Anterior Skull Base Meningioma: Surgical approach and complication avoidance

Background: Endoscopic endonasal approach (EEA) and keyhole transcranial approaches are being increasingly used in anterior skull base meningioma (ASBM) surgery. Objective: We compare tumor resection rates and complication profiles of EEA and supraorbital key hole approach (SOKHA) against conventional transcranial approaches (TCA). Methods: Fifty-four patients with ASBM [olfactory groove (OGM), n=19 and planum sphenoidale/tuberculum sellae (PS/TSM), n=35) operated at a single centre over 7 years were retrospectively analyzed. Results: The overall rate of GTR was higher in OGM (15/19, 78.9%) than PS-TSM group (23/35, 65.7%, p=0.37). GTR rate with OGM was 90% and 75% with TCA and EEA. Death (n=1) following medical complication (TCA) and CSF leak requiring re-exploration (n=2, one each in TCA and EEA) accounted for the major complications in OGM. For the PS/TSM group, the GTR rates were 73.3% (n=11/15), 53.8% (n=7/13) and 71.4% (n=5/7) with TCA, EEA and SOKHA respectively. Seven patients (20%) of PS-TSM developed major postoperative complications including 4 deaths (one each in TCA, SOKHA and 2 in EEA group) and 3 visual deteriorations. Direct and indirect vascular complications were common in lesser invasive approaches to PS-TSM especially if the tumor has encased intracranial arteries. Conclusions: No single approach is applicable to all ASBMs. TCA is still the best approach to obtain GTR but has tissue trauma related problems. SOKHA may be a good alternative to TCA in selected PS-TSMs while EEA may be an alternate option in some OGMs. A meticulous patient selection is needed to derive reported results of EEA for PS-TSM.

In-Hospital Costs Associated With an Expanded Endonasal Approach to Anterior Skull Base Tumors

Objective: To determine in-hospital costs associated with performing an EEA to anterior skull base pathology and to identify drivers of cost variability for patients undergoing endoscopic anterior skull base surgery. Methods: All endoscopic anterior skull base surgeries performed over a period from January 1st, 2015 to October 24th, 2017 were evaluated. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables associated with each hospital stay and univariate analysis was performed using Stata software. Results: An EEA was associated with an average total in-hospital cost of $44 545. Compared to patients undergoing a transsphenoidal approach to pituitary tumor resection, EEA patients incurred higher in-hospital costs across all variables including a total cost increase of $15 921 (95% confidence interval $5720-26 122, P = .002). Univariate analysis of all endoscopic anterior skull base surgery patients showed a cost increase of $30 616 associated with post-operative cerebrospinal fluid (CSF) leak ($10 420-50 811, P = .004), $14 610 with post-operative diabetes insipidus (DI) ($4610-24 609, P = .004), and $11 522 with African-American patients relative to Caucasian patients ($3049-19 995, P = .008). Conclusions: Patients who undergo endoscopic EEA for resection of anterior skull base tumors typically incur greater in-hospital costs than patients undergoing a standard TSA. Post-operative complications such as CSF leak and DI, as well as ethnicity, are significant drivers of cost-variability.

Anterior Skull Base Analysis from Coronal and Reconstructed Computed Tomography: Radio-Anatomical Study

Endoscopic sinus and skull base Surgery has gained significant improvement widely all over the world. A computerized tomography (CT) scan provides a detailed anatomy of the skull base especially the bone framework. This study aims to analyze the fixed anatomical bony landmarks of the anterior skull base through coronal and reconstructed CT in the context of the Nepalese population and guide the surgeon to perform endoscopic sinus and skull base surgery safely. This Prospective study includes 70 Computerized Tomography scans of Paranasal sinuses. The different measurement from nasal floor to skull base was taken in coronal and reformatted sagittal CT scan. Mean, standard deviation, minimum and maximum values were analyzed using descriptive statistics. Student T-test was applied to compare between right and left side. This study includes 75 patients between 18 to 77 years. The measurement from nasal floor to the cribriform plate and ethmoidal roof in right and left side were, mean± SD (47± 4.1, 45.3±4.3, 47.9±5.1, and 49±8.5 mm) respectively. Mean Take off angle at the cribriform plate was 43.9 ±10.9°on right side and 43 ± 9.4° on the left side. The distance from the nasal spine to the skull base (mean ± SD) at nasofrontal recess, bulla ethmoidalis, and the junction of sphenoethmoid levels at right sides were 51.5 ± 4.7, 52.9 ± 4.1, and 61.2 ±4.7 little higher at left side. This study provides a detailed analysis of the anterior skull base in coronal and sagittal CT scans which helps to reduces complications.

USE OF THREE-DIMENSIONAL ENDOSCOPY IN ENDONASAL AND ANTERIOR SKULL BASE SURGERY

Objectives: The three dimensional (3D) endoscope is considered as a new surgical tool which used in different approaches in intranasal and anterior skull base surgical procedures. There are many advantages of the 3D endoscopy over the two dimensional (2D) one that have been demonstrated along clinical applications, surgical training and different experimental studies. Our study aimed to show the difference between using the 3D & 2D endoscopes during endonasal and anterior skull base surgery and its importance specially when used by novice users. Design: Our study is divided into two phases (clinical & cadaveric phases).In the clinical study we have done 52 endonasal & anterior skull base surgical procedures (26 study cases and 26 control cases).We recorded accuracy, duration and intraoperative complication for each case. The cadaveric study was performed on three cadavers, difference in accuracy and dissection time were recorded using 3D & 2D endoscopy for each side chosen by randomization. Results: In the clinical study, the cases done by 3D endoscope were significantly faster and more accurate with less intraoperative complications compared to cases done using 2D endoscope. In cadaveric dissection while using 3D endoscope there was better depth of perception regarding the anatomical landmarks compared to 2D endoscope. Conclusion: 3D endoscopy is an advanced instrument that allows better training for the coming generation of ENT surgeons. Both clinical and cadaveric studies offer a promising outcomes in both endonasal and anterior skull base surgery.