Lesson learned in endoscopic endonasal dens resection for C1-C2 spinal cord decompression.

PURPOSE: Endoscopic endonasal approach (EEA) is the safest and most effective technique for odontoidectomy. Nevertheless, this kind of approach is yet not largely widespread. The aim of this study is to share with the scientific community some tips and tricks with our ten-year-old learned experience in endoscopic endonasal odontoidectomy (EEO), which remains a challenging surgical approach. MATERIAL AND METHODS: Our case series consists of twenty-one (10 males, 11 females; age range of 34-84 years) retrospectively analyzed patients with ventral spinal cord compression for non-reducible CVJ malformation, treated with EEA from July 2011 to March 2019. RESULTS: The results have recently been reported in a previous paper. The only intraoperative complication observed was intraoperative cerebrospinal fluid (CSF) leak (9.5%), without any sign of post-operative CSF leak. CONCLUSIONS: Considering our experience, EEO represents a valid and safe technique to decompress neural cervical structures. Despite its technical complexity, mainly due to the use of endoscope and the challenging surgical area, with this study we encourage the use of EEO displaying our experience-based surgical tips and tricks.

Endoscopic endonasal odontoidectomy: a long-term follow-up results for a cohort of 21 patients.

BACKGROUND: Endoscopic endonasal odontoidectomy (EEO) has been described as a potential approach for craniovertebral junction (CVJ) disease which could cause anterior bulbomedullary compression and encroaching. Due to the atlantoaxial junction's uniqueness and complex biomechanics, treating CVJ pathologies uncovers the challenge of preventing C1-C2 instability. A large series of patients treated with endonasal odontoidectomy is reported, analyzing the feasibility and necessity of whether or not to perform posterior stabilization. Furthermore, the focus is on the long-term follow-up, especially those whom only underwent partial C1 arch preservation without posterior fixation. METHODS: This study is a retrospective analysis of patients with ventral spinal cord compression for non-reducible CVJ malformation, consecutively treated with EEO from July 2011 to March 2019. Postoperative dynamic X-ray and CT scans were obtained in each case in order to document CVJ decompression as well as to exclude instability. The anterior atlas-dens interval, posterior atlas-dens interval and C1-C2 total lateral overhang were measured as a morphological criteria to determine upper cervical spine stability. RESULTS: Twenty-one patients (11:10 F:M) with a mean age of 60.6 years old at the time of surgery (range 34-84 years) encountered the inclusion criteria. For all 21 patients, a successful decompression was achieved at the first surgery. In 11 patients, the partial C1 arch integrity did not require a posterior cervical instrumentation on the bases of postoperative and constant follow-up radiological examination. In 13 cases, an improvement of motor function was recorded at the time of discharge. Only one patient had further motor function improvement at follow-up. Among the patients that did not show any significant motor change at discharge, 4 patients showed an improvement at the last follow-up. CONCLUSIONS: The outcomes, even in C1 arch preservation without posterior fixation, are promising, and it could be said that the endonasal route potentially represents a valid option to treat lesions above the nasopalatine line.

Skull base reconstruction: A question of flow? A critical analysis of 521 endoscopic endonasal surgeries.

INTRODUCTION: Post-operative CSF leak still represents the main drawback of Endoscopic Endonasal Approach (EEA), and different reconstructive strategies have been proposed in order to decrease its rate. OBJECTIVE: To critically analyze the effectiveness of different adopted reconstruction strategies in patients that underwent EEA. MATERIALS AND METHODS: Adult patients with skull base tumor surgically treated with EEA were retrospectively analyzed. Data recorded for each case concerned patient demographics, type of surgical approach, histotype, anatomical site of surgical approach, intra-operative CSF leak grade (no leak (INL), low flow (ILFL), high flow (IHFL)), reconstructive adopted strategy, Lumbar Drain positioning, post-operative CSF leak rate and intra/post-operative complications. RESULTS: A total number of 521 patients (January 2012-December 2019) was included. Intra-operative CSF leak grade showed to be associated with post-operative CSF leak rate. In particular, the risk to observe a post-operative CSF leak was higher when IHFL was encountered (25,5%; Exp(B) 16.25). In particular, vascularized multilayered reconstruction and fat use showed to be effective in lowering post-operative CSF leaks in IHFL (p 0.02). No differences were found considering INL and ILFL groups. Yearly post-operative CSF leak rate analysis showed a significative decreasing trend. CONCLUSION: Intra-operative CSF leak grade strongly affected post-operative CSF leak rate. Multilayer reconstruction with fat and naso-septal flap could reduce the rate of CSF leak in high risk patients. Reconstructive strategies should be tailored according also to the type and the anatomical site of the approach.

Craniovertebral junction chordomas: Case series and strategies to overcome the surgical challenge.

INTRODUCTION: Chordomas are rare and malignant primary bone tumors. Different strategies have been proposed for chordomas involving the craniovertebral junction (CVJ) compared to other locations. The impossibility to achieve en bloc excision, the impact on stability and the need for proper reconstruction make their surgical management challenging. OBJECTIVE: The objective is to discuss surgical strategies in CVJ chordomas operated in a single-center during a 7 years' experience (2013-2019). METHODS: Adult patients with CVJ chordoma were retrospectively analyzed. The clinical, radiological, pathological, and surgical data were discussed. RESULTS: A total number of 8 patients was included (among a total number of 32 patients suffering from skull base chordoma). Seven patients underwent endoscopic endonasal approach (EEA), and posterior instrumentation was needed in three cases. Three explicative cases were reported: EEA for midline tumor involving lower clivus and upper cervical spine (case 1), EEA and complemental posterior approach for occurred occipitocervical instability (case 2), C2 chordoma which required aggressive bone removal and consequent implant positioning, focusing on surgical planning (timing and type of surgical stages, materials and customization of fixation system) (case 3). CONCLUSION: EEA could represent a safe route to avoid injuries to neurovascular structure in clival locations, while a combined approach could be considered when tumor spreads laterally. Tumor involvement or surgical procedures could give raise to CVJ instability with the need of complementary posterior instrumentation. Thus, a tailored preoperative planning should play a key role, especially when aggressive bone removal and implant positioning are needed.