Is Postoperative Radiotherapy Needed in the Management of Adult Craniopharyngiomas?

BACKGROUND: The optimal treatment of adult craniopharyngioma (CP) remains controversial. Although benign, these tumors tend to recur locally. The choice between gross total resection (GTR) versus subtotal resection (STR) with adjuvant or delayed radiotherapy (RT) is debated. The objective of this study is to review our experience with adult CPs over a 20-year period and identify an optimal management strategy. METHODS: From 1999 to 2020, we reviewed all patients diagnosed with CP at our institution. We collected data regarding tumor characteristics, treatments, and toxicity. Disease progression was defined as growth on imaging. Descriptive statistics were used to assess patient characteristics. The Kaplan Meier method was used to assess progression-free survival (PFS) and corresponding 95% confidence intervals (CI) from the time since treatment initiation. RESULTS: Twenty-four patients with a median age of 50 were included in this study. The median follow-up was 85 months. Seven patients had initial GTR, 10 STR, and 7 STR + RT. The overall 5-year PFS was 56% (95% CI: 38-83%): 100% in the STR + RT group, 69% in the GTR group, and 18% in the STR group (p = 0.01). Of the 17 patients initially treated with surgery alone, 3 with GTR and 6 with STR required salvage RT at a median of 46 months, with no further progression after salvage RT. CONCLUSIONS: Our study underscores the importance of RT for local control and suggests that STR + RT should be considered a viable option in the management of these tumors as it may be associated with improved PFS compared to surgery alone.

Aerosolization in Endoscopic Sinus Surgery and Risk Mitigation in the COVID-19 Era: A Scoping Review.

Objective The continually evolving coronavirus disease 2019 (COVID-19) pandemic has created a dire need for rapid reorganization of health care delivery within surgical services. Ensuing initial reports of high infection rates following endoscopic sinus and skull base surgery, various expert and societal guidelines have emerged. We hereby provide a scoping review of the available literature on endoscopic sinus and skull base surgery, exploring both the risk of aerosolization and expert recommendations on surgical management during the pandemic. Methods A literature search of the PubMed database was performed up until May 9th, 2020. Additionally, websites and published statements from otolaryngology associations were searched for recommendations. This scoping review followed the guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta Analyses Extension for Scoping Reviews. Results A total of 29 peer-reviewed publications and statements from expert recommendations or professional associations were included. Current expert guidance relies mainly on scarce, anecdotal evidence, and two cadaveric studies, which have demonstrated potential aerosolization during transnasal surgery. General consensus exists for delaying surgery when possible, ascertaining COVID-19 status preoperatively and donning of adequate personal protective equipment by all operating room staff (including at minimum an N95 mask). Cold, nonpowered surgical instruments are deemed the safest, while thermal instruments (electrocautery and laser) and high-speed drills should be minimized. Conflicting recommendations emerge for use of microdebriders. Conclusion Endoscopic sinus and skull base surgery impart a potential risk of aerosolization. Hence, surgical indications, protective measures for health care workers, and surgical instrumentation must be adapted accordingly in the COVID-19 context.

Preoperative Diagnosis of Suprasellar Hemangioblastoma with Four-Dimensional Computed Tomography Angiography: Case Report and Literature Review.

Purpose Our case report presents the first case of suprasellar hemangioblastoma diagnosed preoperatively with dynamic computed tomography angiography (four-dimensional [4D] CTA) in a patient without Von Hippel-Lindau (VHL) disease. We illustrate the imaging characteristics of these exceedingly rare tumors and discuss the role of 4D CTA in confirming this diagnosis and guiding surgical management. Finally, we present a literature review of imaging findings, differential diagnosis, management, and prognosis. Case A 39-year-old woman known for diabetes mellitus type II and dyslipidemia presented with headache, bitemporal hemianopsia, and mild hyperprolactinemia. Initial diagnosis of suprasellar meningioma separate from pituitary gland was revised to definitive diagnosis of suprasellar hemangioblastoma after 4D CTA. Conclusion Suprasellar hemangioblastomas are extremely rare, often associated to VHL disease. They present as enhancing as suprasellar mass with prominent intra- and peritumoral vascular flow-voids on magnetic resonance imaging. 4D CTA confirms their vascular nature, demonstrates characteristic rapid shunting with feeding arteries, and enlarged draining veins, and is important in guiding surgical management.

Brain Shift in Neuronavigation of Brain Tumors: An Updated Review of Intra-Operative Ultrasound Applications.

Neuronavigation using pre-operative imaging data for neurosurgical guidance is a ubiquitous tool for the planning and resection of oncologic brain disease. These systems are rendered unreliable when brain shift invalidates the patient-image registration. Our previous review in 2015, Brain shift in neuronavigation of brain tumours: A review offered a new taxonomy, classification system, and a historical perspective on the causes, measurement, and pre- and intra-operative compensation of this phenomenon. Here we present an updated review using the same taxonomy and framework, focused on the developments of intra-operative ultrasound-based brain shift research from 2015 to the present (2020). The review was performed using PubMed to identify articles since 2015 with the specific words and phrases: "Brain shift" AND "Ultrasound". Since 2015, the rate of publication of intra-operative ultrasound based articles in the context of brain shift has increased from 2-3 per year to 8-10 per year. This efficient and low-cost technology and increasing comfort among clinicians and researchers have allowed unique avenues of development. Since 2015, there has been a trend towards more mathematical advancements in the field which is often validated on publicly available datasets from early intra-operative ultrasound research, and may not give a just representation to the intra-operative imaging landscape in modern image-guided neurosurgery. Focus on vessel-based registration and virtual and augmented reality paradigms have seen traction, offering new perspectives to overcome some of the different pitfalls of ultrasound based technologies. Unfortunately, clinical adaptation and evaluation has not seen as significant of a publication boost. Brain shift continues to be a highly prevalent pitfall in maintaining accuracy throughout oncologic neurosurgical intervention and continues to be an area of active research. Intra-operative ultrasound continues to show promise as an effective, efficient, and low-cost solution for intra-operative accuracy management. A major drawback of the current research landscape is that mathematical tool validation based on retrospective data outpaces prospective clinical evaluations decreasing the strength of the evidence. The need for newer and more publicly available clinical datasets will be instrumental in more reliable validation of these methods that reflect the modern intra-operative imaging in these procedures.

Split-Pons Syndrome by Epidermoid Cyst: A Case Report and Review of the Literature.

BACKGROUND: Epidermoid cysts are slow-growing extra-axial lesions that account for approximately 1% of all brain tumors. They rarely occur in the brain stem, and those possessing both intra-axial as well as extra-axial components represent an even smaller subset. CASE DESCRIPTION: We report the unusual manifestation of 2 adult male patients, whose recurrent posterior fossa epidermoid cysts progressively invaded the anterior surface of the pons. Over the years, the patients would present with various complaints of ataxia, diplopia, facial spasms, and hearing loss and underwent several interventions for recurrence. Eventually, the epidermoid cysts progressed to completely split the pons, forming a surgical corridor that was amenable to a posterior approach. We describe the patients' favorable clinical courses, pathologic and neuroradiologic findings, as well as review the literature for similar such cases. CONCLUSIONS: To the best of our knowledge, there are only 8 other cases of brainstem epidermoid lesions reported in the literature that are presumed to have originated extrinsically and thereafter transgressed the pons. However, we are the first to provide radiographic documentation confirming the progression of the lesions from extra-axial to intraparenchymal. Furthermore, although clinically subtle, we have decided to coin the term "split-pons syndrome" to better define this radiologic entity. Based on the evolution of the epidermoid's growth pattern, the authors propose a delayed posterior approach (telo-velo-tonsillar) to minimize morbidity.

Growth of Pituitary Macroadenomas Postpartial Resection: Implications for Adjuvant Radiotherapy.

Objective To determine the volumetric growth in macroadenomas (MAs) patients with residual postoperative disease and to identify subpopulations with rapid postoperative growth rate that may benefit from early salvage radiotherapy (RT). Methods Patients who had undergone a partial resection for MAs and did not receive immediate postoperative RT were eligible. Residual tissue was contoured on serial magnetic resonance imaging and planimetric and volumetric changes in size were measured. Growth rates were established by a single observer using serial volumetric measurements. Data were analyzed to find a relationship among growth rate, adjuvant treatment, and patient and tumor characteristics. Results Thirty-one patients met the eligibility criteria. Nine patients (29%) required adjuvant treatment because of tumor growth. Volumetric growth was identified 95% of the time compared with 64% planimetrically. Planimetric growth could not be established in 10% of patients showing volumetric changes. Median growth rate was 0.4464 mL/y. Growth rate positively correlated with size of residual postoperative volume ( p < 0.001). Receiving salvage treatment positively correlated with growth rate ( p = 0.001), particularly at a rate above 2.19 mL/y ( p = 0.0064). Five patients (16%) had a growth rate above this level, all of which required salvage treatment. Patients with postoperative residual volume > 3.95 mL were most likely to experience rapid growth rate and require salvage treatment ( p = 0.007). Conclusion Volumetric measurement was found to be superior to planimetric measurement in detecting changes in patients with residual tumors. Patients with postoperative residual volume > 3.95 mL should be considered for early treatment with RT.

Intra-operative Video Characterization of Carotid Artery Pulsation Patterns in Case Series with Post-endarterectomy Hypertension and Hyperperfusion Syndrome.

Cerebral hyperperfusion syndrome (CHS) is a complication that can occur after carotid endarterectomy (CEA), the treatment of choice to decrease the subsequent risk of fatal or disabling stroke for patients with symptomatic severe stenosis of the carotid artery. Because of its rarity and complexity, the mechanism of the condition is still unclear, making its prevention via prediction and monitoring challenging. This is especially true during surgery, when multiple factors can induce physiological changes, including blood pressure and baroreceptor functions, which are crucial factors for post-CEA hypertension and CHS. Thus, with intra-operative videos taken by surgical microscopes, we employed a new video processing technique to magnify ordinarily invisible carotid artery pulsation patterns as rhythmic color fluctuations. We applied the technique for three CEA cases, two of which developed CHS with post-CEA hypertension. For those with CHS, abnormal pulsation patterns were detected at the site of the baroreceptors. The results suggested that intra-operative baroreceptor dysfunction can potentially be linked with post-operative hypertension, as well as the occurrence of CHS. Guided by the preliminary discovery, further investigation may help establish the introduced technique as a simple and contactless technique to help predict post-CEA hypertension and CHS in order to facilitate the management and understanding of the condition and improve the care of CEA.

Hemi-transseptal Approach for Pituitary Surgery: A Follow-Up Study.

Objectives The hemi-transseptal (Hemi-T) approach was developed to overcome the potential drawbacks of the nasoseptal flap (NSF) in endoscopic endonasal transsphenoidal skull base surgery. In this study, we describe further refinements on the Hemi-T approach, and report long-term outcomes as compared with traditional methods of skull base reconstruction. Design A retrospective case-control study. Setting Montreal Neurological Institute and Jewish General Hospital, Montreal, Canada. Participants Patients who underwent endoscopic endonasal transsphenoidal approach to skull base pathology. Main Outcome Measures Operative time, CSF rhinorrhea, and postoperative nasal morbidity. Results A total of 105 patients underwent the Hemi-T approach versus 40 controls. Operative time was shorter using the Hemi-T technique (180.51 ± 56.9 vs. 202.9 ± 62 minutes; p = 0.048). The rates of nasal morbidity (septal perforation [5/102 vs. 6/37; p = 0.029] and mucosal adhesion [11/102 vs. 10/39 p = 0.027]), fascia lata harvest (21/100 vs. 18/39; p = 0.0028), and postoperative CSF leak rates (7/100 vs. 9/38; p = 0.006) were lower in the Hemi-T group. Conclusion Advantages of the Hemi-T approach over traditional exposure techniques include preservation of the nasal vascular pedicle, shorter operative time, reduced fascia lata harvest rates, and decreased nasal morbidity.

IBIS: an OR ready open-source platform for image-guided neurosurgery.

PURPOSE: Navigation systems commonly used in neurosurgery suffer from two main drawbacks: (1) their accuracy degrades over the course of the operation and (2) they require the surgeon to mentally map images from the monitor to the patient. In this paper, we introduce the Intraoperative Brain Imaging System (IBIS), an open-source image-guided neurosurgery research platform that implements a novel workflow where navigation accuracy is improved using tracked intraoperative ultrasound (iUS) and the visualization of navigation information is facilitated through the use of augmented reality (AR). METHODS: The IBIS platform allows a surgeon to capture tracked iUS images and use them to automatically update preoperative patient models and plans through fast GPU-based reconstruction and registration methods. Navigation, resection and iUS-based brain shift correction can all be performed using an AR view. IBIS has an intuitive graphical user interface for the calibration of a US probe, a surgical pointer as well as video devices used for AR (e.g., a surgical microscope). RESULTS: The components of IBIS have been validated in the laboratory and evaluated in the operating room. Image-to-patient registration accuracy is on the order of [Formula: see text] and can be improved with iUS to a median target registration error of 2.54 mm. The accuracy of the US probe calibration is between 0.49 and 0.82 mm. The average reprojection error of the AR system is [Formula: see text]. The system has been used in the operating room for various types of surgery, including brain tumor resection, vascular neurosurgery, spine surgery and DBS electrode implantation. CONCLUSIONS: The IBIS platform is a validated system that allows researchers to quickly bring the results of their work into the operating room for evaluation. It is the first open-source navigation system to provide a complete solution for AR visualization.

Brain shift in neuronavigation of brain tumors: A review.

PURPOSE: Neuronavigation based on preoperative imaging data is a ubiquitous tool for image guidance in neurosurgery. However, it is rendered unreliable when brain shift invalidates the patient-to-image registration. Many investigators have tried to explain, quantify, and compensate for this phenomenon to allow extended use of neuronavigation systems for the duration of surgery. The purpose of this paper is to present an overview of the work that has been done investigating brain shift. METHODS: A review of the literature dealing with the explanation, quantification and compensation of brain shift is presented. The review is based on a systematic search using relevant keywords and phrases in PubMed. The review is organized based on a developed taxonomy that classifies brain shift as occurring due to physical, surgical or biological factors. RESULTS: This paper gives an overview of the work investigating, quantifying, and compensating for brain shift in neuronavigation while describing the successes, setbacks, and additional needs in the field. An analysis of the literature demonstrates a high variability in the methods used to quantify brain shift as well as a wide range in the measured magnitude of the brain shift, depending on the specifics of the intervention. The analysis indicates the need for additional research to be done in quantifying independent effects of brain shift in order for some of the state of the art compensation methods to become useful. CONCLUSION: This review allows for a thorough understanding of the work investigating brain shift and introduces the needs for future avenues of investigation of the phenomenon.

Decompressive Craniectomy for Ischemic Stroke: Effect of Hemorrhagic Transformation on Outcome.

BACKGROUND: Decompressive hemicraniectomy (DhC) is a life-saving surgical procedure being increasingly employed for malignant middle cerebral artery strokes. We examined the incidence of hemorrhagic transformation following DhC. METHODS: We retrospectively reviewed the charts and radiological images of patients who underwent DhC for malignant middle cerebral artery strokes. We classified the hemorrhagic events and assessed the short-term 30-day outcome associated with these events. RESULTS: A total of 23 DhCs were performed for supratentorial ischemic strokes in 22 patients. There were 16 males and 6 females with an average age of 47 years (21-69 years). Of the 22 patients, 13 (59%) developed a new hemorrhage following DhC. There were 3 mortalities (14%). Of the survivors, 6 (27%) were discharged home with a modified Rankin Scale (mRS) score of 2. The remaining 13 patients (59%) recovered to a degree wherein they were discharged to a rehabilitation center (mRS score 3-4). No patient persisted in a vegetative or semivegetative state (mRS score 5). CONCLUSIONS: In this study, the rate of hemorrhagic transformation following DhC for ischemic stroke was 59%. This is much higher than that reported in the stroke thrombolysis literature. The presence of any type of new hemorrhagic transformation in this patient population does not appear to alter the natural history of their ischemic strokes in terms of Glasgow outcome scores or destination of disposition.

A Simple Scoring System to Predict the Resectability of Skull Base Meningiomas via an Endoscopic Endonasal Approach.

OBJECTIVE: To identify clinico-radiologic factors associated with incomplete anterior cranial fossa (ACF) meningioma resection via an endoscopic endonasal approach. METHOD: Patients undergoing endoscopic endonasal resection of an ACF meningioma were retrospectively accrued from two university-affiliated centers. Demographic profiles and radiologic findings, including tumor dimensions and morphology, anatomic location, and vascular involvement, were stratified according to the extent of resection. RESULTS: Twenty-five patients were included in this study. Factors associated with incomplete surgical resection via an endonasal route were: presence of hyperostosis (P = 0.04), cavernous internal carotid artery involvement (P = 0.001), maximal dural tail length in the transverse plane (P = 0.006), and its ratio to the inter-fovea ethmoidalis distance (P = 0.01). Using a multiple regression analysis, only cavernous internal carotid artery involvement (P = 0.002) and a large dural tail length to inter-foveal distance ratio (P = 0.04) were significant predictors of incomplete resection (multiple correlation coefficient = 0.71). The combination of predictive factors to determine the likelihood of complete endoscopic resection produced a scoring system with a sensitivity and specificity of 85.7% (95% confidence interval [CI], 42.1-99.6] and 100% (95% CI, 81.5-100), respectively. CONCLUSION: The use of a simple scoring system outlined in our study can facilitate proper patient selection for endoscopic endonasal resection of ACF meningiomas.

Indicators of a Reduced Intercarotid Artery Distance in Patients Undergoing Endoscopic Transsphenoidal Surgery.

Objective To identify clinicopathologic factors associated with a reduced intercarotid distance (ICD) and subgroups at risk for internal carotid artery injury during transsphenoidal surgery. Design A retrospective case-control study. Setting This study was conducted at the McGill University Health Centre, a university-affiliated tertiary care center. Participants Patients with a sellar or parasellar tumor and nontumor controls were included in the study. Main Outcome Measures The smallest distance between the internal carotid arteries at the clival, cavernous, and paraclinoid segments on coronal magnetic resonance imaging was measured. Demographic profiles, cephalometric measurements, tumor dimensions, and sphenoid configuration were assessed as potential determinants of the ICD. Results A total of 212 cases and 34 controls were analyzed. Widening of the ICD at the three segments of the internal carotid arteries was found in patients with pituitary macroadenomas (p < 0.01). Patients with a growth hormone-secreting adenoma had a markedly reduced ICD at the clivus compared with controls (1.59 cm versus 1.77 cm; p = 0.02; 95% confidence interval [CI], 0.03-0.32). The paraclinoid ICD was reduced in patients with an anterior fossa meningioma (1.24 cm versus 1.33 cm; p = 0.04; 95% CI, 0.01-0.45). Conclusion Identifying clinicopathologic factors affecting the ICD can help surgeons recognize constraints to endoscopic access of the skull base and avoid inadvertent arterial injury.

Augmented reality in neurovascular surgery: feasibility and first uses in the operating room.

PURPOSE: The aim of this report is to present a prototype augmented reality (AR) intra-operative brain imaging system. We present our experience of using this new neuronavigation system in neurovascular surgery and discuss the feasibility of this technology for aneurysms, arteriovenous malformations (AVMs), and arteriovenous fistulae (AVFs). METHODS: We developed an augmented reality system that uses an external camera to capture the live view of the patient on the operating room table and to merge this view with pre-operative volume-rendered vessels. We have extensively tested the system in the laboratory and have used the system in four surgical cases: one aneurysm, two AVMs and one AVF case. RESULTS: The developed AR neuronavigation system allows for precise patient-to-image registration and calibration of the camera, resulting in a well-aligned augmented reality view. Initial results suggest that augmented reality is useful for tailoring craniotomies, localizing vessels of interest, and planning resection corridors. CONCLUSION: Augmented reality is a promising technology for neurovascular surgery. However, for more complex anomalies such as AVMs and AVFs, better visualization techniques that allow one to distinguish between arteries and veins and determine the absolute depth of a vessel of interest are needed.

The endoscopic hemi-transseptal approach to the sella turcica: operative technique and case-control study.

Background The hemi-transeptal (Hemi-T) approach was developed to facilitate a binasal two-surgeon endoscopic approach for sellar tumors, with preservation of the nasoseptal flap and selective mobilization for reconstruction. Methods A retrospective case-control study was performed comparing the Hemi-T approach with previously used methods of sellar exposure and reconstruction. Outcome measures included operative time and postoperative nasal morbidity. Results A total of 23 patients underwent the Hemi-T approach versus 42 in whom traditional exposure was performed. Operative time was significantly shorter using the Hemi-T technique (152.6 ± 56.8 versus 205.2 ± 61.3 minutes; p = 0.001), as was the length of hospital stay (3.3 ± 1.9 versus 5.4 ± 3.6 days; p = 0.004). There was no difference in the rates of intraoperative or postoperative cerebrospinal fluid leak, cartilage necrosis, septal perforation, or mucosal adhesions. Conclusion The Hemi-T approach facilitates binasal two-surgeon access to the sella without compromise of the pedicle during the extended sphenoidotomies and tumor removal. Operative time and nasal morbidity is not increased, and iatrogenic injury to the nasal cavity is minimized when a flap is not required.

Communicating hydrocephalus and vestibular schwannomas: etiology, treatment, and long-term follow-up.

Background Large vestibular schwannomas (VSs) can cause hydrocephalus by obstructing the fourth ventricle. Little is known about the communicating hydrocephalus that is seen with a smaller VS. Methods The clinicopathological findings and follow up of three patients with communicating hydrocephalus associated with a small VS are presented. Results Four patients aged 40 to 66 years (mean: 57.7) presented with ataxia, dementia, and urinary incontinence. The VS were 2.0 to 2.4 cm. The cerebrospinal fluid (CSF) protein was elevated in three patients in whom it was measured (1.7 to 6 times normal). The VS was resected in two patients. All of the patients required ventriculoperitoneal shunting (VPS). All of the patients were asymptomatic or improved at follow-up at 9 months to 13 years. Conclusion Communicating hydrocephalus associated with a VS can occur in younger patients than was previously thought. An elevated CSF protein appears to be important, but other factors may be involved. A shunting procedure is often required to relieve the symptoms of hydrocephalus even if the tumor is resected. Possible etiological causes of communicating hydrocephalus in patients with a small VS are discussed.

Comparison between manual and semiautomated volumetric measurements of pituitary adenomas.

Linear measurements have many limitations. The aim of this study is to compare manual and semiautomated volumetric measurements of pituitary adenomas. Magnetic resonance imaging (MRI) scans of 38 patients with pituitary adenomas were analyzed. Preoperative MRI was acquired on a 1.5 T. MRI volumes of the pituitary adenomas were obtained by two methods: manual (MA) and semiautomated (SA). The concurrent validity for SA and MA methods on 38 patients in the form of correlation coefficient was 0.97 (p < 0.0001). The intraobserver and the interobserver correlation coefficients for SA volumes were both 0.98, as for the intraobserver MA volumes were 0.98. Although the results of both methods are comparable, analysis of volumetric measurements by SA method is more time-efficient than MA segmentation. Precision in volumetric measurement techniques is likely to increase reliability of posttherapeutic monitoring of pituitary adenomas.

Paraclinoid aneurysm concealed by sphenoid wing meningioma.

The coexistence of brain tumours and aneurysms is rare. In all previously reported cases the aneurysm was detectable by angiography. We report here a case in which a paraclinoid internal carotid artery aneurysm was coexistent and concealed from angiographic detection by an adjacent parasellar meningioma.