Automated Preoperative and Postoperative Volume Estimates Risk of Retreatment in Chronic Subdural Hematoma: A Retrospective, Multicenter Study.

BACKGROUND AND OBJECTIVES: Several neurosurgical pathologies, ranging from glioblastoma to hemorrhagic stroke, use volume thresholds to guide treatment decisions. For chronic subdural hematoma (cSDH), with a risk of retreatment of 10%-30%, the relationship between preoperative and postoperative cSDH volume and retreatment is not well understood. We investigated the potential link between preoperative and postoperative cSDH volumes and retreatment. METHODS: We performed a retrospective chart review of patients operated for unilateral cSDH from 4 level 1 trauma centers, February 2009-August 2021. We used a 3-dimensional deep learning, automated segmentation pipeline to calculate preoperative and postoperative cSDH volumes. To identify volume thresholds, we constructed a receiver operating curve with preoperative and postoperative volumes to predict cSDH retreatment rates and selected the threshold with the highest Youden index. Then, we developed a light gradient boosting machine to predict the risk of cSDH recurrence. RESULTS: We identified 538 patients with unilateral cSDH, of whom 62 (12%) underwent surgical retreatment within 6 months of the index surgery. cSDH retreatment was associated with higher preoperative (122 vs 103 mL; P < .001) and postoperative (62 vs 35 mL; P < .001) volumes. Patients with >140 mL preoperative volume had nearly triple the risk of cSDH recurrence compared with those below 140 mL, while a postoperative volume >46 mL led to an increased risk for retreatment (22% vs 6%; P < .001). On multivariate modeling, our model had an area under the receiver operating curve of 0.76 (95% CI: 0.60-0.93) for predicting retreatment. The most important features were preoperative and postoperative volume, platelet count, and age. CONCLUSION: Larger preoperative and postoperative cSDH volumes increase the risk of retreatment. Volume thresholds may allow identification of patients at high risk of cSDH retreatment who would benefit from adjunct treatments. Machine learning algorithm can quickly provide accurate estimates of preoperative and postoperative volumes.

Interaction of admission platelet count with current medications and the risk for chronic subdural recurrence.

OBJECTIVE: Chronic subdural hematoma (cSDH) has a reported 10%-24% rate of recurrence after surgery, and prognostic models for recurrence have produced equivocal results. The objective of this study was to leverage a data mining algorithm, chi-square automatic interaction detection (CHAID), which can incorporate continuous, nominal, and binary data into a decision tree, to identify the most robust predictors of repeat surgery for cSDH patients. METHODS: This was a retrospective cohort study of all patients with SDH from two level 1 trauma centers at a single institution. All patients underwent cSDH evacuation performed by 15 neurosurgeons between 2011 and 2020. The primary outcome was the rate of repeat surgery for recurrent cSDH following the initial evacuation. The authors used CHAID to identify relevant predictors of repeat surgery, including age, sex, comorbidities, postsurgical complications, platelet count prior to the first procedure, midline shift prior to the first procedure, hematoma volume, and preoperative use of anticoagulants, antiplatelets, or statins. RESULTS: Sixty (13.8%) of 435 study-eligible patients (average age 74.0 years) had a cSDH recurrence. These patients had 2.0 times greater odds of having used anticoagulants. The final CHAID model had an overall accuracy of 87.4% and an area under the curve of 0.76. According to the model, the predictor with the strongest association with cSDH recurrence was admission platelet count. Approximately 26% of patients (n = 23/87) with an admission platelet count < 157 × 109/L had a cSDH recurrence, whereas none of the 44 patients with admission platelets > 313 × 109/L had a recurrence. Approximately 17% of patients in the 157-313 × 109/L platelet group who had used preoperative statins required a second procedure, which was associated with a 2.3 times increased risk for repeat surgery compared to those who had not used statins preoperatively. Among those who had not used preoperative statins, a platelet count ≤ 179 × 109/L on admission for the first procedure was the strongest differentiator for a second surgery (n = 5/22 [23%]), which increased the risk of recurrence by 4.5 times. Among the patients using preoperative statins, the use of anticoagulants was the strongest differentiator for requiring repeat surgery (n = 11/33 [33%]). CONCLUSIONS: The described model identified platelet count on admission as the most important predictor of repeat cSDH surgery, followed by preoperative statin use and anticoagulant use. Critical cutoffs for platelet count were identified, which future studies should evaluate to determine if they are modifiable or reflective of underlying disease states.

The perils and promises of generative artificial intelligence in neurointerventional surgery.

Generative artificial intelligence (AI) holds great promise in neurointerventional surgery by providing clinicians with powerful tools for improving surgical precision, accuracy of diagnoses, and treatment planning. However, potential perils include biases or inaccuracies in the data used to train the algorithms, over-reliance on generative AI without human oversight, patient privacy concerns, and ethical implications of using AI in medical decision-making. Careful regulation and oversight are needed to ensure that the promises of generative AI in neurointerventional surgery are realized while minimizing its potential perils.[ChatGPT authored summary using the prompt "In one paragraph summarize the promises and perils of generative AI in neurointerventional surgery".].

Walrus large bore guide catheter impact on recanalization first pass effect and outcomes: the WICkED study.

BACKGROUND: The use of a balloon-guide catheter (BGC) in acute stroke treatment has been widely adopted after demonstrating optimized procedure metrics and outcomes. Initial technical constraints of previous devices included catheter stiffness and smaller inner diameters. We aim to evaluate the performance and safety of the Walrus BGC, a variable stiffness catheter with a large bore 0.087 inch inner diameter (ID), via the the WICkED study (Walrus Large Bore guide Catheter Impact on reCanalization first pass Effect anD outcomes). METHODS: This is a retrospective, site adjudicated, multicenter study on consecutive patients with large vessel occlusion treated with the Walrus BGC. Baseline characteristics, procedural outcomes and functional outcomes were analyzed. RESULTS: A total of 338 patients met the inclusion criteria. The Walrus was successfully tracked into distal vasculature and allowed therapeutic device delivery in all but 3 cases (0.9%). Large aspiration catheters ≥0.070 inch ID were used in 71.9% of cases. Stent retriever thrombectomy was used as the first-line modality in 59.2% and thromboaspiration in 40.8% of cases. The successful recanalization rate (modified treatment in cerebral ischemia (mTICI) 2b/3) was 94.4%, with 64.8% of the patients achieving mTICI 2b/3 after the first pass. The Walrus-related adverse event rate was 0.6%, corresponding to two vessel dissections. Functional independence was 50% (126/252) and mortality 25% (63/252). Unfavorable outcomes were more likely in older patients, who had unsuccessful reperfusion, longer procedure times, and a higher mean number of passes. CONCLUSION: In acute ischemic stroke patients presenting with large vessel occlusion, the Walrus BGC demonstrated excellent navigability and safety profile, allowed the accommodation of leading large bore aspiration catheters, and demonstrated high vessel recanalization rates.

Comparative study of intracranial access in thrombectomy using next generation 0.088 inch guide catheter technology.

BACKGROUND: Most conventional 0.088 inch guide catheters cannot safely navigate intracranial vasculature. The objective of this study is to evaluate the safety of stroke thrombectomy using a novel 0.088 inch guide catheter designed for intracranial navigation. METHODS: This is a multicenter retrospective study, which included patients over 18 years old who underwent thrombectomy for anterior circulation large vessel occlusions. Technical outcomes for patients treated using the TracStar Large Distal Platform (TracStar LDP) or earlier generation TRX LDP were compared with a matched cohort of patients treated with other commonly used guide catheters. The primary outcome measure was device-related complications. Secondary outcome measures included guide catheter failure and time between groin puncture and clot engagement. RESULTS: Each study arm included 45 patients. The TracStar group was non-inferior to the control group with regard to device-related complications (6.8% vs 8.9%), and the average time to clot engagement was 8.89 min shorter (14.29 vs 23.18 min; p=0.0017). There were no statistically significant differences with regard to other technical outcomes, including time to recanalization (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2B). The TracStar was successfully advanced into the intracranial internal carotid artery in 33 cases (73.33%); in three cases (6.67%), it was swapped for an alternate catheter. Successful reperfusion (mTICI 2B-3) was achieved in 95.56% of cases. Ninety-day follow-up data were available for 86.67% of patients, among whom 46.15% had an modified Rankin Score of 0-2%, and 10.26% were deceased. CONCLUSIONS: Tracstar LDP is safe for use during stroke thrombectomy and was associated with decreased time to clot engagement. Intracranial access was regularly achieved.

Efficacy of beveled tip aspiration catheter in mechanical thrombectomy for acute ischemic stroke.

BACKGROUND: Direct aspiration thrombectomy techniques use large bore aspiration catheters for mechanical thrombectomy. Several aspiration catheters are now available. We report a bench top exploration of a novel beveled tip catheter and our experience in treating large vessel occlusions (LVOs) using next-generation aspiration catheters. METHODS: A retrospective analysis from a prospectively maintained database comparing the bevel shaped tip aspiration catheter versus non-beveled tip catheters was performed. Patient demographics, periprocedural metrics, and discharge and 90-day modified Rankin Scale (mRS) scores were collected. Patients were divided into two groups based on which aspiration catheter was used. RESULTS: Our data showed no significant difference in age, gender, IV tissue plasminogen activator administration, admission NIH Stroke Scale score, baseline mRS, or LVO location between the beveled tip and flat tip groups. With the beveled tip, Thrombolysis in Cerebral Infarction (TICI) 2C or better recanalization was more frequent overall (93.2% vs 74.2%, p=0.017), stent retriever usage was lower (9.1% vs 29%, p=0.024), and patients had lower mRS on discharge (median 3 vs 4, p<0.001) and at 90 days (median 2 vs 4, p=0.008). CONCLUSION: Patients who underwent mechanical thrombectomy with the beveled tip catheter had a higher proportion of TICI 2C or better and had a significantly lower mRS score on discharge and at 90 days.

First attempt recanalization with ADAPT: rate, predictors, and outcome.

INTRODUCTION: The rate of first-attempt recanalization (FAR) with the newer-generation thrombectomy devices, and more specifically with aspiration devices, is not well known. Moreover, the effect of FAR on outcomes after mechanical thrombectomy is not properly understood. OBJECTIVE: To report the rate of FAR using a direct aspiration first pass technique (ADAPT), investigate the association between FAR and outcomes, and identify the predictors of FAR. METHODS: The ADAPT database was used to identify a subgroup of patients in whom FAR was achieved. Baseline characteristics, procedural, and postprocedural variables were collected. Outcome measures included 90-day modified Rankin scale (mRS) score, mortality, and hemorrhagic complications. Multivariate logistic regression was used to identify FAR predictors. RESULTS: A total of 524 patients was included of whom 178 (34.0%) achieved FAR. More patients in the FAR group than in the non-FAR group received IV tPA (46.6% vs 37.6%; p<0.05). For the functional outcome, higher proportions of patients in the FAR group achieved functional independence (mRS score 0-2; 53% vs 37%; p<0.05). Additionally, we observed lower mortality and hemorrhagic transformation rates in the FAR group than the non-FAR group. Independent predictors of FAR in the anterior circulation were pretreatment IV tPA, non-tandem occlusion, and use of larger reperfusion catheters (Penumbra, ACE 64-68). Independent predictors of FAR in the posterior circulation were diabetes, onset-to-groin time, and cardioembolic etiology. CONCLUSION: FAR was associated with better functional outcome and lower mortality rate. When ADAPT is used, a larger aspiration catheter and pretreatment IV tPA should be employed when indicated.

Thrombectomy for acute ischemic stroke in the elderly: a 'real world' experience.

INTRODUCTION: Completed randomized trials on endovascular thrombectomy (ET) did not independently assess the efficacy of ET in the elderly (≥80 years old) who were often excluded or under-represented in trials. There were also inconsistent criteria for patient selection in this population across the different trials. This work evaluates outcomes after ET for acute ischemic stroke (AIS) in the elderly at a high volume stroke center. METHODS: We reviewed all cases of AIS that underwent a direct aspiration first pass technique (ADAPT) thrombectomy for large vessel occlusions between March 2013 and October 2017 while comparing outcomes in the elderly with younger counterparts. We also reviewed AIS cases in elderly patients undergoing medical management who were matched to the ET counterparts by demographics, comorbidities, baseline deficits, and stroke severity. RESULTS: Of 560 patients undergoing ET for AIS, 108 patients were in the elderly group (≥80 years of age), and had a significantly lower likelihood of functional independence (defined as a modified Rankin Scale score of 0-2) at 90 days compared with younger patients (20.5% vs 44.4%, P<0.001), and higher mortality rates (34.3% vs 20%, P<0.001). When compared with patients undergoing medical management, elderly patients did not have a significant improvement in rates of good outcomes (20.5% vs 19.5%, P>0.05), and had significantly higher rates of hemorrhage (40.7% vs 9.3%, P<0.001). We also identified baseline stroke severity and the incidence of hemorrhage as two independent predictors of outcome in the elderly patients. CONCLUSIONS: ET in the elderly did not show a similar benefit to younger patients when compared with medical management. These findings emphasize the need for more optimal selection criteria for the elderly population to improve the risk to benefit ratio of ET.

Equivalent favorable outcomes possible after thrombectomy for posterior circulation large vessel occlusion compared with the anterior circulation: the MUSC experience.

INTRODUCTION: In acute ischemic stroke (AIS), posterior circulation large vessel occlusions (LVOs) have been associated with poorer outcomes compared with anterior circulation LVOs. The outcomes of anterior versus posterior circulation thrombectomy for LVOs were compared at a high volume center employing a direct aspiration first pass technique (ADAPT). METHODS: We retrospectively studied a database of AIS cases that underwent ADAPT thrombectomy for LVOs. Cases were grouped by anatomical location of thrombectomy (posterior vs anterior circulation), and analysis was performed on both entire sample size. RESULTS: A total of 436 AIS patients (50.2% women, mean age 67.3 years) underwent ADAPT thrombectomy for LVO during the study period, of whom 13% of had posterior circulation thrombectomy. Patients with posterior circulation thrombectomy did not show a significant difference in preprocedural variables, including age, baseline National Institutes of Health Stroke Scale (NIHSS), and onset to groin time, compared with anterior circulation (P>0.05). There were also no differences in procedural variables between the two groups. Patients in the posterior group were found to have a similar likelihood of good outcome (modified Rankin Scale score 0-2) at 90 days compared with the anterior group (42.9% vs 43.2%, respectively), and a small but not significant increase in mortality at 90 days. Multilogistic regression analysis showed that the anatomical location (anterior vs posterior) was not an independent predictor of good outcome or mortality after thrombectomy. Prominent predictors of outcome/mortality included age, female gender, procedure time, and baseline NIHSS. CONCLUSIONS: Our findings demonstrate that when patients are carefully selected for thrombectomy, those with posterior circulation LVOs can achieve similar outcomes compared with anterior circulation thrombectomy, indicating comparable safety and efficacy profiles.

Stent-assisted coiling of cerebral aneurysms: a single-center clinical and angiographic analysis.

OBJECTIVE: This study retrospectively compared the clinical and angiographic outcomes of treating cerebral aneurysms with Neuroform (NEU), Enterprise (EP), and Low-profile Visualized Intraluminal Support (LVIS/LVIS Jr) stents. MATERIALS AND METHODS: We conducted a retrospective analysis of a procedural database. All aneurysm procedures using any of the three types of self-expanding nitinol stents (NEU, EP and LVIS/LVIS Jr) were included. Intra-procedure complications, post-procedure complications, and angiographic results (Raymond-Roy grade scale, RRGS) were analyzed retrospectively. A multivariate logistic regression analysis was conducted to identify predictors of intra-procedure and post-procedure complications. RESULTS: Two hundred and forty-three aneurysms in 229 patients treated with stent-assisted coiling were included (NEU group: 109 aneurysms; EP group: 61 aneurysms; LVIS/LVIS Jr: 73 aneurysms). The LVIS/LVIS Jr group was associated with the lowest rate of initial complete occlusion (RRGS I: 47.9%; 35/73). Follow-up showed the proportion of RRGS I increased for all stent groups but was greatest in the LVIS/LVIS Jr group. Overall, 17 intra-procedural complications were seen in 229 patients (7.4%) and 15 post-procedural complications were found in 198 patients at follow-up (7.6%), with no differences between stent groups. Thrombotic events were the most common complications and occurred in 13 patients (13/229, 5.7%). CONCLUSIONS: All three types of stents used to treat cerebral aneurysms with unfavorable neck were safe and effective, providing suitable support for the coil mass. LVIS/LVIS Jr promotes better progressive aneurysm complete occlusion than the other two stents but seems to cause more common intra-procedural stent-related thrombotic events and fewer post-procedural complications.

The golden 35†min of stroke intervention with ADAPT: effect of thrombectomy procedural time in acute ischemic stroke on outcome.

INTRODUCTION: In acute ischemic stroke (AIS), extending mechanical thrombectomy procedural times beyond 60 min has previously been associated with an increased complication rate and poorer outcomes. OBJECTIVE: After improvements in thrombectomy methods, to reassess whether this relationship holds true with a more contemporary thrombectomy approach: a direct aspiration first pass technique (ADAPT). METHODS: We retrospectively studied a database of patients with AIS who underwent ADAPT thrombectomy for large vessel occlusions. Patients were dichotomized into two groups: 'early recan', in which recanalization (recan) was achieved in ≤35 min, and 'late recan', in which procedures extended beyond 35 min. RESULTS: 197 patients (47.7% women, mean age 66.3 years) were identified. We determined that after 35 min, a poor outcome was more likely than a good (modified Rankin Scale (mRS) score 0-2) outcome. The baseline National Institutes of Health Stroke Scale (NIHSS) score was similar between 'early recan' (n=122) (14.7±6.9) and 'late recan' patients (n=75) (15.9±7.2). Among 'early recan' patients, recanalization was achieved in 17.8±8.8 min compared with 70±39.8 min in 'late recan' patients. The likelihood of achieving a good outcome was higher in the 'early recan' group (65.2%) than in the 'late recan' group (38.2%; p<0.001). Patients in the 'late recan' group had a higher likelihood of postprocedural hemorrhage, specifically parenchymal hematoma type 2, than those in the 'early recan' group. Logistic regression analysis showed that baseline NIHSS, recanalization time, and atrial fibrillation had a significant impact on 90-day outcomes. CONCLUSIONS: Our findings suggest that extending ADAPT thrombectomy procedure times beyond 35 min increases the likelihood of complications such as intracerebral hemorrhage while reducing the likelihood of a good outcome.

Evaluation of previously embolized intracranial aneurysms: inter-and intra-rater reliability among neurosurgeons and interventional neuroradiologists.

BACKGROUND: The angiographic evaluation of previously coiled aneurysms can be difficult yet remains critical for determining re-treatment. OBJECTIVE: The main objective of this study was to determine the inter-rater reliability for both the Raymond Scale and per cent embolization among a group of neurointerventionalists evaluating previously embolized aneurysms. METHODS: A panel of 15 neurointerventionalists examined 92 distinct cases of immediate post-coil embolization and 1 year post-embolization angiographs. Each case was presented four times throughout the study, along with alterations in demographics in order to evaluate intra-rater reliability. All respondents were asked to provide the per cent embolization (0-100%) and Raymond Scale grade (1-3) for each aneurysm. Inter-rater reliability was evaluated by computing weighted kappa values (for the Raymond Scale) and intraclass correlation coefficients (ICC) for per cent embolization. RESULTS: 10 neurosurgeons and 5 interventional neuroradiologists evaluated 368 simulated cases. The agreement among all readers employing the Raymond Scale was fair (κ=0.35) while concordance in per cent embolization was good (ICC=0.64). Clinicians with fewer than 10 years of experience demonstrated a significantly greater level of agreement than the group with greater than 10 years (κ=0.39 and ICC=0.70 vs κ=0.28 and ICC=0.58). When the same aneurysm was presented multiple times, clinicians demonstrated excellent consistency when assessing per cent embolization (ICC=0.82), but moderate agreement when employing the Raymond classification (κ=0.58). CONCLUSIONS: Identifying the per cent embolization in previously coiled aneurysms resulted in good inter- and intra-rater agreement, regardless of years of experience. The strong agreement among providers employing per cent embolization may make it a valuable tool for embolization assessment in this patient population.

Long term experience using the ADAPT technique for the treatment of acute ischemic stroke.

INTRODUCTION: The direct aspiration first pass technique (ADAPT) has been introduced as a simple and fast method for achieving good angiographic and clinical outcomes using large bore aspiration catheters for the treatment of acute ischemic stroke (AIS). We present a single center's long term experience with ADAPT. METHODS: Retrospective analysis of a database was gathered on patients undergoing stroke thrombectomy with ADAPT at a stroke center. Specific parameters captured included age, gender, National Institutes of Health Stroke Scale (NIHSS) score at presentation, time to presentation from last normal, and modified Rankin Scale (mRS) score at the 90 day follow-up. Radiological and angiographic imaging was reviewed to document the location of the vascular occlusion, Thrombolysis in Cerebral Infarction (TICI) flow postprocedure, and procedural complications. RESULTS: 191 consecutive patients who suffered an AIS treated with ADAPT were reviewed; 91 were women, and mean age was 67 years. Patients presented with a mean NIHSS score of 15.4, and 71 patients received intravenous tissue plasminogen activator. The average time from onset to puncture was 7.8 h. The average time for recanalization was 37.3 min. TICI 2B or better recanalization was achieved in 180 (94.2%) patients. 98 (54.1%) patients had an mRS of 0-2 at 90 days. Direct aspiration alone was performed in 145 cases, and 43 cases required the additional use of a stent retriever. There was no significant difference in presenting NIHSS score, average time to presentation, average mRS at 90 days, or 90 day mortality between the two groups. Time to recanalization was 29.6 min for direct aspiration compared with 61.4 min in cases that required adjunct devices (p=0.00000201). 79 (57.7%) patients who underwent direct aspiration only achieved a good outcome at 90 days (mRS 0-2) compared with 19 (43.2%) who underwent adjunct therapies (p=0.12). CONCLUSIONS: ADAPT is an effective method to achieve good clinical and angiographic outcomes, and serves as a useful firstline method for revascularization.

Calcifying Pseudoneoplasm of the Cervicomedullary Junction: Case Report and a Literature Review.

BACKGROUND: Calcifying pseudoneoplasm of the neuroaxis (CAPNON) is a rare, slow-growing tumor of a fibro-osseous origin that may present anywhere in the neuroaxis. Although typically benign, symptoms of CAPNONs typically present secondary to compression and surrounding mass effect. Histologically, the tumor has the characteristics of a foreign body reaction with giant cells, ossification, and the formation of psammoma bodies. On imaging, they can easily be confused with malginant lesions such as chondrosarcoma or chondroblastoma or even more benign pathologies like meningioma. CASE DESCRIPTION: We present a case of a patient with an incidentally found calcifying pseudoneoplasm involving the cervicomedullary junction with further involvement of the vertebral artery and the hypoglossal nerve. We also review the literature on these tumors to date. CONCLUSION: Calcifying pseudoneoplasm of the neuroaxis is a slow-growing, benign, noninfiltrative lesion whose pathogensis and natural history remains unclear. It can appear anywhere in the neuroaxis and does not have a prevelant location. Because of the indolent course and relative rarity of this tumor, there are no current guidelines on the immediate and long-term management of CAPNONs. This entity, although quite rare, should be considered in the differential for calcified lesions at the cervicomedullary junction. The consensus for treatment of CAPNONs when symptomatic is surgical resection.

Initial multicenter technical experience with the Apollo device for minimally invasive intracerebral hematoma evacuation.

BACKGROUND: No conventional surgical intervention has been shown to improve outcomes for patients with spontaneous intracerebral hemorrhage (ICH) compared with medical management. OBJECTIVE: We report the initial multicenter experience with a novel technique for the minimally invasive evacuation of ICH using the Penumbra Apollo system (Penumbra Inc, Alameda, California). METHODS: Institutional databases were queried to perform a retrospective analysis of all patients who underwent ICH evacuation with the Apollo system from May 2014 to September 2014 at 4 centers (Medical University of South Carolina, Stony Brook University, University of California at San Diego, and Semmes-Murphy Clinic). Cases were performed either in the neurointerventional suite, operating room, or in a hybrid operating room/angiography suite. RESULTS: Twenty-nine patients (15 female; mean age, 62 ± 12.6 years) underwent the minimally invasive evacuation of ICH. Six of these parenchymal hemorrhages had an additional intraventricular hemorrhage component. The mean volume of ICH was 45.4 ± 30.8 mL, which decreased to 21.8 ± 23.6 mL after evacuation (mean, 54.1 ± 39.1% reduction; P < .001). Two complications directly attributed to the evacuation attempt were encountered (6.9%). The mortality rate was 13.8% (n = 4). CONCLUSION: Minimally invasive evacuation of ICH and intraventricular hemorrhage can be achieved with the Apollo system. Future work will be required to determine which subset of patients are most likely to benefit from this promising technology.

Diagnostic angiography skill acquisition with a secondary curve catheter: phase 2 of a curriculum-based endovascular simulation program.

BACKGROUND: We have previously reported the efficacy of a simulator-based training paradigm for residents in neurosurgery with little or no prior experience in diagnostic cerebral angiography with straightfoward arch anatomy. This study investigates the utility of a simulation-based training curriculum for the acquisition of skills employing a secondary curve catheter to navigate more complex arch anatomy. METHODS: Residents at the Medical University of South Carolina (MUSC) with moderate exposure to diagnostic angiography enrolled into a standardized Institutional Review Board-approved training protocol using SimSuite Compass and Simbionix simulators. The task involved (in order) forming the Simmons catheter in the left subclavian artery and then selecting the brachiocephalic, left common carotid and left vertebral arteries. RESULTS: All participants improved their total time to complete the task over the course from the first to last trial. Each milestone within the overall task also demonstrated an improvement across trials for each participant. Following the hands-on experience, participants' rating of their knowledge of arch anatomy and vessel selection technique improved to that between competence and high competence (values of 3.3±0.49 (p<0.005) and 3.1±0.38 (p<0.01), respectively). Comfort with use of the Simmons catheter improved to a value of 2.9±0.38 (p<0.001), between an experienced learner and competence. Participants rated the usefulness of the training environment as very high (4.1±0.90 out of maximum 5). CONCLUSIONS: Residents became more proficient at vessel selection in a type II and bovine arch over a relatively compressed time period, with both objective and subjective data demonstrating acquisition of skill sets and increased confidence.

Comparison of endovascular treatment approaches for acute ischemic stroke: cost effectiveness, technical success, and clinical outcomes.

INTRODUCTION: The use of mechanical thrombectomy for the treatment of acute ischemic stroke has significantly advanced over the last 5 years. Few data are available comparing the cost and clinical and angiographic outcomes associated with available techniques. The aim of this study is to compare the cost and efficacy of current endovascular stroke therapies. METHODS: A single-center retrospective review was performed of the medical record and hospital financial database of all ischemic stroke cases admitted from 2009 to 2013. Three discrete treatment methodologies used during this time were compared: traditional Penumbra System (PS), stent retriever with local aspiration (SRLA) and A Direct Aspiration first Pass Technique (ADAPT). Statistical analyses of clinical and angiographic outcomes and costs for each group were performed. RESULTS: 222 patients (45% men) underwent mechanical thrombectomy. Successful revascularization was defined as Thrombolysis In Cerebral Infarction (TICI) 2b/3 flow, which was achieved in 79% of cases with PS, 83% of cases with SRLA, and 95% of cases with ADAPT. The average total cost of hospitalization for patients was $51,599 with PS, $54,700 with SRLA, and $33 ,11 with ADAPT (p<0.0001). Average times to recanalization were 88 min with PS, 47 min with SRLA, and 37 min with ADAPT (p<0.0001). Similar rates of good functional outcomes were seen in the three groups (PS 36% vs SRLA 43% vs ADAPT 47%; p=0.4). CONCLUSIONS: The ADAPT technique represents the most technically successful yet cost-effective approach to revascularization of large vessel intracranial occlusions.

Impact of the ASPECT scores and distribution on outcome among patients undergoing thrombectomy for acute ischemic stroke.

INTRODUCTION: This study investigates whether the Alberta Stroke Program Early CT Score (ASPECTS) quantification is associated with outcome following mechanical thrombectomy. OBJECTIVE: To determine whether preintervention non-perfect ASPECT scores involving cortical or subcortical regions and the side of the non-perfect ASPECT score affects outcomes. METHODS: A retrospective review of a prospectively maintained database of patients with acute ischemic stroke involving the anterior circulation who underwent thrombectomy between May 2008 and August 2012 at a single tertiary care center. The device for mechanical thrombectomy used was the penumbra aspiration system (Penumbra Inc, Alameda, California, USA) and the Solitaire stent retriever (ev3, Irvine, California, USA). A 'blinded' neuroradiologist obtained ASPECTS quantification and noted each region demonstrating early changes. RESULTS: 149 patients (51.7% female, mean age 66.1±15.1 years) were included with an average National Institutes of Health Stroke Scale of 16.2±6.7. Patients with non-perfect ASPECT scores on pretreatment imaging were more likely to have a hemorrhagic conversion (p=0.04) evident on post-procedure CT. However, functional outcomes were the same. Patients with both cortical and basal ganglia non-perfect ASPECT scores were more likely to be in a persistent vegetative state or expire. No differences were identified in outcome among patients with left- versus right-sided infarcts affecting the basal ganglia or cortical regions. CONCLUSIONS: These findings support a strategy of selecting candidacy for thrombectomy that does not exclude patients with non-perfect ASPECT scores involving either the basal ganglia or cortical regions. Outcomes were identical among patients with no non-perfect ASPECT scores and those with cortical or subcortical infarcts, despite a higher incidence of hemorrhagic conversion found among those with non-perfect ASPECT scores.

Balloon-augmented Onyx embolization of cerebral arteriovenous malformations using a dual-lumen balloon: a multicenter experience.

INTRODUCTION: Conventional Onyx embolization of cerebral arteriovenous malformations (AVMs) requires lengthy procedure and fluoroscopy times to form an adequate 'proximal plug' which allows forward nidal penetration while preventing reflux and non-targeted embolization. We review our experience with balloon-augmented Onyx embolization of cerebral AVMs using a dual-lumen balloon catheter technique designed to minimize these challenges. METHODS: Retrospectively acquired data for all balloon-augmented cerebral AVM embolizations performed between 2011 and 2014 were obtained from four tertiary care centers. For each procedure, at least one Scepter C balloon catheter was advanced into the AVM arterial pedicle of interest and Onyx embolization was performed through the inner lumen after balloon inflation via the outer lumen. RESULTS: Twenty patients underwent embolization with the balloon-augmented technique over 24 discreet treatment episodes. There were 37 total arterial pedicles embolized with the balloon-augmented technique, a mean of 1.9 per patient (range 1-5). The treated AVMs were heterogeneous in their location and size (mean 3.3±1.6 cm). Mean fluoroscopy time for each procedure was 48±26 min (28 min per embolized pedicle). Two Scepter C balloon catheter-related complications (8.3% of embolization sessions, 5.4% of pedicles embolized) were observed: an intraprocedural rupture of a feeding pedicle and fracture and retention of a catheter fragment. CONCLUSIONS: This multicenter experience represents the largest reported series of balloon-augmented Onyx embolization of cerebral AVMs. The technique appears safe and effective in the treatment of AVMs, allowing more efficient and controlled injection of Onyx with a decreased risk of reflux and decreased fluoroscopy times.