Citations

BACKGROUND: Several microsurgical transcranial approaches (MTAs) and endoscopic transnasal approaches (EEAs) to the anterior cranial fossa (ACF) have been described. OBJECTIVE: To provide a preclinical, quantitative, anatomic, comparative analysis of surgical approaches to the ACF. METHODS: Five alcohol-fixed specimens underwent high-resolution computed tomography. The following approaches were performed on each specimen: EEAs (transcribriform, transtuberculum, and transplanum), anterior MTAs (transfrontal sinus interhemispheric, frontobasal interhemispheric, and subfrontal with unilateral and bilateral frontal craniotomy), and anterolateral MTAs (supraorbital, minipterional, pterional, and frontotemporal orbitozygomatic approach). An optic neuronavigation system and dedicated software (ApproachViewer, part of GTx-Eyes II—UHN) were used to quantify the working volume of each approach and extrapolate the exposure of different ACF regions. Mixed linear models with random intercepts were used for statistical analyses. RESULTS: EEAs offer a large and direct route to the midline region of ACF, whose most anterior structures (ie, crista galli, cribriform plate, and ethmoidal roof) are also well exposed by anterior MTAs, whereas deeper ones (ie, planum sphenoidale and tuberculum sellae) are also well exposed by anterolateral MTAs. The orbital roof region is exposed by both anterolateral and lateral MTAs. The posterolateral region (ie, sphenoid wing and optic canal) is well exposed by anterolateral MTAs. CONCLUSION: Anterior and anterolateral MTAs play a pivotal role in the exposure of most anterior and posterolateral ACF regions, respectively, whereas midline regions are well exposed by EEAs. Furthermore, certain anterolateral approaches may be most useful when involvement of the optic canal and nerves involvement are suspected.

OBJECTIVE Facial nerve palsy is a debilitating condition that can arise from iatrogenic, traumatic, or congenital causes. One treatment to improve function of the facial muscles after facial nerve injury is hypoglossal-to-facial nerve anastomosis (HFA). HFA’s efficacy and predictors of its success vary in the literature. Here, the authors present a patient-level analysis of a literature-based cohort to assess outcomes and investigate predictors of success for HFA. METHODS Seven electronic databases were queried for studies providing baseline characteristics and outcomes of patients who underwent HFA. Postoperative outcomes were measured using the House-Brackmann (HB) grading scale. A change in HB grade of 3 points or more was classified as favorable. A cutoff value for time to anastomosis associated with a favorable outcome was determined using the Youden Index. RESULTS Nineteen articles with 157 patients met the inclusion criteria. The mean follow-up length was 27.4 months, and the mean time to anastomosis after initial injury was 16 months. The end-to-side and end-to-end anastomosis techniques were performed on 84 and 48 patients, respectively. Of the 130 patients who had available preoperative and postoperative HB data, 60 (46.2%) had a favorable outcome. Time from initial injury to anastomosis was significantly different between patients with favorable and unfavorable outcomes (7.3 months vs 29.2 months, respectively; p < 0.001). The optimal cutoff for time to anastomosis to achieve a favorable outcome was 6.5 months (area under the curve 0.75). Patients who underwent anastomosis within 6.5 months of injury were more likely to achieve a favorable outcome (73% vs 31%, p < 0.001). CONCLUSIONS HFA is an effective method for restoring facial nerve function. Favorable outcomes for facial nerve palsy may be more likely to occur when time to anastomosis is within a 6.5-month window.

Abstract Introduction Endoscopic endonasal approaches (EEAs) are increasingly utilized for intracranial pathology. As opposed to sinonasal tumors, the nasal cavity is being used as a corridor to access these intracranial tumors but is not the site of primary surgical intent. Accordingly, there has been recent interest in preserving intranasal structures not directly involved by tumor and improving postoperative sinonasal quality of life (QOL). Objectives The aim of the study is to highlight recent advances in EEA techniques focused on improving sinonasal QOL including turbinate preservation, reducing the morbidity of reconstructive techniques, and the development of alternative minimally invasive EEA corridors. Methods The method of the study involves contemporary literature review and summary of implications for clinical practice. Results Nasoseptal flap (NSF) harvest is associated with significant morbidity including septal perforation, prolonged nasal crusting, and external nasal deformities. Various grafting and local rotational flaps have demonstrated the ability to significantly limit donor site morbidity. Free mucosal grafts have re-emerged as a reliable reconstructive option for sellar defects with an excellent sinonasal morbidity profile. Middle turbinate preservation is achievable in most EEA cases and has not been shown to cause postoperative obstructive sinusitis. Recently developed minimally invasive EEA techniques such as the superior ethmoidal approach have been described to better preserve intranasal structures while allowing intracranial access to resect skull base tumors and have shown promising sinonasal QOL results. Conclusion This contemporary review discusses balancing effective skull base reconstructive techniques with associated morbidity, the role of turbinate preservation in EEA, and the development of unique EEA techniques that allow for increased nasal structure preservation.

BACKGROUND: Selection of skull base approaches is a critical skill for complex cranial surgery, which demands nuanced understanding of neuroanatomy and pathology. OBJECTIVE: To develop novel pedagogical resources for approach selection education and assessment. METHODS: A prospectively maintained skull base registry was screened for posterior fossa tumors amenable to 3-dimensional (3D) modeling of multiple operative approaches. Inclusion criteria were high-resolution preoperative and postoperative computed tomography and MRI studies (≤1 mm) and consensus that at least 3 posterior fossa craniotomies would provide feasible access. Cases were segmented using Mimics and modeled using 3-Matic. Clinical Vignettes, Approach Selection Questionnaire, and Clinical Application Questionnaire were compiled for implementation as a teaching/testing tool. RESULTS: Seven cases were selected, each representing a major posterior fossa approach group. 3D models were rendered using clinical imaging for the primary operative approach, as well as a combination of laboratory neuroanatomic data and extrapolation from comparable craniotomies to generate 2 alternative approaches in each patient. Modeling data for 3D figures were uploaded to an open-sourced database in a platform-neutral fashion (.x3d) for virtual/augmented reality and 3D printing applications. A semitransparent model of each approach without pathology and with key deep structures visualized was also modeled and included for comprehensive understanding. CONCLUSION: We report a novel series of open-source 3D models for skull base approach selection training, with supplemental resources. To the best of our knowledge, this is the first such series designed for pedagogical purposes in skull base surgery or centered on open-source principles.

Abstract Introduction Surgery of the sellar and parasellar regions can be challenging due to the complexity of neurovascular relationships. The main goal of this study is to develop an educational resource to help trainees understand the pertinent anatomy and procedural steps of the endoscopic endonasal approaches (EEAs) to the sellar and parasellar regions. Methods Ten formalin-fixed latex-injected specimens were dissected. Endoscopic endonasal transsphenoidal transsellar, transtuberculum-transplanum, and transcavernous approaches were performed by a neurosurgery trainee, under supervision from the senior authors and a PhD in anatomy with advanced neuroanatomy experience. Dissections were supplemented with representative case applications. Results Endoscopic endonasal transsphenoidal approaches afford excellent direct access to sellar and parasellar regions. After a wide sphenoidotomy, a limited sellar osteotomy opens the space to sellar region and medial portion of the cavernous sinus. To reach the suprasellar space (infrachiasmatic and suprachiasmatic corridors), a transplanum-prechiasmatic sulcus-transtuberculum adjunct is needed. The transcavernous approach gains access to the contents of the cavernous sinus and both medial (posterior clinoid and interpeduncular cistern) and lateral structures of the retrosellar region. Conclusion The anatomical understanding and technical skills required to confidently remove skull base lesions with EEAs are traditionally gained after years of specialized training. We comprehensively describe EEAs to sellar and parasellar regions for trainees to build knowledge and improve familiarity with these approaches and facilitate comprehension and learning in both the surgical anatomy laboratory and the operating room.

AbstractObjectivesTo demonstrate three‐hundred and sixty degrees of maxillary sinus (MS) surgical approaches using cadaveric dissections, highlighting the step‐by‐step anatomy of each procedure.MethodsTwo latex‐injected cadaveric specimens were utilized to perform surgical dissections to demonstrate different approaches to the MS. The procedures were documented with macroscopic images and endoscopic pictures.ResultsDissections were performed to approach the MS medially (endoscopic maxillary antrostomy and ethmoidectomy), anteriorly (Caldwell–Luc), superiorly (transconjunctival/transorbital approach), inferiorly (transpalatal approach), and posterolaterally (preauricular hemicoronal approach).ConclusionA number of approaches have been described to address pathology in the MS. Surgeons should be familiar with indications, limitations, and surgical anatomy from different perspectives to approach the MS. This paper illustrates anatomic approaches to the MS with detailed step‐by‐step cadaveric dissections and case examples.

AbstractObjectiveEsthesioneuroblastoma (ENB) is a rare malignant neoplasm arising from the olfactory epithelium of the cribriform plate. The goal of this study was to update our oncologic outcomes for this disease and explore prognostic factors associated with survival.Materials and methodsWe performed a retrospective analysis of patients with ENB treated at a single tertiary care institution from January 1, 1960, to January 1, 2020. Univariate and multivariate analysis was performed. Overall survival (OS), progression‐free survival (PFS), and distant metastasis–free survival (DMFS) were reported.ResultsAmong 143 included patients, the 5‐year OS was 82.3% and the 5‐year PFS was 51.6%; 5‐year OS and PFS have improved in the modern era (2005–present). Delayed regional nodal metastasis was the most common site of recurrence in 22% of patients (median, 57 months). On univariate analysis, modified Kadish staging (mKadish) had a negative effect on OS, PFS, and DMFS (p < 0.05). Higher Hyams grade had a negative effect on PFS and DMFS (p < 0.05). Positive margin status had a negative effect on PFS (p < 0.05). Orbital invasion demonstrated worsening OS (hazard ratio, 3.1; p < 0.05). On multivariable analysis, high Hyams grade (3 or 4), high mKadish stage (C+D), and increasing age were independent negative prognostic factors for OS (p < 0.05). High Hyams grade (3+4), high mKadish stage (C+D), age, and positive margin status were independent negative prognostic factors for PFS (p < 0.05). High Hyams grade (3+4) was an independent negative prognostic factor for DMFS (p < 0.05).ConclusionsPatients with low Hyams grade and mKadish stage have favorable 5‐year OS, PFS, and DMFS.

Background: Cerebral sinus thrombosis as presentation of acute promyelocytic leukemia (AMPL) is exceptional, with only three cases registered in the literature. Case Description: A 24-year-old female patient was transferred to our center after a car accident. The patient had a witnessed generalized seizure while driving. Computerized tomography (CT) demonstrated a temporal intraparenchymal hemorrhage and CT venogram diagnosed a cerebral sinus thrombosis on the left transverse and sigmoid sinus. The patient underwent surgical evacuation of the hematoma and was treated with anticoagulation 48 h after surgery. Pancytopenia alerted of a possible hematological disorder. The patient was subsequently diagnosed with AMPL and treated with arsenic trioxide. The patient had a complete neurological recovery with no postoperative complications. Conclusion: The management of cerebral sinus thrombosis in patients with AMPL remains controversial. The previous reported cases of cerebral sinus thrombosis preceding the diagnosis of AMPL are reviewed and treatment of cerebral sinus thrombosis with anticoagulation in the setting of intraparenchymal hemorrhage and bleeding disorders is also discussed.