Middle meningeal artery embolization associated with reduced chronic subdural hematoma volume and midline shift in the acute postoperative period

BACKGROUND

Middle meningeal artery (MMA) embolization for endovascular treatment of chronic subdural hematoma (cSDH) is growing in popularity. cSDH volume and midline shift were analyzed in the immediate postoperative window after MMA embolization.

METHODS

A retrospective analysis of cSDHs managed via MMA embolization from January 1, 2018 to March 30, 2021 was performed at a large quaternary center. Pre- and postoperative cSDH volume and midline shift were quantified with CT. Postoperative CT was obtained 12 to 36 hours after embolization. Paired t-tests were used to determine significant reduction. Multivariate analysis was performed using logistic and linear regression for percent improvement from baseline volume.

RESULTS

In total, 80 patients underwent MMA embolization for 98 cSDHs during the study period. The mean (SD) initial cSDH volume was 66.54 (34.67) mL, and the mean midline shift was 3.79 (2.85) mm. There were significant reductions in mean cSDH volume (12.1 mL, 95% CI 9.32 to 14.27 mL, P<0.001) and midline shift (0.80 mm, 95% CI 0.24 to 1.36 mm, P<0.001). In the immediate postoperative period, 22% (14/65) of patients had a>30% reduction in cSDH volume. A multivariate analysis of 36 patients found that preoperative antiplatelet and anticoagulation use was significantly associated with an expansion in volume (OR 0.028, 95% CI 0.000 to 0.405, P=0.03).

CONCLUSION

MMA embolization is safe and effective for the management of cSDH and is associated with significant reductions in hematoma volume and midline shift in the immediate postoperative period.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Recurrent Glioblastoma and Radiation Necrosis: A Single-Surgeon Case Series

OBJECTIVE

To evaluate long-term clinical outcomes among patients treated with laser interstitial thermal therapy (LITT) for predicted recurrent glioblastoma (rGBM).

METHODS

Patients with rGBM treated by LITT by a single surgeon (2013-2020) were evaluated for progression-free survival (PFS), overall survival (OS), and OS after LITT.

RESULTS

Forty-nine patients (33 men, 16 women; mean [SD] age at diagnosis, 58.7 [12.5] years) were evaluated. Among patients with genetic data, 6 of 34 (18%) had IDH-1 R132 mutations, and 7 of 21 (33%) had MGMT methylation. Patients underwent LITT at a mean (SD) of 23.8 (23.8) months after original diagnosis. Twenty of 49 (40%) had previously undergone stereotactic radiosurgery, 37 (75%) had undergone intensity-modulated radiation therapy, and 49 (100%) had undergone chemotherapy. Patients had undergone a mean of 1.2 (0.7) previous resections before LITT. Mean preoperative enhancing and T2 FLAIR volumes were 13.1 (12.8) cm3 and 35.0 (32.8) cm3, respectively. Intraoperative biopsies confirmed rGBM in 31 patients (63%) and radiation necrosis in 18 patients (37%). Six perioperative complications occurred: 3 (6%) cases of worsening aphasia, 1 (2%) seizure, 1 (2%) epidural hematoma, and 1 (2%) intraparenchymal hemorrhage. For the rGBM group, median PFS was 2.0 (IQR, 4.0) months, median OS was 20.0 (IQR, 29.5) months, and median OS after LITT was 6.0 (IQR, 10.5) months. For the radiation necrosis group, median PFS was 4.0 (IQR, 4.5) months, median OS was 37.0 (IQR, 58.0) months, and median OS after LITT was 8.0 (IQR, 23.5) months.

CONCLUSIONS

In a diverse rGBM cohort, LITT was associated with a short duration of posttreatment PFS.

Outcomes in Patients with Aneurysmal Subarachnoid Hemorrhage Receiving Sulfonylureas: A Propensity-Adjusted Analysis

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with increased blood-brain barrier permeability, disrupted tight junctions, and increased cerebral edema. Sulfonylureas are associated with reduced tight-junction disturbance and edema and improved functional outcome in aSAH animal models, but human data are scant. We analyzed neurological outcomes in aSAH patients prescribed sulfonylureas for diabetes mellitus.

METHODS

Patients treated for aSAH at a single institution (August 1, 2007-July 31, 2019) were retrospectively reviewed. Patients with diabetes were grouped by presence or absence of sulfonylurea therapy at hospital admission. The primary outcome was favorable neurologic status at last follow-up (modified Rankin Scale score ≤2). Variables with an unadjusted P-value of <0.20 were included in a propensity-adjusted multivariable logistic regression analysis to identify predictors of favorable outcomes.

RESULTS

Of 1013 aSAH patients analyzed, 129 (13%) had diabetes at admission, and 16 of these (12%) were receiving sulfonylureas. Fewer diabetic than nondiabetic patients had favorable outcomes (40% [52/129] vs. 51% [453/884], P = 0.03). Among diabetic patients, sulfonylurea use (OR 3.90, 95% CI 1.05-15.9, P = 0.046), Charlson Comorbidity Index <4 (OR 3.66, 95% CI 1.24-12.1, P = 0.02), and absence of delayed cerebral infarction (OR 4.09, 95% CI 1.20-15.5, P = 0.03) were associated with favorable outcomes in the multivariable analysis.

CONCLUSIONS

Diabetes was strongly associated with unfavorable neurologic outcomes. An unfavorable outcome in this cohort was mitigated by sulfonylureas, supporting some preclinical evidence of a possible neuroprotective role for these medications in aSAH. These results warrant further study on dose, timing, and duration of administration in humans.

Indications for Fusion With Intradural Spine Tumor Resection in Adults: A Systematic Review and Meta-analysis

BACKGROUND

The evidence for instrumented fusion in the setting of degenerative, traumatic, or congenital deformity is well established. Data on fusion indications in intradural spinal tumors (IDST) are scarce and reduced to retrospective studies. The objective of this work is to systematically review the published literature since 2015 and analyze the change of practice patterns for stabilization and fusion after intradural tumor resection in adults.

METHODS

A systematic literature review was performed via PubMed with the terms: "intradural spinal tumors", "intramedullary spinal tumors", and "intraspinal tumors". The analysis was limited to adult patients with IDST and studies with more than 10 patients. Data on the proportion of patients who underwent instrumentation and had postoperative deformity was pooled in a meta-analysis.

RESULTS

A total of 1073 articles were identified and 47 papers were selected. All the studies were retrospective series and a total of 2473 patients were included. The follow-up ranged from 1 to 96 months, the pooled spinal fixation rate was 6% (95% CI 4.5%-7.6%), the pooled laminoplasty rate was 14.4% (95% CI 5.9%-23%), the pooled rate of postoperative deformity or malalignment in patients with a follow up of at least 6 months was 2.1% (95% CI 1.2%-3%) and just 7 patients were reoperated due to progressive deformity.

CONCLUSIONS

Based on existing evidence, the rate of fusion during resection of intradural spinal tumors is low. Prophylactic fixation is often unnecessary and only indicated in unique cases that require extensive bony resection.

Efficacy and Safety of Primary Stereotactic Radiosurgery in Patients With Intraventricular Meningiomas

Purpose

Primary stereotactic radiosurgery for intraventricular meningiomas remains controversial owing to the potential for life-threatening peritumoral edema and lack of long-term follow-up data. We review the literature and present the largest series to assess efficacy and safety of primary stereotactic radiosurgery.

Methods and Materials

A systematic review of the literature for primary stereotactic radiosurgery for intraventricular meningiomas was conducted. The retrospective series presented here comprised 33 patients who received primary stereotactic radiosurgery between 1999 and 2015 for a radiologically detected intraventricular meningioma. Demographic, diagnostic, and therapeutic data were extracted from medical records, imaging, and treatment-planning systems. Both standalone and pooled analysis were performed.

Results

The mean patient age was 53 years, and 24 patients (73%) were female. The median Karnofsky performance status pretreatment was 80 (range, 60-100). The majority of lesions were located in the lateral ventricles (n = 32; 97%). The mean tumor volume was 8.7 cm³ (range, 0.6-44.55 cm³). The mean delivered dose was 1390.9 cGy. Complete imaging follow-up data were available for 21 patients (64%). Of those, 14 (67%) showed partial or marginal response, 7 (33%) had stable disease, and no patient progressed per Response Assessment in Neuro-Oncology criteria. On last follow-up, 32 patients (97%) had significant improvement in performance status and a decrease in pretreatment symptoms. No high-grade Common Terminology Criteria for Adverse Events (version 5.0) toxicity was observed with the dose range employed.

Conclusions

Primary stereotactic radiosurgery for intraventricular meningiomas shows excellent treatment efficacy and low toxicity in patients with a long follow-up period. The best therapeutic algorithm remains to be established leveraging further clinical investigation.

Anorexia and the hippocampus: A case report

Eating disorders have been shown to be associated with epilepsy, typically associated with the temporal lobe and usually of non-dominant hemisphere origin. We report the case of a 56-year-old woman with drug resistant epilepsy, localized to the dominant left hippocampus. She experienced an increasing frequency of seizures over a two-year period associated with loss of appetite and substantial weight loss independent of antiseizure medication changes. Extensive workup eliminated gastrointestinal and paraneoplastic etiologies. There was no history of psychiatric illness, including anorexia nervosa. Pre-surgical workup showed mesial temporal sclerosis on MRI and video-EEG was consistent with ipsilateral medial temporal seizure onset. The patient underwent laser interstitial ablation of the left amygdala and hippocampus, which resulted in a cessation of seizures. Within 24 h of the laser ablation, her appetite returned to normal and, within 8 months she regained 26 lbs. To our knowledge, this is the first case report of a patient with dominant temporal lobe epilepsy with anorexia that was temporally associated with escalating seizure frequency and stopped with treatment and cessation of seizures, suggesting a causal and pathogenic relationship.

Antifibrinolytics use during surgery for oncological spine diseases: A systematic review

Background

Data exist of the benefits of antifibrinolytics such as tranexamic acid (TXA) in general spine surgery. However, there are limited data of its use in oncological spine patients.

Methods

A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Cochrane, OVID, and Embase databases were searched. Search terms: "tranexamic acid", "aprotinin," "aminocaproic acid," "spine surgery," "spine tumors," and "spine oncology." Included studies were full text publications written in English with patients treated with either agent or who had surgery for oncological spine disease (OSD).

Results

Seven hundred results were reviewed form the different databases, seven were selected. A total of 408 patients underwent spine surgery for OSD and received antifibrinolytics. There was a male predominance (55.2%) and mean age ranged from 43 to 62 years. The most common tumor operated was metastatic renal cancer, followed by breast and lung. Most studies administered TXA as a bolus followed by an infusion during surgery. Median blood loss was of 667 mL (253.3-1480 mL). Patients with TXA required 1-2 units less of transfusion and had 56-63 mL less of postoperative drainage versus no TXA. The median incidence of deep venous thrombosis (DVT) was 2.95% (0-7.9%) and for pulmonary embolism (PE) was 4.25% (0-14.3%). The use of TXA reduced intraoperative blood loss, transfusions and reduced postoperative surgical drainage output compared to no TXA use in patients with OSD.

Conclusion

In this review, we found that TXA may diminish intraoperative blood loss, the need for transfusion and postoperative drainage from surgical drains when used in OSD without major increase in rates of DVT or PE.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Management of Low-Grade Gliomas and Radiation Necrosis: A Single-Institution Case Series

BACKGROUND

Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for ablation of low-grade glioma (LGG) and radiation necrosis (RN).

OBJECTIVE

To evaluate the efficacy, safety, and survival outcomes of patients with radiographically presumed recurrent or newly diagnosed LGG and RN treated with LITT.

METHODS

The neuro-oncological database of a quaternary center was reviewed for all patients who underwent LITT for management of LGG between 1 January 2013 and 31 December 2020. Clinical data including demographics, lesion characteristics, and clinical and radiographic outcomes were collected. Kaplan-Meier analyses comprised overall survival (OS) and progression-free survival (PFS).

RESULTS

Nine patients (7 men, 2 women; mean [SD] age 50 [16] years) were included. Patients underwent LITT at a mean (SD) of 11.6 (8.5) years after diagnosis. Two (22%) patients had new lesions on radiographic imaging without prior treatment. In the other 7 patients, all (78%) had surgical resection, 6 (67%) had intensity-modulated radiation therapy and chemotherapy, respectively, and 4 (44%) had stereotactic radiosurgery. Two (22%) patients had lesions that were wild-type IDH1 status. Volumetric assessment of preoperative T1-weighted contrast-enhancing and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences yielded mean (SD) lesion volumes of 4.1 (6.5) cm³ and 26.7 (27.9) cm³, respectively. Three (33%) patients had evidence of radiographic progression after LITT. The pooled median (IQR) PFS for the cohort was 52 (56) months, median (IQR) OS after diagnosis was 183 (72) months, and median (IQR) OS after LITT was 52 (60) months. At the time of the study, 2 (22%) patients were deceased.

CONCLUSIONS

LITT is a safe and effective treatment option for management of LGG and RN, however, there may be increased risk of permanent complications with treatment of deep-seated subcortical lesions.

Do Multidisciplinary Spine Conferences Alter Management or Impact Outcome?

BACKGROUND

Multidisciplinary spine conferences (MSCs) are a strategy for discussing diagnostic and treatment aspects of patient care. Although they are becoming more common in hospitals, literature investigating how they impact patient care and outcomes is scarce. The aim of this study is to examine the impact of MSCs on surgical management and outcomes in elective spine surgical care.

METHODS

A systematic review of the literature was conducted to evaluate the impact of MSCs on patient management and outcomes. PubMed and Cochrane databases were searched using combinations and variations of search terms "Spine Conferences," "Multidisciplinary," and "Spine Team."

RESULTS

The literature search yielded 435 articles, of which 120 were selected for full-text review. Four articles (N = 529 patients) were included. Surgical plans were discussed in 211 patients. The decision was altered to conservative treatment in 70 patients (33.17%) and a different surgical strategy in 34 patients (16.11%). The differences were significant in 2 studies (P < 0.05). A 51% reduction in 30-day complications rates was observed when MSC was implemented in patients with adult complex scoliosis. Other spinal disorders showed a 30-day complication rate between 0% and 14% after MSC.

CONCLUSIONS

To our knowledge, this is the first systematic review of outcomes of MSCs in elective spine surgery and it confirms that MSCs impact management plan and outcomes. Consistent MSCs that include surgeons and nonsurgeons have the potential to enhance communication between specialists, standardize treatments, improve patient care, and encourage teamwork. More analysis is warranted to determine if patient outcomes are improved with these measures.

Multiple hippocampal transection for mesial temporal lobe epilepsy: A systematic review

PURPOSE

Multiple hippocampal transection (MHT) is a surgical technique that offers adequate seizure control with minimal perioperative morbidity. However, there is little evidence available to guide neurosurgeons in selecting this technique for use in appropriate patients. This systematic review analyzes patient-level data associated with MHT for intractable epilepsy, focusing on postoperative seizure control and memory outcomes.

METHODS

The systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant articles were identified from 3 databases (PubMed, Medline, Embase) up to August 1, 2021. Inclusion criteria were that the majority of patients had received a diagnosis of intractable epilepsy, the article was written in English, MHT was the primary procedure, and patient-level metadata were included.

RESULTS

Fifty-nine unique patients who underwent MHT were identified across 11 studies. Ten (17%) of 59 patients underwent MHT alone. Forty-three (75%) of 57 patients who had a follow-up 12 months or longer were seizure free at last follow-up. With respect to postoperative verbal memory retention, 9 of 38 (24%) patient test scores did not change, 14 (37%) decreased, and 16 (42%) increased. With respect to postoperative nonverbal memory retention, 12 of 38 (34%) patient test scores did not change, 13 (34%) decreased, and 13 (33%) increased.

CONCLUSION

There are few reported patients analyzed after MHT. Although the neurocognitive benefits of MHT are unproven, this relatively novel technique has shown promise in the management of seizures in patients with intractable epilepsy. However, structured trials assessing MHT in isolation are warranted.

No woman alone: Dorothy Russell's legacy to neurosurgery

Dorothy Russell's contributions to neuropathology are pivotal in the evolution of modern neurosurgery. In an era preferential to men in medicine, she entered the second medical school class to include women at the London Hospital Medical College in 1919. In the laboratory of Hubert Turnbull, she met Hugh Cairns, who would become her professional neurosurgeon-neuropathologist partner. In 1929, arriving at McGill's Royal Victoria Hospital in Montreal, where Wilder Penfield and William Cone had just begun a neurosurgical service, Russell elucidated the origin and activity of microglia. Returning to London, Russell continued to work closely with Cairns for many years. Along with J. O. W. Bland, she became the first to culture gliomas and meningiomas. Her work on the effects of and fatality rates associated with head injuries among soldiers during World War II led to the initiation of helmet requirements for motorcyclists. Her textbook, Pathology of the Tumours of the Nervous System, written with Lucien Rubinstein, is considered a landmark text in neurosurgery, neuropathology, and neurooncology. Honored by Penfield and Cone as their first neurosurgery research fellow, Russell was considered a favorite of the Montreal Neurological Institute. Dorothy Russell's extraordinary career elucidating the mysteries of neurosurgical pathology has made an enduring mark on neurosurgery.

Clinical Trials of Microsurgery for Cerebral Aneurysms: Past and Future

BACKGROUND

New findings and research regarding the microsurgical treatment of intracerebral aneurysms (IAs) continue to advance even in the era of endovascular therapies. Research in the past 2 decades has continued to revolve around the question of whether open surgery or endovascular treatment is preferable. The answer remains both complex and in flux.

OBJECTIVE

This review focuses on microsurgery, reflects on the research decisions of previous landmark studies, and proposes future study designs that may further our understanding of IAs and how best to treat them.

RESULTS

The future of IA research may include a combination of pragmatic trials, artificial intelligence integrated tools, and mining of large data sets, in addition to the publication of high-quality single-center studies.

CONCLUSIONS

The future will likely emphasize testing innovative techniques, looking at granular patient data, and considering every patient encounter as a potential source of knowledge, creating a system in which data are updated daily because each patient interaction contributes to answering important research questions.

Volumetric 3-Dimensional Analysis of the Supraorbital vs Pterional Approach to Paramedian Vascular Structures: Comprehensive Assessment of Surgical Maneuverability

BACKGROUND

Both the pterional and supraorbital approaches have been proposed as optimal access corridors to deep and paramedian anatomy.

OBJECTIVE

To assess key intracranial structures accessed through the surgical approaches using the angle of attack (AOA) and the volume of surgical freedom (VSF) methodologies.

METHODS

Ten pterional and 10 supraorbital craniotomies were completed. Data points were measured using a neuronavigation system. A comparative analysis of the craniocaudal AOA, mediolateral AOA, and VSF of the ipsilateral paraclinoid internal carotid artery (ICA), terminal ICA, and anterior communicating artery (ACoA) complex was completed.

RESULTS

For the paraclinoid ICA, the pterional approach produced larger craniocaudal AOA, mediolateral AOA, and VSF than the supraorbital approach (28.06° vs 10.52°, 33.76° vs 23.95°, and 68.73 vs 22.59 mm3 normalized unit [NU], respectively; P < .001). The terminal ICA showed similar superiority of the pterional approach in all quantitative parameters (27.43° vs 11.65°, 30.62° vs 25.31°, and 57.41 vs 17.36 mm3 NU; P < .05). For the ACoA, there were statistically significant differences between the results obtained using the pterional and supraorbital approaches (18.45° vs 10.11°, 29.68° vs 21.01°, and 26.81 vs 16.53 mm3 NU; P < .005).

CONCLUSION

The pterional craniotomy was significantly superior in all instrument maneuverability parameters for approaching the ipsilateral paraclinoid ICA, terminal ICA, and ACoA. This global evaluation of 2-dimensional and 3-dimensional surgical freedom and instrument maneuverability by amalgamating the craniocaudal AOA, mediolateral AOA, and VSF produces a comprehensive assessment while generating spatially and anatomically accurate corridor models that provide improved visual depiction for preoperative planning and surgical decision-making.

Needle Parking Interrupted Suturing Technique for Microvascular Anastomosis: A Technical Note

BACKGROUND

Interrupted and continuous suturing are 2 common techniques for microvascular anastomosis in cerebrovascular surgery. One of the technical complexities of interrupted suturing includes the risk of losing the needle in between interrupted sutures during knot tying, which may result in unnecessary movements and wasted time.

OBJECTIVE

To report a new needle parking technique for microvascular anastomosis that addresses a needle control problem during interrupted suturing.

METHODS

The needle parking technique involves puncturing both vessel walls at the site of the next provisional suture and leaving the needle parked in place while the knots at the first suture are being made. The thread is then cut, the needle is pulled through, and the process is repeated. Illustrative cases in which the needle parking technique was used are presented. We also compared time of anastomosis completion between the conventional interrupted, needle parking interrupted, and continuous suturing techniques during an in vitro study on standardized artificial vessels.

RESULTS

This technique is being used successfully by the senior author for various cerebrovascular bypass surgeries. The in vitro study demonstrated that the needle parking technique can be significantly faster than the conventional interrupted suturing technique and may be as fast as continuous suturing.

CONCLUSION

Needle parking technique is a modification of conventional interrupted suturing and solves the problem of losing the needle during knot tying. This technique is simple, prevents unnecessary movements, and may result in a faster anastomosis time.

Nancy Davis Reagan, First Lady with a Neurosurgical Legacy

Various well-known people associated with the history of the presidency of the United States have experienced neurologic disease or injury, especially trauma to the head or spine. Nancy Reagan, however, as the wife of President Ronald Reagan and First Lady, would leave a significant and lasting mark on the progress of neurosurgical science and education. Recognized for endeavors against drug abuse, Alzheimer disease, and polio, her interest in neurosurgical research is less well known. Nancy's father Loyal Davis was a remarkable neurosurgeon and educator of extraordinary influence. When Barrow Neurological Institute (BNI) founder John Green experienced complications after an illness, Davis served as BNI director during 1966 - 1967. After Davis's death in 1982, Robert Spetzler, who had been a student of Davis at Northwestern University Medical School and was then BNI director, convinced Green, despite his misgivings, to support a neurosurgical laboratory recognizing Davis. In 1988, Nancy Reagan, then First Lady, dedicated the Loyal and Edith Davis Neurosurgical Research Laboratory. At the dedication, she remarked on her years growing up in the home of a pioneering neurosurgeon and remarked that "my father believed deeply in the importance of research to develop new methods for treating patients." Green and Spetzler's unified efforts honored the extraordinary career of Davis in a manner he would have appreciated, were supported by a First Lady with deep involvement in politics and philanthropy dedicated to promoting advances in medicine, and are part of neurosurgery's unique heritage.

Spetzler-Martin Grade III Arteriovenous Malformations: A Comparison of Modified and Supplemented Spetzler-Martin Grading Systems

BACKGROUND

The modified Spetzler-Martin (SM) grading system proposes that grade III arteriovenous malformation (AVM) subtypes are associated with variable microsurgical risks, with small AVMs (III-) having lower risk and medium/eloquent AVMs (III+) having higher risk. Adding patient age and AVM bleeding status and compactness to the SM grade produces a score - the supplemented SM (Supp-SM) grade - to more accurately assess preoperative risk.

OBJECTIVE

To compare the predictive power of the modified SM and Supp-SM grades for risk assessment in patients with grade III AVMs.

METHODS

Patients with SM grade III AVMs treated between 2011 and 2018 were retrospectively reviewed. Good outcomes were defined as modified Rankin Scale (mRS) scores ≤ 2 or unchanged/improved mRS scores (pre- vs postsurgery).

RESULTS

Of 102 patients with SM grade III AVMs, 59% had grade III- and 24% had grade III+ AVMs. Supp SM grade 6 and grade 7 AVMs accounted for 44% and 24%, respectively. Overall, 33% of patients worsened but outcomes did not significantly differ by SM III subtype. Neurological outcomes were associated with Supp-SM grade, with proportions of patients with worsening increasing from 0% with Supp-SM grade 4 AVMs to 54% with Supp-SM grade 7 AVMs. Analyses of factors associated with neurological worsening identified age > 60 yr and Supp-SM grade 7 as significant.

CONCLUSION

Supp-SM grades were more predictive of microsurgical outcomes than modified SM grades for grade III AVMs, with a hard cutoff for acceptable surgical risk at Supp-SM grade 6. Supp-SM grading is a better decision-making tool than subtyping with the modified SM scale.

Delays in presentation and mortality among Black patients with mechanical thrombectomy after large-vessel stroke at a US hospital

OBJECTIVE

The incidence and severity of stroke are disproportionately greater among Black patients. In this study, the authors sought to examine clinical outcomes among Black versus White patients after mechanical thrombectomy for stroke at a single US institution.

METHODS

All patients who underwent mechanical thrombectomy at a single center from January 1, 2014, through March 31, 2020, were retrospectively analyzed. Patients were grouped based on race, and demographic characteristics, preexisting conditions, clinical presentation, treatment, and stroke outcomes were compared. The association of race with mortality was analyzed in multivariable logistic regression analysis adjusted for potential confounders.

RESULTS

In total, 401 patients (233 males) with a reported race of Black (n = 28) or White (n = 373) underwent mechanical thrombectomy during the study period. Tobacco use was more prevalent among Black patients (43% vs 24%, p = 0.04), but there were no significant differences between the groups with respect to insurance, coronary artery disease, diabetes, illicit drug use, hypertension, or hyperlipidemia. The mean time from stroke onset to hospital presentation was significantly greater among Black patients (604.6 vs 333.4 minutes) (p = 0.007). There were no differences in fluoroscopy time, procedural success (Thrombolysis in Cerebral Infarction grade 2b or 3), hospital length of stay, or prevalence of hemicraniectomy. In multivariable analysis, Black race was strongly associated with higher mortality (32.1% vs 14.5%, p = 0.01). The disparity in mortality rates resolved after adjusting for the average time from stroke onset to presentation (p = 0.14).

CONCLUSIONS

Black race was associated with an increased risk of death after mechanical thrombectomy for stroke. The increased risk may be associated with access-related factors, including delayed presentation to stroke centers.

Endovascular treatment of vertebral artery dissecting aneurysms : a 20-year institutional experience

BACKGROUND

The ideal treatment for unruptured vertebral artery dissecting aneurysms (VADAs) and ruptured dominant VADAs remains controversial. We report our experience in the management and endovascular treatment of patients with VADAs.

METHODS

Patients treated endovascularly for intradural VADAs at a single institution from January 1, 1999, to December 31, 2019, were retrospectively reviewed. Primary neurological outcomes were assessed using modified Rankin Scale (mRS) scores, with mRS >2 considered a poor neurological outcome. Additionally, any worsening (increase) in the mRS score from the preoperative neurological examination was considered a poor outcome.

RESULTS

Ninety-one patients of mean (SD) age 53 (11.6) years (48 (53%) men) underwent endovascular treatment for VADAs. Fifty-four patients (59%) presented with ruptured VADAs and 44 VADAs (48%) involved the dominant vertebral artery. Forty-seven patients (51%) were treated with vessel sacrifice of the parent artery, 29 (32%) with flow diversion devices (FDDs), and 15 (17%) with stent-assisted coil embolization (stent/coil). Rates of procedural complications and retreatment were significantly higher with stent/coil treatment (complications 4/15; retreatment 6/15) than with vessel sacrifice (complications 1/47; retreatment 2/47) or FDD (complications 2/29; retreatment 4/29) (p=0.008 and p=0.002, respectively). Of 37 patients with unruptured VADAs treated, only two (5%) had mRS scores >2 on follow-up.

CONCLUSION

Endovascular FDD treatment of VADAs appears to be associated with lower retreatment and complication rates than stenting/coiling, although further study is required for confirmation. Endovascular treatment of unruptured VADAs was safe and was associated with favorable angiographic and neurological outcomes.

Visualization of brain microvasculature and blood flow in vivo: Feasibility study using confocal laser endomicroscopy

OBJECTIVE

Qualitative and quantitative analyses of blood flow in normal and pathologic brain and spinal cord microvasculature were performed using confocal laser endomicroscopy (CLE).

METHODS

Blood flow in cortical, dural, and spinal cord microvasculature was assessed in vivo in swine. We assessed microvasculature under normal conditions and after vessel occlusion, brain injury due to cold or surgical trauma, and cardiac arrest. Tumor-associated microvasculature was assessed in vivo and ex vivo in 20 patients with gliomas.

RESULTS

We observed erythrocyte flow in vessels 5-500 µm in diameter. Thrombosis, flow arrest and redistribution, flow velocity changes, agglutination, and cells rolling were assessed in normal and injured brain tissue. Microvasculature in in vivo CLE images of gliomas was classified as normal in 68% and abnormal in 32% of vessels on the basis of morphological appearance. Dural lymphatic channels were discriminated from blood vessels. Microvasculature CLE imaging was possible for up to 30 minutes after a 1 mg/kg intravenous dose of fluorescein.

CONCLUSIONS

CLE imaging allows assessment of cerebral and tumor microvasculature and blood flow alterations with subcellular resolution intraoperative imaging demonstrating precise details of real-time cell movements. Research and clinical scenarios may benefit from this novel intraoperative in vivo microscopic fluorescence imaging modality.

Intraoperative Confocal Laser Endomicroscopy Ex Vivo Examination of Tissue Microstructure During Fluorescence-Guided Brain Tumor Surgery

Background

Noninvasive intraoperative optical biopsy that provides real-time imaging of histoarchitectural (cell resolution) features of brain tumors, especially at the margin of invasive tumors, would be of great value. To assess clinical-grade confocal laser endomicroscopy (CLE) and to prepare for its use intraoperatively in vivo, we performed an assessment of CLE ex vivo imaging in brain lesions.

Methods

Tissue samples from patients who underwent intracranial surgeries with fluorescein sodium (FNa)–based wide-field fluorescence guidance were acquired for immediate intraoperative ex vivo optical biopsies with CLE. Hematoxylin-eosin–stained frozen section analysis of the same specimens served as the gold standard for blinded neuropathology comparison. FNa 2 to 5 mg/kg was administered upon induction of anesthesia, and FNa 5 mg/kg was injected for CLE contrast improvement. Histologic features were identified, and the diagnostic accuracy of CLE was assessed.

Results

Of 77 eligible patients, 47 patients with 122 biopsies were enrolled, including 32 patients with gliomas and 15 patients with other intracranial lesions. The positive predictive value of CLE optical biopsies was 97% for all specimens and 98% for gliomas. The specificity of CLE was 90% for all specimens and 94% for gliomas. The second FNa injection in seven patients, a mean of 2.6 h after the first injection, improved image quality and increased the percentage of accurately diagnosed images from 67% to 93%. Diagnostic CLE features of lesional glioma biopsies and normal brain were identified. Seventeen histologic features were identified.

Conclusions

Results demonstrated high specificity and positive predictive value of ex vivo intraoperative CLE optical biopsies and justify an in vivo intraoperative trial. This new portable, noninvasive intraoperative imaging technique provides diagnostic features to discriminate lesional tissue with high specificity and is feasible for incorporation into the fluorescence-guided surgery workflow, particularly for patients with invasive brain tumors.

Double-Barrel Superficial Temporal Artery-M2 Middle Cerebral Artery Bypass and Creation of a Middle Communicating Artery via M2-M2 End-to-End Reimplantation for Trapping of a Dolichoectatic Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video

Large dolichoectatic aneurysms of middle cerebral artery (MCA) trifurcations are rare and often require trapping and revascularization of the region with a bypass.1-9 This video describes the treatment of an MCA trifurcation aneurysm by clip trapping and double-barrel superficial temporal artery (STA) to M2-MCA bypass followed by M2-M2 end-to-end reimplantation to create a middle communicating artery (MCoA). The patient, a 60-yr-old woman, presented with headache, a history of smoking, and a family history of ruptured aneurysms. Angiography demonstrated a 1.7-cm dolichoectatic aneurysm of the MCA trifurcation. While the natural history of these lesions is unclear, the aneurysm size and family history of aneurysmal subarachnoid hemorrhage were factors in proceeding with treatment. Informed written consent was obtained from the patient and her family.  The STA branches were harvested microsurgically, a pterional craniotomy was performed, and the aneurysm was exposed through a transsylvian approach. The two STA branches were anastomosed end-to-side to the middle and inferior trunks of the MCA. Due to the significant mismatch between the donor and recipient vessel calibers, we were concerned that the donors might provide insufficient flow in isolation. Therefore, we decided to transect both M2 trunks from the aneurysm, proximal to the inflow of the bypass, and reimplant them end-to-end. This reimplantation created an MCoA, allowing the two donor arteries to supply the new communication between the inferior and middle trunks, redistributing blood flow through the MCoA according to cerebral demand.  Bypass patency and aneurysm obliteration were confirmed on postoperative angiography. At the 6-mo follow-up, the patient's modified Rankin Scale (mRS) score was 0. The MCoA is a novel construct that, like natural communicating arteries, redistributes flow in response to shifting demand, without the need for additional ischemia time during the bypass. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Confocal Laser Endomicroscopy Assessment of Pituitary Tumor Microstructure: A Feasibility Study

This is the first study to assess confocal laser endomicroscopy (CLE) use within the transsphenoidal approach and show the feasibility of obtaining digital diagnostic biopsies of pituitary tumor tissue after intravenous fluorescein injection. We confirmed that the CLE probe reaches the tuberculum sellae through the transnasal transsphenoidal corridor in cadaveric heads. Next, we confirmed that CLE provides images with identifiable histological features of pituitary adenoma. Biopsies from nine patients who underwent pituitary adenoma surgery were imaged ex vivo at various times after fluorescein injection and were assessed by a blinded board-certified neuropathologist. With frozen sections used as the standard, pituitary adenoma was diagnosed as “definitively” for 13 and as “favoring” in 3 of 16 specimens. CLE digital biopsies were diagnostic for pituitary adenoma in 10 of 16 specimens. The reasons for nondiagnostic CLE images were biopsy acquisition <1 min or >10 min after fluorescein injection (n = 5) and blood artifacts (n = 1). In conclusion, fluorescein provided sufficient contrast for CLE at a dose of 2 mg/kg, optimally 1–10 min after injection. These results provide a basis for further in vivo studies using CLE in transsphenoidal surgery.

The astrocyte network in the ventral nerve cord neuropil of the Drosophila third-instar larva

Understanding neuronal function at the local and circuit level requires understanding astrocyte function. We have provided a detailed analysis of astrocyte morphology and territory in the Drosophila third-instar ventral nerve cord where there already exists considerable understanding of the neuronal network. Astrocyte shape varies more than previously reported; many have bilaterally symmetrical partners, many have a high percentage of their arborization in adjacent segments, and many have branches that follow structural features. Taken together, our data are consistent with, but not fully explained by, a model of a developmental growth process dominated by competitive or repulsive interactions between astrocytes. Our data suggest that the model should also include cell-autonomous aspects, as well as the use of structural features for growth. Variation in location of arborization territory for identified astrocytes was great enough that a standardized scheme of neuropil division among the six astrocytes that populate each hemi-segment is not possible at the third instar. The arborizations of the astrocytes can extend across neuronal functional domains. The ventral astrocyte in particular, whose territory can extend well into the proprioceptive region of the neuropil, has no obvious branching pattern that correlates with domains of particular sensory modalities, suggesting that the astrocyte would respond to neuronal activity in any of the sensory modalities, perhaps integrating across them. This study sets the stage for future studies that will generate a robust, functionally oriented connectome that includes both partners in neuronal circuits-the neurons and the glial cells, providing the foundation necessary for studies to elucidate neuron-glia interactions in this neuropil.

Current Trends for Improving Safety of Stereotactic Brain Biopsies: Advanced Optical Methods for Vessel Avoidance and Tumor Detection

Stereotactic brain needle biopsies are indicated for deep-seated or multiple brain lesions and for patients with poor prognosis in whom the risks of resection outweigh the potential outcome benefits. The main goal of such procedures is not to improve the resection extent but to safely acquire viable tissue representative of the lesion for further comprehensive histological, immunohistochemical, and molecular analyses. Herein, we review advanced optical techniques for improvement of safety and efficacy of stereotactic needle biopsy procedures. These technologies are aimed at three main areas of improvement: (1) avoidance of vessel injury, (2) guidance for biopsy acquisition of the viable diagnostic tissue, and (3) methods for rapid intraoperative assessment of stereotactic biopsy specimens. The recent technological developments in stereotactic biopsy probe design include the incorporation of fluorescence imaging, spectroscopy, and label-free imaging techniques. The future advancements of stereotactic biopsy procedures in neuro-oncology include the incorporation of optical probes for real-time vessel detection along and around the biopsy needle trajectory and in vivo confirmation of the diagnostic tumor tissue prior to sample acquisition.