Repeat stereotactic radiosurgery for persistent cerebral arteriovenous malformations in pediatric patients

OBJECTIVE

The purpose of this study was to describe the long-term outcomes and associated risks related to repeat stereotactic radiosurgery (SRS) for persistent arteriovenous malformations (AVMs) in pediatric patients.

METHODS

Under the auspices of the International Radiosurgery Research Foundation, this retrospective multicenter study analyzed pediatric patients who underwent repeat, single-session SRS between 1987 and 2022. The primary outcome variable was a favorable outcome, defined as nidus obliteration without hemorrhage or neurological deterioration. Secondary outcomes included rates and probabilities of hemorrhage, radiation-induced changes (RICs), and cyst or tumor formation.

RESULTS

The cohort included 83 pediatric patients. The median patient age was 11 years at initial SRS and 15 years at repeat SRS. Fifty-seven children (68.7%) were managed exclusively using SRS, and 42 (50.6%) experienced hemorrhage prior to SRS. Median AVM diameter and volume were substantially different between the first (25 mm and 4.5 cm3, respectively) and second (16.5 mm and 1.6 cm3, respectively) SRS, while prescription dose and isodose line remained similar. At the 5-year follow-up evaluation from the second SRS, nidus obliteration was achieved in 42 patients (50.6%), with favorable outcome in 37 (44.6%). The median time to nidus obliteration and hemorrhage was 35.5 and 38.5 months, respectively. The yearly cumulative probability of favorable outcome increased from 2.5% (95% CI 0.5%-7.8%) at 1 year to 44% (95% CI 32%-55%) at 5 years. The probability of achieving obliteration followed a similar pattern and reached 51% (95% CI 38%-62%) at 5 years. The 5-year risk of hemorrhage during the latency period after the second SRS reached 8% (95% CI 3.2%-16%). Radiographically, 25 children (30.1%) had RICs, but only 5 (6%) were symptomatic. Delayed cyst formation occurred in 7.2% of patients, with a median onset of 47 months. No radiation-induced neoplasia was observed.

CONCLUSIONS

The study results showed nidus obliteration in most pediatric patients who underwent repeat SRS for persistent AVMs. The risks of symptomatic RICs and latency period hemorrhage were quite low. These findings suggest that repeat radiosurgery should be considered when treating pediatric patients with residual AVM after prior SRS. Further study is needed to define the role of repeat SRS more fully in this population.

Nationwide trends in intensive care unit utilization in the elective endovascular treatment of unruptured intracranial aneurysms

OBJECTIVE

Multiple studies suggest routine post-operative intensive care unit (ICU) stays after endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs) is unnecessary, though rates of ICU utilization nationwide are unknown. We aim to evaluate rates and characteristics of ICU utilization in patients undergoing elective endovascular repair of UIAs.

METHODS

This is a retrospective cohort study utilizing a nationwide private-payer database in the United States to evaluate the ICU utilization in patients undergoing elective endovascular repair of UIAs between 2005 and 2019. Demographics and pre-operative comorbidities as well as post-procedural complications and discharge status were compared. An analysis of charges and costs was also performed.

RESULTS

Among 6218 patients who underwent elective EVT of a UIA, 4890 (78.6%) were admitted to the ICU post-operatively. There were no differences in age, sex, or Charlson comorbidity scores in patients admitted to the ICU post-operatively compared to those admitted elsewhere. ICU utilization was more common in urban locations compared to rural. 12.7% of patients had ICU-specific needs sufficient to be billed by a critical care provider. Total provider costs were significantly higher in patients utilizing the ICU post-operatively, even among uncomplicated patients with routine discharges.

CONCLUSION

Most patients undergoing elective endovascular UIA repair in the United States are admitted to the ICU postoperatively. Only 12.7% have ICU needs, and these patients are predictable from pre-operative characteristics or peri-operative complications. Reducing ICU use in this subgroup of patients may be an important target to improve healthcare value in this patient population.

Localization of spinal dural arteriovenous fistulas from the spatial relationships of perimedullary vessels on standard MRI

OBJECTIVE

The goal in this study was to explore the spatial relationship of perimedullary vessels visualized on MRI to localize the side and the site of spinal dural arteriovenous fistula (SDAVF).

METHODS

A retrospective analysis of 30 consecutive patients diagnosed with SDAVF on MRI was undertaken. Two experienced reviewers blinded to all reports and angiographic images analyzed T2-weighted as well as postcontrast T1-weighted sequences. A focal prominent zone of perimedullary vessels with lateralization to one side in the thecal space was evaluated to locate the side and the site of the fistula. Spinal digital subtraction angiography served as the gold standard technique.

RESULTS

Good interrater agreement (κ = 0.77) was shown for the diagnosis of SDAVF with perimedullary vessels on T2-weighted MRI. Flow voids on T2-weighted MRI demonstrated a sensitivity of 1.0 (95% CI 1.0-1.0) and an accuracy of 0.87 (95% CI 0.79-0.95) to identify the presence of fistula. The flow voids on T2-weighted MRI also demonstrated 0.88 (95% CI 0.71-1.03) sensitivity and 0.81 (95% CI 0.70-0.92) accuracy to identify the side of SDAVF. Furthermore, flow voids on T2-weighted MRI showed 0.87 (95% CI 0.71-1.03) sensitivity and 0.87 (95% CI 0.79-0.95) accuracy to identify the site of SDAVF within 3 vertebral levels above or below the actual site. Area under the receiver operating characteristic curve demonstrated significant results (0.87 [95% CI 0.73-1.0]; p < 0.001) for flow voids on T2-weighted MRI to identify the site of shunts within 3 vertebral levels in the cranial or caudal direction.

CONCLUSIONS

Spatial distribution of perimedullary vessels observed on standard MRI show promise to locate the side and the site of fistula in patients with SDAVF.

Safety and efficacy of endovascular versus microsurgical treatment of unruptured wide-necked middle cerebral artery aneurysms: a propensity score-matched analysis of the NeuroVascular Quality Initiative Quality Outcomes Database Cerebral Aneurysm Registry

OBJECTIVE

Unruptured, wide-necked middle cerebral artery (WN-MCA) aneurysms have traditionally been considered ideal candidates for microsurgery (MS), although endovascular treatment (EVT) has dramatically increased in popularity with the advent of novel devices such as intrasaccular flow disruptors. The purpose of this study was to evaluate the safety and efficacy of MS versus EVT for unruptured WN-MCA aneurysms.

METHODS

The NeuroVascular Quality Initiative Quality Outcomes Database (NVQI-QOD) Cerebral Aneurysm Registry, a multiinstitutional, prospectively collected procedural database, was queried for cases of unruptured WN-MCA aneurysms treated with MS or EVT between 2015 and 2022. A wide neck was defined as an aneurysm neck ≥ 4 mm or a dome/neck ratio ≤ 2. Demographics and aneurysm characteristics were queried. Propensity score matching (PSM) was utilized to match aneurysm size, number of aneurysms treated, patient age, and aneurysm status. Safety outcomes were evaluated including intraoperative and postoperative complication rates. Aneurysm occlusion status and clinical outcomes using the modified Rankin Scale (mRS) score at discharge and the last follow-up were also assessed.

RESULTS

Of 671 unruptured MCA aneurysms, 319 were wide necked. Thirty cases were excluded, as the aneurysm had been previously treated. Two hundred eighty-nine operations (203 EVT, 86 MS) in 282 patients satisfied inclusion criteria. After PSM, there were 86 operations in each group for analysis. The mean aneurysm width was 5.0 (EVT) versus 4.9 mm (MS; p = 0.285). Safety data showed similar intraoperative (7.0% EVT vs 3.5% MS, p = 0.496) and postoperative (4.7% vs 7%, p = 0.746) complication rates. The MS patients were more likely to have complete aneurysm occlusion at discharge (90.4% vs 58.8%, p < 0.001). In a limited subset of patients (52.9%) for whom outcome data were available, the EVT patients were more likely to have an mRS score 0 at discharge (50/59 [84.7%] vs 29/54 [53.7%], p < 0.0003] and at the last follow-up (36/55 [65.5%] vs 13/36 [36.1%], p = 0.006).

CONCLUSIONS

This study describes a large, modern cohort of propensity score-matched patients who underwent treatment of unruptured WN-MCA aneurysms. Safety data on intraoperative and postoperative complication rates were similar in both treatment groups. MS was more likely to result in complete aneurysm occlusion at discharge. In a subset of patients with available outcome data, EVT was associated with better functional outcomes at discharge and the last follow-up. Given the lack of complete follow-up data and rates of retreatment, these results should be interpreted cautiously.

Effect of cerebral arteriovenous malformation location on outcomes of repeat, single-fraction stereotactic radiosurgery: a matched-cohort analysis

OBJECTIVE

Patients with deep-seated arteriovenous malformations (AVMs) have a higher rate of unfavorable outcome and lower rate of nidus obliteration after primary stereotactic radiosurgery (SRS). The aim of this study was to evaluate and quantify the effect of AVM location on repeat SRS outcomes.

METHODS

This retrospective, multicenter study involved 505 AVM patients managed with repeat, single-session SRS. The endpoints were nidus obliteration, hemorrhage in the latency period, radiation-induced changes (RICs), and favorable outcome. Patients were split on the basis of AVM location into the deep (brainstem, basal ganglia, thalamus, deep cerebellum, and corpus callosum) and superficial cohorts. The cohorts were matched 1:1 on the basis of the covariate balancing score for volume, eloquence of location, and prescription dose.

RESULTS

After matching, 149 patients remained in each cohort. The 5-year cumulative probability rates for favorable outcome (probability difference -18%, 95% CI -30.9 to -5.8%, p = 0.004) and AVM obliteration (probability difference -18%, 95% CI -30.1% to -6.4%, p = 0.007) were significantly lower in the deep AVM cohort. No significant differences were observed in the 5-year cumulative probability rates for hemorrhage (probability difference 3%, 95% CI -2.4% to 8.5%, p = 0.28) or RICs (probability difference 1%, 95% CI -10.6% to 11.7%, p = 0.92). The median time to delayed cyst formation was longer with deep-seated AVMs (deep 62 months vs superficial 12 months, p = 0.047).

CONCLUSIONS

AVMs located in deep regions had significantly lower favorable outcomes and obliteration rates compared with superficial lesions after repeat SRS. Although the rates of hemorrhage in the latency period and RICs in the two cohorts were comparable, delayed cyst formation occurred later in patients with deep-seated AVMs.

Third Stereotactic Radiosurgery for Residual Arteriovenous Malformations: A Retrospective Multicenter Study

BACKGROUND AND OBJECTIVES

There are no studies evaluating the efficacy and safety of more than 2 stereotactic radiosurgery (SRS) procedures for cerebral arteriovenous malformations (AVM). The aim of this study was to provide evidence on the role of third single-session SRS for AVM residual.

METHODS

This multicenter, retrospective study included patients managed with a third single-session SRS procedure for an AVM residual. The primary study outcome was defined as AVM nidus obliteration without AVM bleeding or symptomatic radiation-induced changes (RIC). Secondary outcomes evaluated were AVM obliteration, AVM hemorrhage, asymptomatic, and symptomatic RIC.

RESULTS

Thirty-eight patients (20/38 [52.6%] females, median age at third SRS 34.5 [IQR 20] years) were included. The median clinical follow-up was 46 (IQR 14.8) months, and 17/38 (44.7%) patients achieved favorable outcome. The 3-year and 5-year cumulative probability rates of favorable outcome were 23% (95% CI = 10%-38%) and 53% (95% CI = 29%-73%), respectively. The cumulative probability of AVM obliteration at 3 and 5 years after the third SRS was 23% (95% CI = 10%-37%) and 54% (95% CI = 29%-74%), respectively. AVM bleeding occurred in 2 patients, and 1 of them underwent subsequent resection. The cumulative probability rate of post-SRS AVM hemorrhage remained constant at 5.3% (95% CI = 1%-16%) during the first 5 years of follow-up. Transient symptomatic RIC managed conservatively occurred in 5/38 patients (13.2%) at a median time of 12.5 (IQR 22.5) months from third SRS. Radiation-induced cyst formation was noted in 1 patient (4.2%) 19 months post-SRS. No mortality, radiation-associated malignancy, or permanent symptomatic RIC was noted during follow-up.

CONCLUSION

A third single-session SRS to treat a residual intracranial AVM offers obliteration in most patients. The risk of RIC was low, and these effects were transient. While not often required, a third SRS can be performed in patients with persistent residual AVMs.

Conscious sedation by sedation-trained interventionalists versus anesthesia providers in patients with acute ischemic stroke undergoing endovascular thrombectomy: A propensity score-matched analysis

BACKGROUND

The appropriate choice of perioperative sedation during endovascular thrombectomy for ischemic stroke is unknown. Few studies have evaluated the role of nursing-administered conscious sedation supervised by a trained interventionalist.

OBJECTIVE

To compare the safety and efficacy of endovascular thrombectomy for ischemic stroke performed with nursing-administered conscious sedation supervised by a trained interventionalist with monitored anesthesia care supervised by an anesthesiologist.

METHODS

A retrospective review of a prospectively collected stroke registry was performed. The primary outcome was functional independence at 90 days, defined as a modified Rankin score of 0-2. Propensity score matching was performed to control for known confounders including patient comorbidities, access type, and direct-to-suite transfers.

RESULTS

A total of 355 patients underwent endovascular thrombectomy for large vessel occlusion between 2018 and 2022. Thirty five patients were excluded as they arrived at the endovascular suite intubated. Three hundred and twenty patients were included in our study, 155 who underwent endovascular thrombectomy with nursing-administered conscious sedation and 165 who underwent endovascular thrombectomy with monitored anesthesia care. After propensity score matching, there were 111 patients in each group. There was no difference in modified Rankin score 0-2 at 90 days (26.1% vs 35.1%, p = 0.190). Patients undergoing monitored anesthesia care received significantly more vasoactive medications (23.4% vs 49.5%, p < 0.001) and had a lower intraoperative minimum systolic blood pressure (134 vs 123 mmHg, p < 0.046). There was no difference in procedural efficacy, safety, intubation rates, and postoperative complications.

CONCLUSION

Perioperative sedation with nursing-administered conscious sedation may be safe and effective in patients undergoing endovascular thrombectomy for ischemic stroke.

Outcome Evaluation of Repeat Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations

BACKGROUND

Repeat stereotactic radiosurgery (SRS) for persistent cerebral arteriovenous malformation (AVM) has generally favorable patient outcomes. However, reporting studies are limited by small patient numbers and single-institution biases. The purpose of this study was to provide the combined experience of multiple centers, in an effort to fully define the role of repeat SRS for patients with arteriovenous malformation.

METHODS

This multicenter, retrospective cohort study included patients treated with repeat, single-fraction SRS between 1987 and 2022. Follow-up began at repeat SRS. The primary outcome was a favorable patient outcome, defined as a composite of nidus obliteration in the absence of hemorrhage or radiation-induced neurological deterioration. Secondary outcomes were obliteration, hemorrhage risk, and symptomatic radiation-induced changes. Competing risk analysis was performed to compute yearly rates and identify predictors for each outcome.

RESULTS

The cohort comprised 505 patients (254 [50.3%] males; median [interquartile range] age, 34 [15] years) from 14 centers. The median clinical and magnetic resonance imaging follow-up was 52 (interquartile range, 61) and 47 (interquartile range, 52) months, respectively. At last follow-up, favorable outcome was achieved by 268 (53.1%) patients (5-year probability, 50% [95% CI, 45%-55%]) and obliteration by 300 (59.4%) patients (5-year probability, 56% [95% CI, 51%-61%]). Twenty-eight patients (5.6%) experienced post-SRS hemorrhage with an annual incidence rate of 1.38 per 100 patient-years. Symptomatic radiation-induced changes were evident in 28 (5.6%) patients, with most occurring in the first 3 years. Larger nidus volumes (between 2 and 4 cm³, subdistribution hazard, 0.61 [95% CI, 0.44-0.86]; P=0.005; >4 cm³, subdistribution hazard, 0.47 [95% CI, 0.32-0.7]; P<0.001) and brainstem/basal ganglia involvement (subdistribution hazard, 0.6 [95% CI, 0.45-0.81]; P<0.001) were associated with reduced probability of favorable outcome.

CONCLUSIONS

Repeat SRS confers reasonable obliteration rates with a low complication risk. With most complications occurring in the first 3 years, extending the latency period to 5 years generally increases the rate of favorable patient outcomes and reduces the necessity of a third intervention.

Variation in Carotid Artery Stenosis Measurements Among Facilities Seeking Carotid Stenting Facility Accreditation

BACKGROUND

Based on the inclusion criteria of clinical trials, the degree of cervical carotid artery stenosis is often used as an indication for stent placement in the setting of extracranial carotid atherosclerotic disease. However, the rigor and consistency with which stenosis is measured outside of clinical trials are unclear. In an agreement study using a cross-sectional sample, we compared the percent stenosis as measured by real-world physician operators to that measured by independent expert reviewers.

METHODS

As part of the carotid stenting facility accreditation review, images were obtained from 68 cases of patients who underwent carotid stent placement. Data collected included demographics, stroke severity measures, and the documented degree of stenosis, termed operator-reported stenosis (ORS), by 34 operators from 14 clinical sites. The ORS was compared with reviewer-measured stenosis (RMS) as assessed by 5 clinicians experienced in treating carotid artery disease.

RESULTS

The median ORS was 90.0% (interquartile range, 80.0%-90.0%) versus a median RMS of 61.1% (interquartile range, 49.8%-73.6%), with a median difference of 21.8% (interquartile range, 13.7%-34.4%), P<0.001. The median difference in ORS and RMS for asymptomatic versus symptomatic patients was not statistically different (24.6% versus 19.6%; P=0.406). The median difference between ORS and RMS for facilities granted initial accreditation was smaller compared with facilities whose accreditation was delayed (17.9% versus 25.5%, P=0.035). The intraclass correlation between ORS and RMS was 0.16, indicating poor agreement. If RMS measurements were used, 72% of symptomatic patients and 10% of asymptomatic patients in the population examined would meet the Centers for Medicare and Medicaid Services criteria for stent placement.

CONCLUSIONS

Real-world operators tend to overestimate carotid artery stenosis compared with external expert reviewers. Measurements from facilities granted initial accreditation were closer to expert measurements than those from facilities whose accreditation was delayed. Since decisions regarding carotid revascularization are often based on percent stenosis, such measuring discrepancies likely lead to increased procedural utilization.

Abstract 133: Over Estimation Of Percent Stenosis By Physician Operators May Lead To Carotid Stent Over Utilization

Introduction: Based largely on the inclusion criteria of clinical trials, the degree of cervical carotid artery stenosis is often used as an indication for stent placement in the setting of carotid atherosclerotic disease. However, the rigor and consistency with which such stenosis is measured outside of clinical trials is unclear. We compared the percent stenosis as measured by real world physician operators to that measured by independent expert reviewers.

Hypothesis: We hypothesized that the documented degree of stenosis, termed operator-reported stenosis (ORS), from real world facilities performing carotid stent placement would be larger than the reviewer-measured stenosis (RMS) as assessed by clinicians experienced in treating carotid artery disease.

Methods: Images were selected from patient cases used for carotid stenting facility accreditation. Data collected included demographics, National Institutes of Health Stroke Scale, modified Rankin Score, and the documented degree of stenosis (ORS). The ORS was compared to the RMS, derived from a panel of expert clinicians.

Results: A total of 68 angiograms were reviewed from 39 symptomatic and 29 asymptomatic patients. The RMS values demonstrated excellent agreement with an intra-class correlation of 0.80. The median ORS was 90.0% (IQR 80.0, 90.0) versus a median RMS of 61.1% (IQR 49.8, 73.6), with a median difference of 21.8% (IQR 13.7, 34.4), p < 0.001. This discrepancy persisted within several subpopulations and was larger among asymptomatic patients and those treated at facilities granted delayed accreditation. Based on RMS values, 72% of symptomatic patients and only 10% of asymptomatic patients would meet the Centers for Medicare and Medicaid Services criteria for carotid stent placement.

Conclusions: Real world operators tend to overestimate cervical carotid artery stenosis compared to external expert reviewers. Since decisions regarding carotid revascularization are often based at least partially on percent stenosis, such measuring discrepancies inevitably lead to a higher volume of procedures, which may in turn represent a degree of procedural over utilization.

Neuroendovascular Procedures in Patients with Ehlers-Danlos Type IV: Multicenter Case Series and Systematic Review

BACKGROUND

Ehlers-Danlos type IV or vascular Ehlers-Danlos syndrome (vEDS) is a rare inherited disorder characterized by profound vascular fragility resulting from defective production of type III procollagen. Cerebrovascular diseases including spontaneous dissections, cerebral aneurysms, and cavernous carotid fistulae are common. Endovascular therapies in this patient population are known to be higher risk, although many studies (before 2000) involved older techniques and equipment. The purpose of this study is to investigate the safety and efficacy of modern neuroendovascular techniques in the treatment of cerebrovascular diseases in patients with vEDS.

METHODS

We combined a multi-institutional retrospective case series at 3 quaternary-care centers with a systematic literature review of individual case reports and case series spanning 2000-2021 to evaluate the safety and efficacy of neuroendovascular procedure in patients with vEDS with cerebrovascular diseases.

RESULTS

Fifty-nine patients who underwent 66 neuroendovascular procedures were evaluated. Most of the patients had direct cavernous carotid fistulas (DCCF). Neuroendovascular procedures had a 94% success rate, with a complication rate of 30% and a mortality of 7.5%.

CONCLUSIONS

Neuroendovascular procedures can be performed with a high rate of success in the treatment of cerebrovascular diseases in patients with vEDS, although special care is required because complication rates and mortality are high. Access site and procedure-related vascular injuries remain a significant hurdle in treating vEDS with cerebrovascular diseases, even with modern techniques.

Abstract WP3: The Use Of Monitored Anesthesia Care In Place Of Nurse Administered Conscious Sedation Does Not Result In Delays To Emergent Thrombectomy

Introduction: There has been considerable emphasis on the use of monitored anesthesia care (MAC) versus general anesthesia for emergent mechanical thrombectomy (EMT). However, due to concerns over potential delays many centers do not involve anesthesia services but instead rely on nurse administered conscious sedation (NACS). Since our center switched from NACS to MAC in 2020, we decided to investigate the impact of this switch on our thrombectomy procedures.

Methods: Using a prospectively maintained Comprehensive Stroke Center quality improvement database, we reviewed our hospital EMT cases from June 2018 to April 2020 (pre-anesthesia involvement, NACS only) and May 2020 to March 2022 (post-anesthesia involvement). Main inclusion criteria were evidence of a proximal LVO and emergent transport for EMT. Variables reviewed included, time to arterial access from neurointerventional suite arrival, time to first pass, and time to TICI 2b/3. Median outcomes were compared using Mann-Whitney U test.

Results: From June 2018 through April 2020 there were a total of 146 LVO cases that received EVT, compared to a total of 209 LVO cases receiving EVT from May 2020 to March 2022. The median time to arterial access from arrival in the neurointerventional suite was significantly longer before anesthesia involvement (June 2018 to April 2020, 16 minutes) compared to the period after anesthesia involvement (May 2020 to March 2022, 10 minutes) (p < 0.0001). There was no significant difference in median time to first pass between the pre-anesthesia (25 minutes) versus post-anesthesia (26 minutes) time frame (p = 0.43). Median time to TICI 2b/3 was faster post-anesthesia (35 minutes) versus pre-anesthesia (40 minutes) involvement (p = 0.19).

Conclusion: Our data suggests faster arterial access for EMT and no significant increase in time to first pass or final recanalization after starting to use anesthesia services. The reasons for this are likely multifactorial but may include the offloading of operator responsibilities for managing sedation, blood pressure, and airway security in these often critically ill LVO stroke patients.

Management of neurophysiological monitoring changes during carotid endarterectomy exposure

BACKGROUND

Carotid endarterectomy (CEA) is a safe and effective operation in the management of carotid stenosis. Intraoperative neurophysiologic monitoring (IONM) changes during carotid clamping has been well studied, but there is scant evidence detailing IONM changes during carotid exposure.

OBJECTIVE

We analyzed our experience with IONM changes during CEA exposure to determine whether multimodal IONM changes during exposure predict outcomes and how best to manage this challenging clinical scenario.

METHODS

We reviewed all CEAs performed at our medical center between January 2015 and June 2020 and identified patients with multimodal IONM changes during exposure of the carotid artery. Our primary outcomes were perioperative stroke and functional outcomes. Functional outcomes were measured by modified Rankin scale (mRS), with good functional outcome defined at mRS scores 0-3. We also reviewed our intraoperative IONM change management strategies.

RESULTS

Five patients (4 males, 1 female) with an average age of 67 ± 12 years had intraoperative IONM changes during carotid exposure. Among these, three patients were discharged with good functional outcome, and four patients had a good functional outcome at last follow-up. Two patients had perioperative stroke, half of which resulted in significant disability. One patient was transferred to the neuroendovascular suite intraoperatively for evaluation for thromboembolism followed by angioplasty and stenting with distal protection.

CONCLUSION

Intraoperative IONM changes during carotid exposure predict outcomes in CEA. We propose that transition to the neuroendovascular suite following significant IONM changes during carotid exposure may be a useful strategy for management of this challenging clinical scenario. This approach provides the opportunity to evaluate and treat thromboembolism and still complete carotid revascularization when appropriate. This algorithm may be particularly useful in the era of dual trained vascular neurosurgeons.

Balloon-Assisted Roadmap Technique to Enable Flow Diversion of a High-Flow Direct Carotid-Cavernous Fistula

BACKGROUND

The use of flow diverters as a first-line treatment for direct carotid cavernous fistula (CCF) is a relatively new approach in the neurointerventional field which allows obliteration of the fistula with less mass effect from coils in the cavernous sinus. Safe and successful deployment of a flow diverter requires adequate imaging of the parent vessel, which may be challenging in the setting of high-flow CCF without antegrade flow.

OBJECTIVE

To facilitate adequate parent vessel imaging in the setting of high-flow CCF to enable the safe development of a flow diverter device.

METHODS

Here we present the case of a patient with delayed presentation of post-traumatic direct CCF after a motor vehicle accident, with no antegrade flow past the fistulous connection. We used temporary balloon occlusion of the fistulous connection to enable road-map imaging of the parent vessel and flow-diverter placement. "Drag and drop" device opening in the middle cerebral artery facilitated better deployment of the flow-diverter against retrograde cavernous flow through the fistula.

RESULTS

Temporary balloon occlusion of the fistulous connection was used to acquire a roadmap to facilitate safe deployment of a flow diverter and subsequent treatment of the CCF with transvenous coil embolization, with complete resolution of symptoms.

CONCLUSION

Balloon-assisted roadmap use is a novel means of visualizing the parent vessel in direct CCF to facilitate safe flow diverter deployment.

Patterns of prophylactic anticonvulsant use in spontaneous intracerebral and subarachnoid hemorrhage: results of a practitioner survey

BACKGROUND

The use of prophylactic anti-seizure medications (ASMs) in the management of patients with spontaneous intracerebral hemorrhage (sICH) and aneurysmal subarachnoid hemorrhage (aSAH) is controversial.

OBJECTIVE

The purpose of this survey was to better characterize the current state of prophylactic ASM use in sICH and aSAH in North America.

METHODS

US and Canadian neurosurgeons, neurologists, and interventional neuroradiologists with an interest in or expertise in the management of neurovascular disease were surveyed using an electronic survey tool.

RESULTS

Seven hundred ninety-four survey requests were sent; responses were received from 103 (13%). The majority of respondents were neurosurgeons (84%). Thirty-eight percent of respondents self-identified as vascular neurosurgeons and 10% self-identified as neurocritical care specialists. Seventy-two percent were in academic practice. When asked their preference for ASM prophylaxis (aSAH, sICH, or both), the most common response was to use prophylaxis in both aSAH and sICH (43, 45%). Twenty-one (22%) did not use routine prophylaxis, while 22 (23%) used prophylaxis only in aSAH and 9 (9%) only in sICH. The majority of practitioners (35, 67%) who answered that they used ASM prophylaxis in sICH, used ASMs selectively. For aSAH, the vast majority (53, 82%) used prophylaxis for all patients. Respondents felt that they were more likely to use ASMs for sICH patients if the sICH was in a cortical location, supratentorial location, or was related to a structural abnormality (e.g., tumor, arteriovenous malformation) Levetiracetam (Keppra) was the most commonly used ASM (73, 99%). When asked whether the statement "Current AHA/ASA Guidelines recommend against the use of prophylactic anticonvulsants in spontaneous ICH" was true or false, 78 (83%) responded correctly that the recommendation is true. Only 24 respondents answered the question as to whether they would be willing to randomize sICH and/or aSAH patients to management with or without ASM prophylaxis. Of these, 13 (54%) said they would be willing to randomize sICH patients, while only 6 (25%) were willing to randomize aSAH patients. There were no statistically significant differences in responses to survey questions when analyzed by practice type (academic versus non-academic) or physician specialty (critical care versus non-critical care, or vascular neurology/neurosurgery versus other).

CONCLUSION

The use of ASMs for seizure prophylaxis after sICH and aSAH remains widespread despite the lack of any specific evidence-based guideline to support the practice. A large-scale randomized controlled trial is needed to add clarity to the practice of prophylactic ASM use in patients with spontaneous intracranial hemorrhage.

Self-expanding covered stent placement to treat a pseudoaneurysm caused by iatrogenic vertebral artery injury

Vertebral artery injuries account for approximately 19% of cerebral vascular injuries and are typically managed conservatively. However, some patients require operative intervention to gain control of an active hemorrhage, either via surgical ligation or endovascular intervention. We present a case of iatrogenic vertebral artery injury occurring during cervical spine surgery which was treated emergently with a self-expanding covered stent. A 58-year-old male presented for cervical traction, C5 and C6 corpectomy, and possible C4 to T2 posterior fusion following a motor vehicle accident. Intraoperatively, following drilling the C5 endplate, copious bleeding was observed from injury to the right vertebral artery resulting in pseudoaneurysm formation. The patient was loaded with ticagrelor and a self-expanding covered stent was placed via a transfemoral approach, resulting in obliteration of the pseudoaneurysm prior to completion of his cervical spine surgery. Emergent self-expanding covered stent placement for iatrogenic vertebral artery injury in the setting of an intraoperative injury is a safe and effective option. Ticagrelor is a viable alternative to traditional dual antiplatelet therapy for preventing thromboembolic complications in this urgent setting.

Risk Factors Associated with ICU-Specific Care in Patients Undergoing Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND

Multiple studies suggest routine postoperative intensive care unit (ICUs) stays in presumed high-risk neurosurgical procedures may be unnecessary. Our objective was to evaluate the risk factors associated with ICU-specific needs in patients undergoing elective endovascular treatment of unruptured intracranial aneurysms.

METHODS

A retrospective review of consecutive patients undergoing elective endovascular treatment of unruptured aneurysms was performed between January 2010 and January 2020 in a single academic medical center. Patient demographic information, aneurysm and treatment characteristics, intraoperative and postoperative complications, as well as ICU-specific needs, were abstracted. The primary outcome was ICU-specific needs.

RESULTS

A total of 382 patient encounters in 344 unique patients were abstracted. 13.6% (52 of 382) of patient encounters had an ICU-specific need. Multivariate analysis revealed that age [adjusted odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.07, p = 0.03], procedure duration greater 200 min (adjusted OR 2.75, 95% CI 1.34-5.88, p = 0.007), and any intraoperative complication (adjusted OR 20.41, CI 7.97-56.57, p < 0.001) were independent predictors of postoperative ICU-specific needs. The majority of ICU-specific needs (94%, 49 of 52) occurred within 6 h of surgery.

CONCLUSIONS

Our results show that age, procedure duration greater than or equal to 200 min, and intraoperative complication were independent predictors of postoperative ICU-specific needs in patients presenting for elective endovascular treatment of unruptured intracranial aneurysms. The majority of ICU-specific needs and associated complications occurred in the immediate postoperative period. This data can be used to help decide the appropriate postoperative level of care in this patient population.

Management of Internal Carotid Artery and Intracranial Anterior Circulation Tandem Occlusion with Stenting versus No Stenting: A Multicenter Study

BACKGROUND

Tandem occlusion (TO) describes not only occlusion of the middle cerebral artery but a contemporaneous occlusion of the cervical internal carotid artery. There is a paucity of data over whether mechanical thrombectomy (MT) alone, MT with angioplasty, or MT with carotid artery stent placement is superior. We aim to address a gap in the literature comparing carotid stenting with mechanical thrombectomy (CSMT) and carotid angioplasty with mechanical thrombectomy (CAMT) in patients presenting with acute anterior circulation TOs.

METHODS

This is a multicenter, retrospective study from 2012 to 2020 comparing CSMT and CAMT presenting with acute anterior circulation TOs. Primary outcomes of interest were functional status, perioperative stroke, mortality, and symptomatic intracranial hemorrhage (sICH). A total of 92 patients (66 vs. 26 in CSMT and CAMT, respectively) met inclusion criteria for analysis.

RESULTS

There was no statistically significant difference in functional outcomes at 90-day follow-up (adjusted odds ratio [aOR] 0.82; 95% confidence interval [CI] 0.20-3.5; P = 0.46). In addition, there was no statistically significant difference in 90-day mortality (aOR 0.361; 95% CI 0.016-2.92; P = 0.532) and perioperative stroke rate (aOR 1.76; 95% CI 0.160-15.6; P = 0.613). However, sICH risk was significantly greater in the stent-treated cohort (aOR 3.94; 95% CI 0.529-37.4; P = 0.003).

CONCLUSIONS

Functional outcomes, mortality, and perioperative stroke rates do not significantly differ in CSMT and CAMT procedures in the acute setting. However, CSMT-treated patients do appear to have an increased risk of sICH, potentially due to the use of additional antiplatelet agents following stent placement.

A Systematic Review and Meta-Analysis of Antiepileptic Prophylaxis in Spontaneous Intracerebral Hemorrhage

BACKGROUND

Frequency of clinical seizures may be as high as 16% in patients with spontaneous intracerebral hemorrhage (ICH). Current guidelines recommend against antiepileptic drug (AED) prophylaxis, but this recommendation is based on older trials, and the effect of newer AEDs is uncertain. The aim of this review was to study effects of AEDs on seizure occurrence and outcome in patients with spontaneous ICH.

METHODS

We searched key databases using combinations of the following terms: "levetiracetam," "prophylaxis," "ICH," "intracerebral hemorrhage," "intraparenchymal hemorrhage." Selected studies were reviewed for level of evidence and overall quality of data using Grading of Recommendations, Assessment, Development and Evaluations criteria. A meta-analysis was performed to evaluate seizure prevention, functional outcome, and mortality in patients with seizure prophylaxis compared with no prophylaxis following spontaneous ICH.

RESULTS

Seven articles met inclusion criteria and were graded level III studies. Administration of AEDs was not associated with reduced seizure risk (odds ratio 1.14, 95% confidence interval 0.47-2.77, P = 0.77). There was an association between AED prophylaxis and poor functional outcome (odds ratio 1.65, 95% confidence interval 1.17-2.31, P = 0.004) but not mortality (odds ratio 1.04, 95% confidence interval 0.62-1.72, P = 0.89). The overall quality of evidence using Grading of Recommendations, Assessment, Development and Evaluations criteria was low.

CONCLUSIONS

This systematic review and meta-analysis including recent studies focusing on newer AEDs supports the 2015 guidelines regarding AED use in spontaneous ICH. There are some important caveats, including a possible confounding association between AED use and higher ICH score and the overall poor quality of the available data. A randomized clinical trial may be helpful.

Stereotactic Radiosurgery With Versus Without Embolization for Brain Arteriovenous Malformations

BACKGROUND

Prior comparisons of brain arteriovenous malformations (AVMs) treated using stereotactic radiosurgery (SRS) with or without embolization were inherently flawed, due to differences in the pretreatment nidus volumes.

OBJECTIVE

To compare the outcomes of embolization and SRS, vs SRS alone for AVMs using pre-embolization malformation features.

METHODS

We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Patients were categorized into the embolization and SRS (E + SRS) or SRS alone (SRS-only) cohorts. The 2 cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was defined as AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiologic and symptomatic radiation-induced changes (RIC), and cyst formation.

RESULTS

The matched cohorts each comprised 101 patients. Crude AVM obliteration rates were similar between the matched E + SRS vs SRS-only cohorts (48.5% vs 54.5%; odds ratio = 0.788, P = .399). Cumulative probabilities of obliteration at 3, 4, 5, and 6 yr were also similar between the E + SRS (33.0%, 46.4%, 56.2%, and 60.8%, respectively) and SRS-only (32.9%, 46.2%, 56.0%, and 60.6%, respectively) cohorts (subhazard ratio (SHR) = 1.005, P = .981). Cumulative probabilities of radiologic RIC at 3, 4, 5, and 6 yr were lower in the E + SRS (25.0%, 25.7%, 26.7%, and 26.7%, respectively) vs SRS-only (45.3%, 46.2%, 47.8%, and 47.8%, respectively) cohort (SHR = 0.478, P = .004). Symptomatic and asymptomatic embolization-related complication rates were 8.3% and 18.6%, respectively. Rates of post-SRS hemorrhage, all-cause mortality, symptomatic RIC, and cyst formation were similar between the matched cohorts.

CONCLUSION

This study refutes the prevalent notion that AVM embolization negatively affects the likelihood of obliteration after SRS.

Embolization of Brain Arteriovenous Malformations With Versus Without Onyx Before Stereotactic Radiosurgery

BACKGROUND

Embolization of brain arteriovenous malformations (AVMs) using ethylene-vinyl alcohol copolymer (Onyx) embolization may influence the treatment effects of stereotactic radiosurgery (SRS) differently than other embolysates.

OBJECTIVE

To compare the outcomes of pre-SRS AVM embolization with vs without Onyx through a multicenter, retrospective matched cohort study.

METHODS

We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Embolized AVMs treated with SRS were selected and categorized based on embolysate usage into Onyx embolization (OE + SRS) or non-Onyx embolization (NOE + SRS) cohorts. The 2 cohorts were matched in a 1:1 ratio using de novo AVM features for comparative analysis of outcomes.

RESULTS

The matched cohorts each comprised 45 patients. Crude AVM obliteration rates were similar between the matched OE + SRS vs NOE + SRS cohorts (47% vs 51%; odds ratio [OR] = 0.837, P = .673). Cumulative probabilities of obliteration were also similar between the OE + SRS vs NOE + SRS cohorts (subhazard ratio = 0.992, P = .980). Rates of post-SRS hemorrhage, all-cause mortality, radiation-induced changes, cyst formation, and embolization-associated complications were similar between the matched cohorts. Sensitivity analysis for AVMs in the OE + SRS cohort embolized with Onyx alone revealed a higher rate of asymptomatic embolization-associated complications in this subgroup compared to the NOE + SRS cohort (36% vs 15%; OR = 3.297, P = .034), but the symptomatic complication rates were similar.

CONCLUSION

Nidal embolization using Onyx does not appear to differentially impact the outcomes of AVM SRS compared with non-Onyx embolysates. The embolic agent selected for pre-SRS AVM embolization should reflect both the experience of the neurointerventionalist and target of endovascular intervention.

Safety of the APOLLO Onyx delivery microcatheter for embolization of brain arteriovenous malformations: results from a prospective post-market study

BACKGROUND

Catheter retention and difficulty in retrieval have been observed during embolization of brain arteriovenous malformations (bAVMs) with the Onyx liquid embolic system (Onyx). The Apollo Onyx delivery microcatheter (Apollo) is a single lumen catheter designed for controlled delivery of Onyx into the neurovasculature, with a detachable distal tip to aid catheter retrieval. This study evaluates the safety of the Apollo for delivery of Onyx during embolization of bAVMs.

METHODS

This was a prospective, non-randomized, single-arm, multicenter, post-market study of patients with a bAVM who underwent Onyx embolization with the Apollo between May 2015 and February 2018. The primary endpoint was any catheter-related adverse event (AE) at 30 days, such as unintentional tip detachment or malfunction with clinical sequelae, or retained catheter. Procedure-related AEs (untoward medical occurrence, disease, injury, or clinical signs) and serious AEs (life threatening illness or injury, permanent physiological impairment, hospitalization, or requiring intervention) were also recorded.

RESULTS

A total of 112 patients were enrolled (mean age 44.1±17.6 years, 56.3% men), and 201 Apollo devices were used in 142 embolization procedures. The mean Spetzler-Martin grade was 2.38. The primary endpoint was not observed (0/112, 0%). The catheter tip detached during 83 (58.5%) procedures, of which 2 (2.4%) were unintentional and did not result in clinical sequelae. At 30 days, procedure related AEs occurred in 26 (23.2%) patients, and procedure-related serious AEs in 12 (10.7%). At 12 months, there were 3 (2.7%) mortalities, including 2 (1.8%) neurological deaths, none of which were device-related.

CONCLUSION

This study demonstrates the safety of Apollo for Onyx embolization of bAVMs.

CLINICAL TRIAL REGISTRATION

CNCT02378883.

Effect of Blood Pressure Management Strategies on Outcomes in Patients with Acute Ischemic Stroke After Successful Mechanical Thrombectomy

BACKGROUND

Variability, with no general consensus, exists in how patients' blood pressure should be managed after successful mechanical thrombectomy (MT) for large vessel ischemic stroke. We examined whether exceeding the systolic blood pressure (SBP) targets in patients during the first 24 hours after successful MT led to worse outcomes.

METHODS

We retrospectively studied a consecutive sample of adult patients who had undergone MT. We collected SBP data for the first 24 hours after MT and categorized the patients into 3 groups according to cases of the SBP exceeding 140, 160, or 180 mm Hg. The primary and secondary outcomes were the modified Rankin scale score at discharge and 90 days of follow-up, the incidence of symptomatic intracranial hemorrhage, malignant cerebral edema, and hemicraniectomy, mortality within 90 days, and discharge disposition.

RESULTS

A total of 117 patients were included (mean age, 65 ± 13.12 years; 53% female). The occurrence of ≥1 instance of SBP ≥180 mm Hg was significantly associated with poor functional outcomes at discharge (adjusted odds ratio [OR], 5.83; 95% confidence interval [CI], 1.41-32.9; P = 0.025) but not at 90 days of follow-up. The occurrence of SBP ≥160 mm Hg resulted in an independently increased odds of malignant cerebral edema (adjusted OR, 17.07; 95% CI, 2.56-174.4; P = 0.01), with a trend toward increased odds of symptomatic intracranial hemorrhage (adjusted OR, 4.42; 95% CI, 1.03-21.2; P = 0.0503).

CONCLUSIONS

These results suggest that individual instances of SBP elevation alone after successful MT, rather than a necessarily prolonged increased blood pressure as reflected by the mean or median SBP values, can significantly affect the clinical outcomes after successful MT.

Stereotactic radiosurgery with versus without prior Onyx embolization for brain arteriovenous malformations

OBJECTIVE

Investigations of the combined effects of neoadjuvant Onyx embolization and stereotactic radiosurgery (SRS) on brain arteriovenous malformations (AVMs) have not accounted for initial angioarchitectural features prior to neuroendovascular intervention. The aim of this retrospective, multicenter matched cohort study is to compare the outcomes of SRS with versus without upfront Onyx embolization for AVMs using de novo characteristics of the preembolized nidus.

METHODS

The International Radiosurgery Research Foundation AVM databases from 1987 to 2018 were retrospectively reviewed. Patients were categorized based on AVM treatment approach into Onyx embolization (OE) and SRS (OE+SRS) or SRS alone (SRS-only) cohorts and then propensity score matched in a 1:1 ratio. The primary outcome was AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiological and symptomatic radiation-induced changes (RICs), and cyst formation. Comparisons were analyzed using crude rates and cumulative probabilities adjusted for competing risk of death.

RESULTS

The matched OE+SRS and SRS-only cohorts each comprised 53 patients. Crude rates (37.7% vs 47.2% for the OE+SRS vs SRS-only cohorts, respectively; OR 0.679, p = 0.327) and cumulative probabilities at 3, 4, 5, and 6 years (33.7%, 44.1%, 57.5%, and 65.7% for the OE+SRS cohort vs 34.8%, 45.5%, 59.0%, and 67.1% for the SRS-only cohort, respectively; subhazard ratio 0.961, p = 0.896) of AVM obliteration were similar between the matched cohorts. The secondary outcomes of the matched cohorts were also similar. Asymptomatic and symptomatic embolization-related complication rates in the matched OE+SRS cohort were 18.9% and 9.4%, respectively.

CONCLUSIONS

Pre-SRS AVM embolization with Onyx does not appear to negatively influence outcomes after SRS. These analyses, based on de novo nidal characteristics, thereby refute previous studies that found detrimental effects of Onyx embolization on SRS-induced AVM obliteration. However, given the risks incurred by nidal embolization using Onyx, this neoadjuvant intervention should be used judiciously in multimodal treatment strategies involving SRS for appropriately selected large-volume or angioarchitecturally high-risk AVMs.

Estimating minimal clinically important differences for two scales in patients with chronic traumatic brain injury

BACKGROUND

This study aimed to establish the minimal clinically important difference (MCID) for the Fugl-Meyer Motor Scale (FMMS) and the Disability Rating Scale (DRS) to evaluate interventions in patients with motor deficits in the chronic phase after traumatic brain injury (TBI).

METHODS

MCIDs were established with a structured expert consultation process, the RAND/UCLA modified Delphi method. This process consisted of a literature review and input from a 10-person, multidisciplinary expert panel. The experts were asked to rate meaningfulness of improvements in hypothetical patients and numeric changes via two rounds of ratings and an in-person meeting.

RESULTS

The estimated MCIDs were six and five points on the FMMS Upper and Lower Extremity Scale, respectively, and one point on the DRS. The experts argued against establishing an MCID for the combined FMMS because the same change was more likely to be meaningful if concentrated in one extremity and because a meaningful improvement in one extremity implies meaningfulness irrespective of the changes in the other.

CONCLUSIONS

This study is the first to establish MCIDs for the FMMS and the DRS in the chronic phase after TBI. The results may be helpful for the design and interpretation of clinical trials of interventions.

Continuous improvement in patient safety and quality in neurological surgery: the American Board of Neurological Surgery in the past, present, and future

The American Board of Neurological Surgery (ABNS) was incorporated in 1940 in recognition of the need for detailed training in and special qualifications for the practice of neurological surgery and for self-regulation of quality and safety in the field. The ABNS believes it is the duty of neurosurgeons to place a patient's welfare and rights above all other considerations and to provide care with compassion, respect for human dignity, honesty, and integrity. At its inception, the ABNS was the 13th member board of the American Board of Medical Specialties (ABMS), which itself was founded in 1933. Today, the ABNS is one of the 24 member boards of the ABMS. To better serve public health and safety in a rapidly changing healthcare environment, the ABNS continues to evolve in order to elevate standards for the practice of neurological surgery. In connection with its activities, including initial certification, recognition of focused practice, and continuous certification, the ABNS actively seeks and incorporates input from the public and the physicians it serves. The ABNS board certification processes are designed to evaluate both real-life subspecialty neurosurgical practice and overall neurosurgical knowledge, since most neurosurgeons provide call coverage for hospitals and thus must be competent to care for the full spectrum of neurosurgery. The purpose of this report is to describe the history, current state, and anticipated future direction of ABNS certification in the US.

Neurophysiological Monitoring During Arteriovenous Malformation Embolization

BACKGROUND

Neurophysiological monitoring (NPM) is frequently performed during arteriovenous malformation (AVM) embolization. However, the ability of NPM to predict neurological deficits or improve surgical decision making in this setting has not been studied.

OBJECTIVE

To review our use of NPM during AVM embolization to better define its utility.

METHODS

We retrospectively examined AVM embolization cases from 2004 to 2017. We recorded patient and AVM characteristics as well as outcomes. We then reviewed NPM results from each case, including somatosensory evoked potentials and electroencephalogram. Our primary outcome was postoperative neurological deficit, and secondary outcomes were discharge and 30-d modified Rankin Score (mRS).

RESULTS

There were 173 embolizations in 74 patients. Mean patient age was 40 yr. There were 8 (5%) transient and 2 (1.3%) permanent neurological complications. Among those with neurological complications, 3 had NPM changes during the operation (positive predictive value [PPV] = 50%). This improved to 67% for permanent NPM change. Three patients had NPM changes but did not suffer clinical deficits postoperatively (negative predictive value = 90%). The predictive value of the test was improved for discharge but not 30-d mRS, and the test performance improved dramatically with increased pretest probabilities (likelihood ratio [LR](+) = 14.5, LR(-) = 0.715).

CONCLUSION

We present a large series of AVM embolization operations performed with NPM. The PPV of NPM changes was moderate but improved dramatically with increased pretest probabilities. The rate of permanent neurological complications was among the lowest reported in the literature, suggesting NPM may lead to improved intraoperative decision making.

Abstract WP78: Outcomes After Off-Label Use of the Pipeline Embolization Device for Intracranial Aneurysms: a Multicenter Cohort Study

Objectives: The aim of this retrospective multicenter cohort study is to examine the outcomes of the Pipeline embolization device (PED) for the treatment of intracranial aneurysms outside of United States Food and Drug Administration approved (off-label) indications.

Methods: Data from aneurysm patients treated with the PED for off-label indications was pooled from four different centers. The primary endpoints were decline in modified Rankin Scale (mRS) by at least 1 point and angiographic aneurysm occlusion at follow-up.

Results: The study cohort was comprised of 109 patients. The mean aneurysm size was , 20% were located in the posterior circulation, and 12% were ruptured. The most common reasons for off-label use were aneurysm size (57%), location (11%) or both (12%). The mean follow-up was 9 months. Complete occlusion was achieved in 82% of cases at last angiographic follow-up and mRS decline was found in 18.8% of the cases. In the univariate analysis, only ruptured aneurysm presentation was significantly associated with mRS decline (p=0.016) (Table 1). In the multivariate analysis, size as the indication for off-label use was associated with higher odds of complete aneurysm occlusion on final angiography (Table 2).

Conclusion: The off-label use of the PED has a reasonable risk to benefit profile for appropriately selected aneurysms. Posterior circulation location and fusiform morphology do not appear to be associated with worse clinical or angiographic outcomes.

Accreditation Is Perceived to Improve Echocardiography Laboratory Quality: Results of an Intersocietal Accreditation Commission Survey

The Intersocietal Accreditation Commission (IAC) began accrediting echocardiography laboratories in 1996 to improve quality in diagnostic imaging facilities. With no existing data linking accreditation to improved outcomes, the aim of this study was to examine the perceived value of accreditation among individuals who have successfully achieved IAC echocardiography accreditation. An electronic survey was sent to accredited facilities soliciting demographic data along with questions regarding the perceived value of accreditation related to 15 quality indicators; 10.455 emails were sent with 999 responses (9.6%), and 63% of respondents reported improvement in results due to accreditation. Of the 15 quality indicators, the process was perceived as leading to improvement by a majority for 10 of the quality indicators. Nonphysicians tended to report more improvement compared with physicians (64% vs. 54%, P = .056). The perceptions from hospital-based respondents were more favorable than nonhospital-based respondents (67% vs. 59%, P < .001). More than 90% of respondents reported that maintaining accreditation was important for improved quality and better reimbursement. The study showed that IAC echocardiography facility accreditation is perceived by most facilities to improve operations for most quality indicators, particularly regarding study quality and reporting.

Abstract TMP108: Absence of Cortical Microvessel Spasm During Large Vessel Spasm Following Experimental Subarachnoid Hemorrhage

Introduction: A significant portion of the morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH) is due to delayed ischemic neurological deficits (DIND). Although large vessel vasospasm has been implicated as a cause of DIND, the presence of such spasm is not always correlated with DIND. In the present experiment we examined the cortical microvasculature in awake mice after SAH in an experimental model typically associated with large vessel vasospasm.

Methods: Twenty adult mice underwent cisterna magna (CM) injection of 60ul syngenic donor blood or artificial cerebrospinal fluid (aCSF). The mice were perfused at 72 hours, and Circle of Willis (COW) vessel diameters were measured. In a separate experiment, polished and reinforced thinned skull cranial windows were created in 10 mice that then underwent CM blood or aCSF injection. Cortical microvessels were measured in living, awake mice in the postoperative vasospasm period using two photon laser scanning microscopy.

Results: A pairwise comparison of COW vessels revealed a statistically significant difference in vessel diameter between the experimental and control groups at each of the sites measured (ACA, P=0.0012; MCA, P=0.0259; Pcom, P=0.0053). In the second experiment, there were no significant differences in cortical microvessel diameter between the experimental and control groups.

Conclusions: This study represents the first report of in vivo imaging of cortical microvessels during large vessel spasm following SAH. In a CM injection SAH model, we observed significant large vessel spasm but no cortical microvessel spasm. These results may have important implications for understanding the mechanisms of DIND.

Chronic Stroke Outcome Measures for Motor Function Intervention Trials: Expert Panel Recommendations

BACKGROUND

About half of survivors with stroke experience severe and significant long-term disability. The purpose of this article is to review the state of the science and to make recommendations for measuring patient-centric outcomes in interventions for motor improvement in the chronic stroke phase.

METHODS AND RESULTS

A 9-member expert panel reviewed evidence to identify measures of upper and lower extremity function used to date as outcomes in trials with patients who experienced a stroke ≥6 months before assessment. Outcome measures were screened using StrokEDGE consensus panel recommendations, and evaluated for availability of a published minimal clinically important difference. Measures meeting these criteria were further evaluated with regard to their level of measurement, psychometric properties, and ability of minimal clinically important difference to capture gains associated with improved function and clinical relevance to patients, to arrive at recommendations. A systematic literature review yielded 115 clinical trials of upper and lower extremity function in chronic stroke that used a total of 34 outcome measures. Seven of these had published minimal clinically important differences and were recommended or highly recommended by StrokEDGE. Those are the Fugl-Meyer Upper Extremity and Lower Extremity scales, Wolf Motor Function Test, Action Research Arm Test, Ten-Meter and Six-Minute Walk Tests, and the Stroke Impact Scale. All had evidence for their psychometric performance, although the strength of evidence for validity varied, especially in populations with chronic stroke Fugl-Meyer Upper and Lower Extremity scales showing the strongest evidence for validity.

CONCLUSIONS

The panel recommends that the Fugl-Meyer Upper and Lower Extremity scales be used as primary outcomes in intervention trials targeting motor function in populations with chronic stroke. The other 6 measures are recommended as secondary outcomes.

How Do Noninvasive Imaging Facilities Perceive the Accreditation Process? Results of an Intersocietal Accreditation Commission Survey

The Intersocietal Accreditation Commission (IAC) accredits vascular, echocardiography, nuclear medicine, computed tomography, and magnetic resonance imaging laboratories. How facilities involved in the accreditation process view accreditation is unknown. The objective of this study was to examine the perception of laboratory accreditation from those who had undergone the process. An electronic survey request was sent to all facilities that had received IAC accreditation at least once. Demographic information, as well as opinions on the perceived value of accreditation as it relates to 15 quality metrics was acquired. Responses were obtained from 2782 facilities. Of the 15 quality metrics examined, the process was perceived as leading to improvements by a majority of respondents for 10 (67%) metrics including: report standardization, adherence to guidelines, test standardization, report completeness, identification of deficiencies, improved staff knowledge, report timeliness, distinguished facility, correction of deficiencies, and image quality. Overall, the perceived improvement was greater for hospital-based facilities (global 66% vs 59%; P < 0.001). Survey data demonstrate that the accreditation process has a positive perceived impact on the majority of examined metrics. These findings suggest that those undergoing the process find value in accreditation.

Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this updated statement is to provide comprehensive and evidence-based recommendations for management of patients with unruptured intracranial aneurysms.

METHODS

Writing group members used systematic literature reviews from January 1977 up to June 2014. They also reviewed contemporary published evidence-based guidelines, personal files, and published expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulated recommendations using standard American Heart Association criteria. The guideline underwent extensive peer review, including review by the Stroke Council Leadership and Stroke Scientific Statement Oversight Committees, before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with unruptured intracranial aneurysms. The guidelines address presentation, natural history, epidemiology, risk factors, screening, diagnosis, imaging and outcomes from surgical and endovascular treatment.

Facility perception of nuclear cardiology accreditation: Results of an Intersocietal Accreditation Commission (IAC) survey

BACKGROUND

The Medicare Improvements for Patients and Providers Act requires accreditation for all non-hospital suppliers of nuclear cardiology, nuclear medicine, and positron emission tomography (PET) studies as a condition of reimbursement. The perceptions of these facilities regarding the value and impact of the accreditation process are unknown. We conducted an electronic survey to assess the value of nuclear cardiology accreditation.

METHODS

A request to participate in an electronic survey was sent to the medical and technical directors (n = 5,721) of all facilities who had received Intersocietal Accreditation Commission (IAC) Nuclear/PET accreditation. Demographic information, as well as, opinions on the value of accreditation as it relates to 16 quality metrics was obtained.

RESULTS

There were 664 (11.6%) respondents familiar with the accreditation process of which 26% were hospital-based and 74% were nonhospital-based. Of the quality metrics examined, the process was perceived as leading to improvements by a majority of all respondents for 10 (59%) metrics including report standardization, report completeness, guideline adherence, deficiency identification, report timeliness, staff knowledge, facility distinction, deficiency correction, acquisition standardization, and image quality. Overall, the global perceived improvement was greater for hospital-based facilities (63% vs 57%; P < .001). Ninety-five percent of respondents felt that accreditation was important. Hospital-based facilities were more likely to feel that accreditation demonstrates a commitment to quality (43% vs 33%, P = .029), while nonhospital-based facilities were more likely to feel accreditation is important for reimbursement (50% vs 29%, P≤ .001).

CONCLUSION

Although the accreditation process is demanding, the results of the IAC survey indicate that the accreditation process has a positive perceived impact for the majority of examined quality metrics, suggesting the facilities find the process to be valuable.

Onyx-HD 500 Embolization of a Traumatic Internal Carotid Artery Pseudoaneurysm after Transsphenoidal Surgery

BACKGROUND AND PURPOSE

Traumatic intracranial pseudoaneurysms present a challenge for treatment. Traditionally these lesions have required a deconstructive approach consisting of vessel sacrifice since their fragile nature often makes direct microsurgical repair or coil embolization hazardous. As a high-viscosity liquid embolic agent that results in immediate, vessel sparing aneurysm occlusion, Onyx-HD 500 represents a uniquely efficacious tool for this clinical situation.

CASE SUMMARY

We report the case of a 56-year-old right-handed gentleman who suffered a vascular injury to the ICA during revision transsphenoidal surgery for a recurrent pituitary macroadenoma. The patient was initially treated with nasal packing, but after recurrent episodes of epistaxis and a CT angiogram demonstrating a large traumatic ICA pseudoaneurysm, the patient was referred for invasive treatment. Given the presumed fragility of the lesion, embolization with Onyx-HD 500 was chosen in order to safely achieve immediate aneurysm occlusion without the need for vessel sacrifice. After an early recurrence due to incomplete initial embolization, the patient went on to complete occlusion without further hemorrhage.

CONCLUSION

This case illustrates the utility of a high-viscosity liquid embolic agent in providing immediate protection from rehemorrhage by occluding a large ruptured pseudoaneurysm of the proximal intracranial ICA, while sparing the parent artery.

Recanalization and clinical outcome of occlusion sites at baseline CT angiography in the Interventional Management of Stroke III trial

PURPOSE

To use baseline computed tomographic (CT) angiography to analyze imaging and clinical end points in an Interventional Management of Stroke III cohort to identify patients who would benefit from endovascular stroke therapy.

MATERIALS AND METHODS

The primary clinical end point was 90-day dichotomized modified Rankin Scale (mRS) score. Secondary end points were 90-day mRS score distribution and 24-hour recanalization. Prespecified subgroup was baseline proximal occlusions (internal carotid, M1, or basilar arteries). Exploratory analyses were subsets with any occlusion and specific sites of occlusion (two-sided α = .01).

RESULTS

Of 656 subjects, 306 (47%) underwent baseline CT angiography or magnetic resonance angiography. Of 306, 282 (92%) had arterial occlusions. At baseline CT angiography, proximal occlusions (n = 220) demonstrated no difference in primary outcome (41.3% [62 of 150] endovascular vs 38% [27 of 70] intravenous [IV] tissue-plasminogen activator [tPA]; relative risk, 1.07 [99% confidence interval: 0.67, 1.70]; P = .70); however, 24-hour recanalization rate was higher for endovascular treatment (n = 167; 84.3% [97 of 115] endovascular vs 56% [29 of 52] IV tPA; P < .001). Exploratory subgroup analysis for any occlusion at baseline CT angiography did not demonstrate significant differences between endovascular and IV tPA arms for primary outcome (44.7% [85 of 190] vs 38% [35 of 92], P = .29), although ordinal shift analysis of full mRS distribution demonstrated a trend toward more favorable outcome (P = .011). Carotid T- or L-type occlusion (terminal internal carotid artery [ICA] with M1 middle cerebral artery and/or A1 anterior cerebral artery involvement) or tandem (extracranial or intracranial) ICA and M1 occlusion subgroup also showed a trend favoring endovascular treatment over IV tPA alone for primary outcome (26% [12 of 46] vs 4% [one of 23], P = .047).

CONCLUSION

Significant differences were identified between treatment arms for 24-hour recanalization in proximal occlusions; carotid T- or L-type and tandem ICA and M1 occlusions showed greater recanalization and a trend toward better outcome with endovascular treatment. Vascular imaging should be mandated in future endovascular trials to identify such occlusions. Online supplemental material is available for this article.