Outcomes of Mechanical Thrombectomy for Patients With Stroke Presenting With Low Alberta Stroke Program Early Computed Tomography Score in Early and Late Time Windows

BACKGROUND AND OBJECTIVES

This study aimed to compare outcomes of low Alberta Stroke Program Early Computed Tomography Score (ASPECTS) patients with stroke who underwent mechanical thrombectomy (MT) within 6 hours or 6 to 24 hours after stroke onset.

METHODS

A retrospective cohort study was conducted using data from a large multicenter international registry from 2013 to 2023. Patients with low ASPECTS (2-5) who underwent MT for anterior circulation intracranial large vessel occlusion were included. A propensity matching analysis was conducted for patients presented in the early (<6 hours) vs late (6-24 hours) time window after symptom onset or last known normal.

RESULTS

Among the 10 229 patients who underwent MT, 274 met the inclusion criteria. 122 (44.5%) patients were treated in the late window. Early window patients were older (median age, 74 years [IQR, 63-80] vs 66.5 years [IQR, 54-77]; P < .001), had lower proportion of female patients (40.1% vs 54.1%; P = .029), higher median admission National Institutes of Health Stroke Scale score (20 [IQR, 16-24] vs 19 [IQR, 14-22]; P = .004), and a higher prevalence of atrial fibrillation (46.1% vs 27.3; P = .002). Propensity matching yielded a well-matched cohort of 84 patients in each group. Comparing the matched cohorts showed there was no significant difference in acceptable outcomes at 90 days between the 2 groups (odds ratio = 0.90 [95% CI = 0.47-1.71]; P = .70). However, the rate of symptomatic ICH was significantly higher in the early window group compared with the late window group (odds ratio = 2.44 [95% CI = 1.06-6.02]; P = .04).

CONCLUSION

Among patients with anterior circulation large vessel occlusion and low ASPECTS, MT seems to provide a similar benefit to functional outcome for patients presenting <6 hours or 6 to 24 hours after onset.

Comparative Outcomes of Mechanical Thrombectomy in Acute Ischemic Stroke Patients with ASPECTS 2-3 vs. 4-5

BACKGROUND

The influence of Alberta Stroke Program Early CT Score (ASPECTS) on outcomes following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) patients with low ASPECTS remains unknown. In this study, we compared the outcomes of AIS patients treated with MT for large vessel occlusion (LVO) categorized by ASPECTS value.

METHODS

We conducted a retrospective analysis involving 305 patients with AIS caused by LVO, defined as the occlusion of the internal carotid artery and/or the M1 segments of the middle cerebral artery, stratified into two groups: ASPECTS 2-3 and 4-5. The primary outcome was favorable outcome defined as a 90-day modified Rankin Scale (mRS) score of 0-3. Secondary outcomes were 90-day mRS 0-2, 90-day mortality, any intracerebral hemorrhage (ICH), and symptomatic ICH (sICH). We performed multivariable logistic regression analysis to evaluate the impact of ASPECTS 2-3 vs. 4-5 on outcomes.

RESULTS

Fifty-nine patients (19.3%) had ASPECTS 2-3 and 246 (80.7%) had ASPECTS 4-5. Favorable outcomes showed no significant difference between the two groups (adjusted odds ratio [aOR]= 1.13, 95% confidence interval [CI]: 0.52-2.41, p=0.80). There were also no significant differences in 90-day mRS 0-2 (aOR= 1.65, 95% CI: 0.66-3.99, p=0.30), 90-day mortality (aOR= 1.14, 95% CI: 0.58-2.20, p=0.70), any ICH (aOR= 0.54, 95% CI: 0.28-1.00, p=0.06), and sICH (aOR= 0.70, 95% CI: 0.27-1.63, p = 0.40) between the groups.

CONCLUSIONS

AIS patients with LVO undergoing MT with ASPECTS 2-3 had similar outcomes compared to ASPECTS 4-5.

Thrombectomy in Stroke Patients With Low Alberta Stroke Program Early Computed Tomography Score: Is Modified Thrombolysis in Cerebral Infarction (mTICI) 2c/3 Superior to mTICI 2b?

BACKGROUND AND PURPOSE

Outcomes following mechanical thrombectomy (MT) are strongly correlated with successful recanalization, traditionally defined as modified Thrombolysis in Cerebral Infarction (mTICI) ≥2b. This retrospective cohort study aimed to compare the outcomes of patients with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS; 2-5) who achieved mTICI 2b versus those who achieved mTICI 2c/3 after MT.

METHODS

This study utilized data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which combined databases from 32 thrombectomy-capable stroke centers between 2013 and 2023. The study included only patients with low ASPECTS who achieved mTICI 2b, 2c, or 3 after MT for internal carotid artery or middle cerebral artery (M1) stroke.

RESULTS

Of the 10,229 patients who underwent MT, 234 met the inclusion criteria. Of those, 98 (41.9%) achieved mTICI 2b, and 136 (58.1%) achieved mTICI 2c/3. There were no significant differences in baseline characteristics between the two groups. The 90-day favorable outcome (modified Rankin Scale score: 0-3) was significantly better in the mTICI 2c/3 group than in the mTICI 2b group (adjusted odds ratio 2.35; 95% confidence interval [CI] 1.18-4.81; P=0.02). Binomial logistic regression revealed that achieving mTICI 2c/3 was significantly associated with higher odds of a favorable 90-day outcome (odds ratio 2.14; 95% CI 1.07-4.41; P=0.04).

CONCLUSION

In patients with low ASPECTS, achieving an mTICI 2c/3 score after MT is associated with a more favorable 90-day outcome. These findings suggest that mTICI 2c/3 is a better target for MT than mTICI 2b in patients with low ASPECTS.

Predictors of Angiographic Outcome After Failed Thrombectomy for Large Vessel Occlusion: Insights from the Stroke Thrombectomy and Aneurysm Registry

BACKGROUND

Mechanical thrombectomy failure (MTF) occurs in approximately 15% of cases.

OBJECTIVE

To investigate factors that predict MTF.

METHODS

This was a retrospective review of prospectively collected data from the Stroke Thrombectomy and Aneurysm Registry. Patients who underwent mechanical thrombectomy (MT) for large vessel occlusion (LVO) were included. Patients were categorized by mechanical thrombectomy success (MTS) (≥mTICI 2b) or MTF (

RESULTS

A total of 6780 patients were included, and 1001 experienced anterior circulation MTF. Patients in the MTF group were older (73 vs 72, P = .044) and had higher poor premorbid modified Rankin Scale (mRS) (10.8% vs 8.4%, P = .017). Onset to puncture time was greater in the MTF group (273 vs 260 min, P = .08). No significant differences were found between the access site, use of balloon guide catheter, frontline technique, or first-pass devices between the MTF and MTS groups. More complications occurred in the MTF group (14% vs 5.8%), including symptomatic intracerebral hemorrhage (9.4% vs 6.1%) and craniectomies (10% vs 2.8%) ( P < .001). On UVA, age, poor pretreatment mRS, increased number of passes, and increased procedure time were associated with MTF. Internal carotid artery, M1, and M2 occlusions had decreased odds of MTF. Poor preprocedure mRS, number of passes, and procedure time remained significant on MVA. A subgroup analysis of posterior circulation LVO revealed that number of passes and total procedure time correlated with increased odds of MTF ( P < .001) while rescue stenting was associated with less odds of MTF (odds ratio 0.20, 95% CI 0.06-0.63). Number of passes remained significant on MVA of posterior circulation occlusion subgroup analysis.

CONCLUSION

Anterior circulation MTF is associated with more complications and worse outcomes. No differences were found between techniques or devises used for the first pass during MT. Rescue intracranial stenting may decrease the likelihood of MTF for posterior circulation MT.

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Key Words Collapse

MESH Headings

• Humans
• Stroke/surgery
• Thrombectomy/methods
• Cerebral Hemorrhage
• Retrospective Studies
• Aneurysm
• Registries
• Treatment Outcome
• Brain Ischemia/therapy

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Endovascular Treatment and Peri-interventional Management of Ruptured Cerebrovascular Lesions During Pregnancy : Case Series and Case-based Systematic Review

PURPOSE

Hemorrhagic stroke, particularly occurring from ruptured cerebrovascular malformations, is responsible for 5-12% of all maternal deaths during pregnancy and the puerperium. Whether endovascular treatment is feasible and safe for both the mother and the fetus, is still a matter of debate. The main objective of this case series and systematic review was to share our multi-institutional experience and to assess the feasibility and safety of endovascular treatment during pregnancy, as well as the corresponding maternal and fetal outcomes based on currently available evidence.

METHODS

We report a case series of 12 pregnant women presenting with hemorrhagic stroke from ruptured cerebrovascular arteriovenous malformations or aneurysms who underwent endovascular treatment prior to delivery. A systematic literature review of pregnant patients with endovascular treated cerebrovascular malformations, published between 1995 and 2022, was performed. Clinical patient information, detailed treatment strategies, maternal and fetal outcomes as well as information on the delivery were collected and assessed.

RESULTS

In most patients the course was uneventful and an excellent outcome without significant neurological deficits (mRS ≤ 1) was achieved. Furthermore, the maternal outcome was not worse compared to the general population who underwent endovascular treatment of ruptured vascular brain lesions. Also, in most cases a healthy fetus was born.

CONCLUSION

Endovascular treatment of ruptured cerebrovascular malformations during pregnancy is safe and feasible regarding both aspects, the maternal and fetal outcomes. Still, a stronger knowledge base is needed to correctly approach future cases of intracranial hemorrhage in the pregnant population.

Abstract HUP19: Sex Differences In Incidence Of Intraventricular Hemorrhage And Hydrocephalus In Patients With Non-traumatic Intracerebral Hemorrhage

Introduction: Non-traumatic Intracerebral Hemorrhage (ICH) accounts for 2 million strokes annually worldwide. This stroke burden disproportionately impacts minorities, and results in severe neurological deficits. Sex differences in brain structure and function, such as a larger mean length of frontal horn in males and increased global cerebral blood flow in women, can contribute to hematoma volume and expansion of ICH into nearby structures. No studies have yet to investigate sex differences in the incidence of Intraventricular Hemorrhage (IVH) and hydrocephalus as sequelae of ICH, both or which correlate with poor long-term outcomes.

Methods: A retrospective review of a comprehensive stroke center spontaneous ICH database from 2019-2022 was performed, including patient characteristics such as history of diabetes mellitus, hypertension, coronary artery disease, tobacco use, and anticoagulant use in addition to ICH characteristics such as hematoma location volume, expansion, incidence of IVH and hydrocephalus. A logistic regression model controlling for these covariates was built to investigate sex differences in incidence of IVH and hydrocephalus.

Results: This cohort had 100 patients with spontaneous, non-traumatic ICH, of which 39% were female. Overall, 52/100 (52%) patients had IVH and 21/100 (21%) patients developed hydrocephalus. Among males, 29/61(48%) had IVH as opposed to 23/39 (59%) in females, p = 0.264. There was similar development of hydrocephalus in both males 13/61(21%) and females 8/39 (21%). Logistic regression showed females had higher odds of IVH. Higher diastolic blood pressure and anticoagulant use on admission also had higher odds of IVH.

Conclusion: This pilot study demonstrates a trend towards higher incidence of IVH among females when controlling for history of diabetes mellitus, hypertension, coronary artery disease, tobacco use, and anticoagulant use. Higher odds of IVH in patients with higher diastolic blood pressure on admission adds to the previously investigated association between systolic blood pressure and ICH hematoma volume. Our sample validated the higher odds of IVH in patients with anticoagulant use on admission.

Abstract WP164: Acute Carotid Stenting Versus Conservative Management For Tandem Carotid Occlusions: Insights From STAR

Introduction: Management of anterior circulation emergent large vessel occlusion with tandem carotid occlusion (TCO) remains a challenge during mechanical thrombectomy (MT). To day, there is no consensus regarding emergent carotid stenting (ECS) in the setting of MT with TCO. We aimed to compare the outcomes of ECS versus conservative management (MT alone) among patients with TCO.

Methods: Data from the Stroke Thrombectomy and Aneurysm Registry between 2010 and 2022 was interrogated. Only patients with concomitant occlusions of cervical carotid and proximal ipsilateral intracranial segments of the ICA or MCA were included in the analyses. We compared baseline, procedural charecteristics, successful reperfusion (mTICI 2b-3), favorable 90-day good outcomes (mRS 0-2), intravenous tPA administration and symptomatic ICH between patients who did or did not undergo ECS. Multivariate regression was performed adjusting for variables of clinical importance. Propensity score matching for IV tPA use was performed to explore its safety with stenting.

Results: Among 9812 thrombectomy patients, 688 patients had TCO; 132 underwent emergent stenting and 444 had MT alone. Patients who did not undergo ECS had a higher prevalence of atrial fibrillation (33.9% Vs 9.2%, P<.001), higher admission NIHSS scores (18 Vs 14, P<.001), shorter time from symptom onset to puncture (275 minutes Vs 333 minutes, P=0.029), and were predominantly women (59.2% Vs 33.6%, P<0.001).Patients with stenting had lower mortality rates ( 17.5% Vs 29.6%, P=0.009), and higher rates of successful reperfusion (83% Vs 95%, P=0.001). No difference in mRS 0-2 (37.5% Vs 30.4%, P=0.178) or sICH were seen (11.1% Vs 15.4%, P=0.219). Propensity score matching analysis (n=129 in each group) demonstrated better rates of reperfusion (94.8 Vs 84.4%, P=0.011) in the stenting group. Advanced age, higher admission NIHSS and lower ASPECT scores were associated with worse clinical outcomes.

Conclusion: ECS during MT for TCO appears to be safe and is associated with better clinical and angiographic outcomes compared to conservative management.

Abstract TP154: Outcomes Of Acute Carotid Stenting With Or Without Intravenous Thrombolysis Among Patients With Acute Tandem Occlusion: Insights From STAR

Introduction: Emergency carotid artery stenting during mechanical thrombectomy has emerged as an effective emergent treatment for tandem carotid occlusions. Nevertheless, scarce evidence is available about the safety of this procedure in patients who received intravenous tPA before thrombectomy. Herein, we investigate the safety of acute carotid stenting among patients who received intravenous tPA in a large international multicenter registry.

Methods: Patients from the Stroke Thrombectomy and Aneurysm Registry between 2010 and 2022 were analyzed. Only patients with concomitant occlusions of cervical carotid and proximal ipsilateral intracranial segments of the internal carotid or middle cerebral artery were included in the final analyses. Patients were divided into two groups, depending on tPA administration. The primary outcome was 90-day good clinical outcome (mRS 0-2), and the primary safety outcome was symptomatic intracranial hemorrhage. Univariate and multivariate regressions were performed adjusting for variables of clinical importance.

Results: Among 9812 with acute ischemic stroke in the registry, 132 patients had acute tandem occlusion and underwent carotid stenting; of those, 60 patients received IV tPA. Compared to non-intravenous thrombolytics, patients with IV tPA had a higher male prevalence (78.3% Vs 54.4%, P=0.005) and better ASPECT scores (9 Vs 8, P=0.022) with a shorter time from onset to puncture (241 Vs 672 minutes, P<0.001). There was no difference in rates of successful revascularization (94% Vs 95.5%, P=NS), good clinical outcome (50.8% Vs 61.4%, P=NS), symptomatic intracranial hemorrhage (15.3% Vs 14.5%, P=NS) or procedural complications (15% Vs 11.6%, P=NS) between the tPA and non-tPA groups.

Conclusion: The use of IV tPA did not affect the safety or efficacy of emergent carotid stenting in the setting of acute tandem occlusion.

Temporal profiles of systolic blood pressure variability and neurologic outcomes after endovascular thrombectomy

Introduction

Observational studies have found an increased risk of hemorrhagic transformation and worse functional outcomes in patients with higher systolic blood pressure variability (BPV). However, the time-varying behavior of BPV after endovascular thrombectomy (EVT) and its effects on functional outcome have not been well characterized.

Patients and methods

We analyzed data from an international cohort of patients with large-vessel occlusion stroke who underwent EVT at 11 centers across North America, Europe, and Asia. Repeated time-stamped blood pressure data were recorded for the first 72 h after thrombectomy. Parameters of BPV were calculated in 12-h epochs using five established methodologies. Systolic BPV trajectories were generated using group-based trajectory modeling, which separates heterogeneous longitudinal data into groups with similar patterns.

Results

Of the 2041 patients (age 69 ± 14, 51.4% male, NIHSS 15 ± 7, mean number of BP measurements 50 ± 28) included in our analysis, 1293 (63.4%) had a poor 90-day outcome (mRS ⩾ 3) or a poor discharge outcome (mRS ⩾ 3). We identified three distinct SBP trajectories: low (25%), moderate (64%), and high (11%). Compared to patients with low BPV, those in the highest trajectory group had a significantly greater risk of a poor functional outcome after adjusting for relevant confounders (OR 2.2; 95% CI 1.2-3.9; p = 0.008). In addition, patients with poor outcomes had significantly higher systolic BPV during the epochs that define the first 24 h after EVT (p < 0.001).

Discussion and conclusions

Acute ischemic stroke patients demonstrate three unique systolic BPV trajectories that differ in their association with functional outcome. Further research is needed to rapidly identify individuals with high-risk BPV trajectories and to develop treatment strategies for targeting high BPV.

Multicenter investigation of technical and clinical outcomes after thrombectomy for Proximal Medium Vessel Occlusion (pMeVO) by frontline technique

BACKGROUND

Endovascular thrombectomy(EVT) is the standard of care for large vessel occlusion(LVO) stroke. Data on technical and clinical outcome in proximal medium vessel occlusions(pMeVOs) comparing frontline techniques remain limited.

METHODS

We report an international multicenter retrospective study of patients undergoing EVT for stroke at 32 centers between 2015-2021. Patients were divided into LVOs(ICA/M1/Vertebrobasilar) or pMeVOs(M2/A1/P1) and categorized by thrombectomy technique. Primary outcome was 90-day good functional outcome(mRS ≤ 2). Multivariate logistic regressions were used to evaluate the impact of technical variables on clinical outcomes. Propensity score matching was used to compare outcome in patients with pMeVO treated with aspiration versus stent-retriever.

RESULTS

In the cohort of 5977 LVO and 1287 pMeVO patients, pMeVO did not independently predict good-outcome(p  =  0.55). In pMeVO patients, successful recanalization irrespective of frontline technique(aOR = 3.2,p < 0.05), procedure time ≤ 1-h(aOR = 2.2,p < 0.05), and thrombectomy attempts ≤ 4(aOR =  2.8,p < 0.05) were independent predictors of good-outcomes.In a propensity-matched cohort of aspiration versus stent-retriever pMeVO patients, there was no difference in good-outcomes. The rates of hemorrhage were higher(9%vs.4%,p < 0.01) and procedure time longer(51-min vs. 33-min,p < 0.01) with stent-retriever, while the number of attempts was higher with aspiration(2.5vs.2,p < 0.01). Rates of hemorrhage and good-outcome showed an exponential relationship to procedural metrics, and were more dependent on time in the aspiration group compared to attempts in the stent-retriever group.

CONCLUSIONS

Clinical outcomes following EVT for pMeVO are comparable to those in LVOs. The golden hour or 3-pass rules in LVO thrombectomy still apply to pMeVO thrombectomy. Different techniques may exhibit different futility metrics; SR thrombectomy was more influenced by attempts whereas aspiration was more dependent on procedure time.

Abstract 023: Quantification Of White Matter Lesion Volume From Clinical T1 Weighted Magnetic Resonance Images To Predict Functional Outcomes Post-thrombectomy

Background: Endovascular treatment (EVT) has immense benefits for patients with large vessel occlusion (LVO). However, many patients do not achieve functional independence despite successful EVT. This may be due to concurrent cerebral small vessel disease (CSVD) mitigating recovery. CSVD manifests as white matter hypointensities on T1-weighted (T1w) MRI and is usually qualitatively assessed from clinical-quality MRI, which does not allow for objective quantification.

Objectives: Implement a processing pipeline to quantify white matter hypointensity volume (WMHV) from clinical images and examine WMHV's influence on functional outcomes post successful EVT.

Methods: We performed a retrospective analysis of the Atrium Wake Forest Stroke Thrombectomy and Aneurysm Registry (n=602) collected between 2015 - 2021. We selected patients with LVO who underwent successful EVT, defined as a Thrombolysis in Cerebral Infarction score of 2B or better. Clinical T1w images were transformed into high-resolution images using the convolutional neural network SynthSR. Then, FreeSurfer was used to quantify baseline WMHV from the side of the brain contralateral to the stroke to minimize stroke interference. To correct for head size, WMHV was adjusted to the estimated total intracranial volume and then log-transformed to address skewness.

Results: The analysis included 213 patients (mean age 67.5 ± 14.6, 49.3% (105 of 213) female) who had MRI of sufficient quality for assessment and 90-day mRS. Baseline WMHV was significantly predictive of 90-day mRS in an ordinal regression model adjusted for baseline mRS (p<0.001). After adjusting for confounders and comorbidities, WMHV remained an independent predictor of 90-day mRS (p<0.001).

Conclusions: Increased volume of white matter hypointensities correlates with poorer functional outcomes after mechanical thrombectomy and may attenuate EVT benefit. Furthermore, advances in neural networks enable the quantification of cerebral small vessel disease from clinical T1w MRI. Such approaches expand the utility of clinical imaging for research purposes.

Blood Pressure Trajectory Groups and Outcome After Endovascular Thrombectomy: A Multicenter Study

BACKGROUND

Elevated blood pressure after endovascular thrombectomy (EVT) has been associated with an increased risk of hemorrhagic transformation and poor functional outcomes. However, the optimal hemodynamic management after EVT remains unknown, and the blood pressure course in the acute phase of ischemic stroke has not been well characterized. This study aimed to identify patient subgroups with distinct blood pressure trajectories after EVT and study their association with radiographic and functional outcomes.

METHODS

This multicenter retrospective cohort study included consecutive patients with anterior circulation large-vessel occlusion ischemic stroke who underwent EVT. Repeated time-stamped blood pressure data were recorded for the first 72 hours after thrombectomy. Latent variable mixture modeling was used to separate subjects into five groups with distinct postprocedural systolic blood pressure (SBP) trajectories. The primary outcome was functional status, measured on the modified Rankin Scale 90 days after stroke. Secondary outcomes included hemorrhagic transformation, symptomatic intracranial hemorrhage, and death.

RESULTS

Two thousand two hundred sixty-eight patients (mean age [±SD] 69±15, mean National Institutes of Health Stroke Scale 15±7) were included in the analysis. Five distinct SBP trajectories were observed: low (18%), moderate (37%), moderate-to-high (20%), high-to-moderate (18%), and high (6%). SBP trajectory group was independently associated with functional outcome at 90 days (P<0.0001) after adjusting for potential confounders. Patients with high and high-to-moderate SBP trajectories had significantly greater odds of an unfavorable outcome (adjusted odds ratio, 3.5 [95% CI, 1.8-6.7], P=0.0003 and adjusted odds ratio, 2.2 [95% CI, 1.5-3.2], P<0.0001, respectively). Subjects in the high-to-moderate group had an increased risk of symptomatic intracranial hemorrhage (adjusted odds ratio, 1.82 [95% CI, 1-3.2]; P=0.04). No significant association was found between trajectory group and hemorrhagic transformation.

CONCLUSIONS

Patients with acute ischemic stroke demonstrate distinct SBP trajectories during the first 72 hours after EVT that have differing associations with functional outcome. These findings may help identify potential candidates for future blood pressure modulation trials.

Perceptions of the Virtual Neurosurgery Application Cycle During the Coronavirus Disease 2019 (COVID-19) Pandemic: A Program Director Survey

OBJECTIVE

The novel coronavirus disease 2019 (COVID-19) pandemic has led to a shift to virtual residency interviews for the 2020-2021 neurosurgery match, with unknown implications for stakeholders. This study seeks to analyze the perceptions of residency program directors (PDs) and associate program directors (APDs) regarding the current virtual format used for residency selection and interviews.

METHODS

An anonymous, 30-question survey was constructed and sent to 115 neurosurgery PDs and 26 APDs to assess respondent demographics, factors used to review applicants, perceptions of applicants and applicant engagement, perceptions of standardized letters and interview questions, the effect of the virtual interview format on various stakeholders, and the future outlook for the virtual residency interview format.

RESULTS

A total of 38 PDs and APDs completed this survey, constituting a response rate of 27.0%. Survey respondents received significantly more Electronic Residency Application Service applications in the 2020-2021 cycle compared with the 2019-2020 cycle (P = 0.0029). Subinternship performance by home-rotators, (26.3%), letters of recommendation (23.7%), and Step 1 score (18.4%) were ranked as the most important factors for evaluating candidates during the current virtual application cycle.

CONCLUSIONS

Our study highlights that applicants applied to a greater number of residency programs compared with years prior, that the criteria used by PDs/APDs to evaluate applicants remained largely consistent compared to previous years, and that the virtual residency interview format may disproportionately disadvantage Doctor of Osteopathic medicine and international medical graduate applicants. Further exploring attitudes toward signaling mechanisms and standardized letters may serve to inform changes to future neurosurgery match cycles.

Early Postmarket Results with EmboTrap II Stent Retriever for Mechanical Thrombectomy: A Multicenter Experience

BACKGROUND AND PURPOSE

EmboTrap II is a novel stent retriever with a dual-layer design and distal mesh designed for acute ischemic stroke emergent large-vessel occlusions. We present the first postmarket prospective multicenter experience with the EmboTrap II stent retriever.

MATERIALS AND METHODS

A prospective registry of patients treated with EmboTrap II at 7 centers following FDA approval was maintained with baseline patient characteristics, treatment details, and clinical/radiographic follow-up.

RESULTS

Seventy patients were treated with EmboTrap II (mean age, 69.9 years; 48.6% women). Intravenous thrombolysis was given in 34.3%, and emergent large-vessel occlusions were located in the ICA (n = 18), M1 (n = 38), M2 or M3 (n = 13), and basilar artery (n = 1). The 5 × 33 mm device was used in 88% of cases. TICI ≥ 2b recanalization was achieved in 95.7% (82.3% in EmboTrap II-only cases), and first-pass efficacy was achieved in 35.7%. The NIHSS score improved from a preoperative average of 16.3 to 12.1 postprocedure and to 10.5 at discharge. An average of 2.5 [SD, 1.8] passes was recorded per treatment, including non-EmboTrap attempts. Definitive treatment was performed with an alternative device (aspiration or stent retriever) in 9 cases (12.9%). Some hemorrhagic conversion was noted in 22.9% of cases, of which 4.3% were symptomatic. There were no device-related complications.

CONCLUSIONS

Initial postmarket results with the EmboTrap II stent retriever are favorable and comparable with those of other commercially available stent retrievers. Compared with EmboTrap II, the first-generation EmboTrap may have a higher first-pass efficacy; however, data are limited by retrospective case analysis, incomplete clinical follow-up, and small sample size, necessitating future trials.

Improving medical student recruitment to neurosurgery

OBJECTIVE

Neurosurgery seeks to attract the best and brightest medical students; however, there is often a lack of early exposure to the field, among other possible barriers. The authors sought to identify successful practices that can be implemented to improve medical student recruitment to neurosurgery.

METHODS

United States neurosurgery residency program directors were surveyed to determine the number of medical student rotators and medical students matching into a neurosurgery residency from their programs between 2010 and 2016. Program directors were asked about the ways their respective institutions integrated medical students into departmental clinical and research activities.

RESULTS

Complete responses were received from 30/110 institutions. Fifty-two percent of the institutions had neurosurgery didactic lectures for 1st- and 2nd-year medical students (MS1/2), and 87% had didactics for MS3/4. Seventy-seven percent of departments had a neurosurgery interest group, which was the most common method used to integrate medical students into the department. Other forms of outreach included formal mentorship programs (53%), lecture series (57%), and neurosurgery anatomy labs (40%). Seventy-three percent of programs provided research opportunities to medical students, and 57% indicated that the schools had a formal research requirement. On average, 3 medical students did a rotation in each neurosurgery department and 1 matched into neurosurgery each year. However, there was substantial variability among programs. Over the 2010-2016 period, the responding institutions matched as many as 4% of the graduating class into neurosurgery per year, whereas others matched 0%-1%. Departments that matched a greater (≥ 1% per year) number of medical students into neurosurgery were significantly more likely to have a neurosurgery interest group and formal research requirements. A greater percentage of high-matching programs had neurosurgery mentorship programs, lecture series, and cadaver training opportunities compared to the other institutions.

CONCLUSIONS

In recent decades, the number of applicants to neurosurgery has decreased. A major deterrent may be the delayed exposure of medical students to neurosurgery. Institutions with early preclinical exposure, active neurosurgery interest groups, research opportunities, and strong mentorship recruit and match more students into neurosurgery. Implementing such initiatives on a national level may increase the number of highly qualified medical students pursuing neurosurgery.

Will immunotherapy change the role of spine radiosurgery in high-grade epidural disease? A case report and a call for an update of current treatment algorithms

Epidural disease closer than 3 mm from the spinal cord is sometimes regarded as a contraindication to spine radiosurgery (SRS) or stereotactic body radiotherapy (SBRT). Current guidelines on the management of high-grade epidural disease recommend surgical decompression followed by conventionally fractionated external-beam radiotherapy (EBRT) or post-operative SBRT [1, 2]. For patients with high-grade epidural disease who are medically inoperable, conventional EBRT is typically recommended, even though clinical response rates are lower and durability is limited[3]. A few expert centers use decompressive SRS in a single fraction for high-grade epidural disease[4, 5], but this technique has not been incorporated into treatment algorithms such as the neurologic, oncologic, mechanical, and systemic (NOMS) decision framework [1, 2]. Here we present a case where five-fraction SBRT followed by immunotherapy resulted in a complete radiographic and clinical response for a patient with epidural disease that was compressing the thecal sac. We compare the radiographic response in this patient to data in a prior publication that quantified the improvement in thecal sac patency after decompressive SRS, and we suggest that current treatment algorithms need to be updated in the era of immunotherapy.

A Comparison of the Existing Wellness Programs in Neurosurgery and Institution Champion's Perspectives

Once the accepted norm during Harvey Cushing's time, the mantra of work to the exclusion of family and lifestyle is now recognized as deleterious to overall well-being. A number of neurosurgical residency training programs have implemented wellness programs to enhance the physical, mental, and emotional well-being of trainees and faculty. This manuscript highlights existing organized wellness education within neurosurgery residency programs in order to describe the motivations behind development, structure, and potential implementation strategies, cost of implementation, and identify successes and barriers in the integration process. This manuscript is designed to serve as a “how-to” guide for other programs who may identify a need in their own trainees and begins the discussion of how to develop wellness, leadership, grit, and resiliency within our future generation of neurosurgeons.

An assessment of data and methodology of online surgeon scorecards

OBJECTIVE Recently, 2 surgeon rating websites (Consumers' Checkbook and ProPublica) were published to allow the public to compare surgeons through identifying surgeon volume and complication rates. Among neurosurgeons and orthopedic surgeons, only cervical and lumbar spine, hip, and knee procedures were included in this assessment. METHODS The authors examined the methodology of each website to assess potential sources of inaccuracy. Each online tool was queried for reports on neurosurgeons specializing in spine surgery and orthopedic surgeons specializing in spine, hip, or knee surgery. Surgeons were chosen from top-ranked hospitals in the US, as recorded by a national consumer publication ranking system, within the fields of neurosurgery and orthopedic surgery. The results were compared for accuracy and surgeon representation, and the results of the 2 websites were also compared. RESULTS The methodology of each site was found to have opportunities for bias and limited risk adjustment. The end points assessed by each site were actually not complications, but proxies of complication occurrence. A search of 510 surgeons (401 orthopedic surgeons [79%] and 109 neurosurgeons [21%]) showed that only 28% and 56% of surgeons had data represented on Consumers' Checkbook and ProPublica, respectively. There was a significantly higher chance of finding surgeon data on ProPublica (p < 0.001). Of the surgeons from top-ranked programs with data available, 17% were quoted to have high complication rates, 13% with lower volume than other surgeons, and 79% had a 3-star out of 5-star rating. There was no significant correlation found between the number of stars a surgeon received on Consumers' Checkbook and his or her adjusted complication rate on ProPublica. CONCLUSIONS Both the Consumers' Checkbook and ProPublica websites have significant methodological issues. Neither site assessed complication occurrence, but rather readmissions or prolonged length of stay. Risk adjustment was limited or nonexistent. A substantial number of neurosurgeons and orthopedic surgeons from top-ranked hospitals have no ratings on either site, or have data that suggests they are low-volume surgeons or have higher complication rates. Consumers' Checkbook and ProPublica produced different results with little correlation between the 2 websites in how surgeons were graded. Given the significant methodological issues, incomplete data, and lack of appropriate risk stratification of patients, the featured websites may provide erroneous information to the public.

Positive trends in neurosurgery enrollment and attrition: analysis of the 2000-2009 female neurosurgery resident cohort

OBJECTIVE

Women compose a minority of neurosurgery residents, averaging just over 10% of matched applicants per year during this decade. A recent review by Lynch et al. raises the concern that women may be at a higher risk than men for attrition, based on analysis of a cohort matched between 1990 and 1999. This manuscript aims to characterize the trends in enrollment, attrition, and postattrition careers for women who matched in neurosurgery between 2000 and 2009.

METHODS

Databases from the American Association of Neurological Surgeons (AANS) and the American Board of Neurological Surgery (ABNS) were analyzed for all residents who matched into neurosurgery during the years 2000-2009. Residents were sorted by female gender, matched against graduation records, and if graduation was not reported from neurosurgery residency programs, an Internet search was used to determine the residents' alternative path. The primary outcome was to determine the number of women residents who did not complete neurosurgery training programs during 2000-2009. Secondary outcomes included the total number of women who matched into neurosurgery per year, year in training in which attrition occurred, and alternative career paths that these women chose to pursue.

RESULTS

Women comprised 240 of 1992 (12%) matched neurosurgery residents during 2000-2009. Among female residents there was a 17% attrition rate, compared with a 5.3% male attrition rate, with an overall attrition rate of 6.7%. The majority who left the field did so within the first 3 years of neurosurgical training and stayed in medicine--pursuing anesthesia, neurology, and radiology.

CONCLUSIONS

Although the percentage of women entering neurosurgical residency has continued to increase, this number is still disproportionate to the overall number of women in medicine. The female attrition rate in neurosurgery in the 2000-2009 cohort is comparable to that of the other surgical specialties, but for neurosurgery, there is disparity between the male and female attrition rates. Women who left the field tended to stay within medicine and usually pursued a neuroscience-related career. Given the need for talented women to pursue neurosurgery and the increasing numbers of women matching annually, the recruitment and retention of women in neurosurgery should be benchmarked and assessed.

Gauging the feasibility of cost-sharing and medical student interest groups to reduce interview costs

Indirect costs of the interview tour can be prohibitive. The authors sought to assess the desire of interviewees to mitigate these costs through ideas such as sharing hotel rooms and transportation, willingness to stay with local students, and the preferred modality to coordinate this collaboration. A survey link was posted on the Uncle Harvey website and the Facebook profile page of fourth-year medical students from 6 different medical schools shortly after the 2014 match day. There were a total of 156 respondents to the survey. The majority of the respondents were postinterview medical students (65.4%), but preinterview medical students (28.2%) and current residents (6.4%) also responded to the survey. Most respondents were pursuing a field other than neurosurgery (75.0%) and expressed a desire to share a hotel room and/or transportation (77.4%) as well as stay in the dorm room of a medical student at the program in which they are interviewing (70.0%). Students going into neurosurgery were significantly more likely to be interested in sharing hotel/transportation (89.2% neurosurgery vs 72.8% nonneurosurgery; p = 0.040) and in staying in the dorm room of a local student when on interviews (85.0% neurosurgery vs 57.1% nonneurosurgery; p = 0.040) than those going into other specialties. Among postinterview students, communication was preferred to be by private, email identification–only chat room. Given neurosurgery resident candidates' interest in collaborating to reduce interview costs, consideration should be given to creating a system that could allow students to coordinate cost sharing between interviewees. Moreover, interviewees should be connected to local students from neurosurgery interest groups as a resource.

Term neonate with intracranial hemorrhage and hereditary hemorrhagic telangiectasia: a case report and review of the literature

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by mucocutaneous telangiectases and arteriovenous malformations (AVMs). The disease rarely presents in the neonatal period, primarily manifesting with epistaxis and gastrointestinal bleeding in adulthood. Occasionally, HHT can also present with symptoms related to AVMs in the cerebral, pulmonary or gastrointestinal vasculature. In prior reports, intracranial hemorrhage (ICH) secondary to cerebral AVM in neonates with HHT has been catastrophic and uniformly fatal. Here we report a case of a newborn with HHT and ICH from a suspected AVM who survived with aggressive medical management and surgical intervention, and provide a comprehensive review of the literature on ICH in neonates with HHT.

Intramedullary abscess of the cervical spinal cord in an otherwise healthy man

BACKGROUND

An intramedullary spinal cord abscess is a rare, albeit widely publicized entity. Classically, patients have an acute onset of symptoms with fevers and leukocytosis supporting the diagnosis. We present a case of intramedullary spinal cord without classic history or imaging characteristics in which the diagnosis was made with diffusion weighted magnetic resonance imaging (MRI).

CASE DESCRIPTION

A 57-year-old physician presented with severe neck and shoulder pain, which progressed over several days to right-sided hemiparesis with dysesthesias. There was no history of fevers, rigors, or illness. A contrast enhanced MRI of the cervical spine revealed an intramedullary lesion centered around C6-T1 that showed peripheral enhancement with gadolinium and edema extending rostrally and caudally. He was then transferred to our institution where the novel application of diffusion weighted MRI of the spinal cord was performed, suggesting an abscess. He then underwent focal laminectomies and biopsy of this lesion with drainage of the necrotic cavity. Intraoperative Gram stain revealed gram-positive cocci, and cultures were sent to the laboratory. After draining the purulent material and completing a course of tailored antibiotics, the patient showed improvement of his neurologic deficit.

CONCLUSIONS

The use of diffusion weighted imaging in the spine is a novel application of technology that provided an accurate preoperative diagnosis and allowed us to tailor our surgical approach and provide a rapid focal decompression.

Carotid artery sacrifice for unclippable and uncoilable aneurysms: endovascular occlusion vs common carotid artery ligation

BACKGROUND

Optimal treatment of intracranial aneurysms involves complete occlusion of the aneurysm with preservation of the parent artery and all of its branches. Attempts to occlude the aneurysm and preserve the parent artery may be associated with a higher level of risk than parent vessel occlusion or trapping.

OBJECTIVE

To evaluate our series of patients with large and giant aneurysms who underwent treatment via endovascular coiling with parent artery sacrifice or surgical ligation of the common carotid artery (CCA) and gain insight into the advantages and risks of each of these alternatives.

METHODS

We retrospectively reviewed all patients with aneurysms who underwent carotid sacrifice via endovascular occlusion or surgical CCA ligation during an 8-year period at our institution.

RESULTS

Twenty-seven patients with large and giant aneurysms of the internal carotid artery underwent carotid artery sacrifice via endovascular occlusion (n = 15) or CCA ligation (n = 12). Of the patients who underwent endovascular occlusion, 3 developed groin complications, 1 developed a new sixth nerve palsy, 1 died from vasospasm related to subarachnoid hemorrhage, and 1 died secondary to rupture of an associated 3-mm anterior communicating artery aneurysm 5 days postoperatively. Of the patients undergoing CCA ligation, 1 patient developed a partial hypoglossal palsy. Clinical improvement of presenting symptoms was observed in all surviving patients regardless of the method of treatment. Complete aneurysm obliteration was documented in all patients during the initial hospital stay. The mean radiographic long-term follow-up was 14.2 months, which was available in 20 of the 25 surviving patients (80%). Complete obliteration was confirmed at follow-up in all but 2 patients with large cavernous aneurysms; 1 was initially treated with endovascular occlusion and the other with carotid ligation.

CONCLUSION

Parent artery sacrifice is still a viable treatment for some complex aneurysms of the internal carotid artery. CCA ligation is a reasonable alternative to endovascular arterial sacrifice.

Subarachnoid Transplant of the Human Neuronal hNT2.19 Serotonergic Cell Line Attenuates Behavioral Hypersensitivity without Affecting Motor Dysfunction after Severe Contusive Spinal Cord Injury

Transplant of cells which make biologic agents that can modulate the sensory and motor responses after spinal cord injury (SCI) would be useful to treat pain and paralysis. To address this need for clinically useful human cells, a unique neuronal cell line that synthesizes and secretes/releases the neurotransmitter serotonin (5HT) was isolated. Hind paw tactile allodynia and thermal hyperalgesia induced by severe contusive SCI were potently reversed after lumbar subarachnoid transplant of differentiated cells, but had no effect on open field motor scores, stride length, foot rotation, base of support, or gridwalk footfall errors associated with the SCI. The sensory effects appeared 1 week after transplant and did not diminish during the 8-week course of the experiment when grafts were placed 2 weeks after SCI. Many grafted cells were still present and synthesizing 5HT at the end of the study. These data suggest that the human neuronal serotonergic hNT2.19 cells can be used as a biologic minipump for receiving SCI-related neuropathic pain, but likely requires intraspinal grafts for motor recovery.

Endoscopically assisted intratumoral embolization of juvenile nasopharyngeal angiofibroma using Onyx

Juvenile nasopharyngeal angiofibromas are vascular tumors that may make resection difficult and potentially dangerous. Preoperative embolization is frequently used to decrease surgical morbidity and blood loss. Embolization has typically been performed via a transarterial route using a variety of embolic materials. The authors present a case in which endoscopic assistance was used for direct transnasal tumor puncture and intratumoral embolization using the liquid embolic agent Onyx. In this case there was excellent infiltration of the parenchymal vasculature with complete angiographic obliteration. There were no complications related to the embolization. The tumor was resected with minimal blood loss. To the authors' knowledge, there have been no previous reports of this novel direct intratumoral embolization technique using endoscopic guidance.

Cavernous Malformation of the Oculomotor Nerve Mimicking a Partially Thrombosed Posterior Communicating Artery Aneurysm: Report of Two Cases

BACKGROUND AND IMPORTANCE:

Cavernous malformations of the cranial nerves are exceedingly rare. The classic radiographic appearance of cavernous malformations may not be obvious when located in a cranial nerve.

CLINICAL PRESENTATION:

We present 2 cases of acute oculomotor paresis caused by cavernous malformations of the oculomotor nerve that were mistaken for a thrombosed posterior communicating artery aneurysm on magnetic resonance imaging, magnetic resonance angiography, and digital subtraction angiography. Both patients underwent a craniotomy with exploration of the lesion. Both cavernous malformations were completely resected while the integrity of the third cranial nerve was maintained. One patient experienced complete resolution of the oculomotor palsy.

CONCLUSION:

Although rare, cavernous malformations should be included in the differential diagnosis of a partially thrombosed posterior communicating artery aneurysm. Exploration and complete lesional resection are possible with improvement of the cranial nerve function.

Supraselective intra-arterial chemotherapy: evaluation of treatment-related complications in advanced retinoblastoma

PURPOSE

The purpose of this study is to report the complication profile and safety evaluation of supraselective intra-arterial melphalan chemotherapy in children undergoing treatment with advanced retinoblastoma.

METHODS

Twelve eyes of 10 children with advanced retinoblastoma (Reese-Ellsworth Group Vb or International Classification Group D) were treated with supraselective intra-ophthalmic artery infusion of melphalan. Eleven eyes of nine children had previously failed traditional management with systemic chemotherapy and laser ablation and underwent intra-ophthalmic artery infusion of melphalan as an alternative to enucleation. Serial ophthalmic examinations, retinal photography, and ultrasonographic imaging were used to evaluate treatment regime.

RESULTS

Ophthalmic artery cannulation was successfully performed in 12 eyes of 10 patients (total 16 times). Striking regression of tumor, subretinal and vitreous seeds were seen early in each case. No severe systemic side effects occurred. Grade III neutropenia was seen in one patient. No transfusions were required. Three patients developed a vitreous hemorrhage obscuring tumor visualization. One patient developed periocular edema associated with inferior rectus muscle inflammation per orbital MRI. This same patient had scattered intraretinal hemorrhages and peripapillary cotton wool spots consistent with a Purtscher's-like retinopathy that resolved spontaneously. At the 6-month follow-up examination, nine eyes had no evidence of tumor progression, whereas three eyes were enucleated for tumor progression. In each enucleated case, viable tumor was identified on histopathologic examination.

CONCLUSIONS

Ophthalmic intra-arterial infusion with melphalan is an excellent globe-conserving treatment option in advanced retinoblastoma cases with minimal systemic side effects. Local toxicities include microemboli to the retina and choroid (1/12, 8%), vitreous hemorrhage (3/12, 25%), and myositis (1/12, 8%). Enucleation remained a definitive treatment for tumor progression in 3 of 12 eyes in this small case series with limited follow-up. Further studies are necessary to establish the role of supraselective intra-arterial melphalan chemotherapy for children with retinoblastoma.

Operative approach via the superior ophthalmic vein for the endovascular treatment of carotid cavernous fistulas that fail traditional endovascular access

BACKGROUND

Endovascular embolization is the preferred treatment for carotid-cavernous fistulas (CCFs), but failure to catheterize the cavernous sinus may occur as a result of tortuosity, hypoplasia, or stenosis of the normal venous routes. In these cases, direct operative cannulation of the arterialized superior ophthalmic vein (SOV) offers an excellent alternative approach.

METHODS

We reviewed the records of patients who underwent surgical cannulation of the SOV in preparation for embolization and identified 10 patients with indirect CCF, all of whom presented with ocular signs and symptoms. All had previously undergone unsuccessful endovenous attempts at treatment at our institution. In the operating room, the SOV was catheterized under microscopic magnification through an eyelid or eyebrow incision, and the patients were taken directly to the angiographic suite for embolization.

RESULTS

In 9 of 10 patients, embolization of the CCF was complete with clinical improvement. In 1 case, navigation of the catheter into the SOV proved difficult, and the procedure was aborted because of contrast extravasation after partial embolization. One patient required a small orbital osteotomy to localize the SOV. There were no clinical complications and no known recurrences. Cosmetic results were excellent in all patients.

CONCLUSION

Surgical access to the superior ophthalmic vein for embolization of a CCF is an excellent and definitive alternative treatment when traditional endovenous routes are inaccessible. The operative approach to the SOV is straightforward and can be performed safely and expeditiously by the neurovascular team.

Ophthalmic vasculature alterations following systemic chemotherapy and periocular Carboplatin treatment of advanced retinoblastoma

The purpose of this study was to report significant alterations in orbital vasculature following combined systemic chemoreduction/laser ablation and periocular carboplatin treatment and to discuss treatment implications in two cases of advanced retinoblastoma. Assessment of orbital and ophthalmic vasculature was done following nine cycles of systemic chemotherapy. Intra-arterial chemotherapy was provided 6 months following completion of systemic chemoreduction, when the tumor was clearly active and progressive. Orbital angiography of both eyes, performed prior to the intra-arterial melphalan injection, documented sclerosis of the ophthalmic artery vasculature with delayed transit time, decreased choroidal blush, and anomalous vessels in the eye receiving periocular carboplatin injections. The orbital vasculature in the contralateral eye was not affected. Orbital and ophthalmic vascular alterations may occur with the use of combined systemic chemotherapy and periocular carboplatin. Systemic chemotherapy and focal transpupillary laser tumor ablation, alone, did not appear to impact the orbital and ophthalmic vascular supply. Impaired vascular supply may have significant influence on the impact of the efficacy of standard and future experimental therapeutic options.

Intraaneurysmal balloon assistance for navigation across a wide-necked aneurysm

Endovascular obliteration of wide-necked aneurysms may be precluded by the inability to navigate across the aneurysm neck. The authors present a technique in which a Hyperform balloon is inflated within the aneurysm and used as a contact surface to "bounce" the remodeling balloon across the aneurysm neck. They have successfully used this technique in 3 patients to efficiently overcome vessel tortuosity, aneurysmal dead space, and balloon prolapse, allowing for obliteration of large, wide-necked aneurysms.

Safety and efficacy of vascular tumor embolization using Onyx: is angiographic devascularization sufficient?

OBJECT

The authors assessed the safety and efficacy of embolization of head, neck, and spinal tumors with Onyx and determined the correlation between tumor embolization and intraoperative blood loss.

METHODS

The authors prospectively collected all head, neck, and spinal tumors embolized with Onyx at their institution over a 28-month period. Information on tumor type, location, extent of tumor devascularization, endovascular and surgical complications, and intraoperative estimated blood loss (EBL) was evaluated.

RESULTS

Forty-three patients with various head, neck, and spinal lesions underwent vascular tumor embolization with Onyx. Indications for embolization included uncontrolled tumor bleeding in 8 cases, elective preoperative devascularization in 34, and tumor-induced consumptive thrombocytopenia in 1 case. Embolization was performed via direct tumoral puncture in 14 cases and through the traditional transarterial route in the remaining lesions. Embolization was successful in ending uncontrolled tumor bleeding in all 8 cases and in reversing the consumptive coagulopathy in 1 case. Intraparenchymal penetration of embolic material was possible in all percutaneously embolized tumors and in 4 of the 20 tumors embolized preoperatively via the transarterial route. The mean percentage of devascularization in tumors with intraparenchymal penetration of Onyx was 90.3% compared with 83.7% in tumors without intraparenchymal penetration. The mean EBL with intraparenchymal penetration of Onyx was significantly lower than when there was no intraparenchymal penetration (459 vs 2698 ml; p = 0.0067). There were no neurological complications related to the embolization procedures.

CONCLUSIONS

Embolization of vascular tumors with Onyx can be performed safely but may not reach optimal effectiveness in reducing intraoperative EBL if the embolic material does not penetrate the tumor vasculature. In the authors' experience, the best method of intraparenchymal penetration is achieved with direct tumor puncture. Transarterial embolization may not result in tumor penetration, particularly when injected from a long distance through small caliber or slow flow vessels.

Onyx embolization of carotid-cavernous fistulas

Object

The authors conducted a study to determine the safety and efficacy of embolization of carotid-cavernous fistulas (CCFs) with the ethylene vinyl alcohol copolymer, Onyx.

Methods

They prospectively collected data in all patients with CCFs who underwent Onyx-based embolization at their institution over a 3-year period. The type of fistula, route of embolization, viscosity of Onyx, additional use of coils, extent of embolization, procedural complications, and clinical follow-up were recorded.

Results

A total of 12 patients (5 men and 7 women who were age 24–88 years) underwent embolization in which Onyx was used. There were 1 Barrow Type A, 1 Type B, 3 Type C, and 7 Type D fistulas. Embolization was performed via a transvenous route in 8 cases and a transarterial route in 4 cases. Onyx 34 was used in all but 2 cases: a direct Type A fistula embolized with Onyx 500 and an indirect Type C fistula embolized with Onyx 18. Adjuvant embolization with framing coils was performed in 7 cases. All procedures were completed in a single session. Immediate fistula obliteration was achieved in all cases. Clinical resolution of presenting symptoms occurred in 100% of the patients by 2 months. Neurological complications occurred in 3 patients. One patient developed a complete cranial nerve (CN) VII palsy that has not resolved. Two patients developed transient neuropathies—1 a Horner syndrome and partial CN VI palsy, and 1 a complete CN III and partial CN V palsy. Radiographic follow-up (mean 16 months, range 4–35 months) was available in 6 patients with complete resolution of the lesion in all.

Conclusions

Onyx is a liquid embolic agent that is effective in the treatment of CCFs but not without hazards. Postembolization cavernous sinus thrombosis and swelling may result in transient compressive cranial neuropathies. The inherent gradual polymerization properties of Onyx allow for casting of the cavernous sinus but may potentially result in deep penetration within arterial collaterals that can cause CN ischemia/infarction. Although not proven, the angiotoxic effects of dimethyl sulfoxide may also play a role in postembolization CN deficits.

Transarterial embolization of a scalp hemangioma presenting with Kasabach-Merritt syndrome

A 2-month-old infant presented with an enlarging scalp hemangioma and consumptive coagulopathy. The patient became severely thrombocytopenic despite medical treatment. Transarterial embolization with Onyx was performed with significant reduction in the size of the tumor and complete resolution of the thrombocytopenia within 12 hours. Onyx embolization appears to be an excellent treatment option for hemangiomas presenting with Kasabach-Merritt syndrome that are unresponsive to standard medical therapy.

Primary central nervous system lymphoma mimicking pituitary apoplexy: case report

Lymphoma involving the pituitary gland is very rare and usually results from metastatic spread of systemic lymphoma. We present a case of primary central nervous system (CNS) large B cell lymphoma that manifested as pituitary apoplexy. A 45-year-old woman presented with headache, and then rapidly developed a third nerve palsy and bitemporal hemianopsia. Imaging suggested a pituitary macroadenoma, with spontaneous necrosis, extending into the suprasellar region, compressing the optic chiasm and invading the right cavernous sinus. The patient underwent transsphenoidal resection which revealed a vascular, firm tumor. An aggressive decompression of the optic chiasm was performed with complete resolution of both visual fields and third nerve palsy. Final pathology showed B cell lymphoma. Systemic work-up including bone marrow aspiration and CSF studies showed no other foci of lymphoma, and the patient was HIV-negative. Chemotherapy with methotrexate, vincristine, procarbazine, and dexamethasone was administered for primary CNS lymphoma. This is an uncommon diagnosis of which the clinician should be aware in order to tailor surgical intervention and provide early institution of proper therapy.

PITUICYTOMA

OBJECTIVE

Pituicytoma is a rare but distinct low-grade glioma of the neurohypophysis. To date, we have found only 28 cases reported in the literature and have reviewed these in addition to our own case to delineate the clinical implications of this relatively recently defined tumor.

CLINICAL PRESENTATION

A 71-year-old woman presented with bitemporal hemianopsia and was found to have a large sellar tumor, resembling a pituitary adenoma. Transsphenoidal resection was attempted but was complicated by significant tumor vascularity. Pathology at that time was interpreted as a “granular cell tumor.” The patient was then referred to our institution for management of the residual tumor.

INTERVENTION

The patient underwent preoperative embolization to decrease tumor vascularity, and subtotal tumor resection was performed via a craniofacial approach. Postoperatively, the patient has enjoyed significantly improved visual fields despite residual tumor. No adjuvant treatment was given. There has been no regrowth of the residual tumor, as shown on magnetic resonance imaging, over a follow-up period of 1.5 years. The final pathological diagnosis was pituicytoma.

CONCLUSION

Pituicytomas are benign, slow-growing tumors that seem to be cured by gross total resection. The role of radiation therapy is controversial. We advocate an aggressive surgical approach with possible preoperative embolization to reduce the vascularity of the tumor.

Engorged epidural venous plexus and cervical myelopathy due to cerebrospinal fluid overdrainage: a rare complication of ventricular shunts

The authors report on a 17-year-old boy with cervical myelopathy from dilated epidural veins due to cerebrospinal fluid (CSF) overdrainage. The patient had a long-standing subdural-peritoneal shunt and presented with incapacitating spastic tetraparesis. Magnetic resonance imaging revealed significant cervical spinal cord compression from a markedly dilated epidural venous plexus. The shunt was externalized so that CSF flow dynamics could be assessed, and the patient was found to have low intracranial pressure (ICP). The patient was gradually acclimated to higher ICPs, and a new shunt was placed with an antisiphon device and a programmable valve set at the higher pressure. Postoperatively the child experienced significant clinical improvement, and reduction of spinal cord compression was evident on images. Compensatory engorgement of the epidural venous plexus due to long-term shunt usage should be considered in the differential diagnosis when cervical myelopathy due to a dilated epidural venous plexus is present.

Optimizing the transplant dose of a human neuronal cell line graft to treat SCI pain in the rat

Neuropathic pain is a prevalent and difficult problem in the setting of spinal cord injury (SCI). The use of cellular transplant therapy to treat this pain has been successful with the use of a human neuronal cell line, hNT2.17 [M.J. Eaton, S.Q. Wolfe, M.A. Martinez, M. Hernandez, C. Furst, J. Huang, B.R. Frydel, O. Gomez-Marin, Subarachnoid transplant of a human neuronal cell line attenuates chronic allodynia and hyperalgesia after excitotoxic SCI in the rat, J. Pain 8 (2007) 33-50]. Intrathecal transplant of these cells potently reverses behavioral hypersensitivity after excitotoxic spinal cord injury in the rat model. This study focuses on delineating the optimal dose of these cell grafts in the same model. Two weeks after intraspinal injection of quisqualic acid (QUIS) with subsequent behavioral hypersensitivity, terminally differentiated hNT2.17 cells were transplanted into 300 g Wistar-Furth rats in a logarithmic variation of doses: 10(6), 10(5) and 10(3) cells. Behavioral hypersensitivity testing was performed weekly for 6 weeks following transplant. The dose of 10(6) cells (or approximately 3 million/kg) potently and permanently reversed both cutaneous allodynia (CA) and thermal hyperalgesia (TH). Reduced transplant doses of the hNT2.17 cell line did not permanently reverse behavioral hypersensitivity, suggesting that there is an optimal dose that can be used as a clinical tool to treat SCI-associated neuropathic pain.