Comparative analysis of mechanical thrombectomy outcomes of middle cerebral artery M1, M2 superior and M2 inferior occlusion strokes.

BACKGROUND: The M1 middle cerebral artery (MCA) commonly bifurcates into an M2 superior and an M2 inferior segment. However, MCA anatomy is highly variable rendering classification for mechanical thrombectomy (MT) trials difficult. Safety and effectiveness of M2 MCA stroke thrombectomy stratified by M2 MCA anatomy remains to be explored. METHODS: Large vessel occlusion strokes undergoing MT between 02/2016-08/2022 were reviewed (n=784). M1 (n=431) and M2 MCA (n=118) occlusions were assessed. Among M2 MCA occlusions only prototypical MCA bifurcation anatomy cases were included (n=99). Dominance was assessed based on angiography. Procedural and outcome data was compared between M1, M2 superior and M2 inferior MCA occlusions. RESULTS: Baseline demographics and periprocedural criteria of M2 superior (n=56) and M2 inferior (n=43) occlusion MTs were comparable. Among M2 inferior cases, the occluded branch was dominant in 41/43 (95.3%) but only in 37/56 (66.1%) among M2 superior cases (p<0.001). The 90-day favorable functional outcome (mRS 0-2) and mortality (mRS 6) rates were 60.0% and 8.9% in the M2 superior, 42.9% and 32.6% in the M2 inferior, and 44.1% and 26.0% in the M1 group (n=431). Compared to M2 superior, M2 inferior favorable outcome rates were lower (p=0.094) and mortality rates were higher (p=0.003) and resembled M1 outcome rates (p=0.750 and p=0.355, respectively). CONCLUSION: In setting of prototypical MCA bifurcation anatomy, thrombectomy of dominant M2 inferior occlusions had outcome rates like M1 occlusions. In contrast, M2 superior occlusions had significantly lower mortality rates and a trend towards better favorable functional outcome rates.

Proper ophthalmic artery aneurysms.

Background: The ophthalmic segment of the internal carotid artery (ICA) represents a common site for cerebral aneurysms. However, aneurysms of the ophthalmic artery (OphA) itself represent rare lesions and have been associated with trauma and flow-related lesions such as arteriovenous fistulas or malformations. Here, we explore clinical and radiological features of four patients managed for five proper ophthalmic artery aneurysms (POAAs). Methods: Patients undergoing diagnostic cerebral angiogram (DCA) between January 2018 and November 2021 with newly or previously identified POAA were retrospectively reviewed. Clinical and radiological data were analyzed to identify common and unique features. Results: Four patients with identification of five POAA were identified. Three patients suffered traumatic brain injury with subsequent identification of POAA on DCA. Patient 1 presented with a traumatic carotid-cavernous-sinus fistula requiring transvenous coil embolization and second stage flow diversion of the ICA. Patient 2 suffered a gunshot wound with ICA compromise, ethmoidal dural arteriovenous fistula (dAVF) development with rapid growth of two POAAs eventually requiring Onyx embolization. Patient 3 was assaulted and DCA showed a POAA without any other cerebrovascular pathology. Patient 4 had undergone N-butyl cyanoacrylate embolization of an ethmoidal dAVF 13 years ago with the feeding OphA carrying a large POAA. Re-DCADCA was performed for a newly developed and unrelated transverse-sigmoid-sinus dAVF. Conclusion: Management of POAAs poses a challenge to neurovascular surgeons since POAAs inherit a risk for visual deterioration or hemorrhage. DCA facilitates identification of coexisting cerebrovascular pathology. If clinically silent and not accompanied by cerebrovascular disease, observation appears reasonable.

Transradial Versus Transfemoral Intraoperative Cerebral Angiography for Open Cerebrovascular Surgery: Effectiveness, Safety, and Learning Curve.

BACKGROUND: Intraoperative cerebral angiography (IOA) is a valuable adjunct in open and hybrid cerebrovascular surgery. Commonly, transfemoral access (TFA) is used. Lately, transradial access (TRA) has gained popularity for neurointervention. However, the TRA has not yet been compared with the TFA for IOA. OBJECTIVE: To compare the effectiveness and safety of the TRA and TFA for IOA. In addition, the learning curve for implementing the TRA for IOA was evaluated. METHODS: Between July 2020 and 2022, 92/1787 diagnostic cerebral angiographies met inclusion criteria for IOA. Sheath run time to primary target vessel run time (STT), amount of contrast dye (CD), fluoroscopy time (FT), and dose-area products (DAPs) were compared between TRA and TFA, different aortic arch types, and both study years. RESULTS: One case required transitioning from TRA to TFA (1/26, 3.8%) because of a minute proximal radial vasculature. The STT, CD, FT, and DAP were similar for the TRA (n = 25) and the TFA groups (n = 67) (p = ns). One groin hematoma (1.5%) was observed in the TFA group. No other complications or any change in modified Rankin Scale were observed. Aortic arch type II/III was associated with longer STT ( P = .032) but not CD, FT, or DAP. There was a nonsignificant decline of STTs among the TRA cases ( P = .104) but stable STTs among TFA cases ( P = .775). CONCLUSION: The TRA and TFA represent equally effective and safe routes for IOA. In addition, expertise with the TRA can rapidly be gained and facilitates tailoring the access for IOA to patient's individual anatomy and surgeon's needs.

Tenecteplase versus alteplase before mechanical thrombectomy: experience from a US healthcare system undergoing a system-wide transition of primary thrombolytic.

BACKGROUND: Tenecteplase (TNK) is a genetically modified variant of alteplase (TPA) and has been established as a non-inferior alternative to TPA in acute ischemic stroke (AIS). Whether TNK exerts distinct benefits in large vessel occlusion (LVO) AIS is still being investigated. OBJECTIVE: To describe our first-year experience after a healthcare system-wide transition from TPA to TNK as the primary thrombolytic. METHODS: Patients with AIS who received intravenous thrombolytics between January 2020 and August 2022 were retrospectively reviewed. All patients with LVO considered for mechanical thrombectomy (MT) were included in this analysis. Spontaneous recanalization (SR) after TNK/TPA was a composite variable of reperfusion >50% of the target vessel territory on cerebral angiography or rapid, significant neurological recovery averting MT. Propensity score matching (PSM) was performed to compare SR rates between TNK and TPA. RESULTS: A total of 148 patients were identified; 51/148 (34.5%) received TNK and 97/148 (65.5%) TPA. The middle cerebral arteries M1 (60.8%) and M2 (29.7%) were the most frequent occlusion sites. Baseline demographics were comparable between TNK and TPA groups. Spontaneous recanalization was significantly more frequently observed in the TNK than in the TPA groups (unmatched: 23.5% vs 10.3%, P=0.032). PSM substantiated the observed SR rates (20% vs 10%). Symptomatic intracranial hemorrhage, 90-day mortality, and functional outcomes were similar. CONCLUSIONS: The preliminary experience from a real-world setting demonstrates the effectiveness and safety of TNK before MT. The higher spontaneous recanalization rates with TNK are striking. Additional studies are required to investigate whether TNK is superior to TPA in LVO AIS.

Full Endoscopic Repair of Spontaneous Ventral Cerebrospinal Fluid Leaks in the Spine: Systematic Review of Surgical Treatment Options and Illustrative Case.

BACKGROUND: Spontaneous spinal cerebrospinal fluid (CSF) leaks are a rare entity that can lead to intracranial hypotension and associated headaches, meningismus, and patient debility. Surgical treatment may be necessary for patients who do not respond to conservative management. Surgical repair of CSF leaks located in the ventral thoracic spine traditionally require an invasive, open approach. METHODS: We describe the case of a patient with a ventral thoracic spontaneous spinal CSF leak associated with a ventral bony osteophyte successfully treated with spinal endoscopy. We also provide a systematic review of the literature to better understand outcomes of this approach. RESULTS: A total of 55 patients were included in the systematic review. The study designs found in the literature review included case reports (66.7%), retrospective cohorts (22.2%), and prospective cohorts (11.1%). Of the studies reporting data, 50% of studies stated they used an open posterior approach to the dural defect, while 37.5% reported using an open anterior approach to the pathology. Only 1 (12.5%) study reported using an endoscope. Most studies (62.5%) used primary closure of the dura in their technique, while 37.5% reported using a local tissue graft (fat or muscle) or a dural sealant for their closure technique, and 25% of studies reported using a dural substitute for their closure technique. Overall mean clinical follow-up was 19.8 months. CONCLUSIONS: The endoscopic approach described here for treatment of this rare entity allows for removal of bony spicules/osteophytes and dural repair without the morbidity associated with traditional open dorsolateral or ventrolateral approaches.

In-hospital mortality rates, complication rates, length of stay, and total costs of >14,000 chronic subdural hematomas treated in the U.S. between 2016 and 2020: Query of the premier health-care database.

Background: With the drastically aging population in the U.S., chronic subdural hematomas (cSDHs) are projected to represent the most common neurosurgical diagnosis requiring treatment within the next two decades. There is lack of contemporary outcome data in patients treated for nontraumatic and nonacute subdural hematoma. We aim to portray current mortality rates, complication rates, length of stay, and costs associated with inpatient cSDH care. Methods: The Premier Health-care Database, Premier Inc., Charlotte/NC was queried for encounters October 2016-December 2020 with the ICD-10 diagnoses of nontraumatic nonacute subdural hematoma as the principal diagnosis among patients age ≥40 years. Per database in-hospital mortality is defined as mortality in an inpatient who is not discharged. Complications represent medical conditions not present on admission that affects mortality, length of stay, and costs within the database. Results: The query identified 14,136 inpatient encounters. Between October 2016 and December 2020, in-hospital mortality rates averaged 10.9% in the medical group (MG) and 3.6% in the surgical group (SG) (P < 0.001). Complication rates averaged between 8.9 % in the MG and 19.9% in the SG (P < 0.001). LOS averaged 3.0 days in the MG and 5.7 days in the SG (P < 0.001). Total costs averaged $ 10,233 in the MG and $ 26,658 in the SG. Conclusion: The standardized outcomes presented represent an objective benchmark of contemporary cSDH treatment outcomes in the U.S. With the projected substantial increase of cSDH cases within the next decades, new treatment strategies such as middle meningeal embolization need to be explored and outperform current outcome metrics.

Lower complication rates associated with transradial versus transfemoral flow diverting stent placement.

BACKGROUND: Currently, there are no large-scale studies in the neurointerventional literature comparing safety between transradial (TRA) and transfemoral (TFA) approaches for flow diversion procedures. This study aims to assess complication rates in a large multicenter registry for TRA versus TFA flow diversion. METHODS: We retrospectively analyzed flow diversion cases for cerebral aneurysms from 14 institutions from 2010 to 2019. Pooled analysis of proportions was calculated using weighted analysis with 95% CI to account for results from multiple centers. Access site complication rate and overall complication rate were compared between the two approaches. RESULTS: A total of 2,285 patients who underwent flow diversion were analyzed, with 134 (5.86%) treated with TRA and 2151 (94.14%) via TFA. The two groups shared similar patient and aneurysm characteristics. Crossover from TRA to TFA was documented in 12 (8.63%) patients. There were no access site complications in the TRA group. There was a significantly higher access site complication rate in the TFA cohort as compared with TRA (2.48%, 95% CI 2.40% to 2.57%, vs 0%; p=0.039). One death resulted from a femoral access site complication. The overall complications rate was also higher in the TFA group (9.02%, 95% CI 8.15% to 9.89%) compared with the TRA group (3.73%, 95% CI 3.13% to 4.28%; p=0.035). CONCLUSION: TRA may be a safer approach for flow diversion to treat cerebral aneurysms at a wide range of locations. Both access site complication rate and overall complication rate were lower for TRA flow diversion compared with TFA in this large series.

Utility of P2Y12 Reactive Unit Assessment on Ticagrelor in Cerebral Aneurysms Treated with Intracranial Stenting and Flow Diversion: Cohort Study and Case Report From Two Neurovascular Centers.

BACKGROUND: Dual antiplatelet therapy consisting of aspirin and clopidogrel is the standard of care for neurointerventional stenting and flow diversion. Platelet function testing has been increasingly performed to identify patients with a hypo- or hyper-response to clopidogrel. Ticagrelor has been a popular alternative antiplatelet agent for such patients. We assessed the role of platelet function testing in patients receiving ticagrelor and undergoing stenting or flow diversion. METHODS: The data from patients who had undergone stent-assisted coiling or Pipeline flow diversion of a cerebral aneurysm with ticagrelor therapy at any point during their treatment course from May 2017 to August 2019 at a single academic institution in the United States were retrospectively reviewed. Platelet function testing was used to determine the P2Y12 reactive units (PRUs), and the results were correlated with the procedural complications. RESULTS: A total of 28 patients with 29 aneurysms were treated while receiving ticagrelor. Of the 29 aneurysms, 16 (55.2%) were treated with flow diversion and 13 (44.8%) with stent-assisted coiling. Four thromboembolic complications (13.8%) and no hemorrhagic complications developed. Of the 8 patients with ≥1 PRU value >100, 4 (50%) had experienced a thromboembolic complication. The patients without a PRU value >100 did not experience any complications. CONCLUSION: A risk of thromboembolic complications exists for patients receiving ticagrelor, which correlated with the PRUs in the present preliminary study. The findings from the present study suggest that the safe PRU range for patients receiving ticagrelor should be shifted to 0-100, which is lower than that of clopidogrel, thought to be 60-210. Further validation of the optimal PRU range for patients receiving ticagrelor is necessary.

Intraoperative 3-Dimensional Rotational Angiography in Cerebrovascular Surgery: A Case Series.

OBJECTIVE: Intraoperative imaging is critical in cerebrovascular surgery to assess the technical success of the operation. This case series aimed to evaluate the safety and efficacy of 3-dimensional rotational angiogram (3D-RA) in addition to 2-dimensional intraoperative angiography (2D-IOA) during cerebrovascular surgery in the hybrid operating room. METHODS: All consecutive patients who underwent open cerebrovascular surgery and intraoperative 2D-IOA with 3D-RA in a hybrid operating room at 2 academic centers between August 2018 and December 2019 were identified from a prospectively maintained institutional database. Medical charts and operative videos including intraoperative angiography were reviewed, and clinical and angiographic outcomes assessed. RESULTS: A total of 40 cerebrovascular surgeries in 39 patients (mean age, 53 ± 13 years; 51% female) were carried out with the addition of 3D-RA to 2D-IOA in the hybrid operating room. After 3D-RA in addition to 2D-IOA, 1 (2.5%) surgical alteration occurred in an aneurysm clipping. Other procedures were not altered with the addition of 3D-RA to 2D-IOA. There were no complications from the addition of 3D-RA to 2D-IOA. CONCLUSIONS: Using a combination of 3D-RA and 2D-IOA in the hybrid operating room may enhance the likelihood of achieving an optimal result when employing microsurgical cerebrovascular surgery and avoid unanticipated incomplete outcomes, complications, and returns to the operating room. Whereas the addition of 3D-RA elucidated residual aneurysm not otherwise visualized on the 2D-IOA, in other cerebrovascular procedures studied, there was no additional value of the 3D-RA over the 2D-IOA.

The Utility of a Diagnostic Angiogram Following Mechanical Thrombectomy for Treatment of Acute Ischemic Stroke.

OBJECTIVE: Digital subtraction angiography is the gold standard for diagnosis of vascular pathology. The value of angiography of non-target vessels following mechanical thrombectomy for the treatment of acute ischemic stroke (AIS) is unknown. PATIENTS AND METHODS: Consecutive patients treated with mechanical thrombectomy for AIS due to large vessel occlusion (LVO) at an academic institution between February 2016 and December 2018 were retrospectively reviewed. Demographic information, clinical data, and procedure details were recorded. Descriptive statistics were used to evaluate the utility of non-target vessel angiography. RESULTS: One hundred and fifty-six patients presenting with AIS due to LVO were treated with 159 mechanical thrombectomy procedures. Median age was 71.5 years. Ninety-one (57.2%) procedures were followed with a diagnostic cerebral angiogram of non-target vessels. Previously unknown findings were identified in 4 (4.4%) procedures. Management change due to the non-target vessel angiogram finding occurred in 3 (3.3%) cases and included one contralateral mechanical thrombectomy. No complications occurred as a result of the non-target vessel angiogram. CONCLUSION: Angiographic imaging of non-target vessels following mechanical thrombectomy identified previously unknown vascular pathology in 4.4% of procedures and resulted in a clinical management change in 3.3% of cases.

Utility of platelet function testing in stent-assisted coiling of cerebral aneurysms.

BACKGROUND: Thromboembolic complications are the primary risks of stent-coiling of cerebral aneurysms. The utility of platelet function testing in stent-assisted aneurysm coiling remains controversial. This study aimed to assess a pharmacy-mediated antiplatelet management protocol for stent-assisted coiling. METHODS: Stent-coiled aneurysms at an academic institution in the United States between 2015 and 2018 were retrospectively reviewed. All patients were managed using a pharmacy-mediated antiplatelet protocol, which required repeated platelet function testing and subsequent dose adjustments. Medication dosage, number of adjustments, aspirin reaction units (ARU) and P2Y12 reaction units (PRU), as well as complication rates, angiographic and functional outcome were analyzed. RESULTS: A total of 56 aneurysms (median size 5 mm, range 2.6-14.0 mm) in 54 patients (median age 58.5 years) were treated with stent-assisted coil embolization. Most aneurysms were located at the basilar tip (28.6%). Median pre-procedure ARU and PRU were 442.5 (range 363-594) and 123.5 (range 1-252), respectively. Approximately two-thirds of all procedures required at least one aspirin dose adjustment and 88.5% of procedures required at least one clopidogrel dose adjustment. There were two (3.6%) thromboembolic complications. One of the thromboembolic complications occurred in a patient where the pharmacy-mediated protocol was violated. There were no hemorrhagic complications. Last imaging follow-up demonstrated complete aneurysm occlusion in 83.9%. CONCLUSION: In patients where the pharmacy-mediated antiplatelet protocol was followed, the thromboembolic complication rate was 1.8%. This complication rate compares favorably to those reported in large contemporary series. Nevertheless, the pharmacy-mediated protocol places a significant burden on both the patient and healthcare system.

Predictor of 90-day functional outcome after mechanical thrombectomy for large vessel occlusion stroke: NIHSS score of 10 or less at 24 hours.

OBJECTIVE: Mechanical thrombectomy is the established treatment for acute ischemic stroke due to large vessel occlusion (LVO). The authors sought to identify early predictors of a favorable outcome in stroke patients treated with mechanical thrombectomy. METHODS: Consecutive patients with ischemic stroke due to LVO who underwent mechanical thrombectomy at a Comprehensive Stroke Center in the US between 2016 and 2018 were retrospectively reviewed. Demographics, stroke and treatment characteristics, as well as functional outcome at 90 days were collected. Clinical predictors of 90-day functional outcome were assessed and compared to existing indices for prompt neurological improvement. Analyses of area under the receiver operating characteristic curve were performed to estimate the optimal thresholds for absolute 24-hour and delta (change in) National Institutes of Health Stroke Scale (NIHSS) scores for functional outcome prediction. RESULTS: A total of 156 patients (median age 71.5 years) underwent 159 mechanical thrombectomies. The M1 segment of the middle cerebral artery was the most frequent site of occlusion (57.2%). The median NIHSS score before thrombectomy was 18 (IQR 14-24). A postthrombectomy Thrombolysis in Cerebral Infarction score of 2B or 3 was achieved in 147 procedures (92.4%). The median NIHSS score 24 hours after thrombectomy was 14 (IQR 6-22). Good functional outcome at 90 days (modified Rankin Scale score 0-2) was achieved in 37 thrombectomies (23.9%). An absolute 24-hour NIHSS score ≤ 10 (OR 25.929, 95% CI 8.448-79.582, p < 0.001) and a delta NIHSS score ≥ 8 between baseline and 24 hours (OR 4.929, 95% CI 2.245-10.818, p < 0.001) were associated with good functional outcome at 90 days. The 24-hour NIHSS score cutoff of 10 outperformed existing indices for prompt neurological improvement in the ability to predict 90-day functional outcome. CONCLUSIONS: An NIHSS score ≤ 10 at 24 hours after mechanical thrombectomy was independently associated with good functional outcome at 90 days.

Modern Training and Credentialing in Neuroendovascular Acute Ischemic Stroke Therapy.

BACKGROUND: Acute ischemic stroke (AIS) remains a significant source of morbidity and mortality worldwide. Multiple recent randomized clinical trials for AIS patients presenting with large vessel occlusion have demonstrated radical improvement in outcomes with mechanical thrombectomy (MT), which is now recognized as the new standard of care for patients presenting up to 24 hr. OBJECTIVE: To provide a perspective on training and credentialing requirements for practitioners in this field. METHODS: Relevant articles were systematically searched and analyzed. Standards for Reporting Qualitative Research guidelines were utilized. RESULTS: : The Committee for Advanced Subspecialty Training (CAST) brings together the principal specialties of Radiology, Neurology, and Neurosurgery. Their training standards document the most recent consensus on training for neuroendovascular surgery (NES) and include the endovascular treatment of AIS as a part of the field of NES. This unified consensus represents a significant landmark in the evolution of stroke therapy. Presently, training at most centers follows an apprenticeship type model. Simulation methods and objective performance metrics have not been widely incorporated. Maintenance of proficiency has not been conclusively addressed reflecting the overall developing nature of the field. CONCLUSION: The evolution of the standard of care interventional therapy for large vessel AIS utilizing MT raises concerns regarding work force needs, training standards, competency, and credentialing requirements for practitioners. The CAST framework represents the most modern and flexible approach for both individuals and training programs. Methods based on objective performance metrics utilizing simulation as primary vehicle may be the logical next steps in the evolution of NES.

Seeing Is Believing: Headway27 as a Highly Visible and Versatile Microcatheter with Ideal Dimensions for Stroke Thrombectomy.

INTRODUCTION: Microcatheter selection is an infrequent focus of stroke thrombectomy technique evaluation. The Headway27 microcatheter strikes an excellent balance of microcatheter dimensions (156 cm length, 2.6 Fr distal OD, ID 0.027 inches) and visibility, making it ideal for stroke thrombectomy. METHODS: We evaluated a prospectively maintained acute stroke thrombectomy database containing 50 consecutive cases using the Headway27 microcatheter. From the database, patient demographics, clinical and angiographic information as well as procedural technical details and complications were extracted. RESULTS: Manual aspiration thrombectomy (MAT) was performed alone in 72% of cases, stentriever-assisted MAT was performed in 6% of cases, and a combination was used in 22% of cases. Median groin puncture to final recanalization time was 27 min and mTICI 2B/3 recanalization was achieved in 94% of cases. There were 2 intra-procedural complications, neither related to the microcatheter. In all cases, the Headway27 reached the intended target vessel: M1 (n = 4), M2 (n = 26), M3 (n = 13), P2 (n = 3), P3 (n = 1), and basilar artery (n = 3). There were no cases requiring usage of an additional or alternative microcatheter. In 45/47 cases of MAT, the reperfusion catheter tracked over the Headway to the clot/intended target; in two cases, the microcatheter was used to deploy a stentriever that then allowed the reperfusion catheter to track to the clot. CONCLUSION: The Headway27 microcatheter reliably facilitated rapid clot access in anterior and posterior circulation acute large vessel occlusions with no microcatheter-associated complications.