Kaisorn L. Chaichana

Minimally Invasive Resection of Deep-seated High-grade Gliomas Using Tubular Retractors and Exoscopic Visualization

Abstract Background and Study Aims/Objective Deep‐seated high‐grade gliomas (HGGs) represent a unique surgical challenge because they reside deep to critical cortical and subcortical structures and infiltrate functional areas of the brain. Therefore, accessing and resecting these tumors can often be challenging and associated with significant morbidity. We describe the use of minimally invasive approaches to access deep‐seated HGGs to achieve extensive resections while minimizing surgical morbidity. Materials and Methods All patients who underwent resection of a deep‐seated intraparenchymal HGG with the use of a tubular retractor with exoscopic visualization from January 2016 to May 2017 were identified prospectively at a single institution. Variables evaluated included tumor location, pre‐ and postoperative neurologic function, extent of resection, and length of hospital stay. Results Overall, 14 patients underwent resection of an HGG (11 glioblastomas, 3 anaplastic astrocytomas) with a tubular retractor under exoscopic visualization. Seven tumors (50%) involved the thalamus, three (21%) the motor corticospinal tract, two (14%) the inferior frontal occipital fasciculus, one (7%) each the basal ganglia and optic pathway. The median preoperative Karnofsky Performance Score (KPS) was 70 (interquartile range: 55‐80), where the major presenting symptom was motor weakness in seven (50%). The average plus or minus the standard error of the mean percentage resection was 97.0 ± 1.2%. The median hospital stay was 4 days (range: 2‐7). At 1 month postoperatively, median postoperative KPS (within 30 days) was 87 (range: 77‐90), where eight (57%) were improved, five (36%) were stable, and one (7%) was worse postoperatively. Conclusions Deep‐seated HGGs can be accessed, visualized, and resected using tubular retractors and exoscopic visualization with minimal morbidity.

The Radiographic Effects of Surgical Approach and Use of Retractors on the Brain After Anterior Cranial Fossa Meningioma Resection

OBJECTIVEnThere is an increasing trend toward skull base (SB) approaches and retractorless surgery to minimize brain manipulation during surgery. We evaluated the radiographic changes over time after surgical resection of anterior cranial fossa meningiomas with and without both SB approaches and/or fixed retractor systems.nnnMETHODSnAll adults undergoing primary resection of an anterior cranial fossa World Health Organization grade I meningioma through a craniotomy at a single academic tertiary-care institution from 2010 to 2015 were retrospectively reviewed. Magnetic resonance imaging scans were reviewed and contrast-enhanced tumor and fluid-attenuated inversion recovery (FLAIR) volumes were measured. Matched-pair analyses between patients who underwent SB and non-SB approaches, as well as retractorless and retractor-assisted (RA) surgery, were made.nnnRESULTSnOf the 136 total patients, 20 (15%), 12 (9%), 46 (34%), and 58 (43%) underwent SB/retractorless, SB/RA, non-SB/retractorless, and non-SB/RA surgery, respectively. Patients who underwent non-SB and RA surgery each independently had longer times to FLAIR resolution than those who underwent SB (20.9 vs. 5 months; Pxa0= 0.04) and retractorless (12 vs. 5.2 months; Pxa0= 0.02) surgery, respectively. Patients who underwent both non-SB and RA surgery had the longest median time to FLAIR resolution (30xa0months vs. 4 months in SB/retractorless, 3.6 months in SB/RA, and 3 months in non-SB/retractorless; P < 0.05).nnnCONCLUSIONSnThe use of SB approaches in combination with retractorless surgery may decrease the duration needed for FLAIR resolution after surgery. The results from this study therefore advocate SB approaches and retractorless surgery along the anterior SB when possible.

Minimally Invasive Resection of Intra-axial Posterior Fossa Tumors Using Tubular Retractors

OBJECTIVEnPosterior fossa tumor surgery is associated with a significant risk of complications, and the complications are typically more frequent compared with similar supratentorial surgeries. This study aimed to evaluate 1) the extent of resection and neurologic outcomes and 2) perioperative complications with use of minimally invasive approaches for intra-axial posterior fossa tumors from our case series.nnnMETHODSnAll consecutive patients who underwent nonbiopsy surgery of a posterior fossa tumor using tubular retractors and exoscopic visualization from January 2016 to May 2018 were prospectively identified and included.nnnRESULTSnDuring the reviewed period, 15 patients underwent resection of an intra-axial posterior fossa tumor. Eight (53%) patients were men, and the median age was 63.0 years (interquartile range: 45.0-67.5 years). The tumor was located in the cerebellar hemisphere in 11 (73%) cases, vermis in 3 (20%) cases, and middle cerebellar peduncle in 1 (7%) case. The median preoperative and postoperative lesion volumes were 21.6 cm3 (interquartile range: 10.1-33.0 cm3) and 0 cm3 (interquartile range: 0-1.2 cm3), respectively. The percent resection was 100% (92%-100%). Following surgery, 12 (80%) patients had improved and 3 (20%) patients had stable Karnofsky performance scale scores, whereas no patients had a decline in Karnofsky performance scale score postoperatively. No patients incurred other postoperative regional or medical complications.nnnCONCLUSIONSnWe demonstrated the possible efficacy of a minimally invasive approach with the use of tubular retractors and exoscopic visualization for resecting posterior fossa intra-axial tumors with relatively high efficacy and low morbidity.

Angel Wing Pneumocephalus Sign Following Transsphenoidal Surgery

After transsphenoidal resection of papillary craniopharyngioma 2 weeks prior, a 47-year-old man developed postoperative cerebrospinal fluid leak and rhinorrhea for 2 days before presentation. The patient was noted to be aggressively sniffing his nose to counteract nasal cerebrospinal fluid leakage. Following a large sniff, the patient seized and became stuporous. Computed tomography (CT) of the head (Figure 1) demonstrated the intracranial Angel Wing Sign of intraventricular pneumocephalus. The patient received normobaric hyperoxia with 100% non-rebreather, followed by intraoperative closure of the surgical leak site. Pneumocephalus requires both medical and surgical management to prevent potentially fatal intracranial hypertension, mass effect, and bacterial meningitis. The Mt Fuji sign was previously described for cranial wounds that suck air typically through a lateral skull wound into the intracranial vault with external brain compression creating a “peak” or summit appearance to the brain (Figure 2). The Angel Wing Sign was previously described on chest radiography in pediatric population due to tension pneumomediastinum, but not in intracranial imaging. We, therefore, introduce the intracranial Angel Wing Sign, which has a distinct intraventricular pneumocephalus pattern due to entrainment after transsphenoidal surgery with intraventricular dilatation and pressure of surrounding brain tissue intrinsically, requiring medical and Figure 1. Angel Wing Sign of intraventricular pneumocephalus. Figure 2. Different patient with right frontal craniotomy and tension pneumocephalus causing Mt Fuji “peak,” or compressed brain appearance versus left brain with more normal appearance.

Risk of Developing Postoperative Deficits Based on Tumor Location after Surgical Resection of an Intracranial Meningioma

Object Meningiomas occur in various intracranial locations. Each location is associated with a unique set of surgical nuances and risk profiles. The incidence and risk factors that predispose patients to certain deficits based on tumor locations are unclear. This study aimed to determine which preoperative factors increase the risk of patients having new deficits after surgery based on tumor location for patients undergoing intracranial meningioma surgery. Methods Adult patients who underwent primary, nonbiopsy resection of a meningioma at a tertiary care institution between 2007 and 2015 were retrospectively reviewed. Stepwise multivariate logistic regression analyses were used to identify associations with postoperative deficits based on tumor location. Results Postoperatively, from the 761 included patients, there were 39 motor deficits (5.1%), 23 vision deficits (3.0%), 19 language deficits (2.5%), 27 seizures (3.5%), and 26 cognitive deficits (3.4%). The factors independently associated with any postoperative deficits were preoperative radiation (hazard ratio [HR] [95% confidence interval, CI] 3.000 [1.346‐6.338], p = 0.008), cerebellopontine angle tumors (HR [95% CI] 2.126 [1.094‐3.947], p = 0.03), Simpson grade 4 resections (HR [95% CI] 2.000 [1.271‐3.127], p = 0.003), preoperative motor deficits (HR [95% CI] 1.738 [1.005‐2.923], p = 0.048), preoperative cognitive deficits (HR [95% CI] 2.033 [1.144‐3.504], p = 0.02), and perioperative pulmonary embolisms (HR [95% CI] 11.741 [2.803‐59.314], p = 0.0009). Conclusion Consideration of the factors associated with postoperative deficits in this study may help guide treatment strategies for patients with meningiomas.

Primary histiocytic sarcoma of the central nervous system: a case report with platelet derived growth factor receptor mutation and PD-L1/PD-L2 expression and literature review

BackgroundHistiocytic sarcoma (HS) is an aggressive malignant neoplasm. HS in the central nervous system is exceptionally rare and associated with a poor prognosis. This report documents a case of primary HS of the central nervous system with treatment including surgery, radiotherapy, and chemotherapy.Case presentationOur patient was a 47xa0year old female presenting with progressive ataxia, headaches, imbalance, nausea, vomiting, and diplopia. MRI showed a heterogeneously enhancing lesion approximately 2.9u2009×u20093.0u2009×u20092.3xa0cm centered upon the cerebellar vermis with mild surrounding vasogenic edema and abnormal enhancement of multiple cranial nerves. The patient underwent surgical debulking, which revealed histiocytic sarcoma with grossly purulent drainage. Staging revealed diffuse leptomeningeal involvement, primarily involving the brain and lower thoracic and lumbar spine. She underwent adjuvant radiotherapy to the brain and lower spine and was started on high dose methotrexate. However, she experienced progressive disease in the cervical and thoracic spine as well as pulmonary involvement. Genomic sequencing of her tumor showed a mutation in the platelet-derived growth factor receptor A (p.V0681) which could be targeted with Dasatinib. However, she did not tolerate Dasatinib and she succumbed to progressive disseminated disease eight months from original diagnosis. Our pathologic evaluation also revealed expression of PD-L1 and PD-L2 by tumor cells raising the potential therapeutic role for immune checkpoint inhibition.ConclusionsThis case provides an example of effective CNS control with resection and moderate doses of radiation therapy. A review of the literature confirms aggressive multidisciplinary treatment is the most effective treatment against this disease. In addition, genomic sequencing may play an important role in determining new therapeutic options. However, CNS histiocytic sarcoma remains an aggressive disease with a propensity for early widespread dissemination and few long term survivors.

The reliability of YouTube videos in patients education for Glioblastoma Treatment

BACKGROUNDnGlioblastomas (GBMs) are one of the most devastating primary tumors in humans and often results in minimal survival rates. Over the past 2 decades, patients have accessed the internet to obtain information related to their diagnoses. In this study, we aimed to evaluate the accuracy and the reliability of GBM-related YouTube videos.nnnMETHODSnIn June of 2017, a search was conducted on YouTube using 6 keywords. Videos were sorted using Relevance-Based Ranking option, and the first 3 pages for each search were selected for further analysis. Three independent reviewers evaluated the videos using the validated DISCERN Tool.nnnRESULTSnAfter sorting 23,100 videos, 9 videos were identified and included for analysis. Of the 9 videos analyzed, 88% (8/9) were from hospitals affiliated with prestigious universities across the country. Of the nine videos included in the analysis, two (22%) scored above a 3. There was an average 55% overlap in the videos analyzed by key term and the keyword search of Malignant Glioma Treatment had the highest percentage of videos above a score of 3 (66%).nnnCONCLUSIONnMany patients with GBM and their families access information on YouTube to familiarize themselves with the epidemiology, survival, and treatment options for this form of tumor. However, the information that is currently available online is not monitored or vetted using an official filtering process prior to its release. Medical institutions must work to produce more peer-reviewed content in order to improve the availability of credible health information on internet platforms.

Postoperative Cavity Stereotactic Radiosurgery for Brain Metastases

During the past decade, tumor bed stereotactic radiosurgery (SRS) after surgical resection has been increasingly utilized in the management of brain metastases. SRS has risen as an alternative to adjuvant whole brain radiation therapy (WBRT), which has been shown in several studies to be associated with increased neurotoxicity. Multiple recent articles have shown favorable local control rates compared to those of WBRT. Specifically, improvements in local control can be achieved by adding a 2 mm margin around the resection cavity. Risk factors that have been established as increasing the risk of local recurrence after resection include: subtotal resection, larger treatment volume, lower margin dose, and a long delay between surgery and SRS (>3 weeks). Moreover, consensus among experts in the field have established the importance of (a) fusion of the pre-operative magnetic resonance imaging scan to aid in volume delineation (b) contouring the entire surgical tract and (c) expanding the target to include possible microscopic disease that may extend to meningeal or venous sinus territory. These strategies can minimize the risks of symptomatic radiation-induced injury and leptomeningeal dissemination after postoperative SRS. Emerging data has arisen suggesting that multifraction postoperative SRS, or alternatively, preoperative SRS could provide decreased rates of radiation necrosis and leptomeningeal disease. Future prospective randomized clinical trials comparing outcomes between these techniques are necessary in order to improve outcomes in these patients.

Extending the resection beyond the contrast-enhancement for glioblastoma: feasibility, efficacy, and outcomes

Abstract 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 pu2009<u20090.05 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 (pu2009>u20090.05). However, the postoperative CE tumour volume was significantly associated with both recurrence [HR (95%CI); 1.026 (1.005–1.048), pu2009=u20090.01] and survival [HR (95%CI); 1.027 (1.007–1.032), pu2009=u20090.001]. 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 survival for patients with GBM.

Volumetric tumor growth rates of meningiomas involving the intracranial venous sinuses

ObjectThere 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.MethodsAdult 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.ResultsOf 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 (r2u2009=u20090.93). 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], pu2009=u20090.008).ConclusionsThis 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.