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Background: The craniovertebral junction (CVJ) may be affected by several diseases. It is an anatomically complex region, involving the osteoligamentous, vascular, and nervous structures, which makes surgery challenging. In a case of ventral compression, an anterior approach is preferable, although posterior fixation is often required. Anterior transmucosal approaches are associated with high rates of complications. However, decompression and fixation by the use of retropharyngeal extramucosal approaches may be challenging. Objective: To investigate the feasibility of a single-stage, anterior, extramucosal submandibular (SM) approach modification to the CVJ for simultaneous decompression and stabilization. Materials and Methods: This was a preliminary cadaveric feasibility study on 2 injected specimens. A variation of the SM approach with a short “boomerang” incision, microsurgical decompression of the ventral CVJ, and a new hybrid construct for an anterior atlantoaxial stabilization was investigated. The surgical approach, the decompression, and the instrumentation technique have been described. In addition, intraprocedural images and radiographs and also postprocedural computed tomographic images were collected. Furthermore, surgical exposure, working corridors and angles, and decompression grade were measured. Results: The SM approach provided wide exposure of the ventral CVJ and the possibility for instrumentation and decompression by removing the anterior arch of C1 and the odontoid process. Conclusion: A single- stage anterior extramucosal SM approach for decompression and stabilization of the CVJ is feasible and could result in shorter surgical duration, avoiding the complications related to both the transmucosal approach and the prone position, although specific related risks exist. Mechanical investigation of this hybrid system and in vivo studies are needed to confirm our results.

Object: It is becoming well-established that increasing extent of resection with decreasing residual volume is associated with delayed recurrence and prolonged survival for patients with glioblastoma (GBM). These prior studies are based on evaluating the contrast-enhancing (CE) tumour and not the surrounding fluid attenuated inversion recovery (FLAIR) volume. It therefore remains unclear if the resection beyond the CE portion of the tumour if it translates into improved outcomes for patients with GBM. Methods: Adult patients who underwent resection of a primary glioblastoma at a tertiary care institution between January 1, 2007 and December 31, 2012 and underwent radiation and temozolomide chemotherapy were retrospectively reviewed. Pre and postoperative MRI images were measured for CE tumour and FLAIR volumes. Multivariate proportional hazards were used to assess associations with both time to recurrence and death. Values with p < 0.05 were considered statistically significant. Results: 245 patients met the inclusion criteria. The median [IQR] preoperative CE and FLAIR tumour volumes were 31.9 [13.9–56.1] cm3 and 78.3 [44.7–115.6] cm3, respectively. Following surgery, the median [IQR] postoperative CE and FLAIR tumour volumes were 1.9 [0–7.1] cm3 and 59.7 [29.7–94.2] cm3, respectively. In multivariate analyses, the postoperative FLAIR volume was not associated with recurrence and/or survival (p > 0.05). However, the postoperative CE tumour volume was significantly associated with both recurrence [HR (95%CI); 1.026 (1.005–1.048), p= 0.01] and survival [HR (95%CI); 1.027 (1.007–1.032), p= 0.001]. The postoperative FLAIR volume was also not associated with recurrence and/or survival among patients who underwent gross total resection of the CE portion of the tumour as well as those who underwent supratotal resection. Conclusions: In this study, the volume of CE tumour remaining after resection is more important than FLAIR volume in regards to recurrence and survi

Object: There is currently no consensus as to whether meningiomas located inside the venous sinuses should be aggressively or conservatively treated. The goals of this study were to identify how sinus-invading meningiomas grow, report and compare growth rates of tumor components inside and outside the different venous sinuses, identify risk factors associated with increased tumor growth, and determine the effects of the extent of tumor resection on recurrence for meningiomas that invade the dural venous sinuses. Methods: Adult patients who underwent primary, non-biopsy resection of a WHO grade 1 meningioma invading the dural venous sinuses at a tertiary care institution between 2007 and 2015 were retrospectively reviewed. Rates of tumor growth were fit to several growth models to evaluate the most accurate model. Cohen’s d analysis was used to identify associations with increased growth of tumor in the venous sinuses. Logistic regression was used to compare extent of resection with recurrence. Results: Of the 68 patients included in the study, 34 patients had postoperative residual tumors in the venous sinuses that were measured over time. The growth model that best fit the growth of intrasinus meningiomas was the Gompertzian growth model (r2 = 0.93). The annual growth rate of meningiomas inside the sinuses was 7.3%, compared to extrasinus tumors with 13.6% growth per year. The only factor significantly associated with increased tumor growth in sinuses was preoperative embolization (effect sizes (ES) [95% CI], 1.874 [7.633–46.735], p = 0.008). Conclusions: This study shows that meningiomas involving the venous sinuses have a Gompertzian-type growth with early exponential growth followed by a slower growth rate that plateaus when they reach a certain size. Overall, the growth rate of the intrasinus portion is low (7.3%), which is half of the reported growth rates for other studies involving primarily extrasinus tumors.