Brian Snelling

Predictors of Long-Term Survival in Patients With Glioblastoma Multiforme: Advancements From the Last Quarter Century

Over the last quarter century there has been significant progress toward identifying certain characteristics and patterns in GBM patients to predict survival times and outcomes. We sought to identify clinical predictors of survival in GBM patients from the past 24 years. We examined patient survival related to tumor locations, surgical treatment, postoperative course, radiotherapy, chemotherapy, patient age, GBM recurrence, imaging characteristics, serum, and molecular markers. We present predictors that may increase, decrease, or play no significant role in determining a GBM patients long-term survival or affect the quality of life.

The role of magnetic resonance-guided laser ablation in neurooncology

Abstract Introduction. The use of magnetic resonance-guided laser-induced thermal therapy (MR-LITT) as a minimally invasive method of treating intra-cranial pathology is a rapidly growing field. The use of MR-LITT in neurooncology has shown promising results; however, there has been no review to date of the current literature. Methods. A review of the published literature regarding MR-LITT in neurooncology was performed. Studies on PubMed were included if at least one patient with a cerebral tumour or radiation necrosis was treated using quantitative MR thermography-guided LITT, as well as if either safety or outcomes were discussed. Results. In treating recurrent Grade-III and -IV gliomas, we found improved median overall survival of 20.9 months from diagnosis of recurrence, which is comparable with that of 18.9 months for high-dose-rate brachytherapy and 24.4 months for repeated open surgery. Median progression-free survival (PFS) of recurrent glioma is noted to be 4.5 months. For metastatic lesions, we found a median overall survival (OS) to vary between 9.0 and 19.8 months with a PFS between 3.8 and 8.5 months. Current literature reports median OS in similar patients to lie between 7.0 and 28.6 months. Severe complication rates (with permanent deficits) are found to be between 12 and 16.7%, comparable with 11% found in literature for open surgery. Conclusions. The current literature shows that MR-LITT is safe and shows promising local tumour control rates. Larger randomised studies are warranted to further investigate this adjuvant therapy in the treatment of recurrent high-grade gliomas and metastases.

Bilateral cerebral infarction in the setting of pituitary apoplexy: a case presentation and literature review

BackgroundPituitary tumor apoplexy (PTA) is a potentially fatal condition caused by hemorrhage and rapid expansion of a pituitary tumor. One rare consequence of PTA is occlusion of the intracavernous carotid arteries, very rarely leading to cerebral infarction.PurposeTo describe a case of PTA leading to bilateral cerebral infarction and provide an extensive literature review of all previously reported cases of PTA leading to cerebral infarction. We discuss how these cases contribute to our understanding of the management of PTA, and we also discuss the differences between cases associated with the reported mechanism of carotid occlusion (compression vs. vasospasm).Case presentationA 56-year-old previously healthy woman complained of severe headache and visual loss one day after sustaining a fall from standing. Computed tomography demonstrated an enlarged sellar and suprasellar mass displacing both cavernous ICAs laterally, with multiple bilateral hypodense areas in the ICA distribution consistent with infarction. She clinically deteriorated and underwent endoscopic transsphenoidal gross total resection for suspected PTA within 48 hours after falling. Her prognosis remained poor after 5 days, and support was withdrawn.ConclusionTwenty-four cases of PTA leading to cerebral infarction have been previously documented—four bilateral, our case being the fifth. Based on our review, the presence of infarction itself does not seem to warrant surgical management in the absence of previously established indications for surgery (such as a deteriorating visual field), despite a 3–5 times mortality increase. No conclusion regarding the role of the mechanism of occlusion can be made at this time.

Posterior communicating and vertebral artery configuration and outcome in endovascular treatment of acute basilar artery occlusion

Background We aimed to evaluate if vertebrobasilar anatomic variations impact reperfusion and outcome in intra-arterial therapy (IAT) for basilar artery occlusion (BAO). Methods Consecutive BAO patients with symptom onset <24 h treated with IAT were included. Vertebral artery (VA) V3 and posterior communicating artery (PCoA) diameters were measured (CT angiography or MR angiography). The presence of PCoA atresia, VA hypoplasia, VAs that end in the posterior inferior cerebellar artery (PICA), and extracranial VA occlusion was recorded. Results 38 BAO patients were included. Mean age was 63±15 years; 52% were men. Baseline National Institutes of Health Stroke Scale score was 21±9, and mean/median time from symptom onset to IAT were 10/7 h. First generation thrombectomy devices were mostly used. Overall Treatment in Cerebral Ischemia 2b-3 reperfusion was 68.4%. Good outcome (modified Rankin Scale score ≤2) was observed in 17.8% and mortality in 64.3% of cases at 90 days. 55% of patients had an atretic PCoA while 47% had a hypoplastic VA. The mean sum of the bilateral PCoA and VA diameters were 2.3±1.2 and 5.2±5.2 mm, respectively. VAs that end in the PICA was noted in 23% of patients, and extracranial VA occlusion in 42%. BAO was proximal/mid/distal in 36%/29%/34%. Multivariate linear regression analysis indicated hypertensive disease (β=2.97; 95% CI 1.15 to 4.79; p<0.01) and reperfusion rate (β=−0.40; 95% CI −0.74 to −0.70; p=0.02) independently associated with outcome. Multivariate analysis for predictors of reperfusion failed to identify other associations. A trend for better reperfusion with stent retrievers was noted (β=1.82; 95% CI −0.24 to 3.88; p=0.08). Conclusions Reperfusion emerged as a predictor of good outcome in patients that underwent IAT for BAO. Angioarchitectural variations of the posterior circulation were not found to impact reperfusion or clinical outcome.

Delayed ischemic stroke following spontaneous thrombosis of an arteriovenous malformation

Spontaneous obliteration of an arteriovenous malformation (SOAVM) is a rare event that is not completely understood. Less than 100 cases of SOAVMs have been reported in the literature. We present a unique case of a middle-aged patient with spontaneous obliteration of a cerebral arteriovenous malformation (AVM) who developed an ischemic stroke due to thrombosis of the stagnant proximal segment of the inferior branch of the middle cerebral artery feeder. Although the pathophysiology is not well understood, the arterial feeder hemodynamic changes post SOAVM may behave similarly to what occurs in rare cases after surgical resection of AVMs. Our case raises the hypothesis that stagnation of flow in spontaneous AVM obliteration may lead to delayed ischemic stroke in the territory of the feeding artery.

Transradial access: lessons learned from cardiology

Innovations in interventional cardiology historically predate those in neuro-intervention. As such, studying trends in interventional cardiology can be useful in exploring avenues to optimise neuro-interventional techniques. One such cardiology innovation has been the steady conversion of arterial puncture sites from transfemoral access (TFA) to transradial access (TRA), a paradigm shift supported by safety benefits for patients. While neuro-intervention has unique anatomical challenges, the access itself is identical. As such, examining the extensive cardiology literature on the radial approach has the potential to offer valuable lessons for the neuro-interventionalist audience who may be unfamiliar with this body of work. Therefore, we present here a report, particularly for neuro-interventionalists, regarding the best practices for TRA by reviewing the relevant cardiology literature. We focused our review on the data most relevant to our audience, namely that surrounding the access itself. By reviewing the cardiology literature on metrics such as safety profiles, cost and patient satisfaction differences between TFA and TRA, as well as examining the technical nuances of the procedure and post-procedural care, we hope to give physicians treating complex cerebrovascular disease a broader data-driven understanding of TRA.

Role of follow-up imaging after resection of brain arteriovenous malformations in pediatric patients: a systematic review of the literature.

OBJECTIVE Pediatric patients are at risk for the recurrence of brain arteriovenous malformation (AVM) after resection. While there is general consensus on the importance of follow-up after surgical removal of an AVM, there is a lack of consistency in the duration of that follow-up. The object of this systematic review was to examine the role of follow-up imaging in detecting AVM recurrence early and preventing AVM rupture. METHODS This systematic review was performed using articles obtained through a search of the literature contained in the MeSH database, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS Search results revealed 1052 articles, 13 of which described 31 cases of AVM recurrence meeting the criteria for inclusion in this study. Detection of AVM occurred significantly earlier (mean ± SD, 3.56 ± 3.67 years) in patients with follow-up imaging than in those without (mean 8.86 ± 5.61 years; p = 0.0169). While 13.34% of patients who underwent follow-up imaging presented with rupture of a recurrent AVM, 57.14% of those without follow-up imaging presented with a ruptured recurrence (p = 0.0377). CONCLUSIONS Follow-up imaging has an integral role after AVM resection and is sometimes not performed for a sufficient period, leading to delayed detection of recurrence and an increased likelihood of a ruptured recurrent AVM.

The Use of MR Perfusion Imaging in the Evaluation of Tumor Progression in Gliomas

Objective Diagnosing tumor progression and pseudoprogression remains challenging for many clinicians. Accurate recognition of these findings remains paramount given necessity of prompt treatment. However, no consensus has been reached on the optimal technique to discriminate tumor progression. We sought to investigate the role of magnetic resonance perfusion (MRP) to evaluate tumor progression in glioma patients. Methods An institutional retrospective review of glioma patients undergoing MRP with concurrent clinical follow up visit was performed. MRP was evaluated in its ability to predict tumor progression, defined clinically or radiographically, at concurrent clinical visit and at follow up visit. The data was then analyzed based on glioma grade and subtype. Resusts A total of 337 scans and associated clinical visits were reviewed from 64 patients. Sensitivity, specificity, positive and negative predictive value were reported for each tumor subtype and grade. The sensitivity and specificity for high-grade glioma were 60.8% and 87.8% respectively, compared to low-grade glioma which were 85.7% and 89.0% respectively. The value of MRP to assess future tumor progression within 90 days was 46.9% (sensitivity) and 85.0% (specificity). Conclusion Based on our retrospective review, we concluded that adjunct imaging modalities such as MRP are necessary to help diagnose clinical disease progression. However, there is no clear role for stand-alone surveillance MRP imaging in glioma patients especially to predict future tumor progression. It is best used as an adjunctive measure in patients in whom progression is suspected either clinically or radiographically.

Role of heparin during endovascular therapy for acute ischemic stroke

OBJECTIVES Systemic heparinization has become the mainstay anticoagulant in neurointerventional procedures to prevent thromboembolic complications. Its benefit during endovascular therapy for acute stroke however has not been established. The purpose of this study is to retrospectively evaluate the impact of heparin during endovascular therapy for acute ischemic stroke (AIS). PATIENTS AND METHODS We performed a retrospective review of our interventional stroke database from February 2009 to September 2012 for patients with anterior circulation AIS with ICA-T or MCA M1 occlusions. 76 patients were categorized into 2 groups: intraprocedural vs. no intraprocedural heparin use. Outcomes measured included reperfusion (modified TICI scale), cerebral hemorrhages (ECASS criteria), and 90-day outcomes (modified Rankin scale). RESULTS Baseline characteristics were similar between heparin and non-heparin treated patients, except for presence of CAD (6% vs. 30%, p=0.01), Coumadin (0% vs. 11%, p=0.04), and NIHSS (15.6±5.0 vs. 18.1±4.6, p=0.03). There was a nonsignificantly higher reperfusion rate achieved in heparin-treated patients compared to non heparin-treated patients (63% vs. 50%, p=0.35). Patients who received heparin had significantly lower rates of hemorrhage (p=0.02). Multivariate logistic regression for good outcome revealed only age (OR 0.86; 95% CI 0.78-0.95; p<0.01), ASPECTS (OR 2.14; 95% CI 1.01-4.50; p=0.04), and successful reperfusion (OR 19.25; 95% CI 2.37-155.95; p<0.01) independently associated with mRS 0-2 at 90 days. CONCLUSION The use of intraprocedural heparin in patients with AIS from MCA M1 or ICA-T occlusion was found safe. The impact of heparinization is unclear and warrants further evaluation.

Transradial cerebral angiography: techniques and outcomes

Background Despite several retrospective studies analyzing the safety and efficacy of transradial access (TRA) versus transfemoral access (TFA) for cerebral angiography, this transition for neurointerventional procedures has been gradual. Nonetheless, based on our positive initial institutional experience with TRA for mechanical thrombectomy in acute ischemic stroke patients, we have started transitioning more of our cerebral angiography cases to TRA. Here we present our single institution experience. Methods We performed a retrospective review of patients receiving TRA cerebral angiography at our institution between January 2016 and February 2017. We present our experience transitioning from TFA to TRA, including our criteria for patient selection, technical nuances, patient experience, complications, and operator learning curve. Results We included 148 angiograms performed in 141 people by one of four operators. No major complications were observed, and the technical success of the procedures was consistent with those of TFA. Marked improvement in operator efficiency was achieved in a short number of cases during this transition when looking at operator proficiency as a function of angiograms performed and days of exposure to TRA (4.3 vs 3.6 min/vessel, P<0.05). Conclusions Safety and efficiency can be preserved while transitioning to TRA. While further investigation is necessary to support transition to TRA, these findings should call for a re-evaluation of the role of TRA in catheter cerebral angiography.