Clival chordomas: considerations after 16 years of endoscopic endonasal surgery

Lessons learned in the evolution of endoscopic skull base surgery

OBJECTIVEEndoscopic skull base surgery (ESBS) is a relatively recent addition to the neurosurgical armamentarium. As with many new approaches, there has been significant controversy regarding its value compared with more traditional approaches to ventral skull base pathology. Although early enthusiasm for new approaches that appear less invasive is usually high, these new techniques require rigorous study to ensure that widespread implementation is in the best interest of patients.METHODSThe authors compared surgical results for ESBS with transcranial surgery (TCS) for several different pathologies over two different time periods (prior to 2012 and 2012-2017) to see how results have evolved over time. Pathologies examined were craniopharyngioma, anterior skull base meningioma, esthesioneuroblastoma, chordoma, and chondrosarcoma.RESULTSESBS offers clear advantages over TCS for most craniopharyngiomas and chordomas. For well-selected cases of planum sphenoidale and tuberculum sellae meningiomas, ESBS has similar rates of resection with higher rates of visual improvement, and more recent results with lower CSF leaks make the complication rates similar between the two approaches. TCS offers a higher rate of resection with fewer complications for olfactory groove meningiomas. ESBS is preferred for lower-grade esthesioneuroblastomas, but higher-grade tumors often still require a craniofacial approach. There are few data on chondrosarcomas, but early results show that ESBS appears to offer clear advantages for minimizing morbidity with similar rates of resection, as long as surgeons are familiar with more complex inferolateral approaches.CONCLUSIONSESBS is maturing into a well-established approach that is clearly in the patients' best interest when applied by experienced surgeons for appropriate pathology. Ongoing critical reevaluation of outcomes is essential for ensuring optimal results.

Endoscopic endonasal approach to primitive Meckel's cave tumors: a clinical series

INTRODUCTION

Recently, an alternative endoscopic endonasal approach to Meckel's cave (MC) tumors has been proposed. To date, few studies have evaluated the results of this route. The aim of our study was to evaluate long-term surgical and clinical outcome associated with this technique in a cohort of patients with intrinsic MC tumors.

METHODS

All patients with MC tumors treated at out institution by endoscopic endonasal approach (EEA) between 2002 and 2016 were included. Patients underwent brain MRI, CT angiography, and neurological evaluation before surgery. Complications were considered based on the surgical records. All examinations were repeated after 3 and 12 months, then annually. The median follow-up was of 44.1 months (range 16-210).

RESULTS

The series included 8 patients (4 F): 5 neuromas, 1 meningioma, 1 chondrosarcoma, and 1 epidermoid cyst. The median age at treatment was 54.5 years (range 21-70). Three tumors presented with a posterior fossa extension. Radical removal of the MC portion of the tumor was achieved in 7 out of 8 cases. Two patients developed a permanent and transitory deficit of the sixth cranial nerve, respectively. No tumor recurrence was observed at follow-up.

CONCLUSION

In this preliminary series, the EEA appeared an effective and safe approach to MC tumors. The technique could be advantageous to treat tumors located in the antero-medial aspects of MC displacing the trigeminal structures posteriorly and laterally. A favorable index of an adequate working space for this approach is represented by the ICA medialization, while tumor extension to the posterior fossa represents the main limitation to radical removal of this route.

Endoscopic transnasal surgery of clival lesions: our experience

BACKGROUND

The clivus is a region characterized by complex anatomy, with vascular and neural structures that are located in close proximity. Different pathologies can affect this area, and traditional surgical approaches were open approaches. Recently, the endoscopic transnasal technique has been introduced, and currently represents a good alternative for the surgical management of these lesions. This is a preliminary report on patients treated endoscopically for clival lesions by the authors' Skull Base Team.

PATIENTS AND METHODS

This was a retrospective chart review of patients who underwent an endoscopic exclusive transnasal approach (EEA) or a transoral one (TO) for clival lesions between June 2015 and November 2017 at our Skull Base Referral Center. Patient characteristics and symptoms, preoperative neuroradiological evaluation, surgical approach, complications, and postoperative results were evaluated.

RESULTS

Nine patients (6 females and 3 males; age range 6-82 years, mean 50.8 years) underwent EEA or TO. From histological analysis, we found chordomas (6/9 subjects), chondrosarcoma (1/9), craniopharyngioma (1/9), and eosinophilic granuloma (1/9). Three patients had previously been operated for a parasellar chondrosarcoma (1/9), a pituitary macroadenoma (1/9), or a chondroid chordoma (1/9). The lesions were totally (2/9) or sub-totally (5/9) resected, debulked (1/9), or analyzed with a biopsy (1/9). Reconstruction was accomplished with a multilayer technique (7/9), or with a gasket-seal (1/9), using a mucoperichondrial graft, a single/double nasoseptal flap, a middle turbinate flap, a fascia lata, or a synthetic fascia. One patient (11.1%) was re-operated on due to cerebrospinal leakage, without further complications. Two patients (22.2%) were re-operated on due to chordoma regrowth. Adjuvant chemotherapy was administered to 1/9 patient with progressive healing. All of the other patients underwent proton-beam radiotherapy with no documented tumor growth (median follow-up: 20 months; range 5.1-29.9 months).

CONCLUSIONS

Clival lesions represent a heterogeneous group of lesions located in a very complex and difficult area. EEA and TO approaches are safe and mini-invasive, with lower morbidity and with postoperative complications when compared to the traditional open approaches, according to the extent and type of pathology.

Transnasal Endoscopic and Lateral Approaches to the Clivus: A Quantitative Anatomic Study

BACKGROUND

Transnasal endoscopic approaches to the clivus have been established recently. Comparative analyses with classic lateral approaches are limited. In this study, we compared transnasal endoscopic and lateral approaches to the clivus, quantifying the exposure and working volume of each approach in the anatomy laboratory.

METHODS

High-resolution computed tomography scans were performed on 5 injected specimens (10 sides). In each specimen, transnasal endoscopic approaches (i.e., paraseptal, transrostral, extended transrostral, transethmoidal, and extended transclival without and with intradural hypophysiopexy) and lateral approaches (i.e., retrosigmoid, far-lateral, presigmoid retrolabyrinthine and translabyrinthine) to the clivus were performed. An optic neuronavigation system and dedicated software (ApproachViewer; Guided Therapeutics Program, University Health Network, Toronto, Ontario, Canada) were used to quantify the working volume and exposed clival area of each approach. Statistical evaluation was performed with the Kruskal-Wallis test and Steel-Dwass-Critchlow-Fligner post hoc test.

RESULTS

Endoscopic transnasal transclival approaches showed higher working volume and larger clival exposure compared with lateral approaches. Incremental volumetric values were evident for transnasal approaches; presigmoid approaches provided less working volume than retrosigmoid approaches. A transnasal transclival approach with hypophysiopexy provided significant exposure of the upper clivus (84.4%). The transrostral approach was the first transnasal approach providing satisfactory access to the midclivus (66%); retrosigmoid and far-lateral approaches provided exposure of approximately one half of the midclivus. The lower clivus was optimally exposed with endoscopic transclival approaches (83%), whereas access to this region was limited with lateral approaches.

CONCLUSIONS

This quantitative anatomic study shows that endoscopic transnasal approaches to the clivus provide a larger working volume and wider exposure of the clivus compared with lateral approaches.