Rates of cerebrospinal fluid leak and pseudomeningocele formation after posterior fossa craniotomy versus craniectomy: A systematic review and meta-analysis.

Background: Postoperative cerebrospinal fluid (CSF) leak is a major concern after posterior fossa surgery with significant clinical implications. It has been postulated that replacing the bone flap, performing a craniotomy, would reinforce the surgical closure and decrease rates of CSF leak. This systematic review and meta-analysis compared the rate of CSF leak after posterior fossa craniotomies versus craniectomies. Methods: Three databases were searched for English studies comparing the primary outcome, rate of CSF leak, after adult posterior fossa craniotomies versus craniectomies. Secondary outcomes included the rate of postoperative pseudomeningocele formation, CSF leak and pseudomeningocele formation, CSF diversion, revision surgery, and infection. Pooled estimates and relative risks for dichotomous outcomes were calculated using Review Manager 5.4, with corresponding 95% confidence intervals (CIs). Results: A total of 1250 patients (635 craniotomies and 615 craniectomies), from nine studies, were included in the final analysis. Even though rates of CSF leak favored craniotomies, the difference did not reach statistical significance in our pooled analysis (Risk Ratio: 0.71, 95% Confidence Interval: 0.45-1.14, p-value = 0.15, Heterogeneity I-squared = 0%). On the other hand, comparing the rates of pseudomeningocele formation and CSF leak, as a combined outcome, or pseudomeningocele formation only showed a significant difference favoring craniotomies. The quality of evidence in this meta-analysis was graded as having a high risk of bias based on the risk of bias in non-randomized studies - of exposure criteria. Conclusion: Based on evidence with high risk of bias, rates of postoperative CSF leak and pseudomeningocele formation favored posterior fossa craniotomies over craniectomies. Further research with more robust methodology is required to validate these findings.

Genomic targets of HOP2 are enriched for features found at recombination hotspots.

HOP2 is a conserved protein that plays a positive role in homologous chromosome pairing and a separable role in preventing illegitimate connections between nonhomologous chromosome regions during meiosis. We employed ChIP-seq to discover that Arabidopsis HOP2 binds along the length of all chromosomes, except for centromeric and nucleolar organizer regions, and no binding sites were detected in the organelle genomes. A large number of reads were assigned to the HOP2 locus itself, yet TAIL-PCR and SNP analysis of the aligned sequences indicate that many of these reads originate from the transforming T-DNA, supporting the role of HOP2 in preventing nonhomologous exchanges. The 292 ChIP-seq peaks are largely found in promoter regions and downstream from genes, paralleling the distribution of recombination hotspots, and motif analysis revealed that there are several conserved sequences that are also enriched at crossover sites. We conducted coimmunoprecipitation of HOP2 followed by LC-MS/MS and found enrichment for several proteins, including some histone variants and modifications that are also known to be associated with recombination hotspots. We propose that HOP2 may be directed to chromatin motifs near double strand breaks, where homology checks are proposed to occur.

Computed Tomography Angiography Compared with Computed Tomography Perfusion in the Diagnosis of Cerebral Vasospasm: A Systematic Review and Meta-Analysis.

INTRODUCTION: Cerebral vasospasm (CV) is a serious complication after subarachnoid hemorrhage; however, swift identification can be challenging. Computed tomography perfusion (CTP) directly measures tissue perfusion and may better screen for CV compared with other modalities. This systematic review summarizes studies assessing the diagnostic performance of computed tomography angiography (CTA) and CTP in identifying CV. METHODS: The search strategy drew from English language publications in the PubMed, Embase, Medline, and Cochrane databases from January 1996 to September 2021. Diagnosis of CV by digital subtraction angiography was the reference standard. Pooled sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), positive likelihood ratios, negative likelihood ratios, and summary receiver operating characteristic curve were calculated. The methodological index for nonrandomized studies tool was employed to assess the quality of the studies. RESULTS: The search generated 22 studies. Seven CTA studies and 6 CTP investigations provided sufficient data for meta-analysis. Following pooled estimates, CTA carried a sensitivity of 0.76 (95% confidence interval [CI], 0.72-0.80), specificity of 0.93 (95% CI, 0.92-0.95), PPV of 0.77 (95%, 0.76-0.79), and NPV of 0.81 (95%, 0.79-0.82). CTP carried a sensitivity of 0.86 (95%, 0.81-0.92), specificity of 0.97 (95%, 0.95-0.98), PPV of 0.94 (0.89-0.98), and NPV of 0.94 (0.91-0.97). Using the methodological index for nonrandomized studies tool, the evidence was rated as overall moderate quality. CONCLUSIONS: This meta-analysis on the diagnostic performance of CTA and CTP in identifying CV suggests that CTP may carry greater diagnostic accuracy compared with CTA. The clinical significance of this difference should be delineated through future prospective studies.

Frame-based versus frameless stereotactic brain biopsies: A systematic review and meta-analysis.

BACKGROUND: Stereotactic brain biopsy techniques have been a focus of rapid technological innovation. The recent advent of frameless stereotaxy has invited the question of whether it can provide the same diagnostic yield as frame-based techniques, without increasing risk of harm to patients. The goal of this meta-analysis was to compare each of these techniques in terms of yield and safety. METHODS: We independently searched four databases for English studies comparing frameless and frame-based stereotactic brain biopsies. Our primary outcome was biopsy diagnostic yield. Our secondary outcomes included mortality, morbidity (e.g., symptomatic postbiopsy intracranial hemorrhage, asymptomatic postbiopsy intracranial hemorrhage, new postbiopsy neurological deficit, and postbiopsy seizure), and frequency of repeat biopsy. We calculated pooled estimates and relative risks for dichotomous outcomes using Review Manager 5.3, with corresponding 95% confidence intervals. RESULTS: A total of 3256 stereotactic brain biopsies (2050 frame based and 1206 frameless), from 20 studies, were included in our final analysis. The results did not demonstrate any significant difference between the two stereotactic systems in terms of diagnostic yield (risk ratio [RR] 1.00, 95% confidence interval [CI] 0.99-1.02, P = 0.64, I2 = 0%). The only significant difference was the increased frequency of asymptomatic hemorrhages in the frameless group (RR 1.37, 95% CI 1.06-1.75, P = 0.01, I2 = 0%). Application of Grading of Recommendations Assessment, Development, and Evaluation to the results yielded very low quality of all outcomes. CONCLUSION: Based on very low-quality evidence, both frame-based and frameless stereotaxy are safe and effective for biopsy of intracranial tumors. Further study of patient preference and cost comparing analysis is required to identify if either modality should be preferred.

Assessment of Frailty in Predicting Surgical Outcomes in Patients with Chronic Subdural Hematomas: Retrospective Chart Review.

BACKGROUND: The aim of this study is to determine if frailty, defined as modified frailty index (MFI) >2.7, correlated with worse postoperative outcomes in patients with chronic subdural hematomas (CSDHs). We also compare the predictive ability of the MFI with another widely used frailty measure, the Clinical Frailty Scale (CFS). METHODS: We conducted a retrospective chart review of elderly patients (≥65 years) who underwent a twist-drill craniostomy for the evacuation of CSDH at Hamilton General Hospital, Canada, between 2016 and 2018. The primary outcome was the modified Rankin Scale scores at discharge. Logistic regression analyses and receiver operating characteristic curves were carried out to further analyze the factors that influenced independence and functional improvement at discharge. RESULTS: Frail patients were significantly more dependent at discharge (P < 0.0001) and had a lower rate of functional improvement (P = 0.003). When compared with frailty measured by the MFI, frailty as measured by the CFS had a stronger association with functional independence (odds ratio [OR]: 0.081 [0.031, 0.211] vs. OR: 0.256 [0.124, 0.529]) and functional improvement (OR: 0.272 [0.106, 0.693] vs. OR: 0.406 [0.185,0.889]) on logistic regression analyses. Area under the receiver operating characteristic curve analyses showed that the inclusion of frailty into our predictive models improved accuracy. CONCLUSIONS: Elderly patients presenting with CSDH who are frail (MFI >0.27) have significantly worse functional outcomes following twist-drill craniostomies. Therefore assessing frailty in this population is important before managing these patients, and for this purpose the CFS is a superior predictor of postoperative function than the MFI.

Hemorrhagic giant cerebral capillary telangiectasia resulting in death: Case report and literature review.

We report a rare case of death caused by hemorrhage of a giant cerebral central nervous system capillary telangiectasia (CCT). A 49-year-old female presented comatose after suffering a traumatic head injury due to an unwitnessed fall. Computed tomography of the head revealed an acute 8.1 × 5.2 cm right intraparenchymal hematoma. Postmortem pathology found thin-walled dilated capillaries consistent with a giant cerebral CCT. The radiological complexity and rarity of giant CCTs result in these malformations often going undiagnosed. We review other cases of giant intracranial CCTs reported in the English literature and confirm that this is the first case of a hemorrhagic giant cerebral CCT causing death. This report emphasizes the existence and complications of giant CCTs and stresses the importance of their investigation to ensure patients receive optimal treatment and follow-up.