Thien Nguyen

Restrictive transfusion threshold is safe in high-risk patients undergoing brain tumor surgery

OBJECTIVE To assess the safety of a restrictive threshold for the transfusion of red blood cells (RBCs) compared to a liberal threshold in high-risk patients undergoing brain tumor surgery. PATIENTS AND METHODS We reviewed patients who were 50 years of age or older with a preoperative American Society of Anesthesiologists physical status class II to V who underwent open craniotomy for tumor resection and were transfused packed RBCs during or after surgery. We retrospectively assigned patients to a restrictive-threshold (a pretransfusion hemoglobin level <8g/dL) or a liberal-threshold group (a pretransfusion hemoglobin level of 8-10/dL). The primary outcome was in-hospital mortality rate. Secondary outcomes were in-hospital complication rates, length of stay, and discharge disposition. RESULTS Twenty-five patients were included in the study, of which 17 were assigned to a restrictive-threshold group and 8 patients to a liberal-threshold group. The in-hospital mortality rates were 12% for the restrictive-threshold group (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.07-12.11) and 13% for the liberal-threshold group. The in-hospital complication rates were 52.9% for the restrictive-threshold group (OR 1.13, 95% CI 0.21-6.05) and 50% for the liberal-threshold group. The average number of days in the intensive care unit and hospital were 8.6 and 22.4 days in the restrictive-threshold group and 6 and 15 days in the liberal-threshold group, respectively (P=0.69 and P=0.20). The rates of non-routine discharge were 71% in the restrictive-threshold group (OR 2.40, 95% CI 0.42-13.60) and 50% in the liberal-threshold group. CONCLUSIONS A restrictive transfusion threshold did not significantly influence in-hospital mortality or complication rates, length of stay, or discharge disposition in patients at high operative risk.

Hypo-fractionated stereotactic radiotherapy of five fractions with linear accelerator for vestibular schwannomas: a systematic review and meta-analysis

Vestibular schwannomas (VS) are benign tumors stemming from the eighth cranial nerve. Treatment options for VS include conservative management, microsurgery, stereotactic radiosurgery, and fractionated radiotherapy. Though microsurgery has been the standard of care for larger lesions, hypo-fractionated stereotactic radiotherapy (hypo-FSRT) is an emerging modality. However, its clinical efficacy and safety have yet to be established. We conducted a systematic review and meta-analysis of manuscripts indexed in PubMed, Scopus, Web of Science, Embase, and Cochrane databases reporting outcomes of VS cases treated with hypo-FSRT. Five studies representing a total of 228 patients were identified. Across studies, the pooled rates of tumor control, hearing, facial nerve, and trigeminal nerve preservation were 95%, 37%, 97%, and 98%. No instances of malignant induction were observed at median follow-up of 34.8 months. Complications included trigeminal neuropathy (n = 3), maxillary paresthesia (n = 1), neuralgia (n = 1), vestibular dysfunction (n = 1), radionecrosis (n = 1), and hydrocephalus (n = 1). Hypo-FSRT may be another useful approach to manage VS, but studies with extended follow-up times are required to establish long-term safety.

Survival Outcomes After Intracranial Hemorrhage in Liver Disease

BACKGROUND Survival outcomes for patients with liver disease who suffer an intracranial hemorrhage (ICH) have not been thoroughly investigated. OBJECTIVE To understand survival outcomes for 3 groups: (1) patients with an admission diagnosis of liver disease (end-stage liver disease [ESLD] or non-ESLD) who developed an ICH in the hospital, (2) patients with ESLD who undergo either operative vs nonoperative management, and (3) patients with ESLD on the liver transplant waitlist who developed an ICH in the hospital. METHODS We retrospectively reviewed hospital charts from March 2006 through February 2017 of patients with liver disease and an ICH evaluated by the neurosurgery service at a single academic medical center. The primary outcome was survival. RESULTS We included a total of 53 patients in this study. The overall survival for patients with an admission diagnosis of liver disease who developed an ICH (n = 29, 55%) in the hospital was 22%. Of those patients with an admission diagnosis of liver disease, 27 patients also had ESLD. Kaplan-Meier analysis found no significant difference in survival for ESLD patients (n = 33, 62%) according to operative status. There were 11 ESLD patients on the liver transplant waitlist. The overall survival for patients with ESLD on the liver transplant waitlist who suffered an in-hospital ICH (n = 7, 13%) was 14%. CONCLUSION ICH in the setting of liver disease carries a grave prognosis. Also, a survival advantage for surgical hematoma evacuation in ESLD patients is not clear.

Neuroglial ectopia of the vestibular nerve masquerading as a vestibular schwannoma: A case report: Neuroglial ectopia of vestibular nerve

Neuroglial ectopia is a rare entity of undetermined clinical significance. Here, we report a unique case of neuroglial ectopia of the vestibular nerve. A 27‐year‐old pharmacy student with a previous radiological diagnosis of vestibular schwannoma presented to our clinic for surgical evaluation. Magnetic resonance imaging (MRI) of the brain revealed a 17‐mm T1 hypo‐ to isointense, T2 iso‐ to hyperintense, poorly enhancing left cerebellopontine angle mass extending into the left internal auditory canal compatible by imaging with a vestibular schwannoma. The lesion was resected under MRI guidance. The frozen specimen came back as a benign hypocellular lesion. Histological assessment revealed a peripheral nerve engulfed by glial fibrillary acidic protein‐positive, S‐100‐negative cells, suggestive of neuroglial ectopia. There was no evidence of schwannoma. The main concerns were benign neoplasm with potential for progression or sampling artifact. The patient had an uncomplicated hospital course. This case report demonstrates an unusual case of neuroglial ectopia of the vestibular nerve. The differential diagnoses for a poorly enhancing cerebellopontine angle mass should include neuroglial ectopia.

The Meningioma Vascularity Index: a volumetric analysis of flow voids to predict intraoperative blood loss in nonembolized meningiomas

OBJECTIVEMeningiomas that appear hypervascular on neuroimaging could be amenable to preoperative embolization. However, methods for measuring hypervascularity have not been described, nor has the benefit of preoperative embolization been adjudicated. The objective of this study was to show a relationship between flow void volume (measured on MRI) and intraoperative estimated blood loss (EBL) in nonembolized meningiomas.METHODSThe authors performed volumetric analyses of 51 intracranial meningiomas (21 preoperatively embolized) resected at their institution. Through the use of image segmentation software and a voxel-based segmentation method, flow void volumes were measured on T2-weighted MR images. This metric was named the Meningioma Vascularity Index (MVI). The primary outcomes were intraoperative EBL and perioperative blood transfusion.RESULTSIn the nonembolized group, the MVI correlated with intraoperative EBL when controlling for tumor volume (r = 0.55, p = 0.002). The MVI also correlated with perioperative blood transfusion (point-biserial correlation [rpb] = 0.57, p = 0.001). A greater MVI was associated with an increased risk of blood transfusion (odds ratio [OR] 5.79, 95% confidence interval [CI] 1.15-29.15) and subtotal resection (OR 7.64, 95% CI 1.74-33.58). In the embolized group, those relationships were not found. There were no significant differences in MVI, intraoperative EBL, or blood transfusion across groups.CONCLUSIONSThis study clearly shows a relationship between MVI and intraoperative EBL in nonembolized meningiomas when controlling for tumor volume. The MVI is a potential biomarker for tumors that would benefit from embolization.

Risk factors for platelet transfusion in glioblastoma surgery

The objectives of this study are to identify risk factors for and to evaluate clinical outcomes of platelet transfusion in glioblastoma surgery. The medical records of adult patients who underwent craniotomy for glioblastoma resection at a single academic medical center were retrospectively reviewed. We stratified patients into 2 groups: those who were transfused at least 1 unit of platelets intraoperatively or postoperatively (no more than 7 days after surgery), and those who were not transfused with platelets. Through the use of a 1:3 matched cohort analysis, we compared complications, length of stay, discharge disposition, and mortality, across groups. One hundred and five consecutive adult patients were included in this study. Thirteen patients (12.38%) received platelet transfusions. Prior antiplatelet therapy (odds ratio [OR] 8.21, 95% confidence interval [CI]: 2.36-28.58), preoperative platelet count less than 200,000 cells/µL (OR 8.46, 95% CI: 2.16-33.22), and longer operative times (OR 1.73, 95% CI: 1.10-2.72) were significant risk factors for platelet transfusion. There were no significant differences in the outcomes of interest in the matched cohort analysis.

Risk of Brain Tumor Induction from Pediatric Head CT Procedures: A Systematic Literature Review

Head computed tomography (CT) is instrumental for managing patients of all ages. However, its low dose radiation may pose a low but non-zero risk of tumor induction in pediatric patients. Here, we present a systematic literature review on the estimated incidence of brain tumor induction from head CT exams performed on children and adolescents. MEDLINE was searched using an electronic protocol and bibliographic searches to identify articles related to CT, cancer, and epidemiology or risk assessment. Sixteen studies that predicted or measured head CT-related neoplasm incidence or mortality were identified and reviewed. Epidemiological studies consistently cited increased tumor incidence in pediatric patients (ages 0–18) exposed to head CTs. Excess relative risk of new brain tumor averaged 1.29 (95% confidence interval, 0.66–1.93) for pediatric patients exposed to one or more head CTs. Tumor incidence increased with number of pediatric head CTs in a dose-dependent manner, with measurable excess incidence even after a single scan. Converging evidence from epidemiological studies supported a small excess risk of brain tumor incidence after even a single CT exam in pediatric patients. However, refined epidemiological methods are needed to control for confounding variables that may contribute to reverse causation, such as patients with pre-existing cancer or cancer susceptibility. CT remains an invaluable technology that should be utilized so long as there is clinical indication for the study and the radiation dose is as small as reasonably achievable.

Impact of Cochlear Dose on Hearing Preservation following Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy for the Treatment of Vestibular Schwannoma

Objective The objective of this study was to examine the effect of cochlear dose on hearing preservation in stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (fSRT) for vestibular schwannoma (VS). Design This is a retrospective case‐control study. Setting This study was completed at the Ronald Reagan UCLA Medical Center, a university‐affiliated tertiary care center. Participants Patients who underwent SRS (marginal dose of 12 Gy) or fSRT (marginal dose of 50.4 Gy) procedures for VS were included in the study. Main Outcome Measures The main outcome measure was hearing preservation. Audiometric data, when available, were used to determine the level of hearing according to the Gardner Robertson scale. Results A total of 38 patients (14 SRS and 24 fSRT) were analyzed. SRS patients with decreased hearing received a significantly higher minimum cochlear dose (7.41 vs. 4.24 Gy, p = 0.02) as compared with those with stable hearing. In fSRT patients, there were no significant differences in cochlear dose for patients with decreased hearing as compared with those with stable hearing. For SRS patients, who received a minimum cochlear dose above 6 Gy, there was a significant risk of decreased hearing preservation (odds ratio: 32, p = 0.02). Conclusion Higher minimum cochlear dose was predictive of decreased hearing preservation following SRS. Though the study is low powered, the radiation dose to the cochlea should be a parameter that is considered when planning SRS or fSRT therapies for patients with VS.

Insights into CCL21's roles in immunosurveillance and immunotherapy for gliomas

Chemokine (C-C) motif ligand 21 (CCL21) is involved in immunosurveillance and has recently garnered the attention of neuro-oncologists and neuroscientists. CCL21 contains an extended C-terminus, which increases binding to lymphatic glycosaminoglycans and provides a mechanism for cell trafficking by forming a stationary chemokine concentration gradient that allows cell migration via haptotaxis. CCL21 is expressed by endothelial cells of the blood-brain barrier in physiologic and pathologic conditions. CCL21 has also been implicated in leukocyte extravasation into the central nervous system. In this review, we summarize the role of CCL21 in immunosurveillance and explore its potential as an immunotherapeutic agent for the treatment of gliomas.

Genomic and Molecular Characterization of Brain Tumors in Asian and Non-Asian Patients of Los Angeles: A Single Institution Analysis

Background Worldwide, approximately 2% of new cancers are of the brain. Five-year survival rates among brain cancer patients have been reported as a little over a third. Differences in clinical outcomes between brain tumor patients of different races remain poorly understood. Methods A retrospective chart review was performed on brain tumor resection patients≥18 years old. Demographics, treatment variables, and survival outcomes were collected. Primary outcomes were length of stay, recurrence rate, progression-free survival (PFS), and overall survival (OS). Results A total of 452 patients were included in analysis. Females and males had nearly a 1:1 ratio (n=242 and n=220, respectively). Mean age was 54.8 years (SD: 14.5 range: 18–90). Females composed 69% (n=48) of Asian patients; males constituted 31% (n=22). Mean age of the Asian patients was 55.9 years (SD: 14.6 range: 26–89). Asian-only cohort tumor pathologies included glioblastoma (GBM) (n=14), high-grade glioma (n=7), low-grade glioma (n=4), meningioma (n=38), and metastases (n=7). Of the 185 meningioma patients, non-Asian patients comprised 79% of the group (n=146). Of the 65 GBM patients in total, non-Asian patients made up 89% of the GBM cohort (n=58). There were no statistically significant differences between these groups of both cohorts in recurrence (p=0.1580 and p=0.6294, respectively), PFS (p=0.9662 and p=0.4048, respectively), or OS (p=0.3711 and p=0.8183, respectively). Conclusion Studies evaluating the survival between patients of different racial backgrounds against several tumor varieties are rare. Patients of certain racial backgrounds may need additional consideration when being attended to despite the same mutational composition as their counterparts. Repeated studies using national databases may yield more conclusive results.