuberculum, hypoglossal nerve hole, and occipital condyle.