Management of failed flow diversion for intracranial aneurysm beyond the first 6 months of follow-up: an international Delphi consensus.

OBJECTIVE: The placement of flow-diverting devices has become a common method of treating unruptured intracranial aneurysms of the internal carotid artery. The progressive improvement of aneurysm occlusion after treatment-with low complication and rupture rates-has led to a dilemma regarding the management of aneurysms in which occlusion has not occurred within 6-24 months. The authors aimed to identify clinical consensus regarding management of intracranial aneurysms displaying persistent filling 6-24 months after flow diversion and to ascertain questions that may drive future investigation. METHODS: An international panel of 67 experts was invited to participate in a multistep Delphi consensus process on the treatment of intracranial aneurysms after failed flow diversion. RESULTS: Of the 67 experts invited, 23 (34%) participated. Qualitative analysis of an initial survey with open-ended questions resulted in 51 statements regarding management of aneurysms showing persistent filling after flow diversion. The statements were grouped into 8 categories, and in the second round, respondents rated the degree of their agreement with each statement on a 5-point Likert scale. Flow diverters with surface modifiers did not influence administration of dual-antiplatelet therapy according to 83%. Consensus was also reached regarding the definition of treatment failure at specific time points, including at 6 months if there is aneurysm growth or persistent rapid flow through the entirety of the aneurysm (96%), at 12 months if there is aneurysm growth or symptom onset (78%), and at 24 months if there is persistent filling regardless of size and filling characteristics (74%). Although experts agreed that the degree of intimal hyperplasia or in-device stenosis could not be ascertained by noninvasive imaging alone (83%), only 65% chose digital subtraction angiography as the preferred modality. At 6 and 12 months, retreatment is preferred if there is persistent filling with aneurysm growth (96%, 96%), device malposition (48%, 87%), or a history of subarachnoid hemorrhage (65%, 70%), respectively, and at 24 months if there is persistent filling without reduction in aneurysm size (74%). Experts favored treatment with an additional flow diverter (87%) over aneurysm clipping, applying the same principles for follow-up (83%) and treatment failure (91%) as for the first flow diverter. CONCLUSIONS: The authors present the consensus practices of experts in the management of intracranial aneurysms without occlusion 6-24 months after treatment with a flow-diverting device.

Dynamic internal jugular vein venography: a descriptive study in 89 patients with suspected cerebral venous outflow disorders.

BACKGROUND: Internal jugular vein (IJV) stenosis has recently been recognized as a plausible source of symptom etiology in patients with cerebral venous outflow disorders (CVD). Diagnosis and determining surgical candidacy remains difficult due to a poor understanding of IJV physiology and positional symptom exacerbation often reported by these patients. METHODS: A retrospective single-center chart review was conducted on adult patients who underwent diagnostic cerebral venography with rotational IJ venography from 2022 to 2024. Patients were divided into three groups for further analysis based on symptoms and diagnostic criteria: presumed jugular stenosis, near-healthy venous outflow, and idiopathic intracranial hypertension. RESULTS: Eighty-nine patients were included in the study. Most commonly, ipsilateral rotation resulted in ipsilateral IJV stenosis and gradient development at C4-6 and contralateral stenosis and gradient appearance in the contralateral IJV at C1, with stenosis and gradient development in bilateral IJVs at C1-3 bilaterally during chin flexion. In all patients, 93.3% developed at least moderate dynamic stenosis of at least one IJV, more than two-thirds (69.7%) developed either severe or occlusive stenosis during rightward and leftward rotation, and 81.8% developed severe or occlusive stenosis with head flexion. Dynamic gradients of at least 4 mmHg were seen in 68.5% of patients, with gradients of at least 8 mmHg in 31.5% and at least 10 mmHg in 12.4%. CONCLUSION: This study is the first to document dynamic changes in IJV caliber and gradients in different head positions, offering insights into the complex nature of venous outflow and its impact on CVD.

A core-lab adjudicated analysis of single-stent assisted coiling of wide-neck bifurcation aneurysms.

BACKGROUND AND PURPOSE: Core-lab adjudicated data regarding the efficacy of the single-stent assisted aneurysm coiling technique 'L-stenting' are lacking. We present a multicenter, core-lab adjudicated study evaluating the safety and effectiveness of single-stent assisted coiling in the treatment of wide-neck bifurcation aneurysms (WNBAs). METHODS: Consecutive patients who underwent L-stenting for WNBAs at three academic institutions between 2015 and 2019 were included in this retrospective study. Clinical safety and efficacy outcomes were gathered from the patient chart, and angiographic imaging was evaluated by core lab analysis. Safety and efficacy outcomes were summarized and predictors of safety and efficacy were calculated. RESULTS: Of 128 patients treated, 124 had angiographic outcome data at last follow-up. Of those, 110 had adequate (core-lab adjudicated modified Raymond Roy (mRR) score of 1 or 2) occlusion (88.7%). During follow-up, 19 patients (14.8%) required retreatment. There were 17 complications experienced in 12 patients: intraoperative (n=8, 6.25%), perioperative (n=5, 3.9%), or delayed (n=6; n=4 attributed to device/procedure, 3.1%). Significant predictors of complete occlusion were smaller aneurysm size and use of the jailing technique (P=0.0276). Significant predictors of retreatment were larger size, neck size, and larger dome to neck ratio (P=0.0008). CONCLUSION: This study provides multicenter, core-lab adjudicated angiographic data regarding the efficacy of single-stent assisted coiling for WNBAs. This study acts as a validated comparator for future studies investigating novel devices or techniques for treating this challenging subgroup of aneurysms.

Endovascular vs surgical treatment of sigmoid sinus diverticulum causing pulsatile tinnitus: A systematic review.

INTRODUCTION: Sigmoid sinus diverticulum (SSD) has been increasingly reported as a cause of pulsatile tinnitus (PT). While both endovascular and surgical treatments have been used, there is a lack of consensus on the treatment modality to treat SSD. We conducted a systematic review of the available literature to compare the clinical outcomes and safety of endovascular versus surgical approaches for treating SSD. METHODS: A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses to identify studies encompassing the management of SSD. Studies reporting the clinical outcomes and safety of endovascular or surgical treatments for SSD between January 2000 and January 2023 were included. Results were characterized using descriptive statistics. RESULTS: Endovascular treatment (EVT) was reported by 17 articles, yielding 26 patients with 27 diverticula. Surgical treatment was reported by 20 articles, yielding 105 patients with 107 diverticula. EVT led to complete or near-complete resolution in all patients with SSD and PT. Complications occurred in 3.7% (1/27) with a return to baseline after 2 months. There were no permanent complications from EVT. Surgical treatment resulted in complete resolution in 77.6% (83/107) of cases, incomplete resolution in 11.2% (12/107), and no resolution in 11.2% (12/107). Significant complications occurred in 9.3% (10/107) of the surgical-treated patients. CONCLUSION: EVT in patients with PT and venous diverticulum appears more effective and safer than surgical treatment, but large studies are lacking. Studies directly comparing endovascular and surgical treatment are needed.

Redefining treatment expectations: exploring mid- and long-term outcomes of venous sinus stenting in idiopathic intracranial hypertension.

BACKGROUND: Venous sinus stenting (VSS) is recognized as a safe and effective intervention for medically-refractory idiopathic intracranial hypertension (IIH). However, its long-term efficacy remains uncertain. METHODS: This retrospective review analyzed a single-center database of adult patients with severe, medically-refractory IIH, who underwent VSS and had minimum 3-month follow-up (FU). Patients were divided into three groups based on post-stenting symptom trajectories: group 1 (sustained improvement without relapse), group 2 (temporary improvement with relapse), and group 3 (no improvement). RESULTS: Of 178 patients undergoing VSS, the majority were female (94%), with a median opening pressure (OP) of 31 cm H2O and trans-stenosis gradient of 14 mm Hg. Of these, 153 (86%) received transverse sinus (TS) stenting, and 19 (11%) underwent concurrent TS and superior sagittal sinus stenting. At a mean FU of 166 days, 53 patients (30%) showed long-term improvement without relapse (group 1). Symptomatic recurrence was noted in 101 patients (57%; group 2) within a mean FU of 390 days. Despite recurrent headache and tinnitus, the average OP reduction was 9.6 cm H2O on repeat lumbar puncture, with 75% showing papilledema improvement or resolution post-VSS. Only 17% required further surgical intervention. CONCLUSIONS: The most common clinical outcome post-VSS in IIH patients is initial symptomatic improvement followed by symptom recurrence in about 60% at a mean of 274 days, despite a consistent intracranial pressure reduction. These findings can guide physicians in setting realistic expectations with patients regarding VSS outcomes.

A comprehensive review on the development of sporadic cerebral arteriovenous malformations: from Padget to next-generation sequencing.

Cerebral arteriovenous malformations (AVMs) are a leading cause of intracerebral hemorrhage in both children and young adults. With the continued advancement of science and technology, the understanding of the pathophysiology behind the development of these lesions has evolved. From early theory published by Harvey Cushing and Percival Bailey in 1928, Tumors Arising from the Blood-vessels of the Brain: Angiomatous Malformations and Hemangioblastoma, which regarded AVMs as tumors arising from blood vessels, to the meticulous artistry of Dorcas Padget's embryological cataloguing of the cerebral vasculature in 1948, to the proliferative capillaropathy theory of Yasargil in 1987, to Ramey's 2014 hierarchical model of vascular development, there have been multiple hypotheses of congenital, developmental, and genetic two-hit theories in the pathogenesis of AVMs. Most recent evidence implicates somatic KRAS mutations in the cerebral endothelium, producing an important understanding of the pathogenesis of this disease, which is critical to the development of targeted therapeutics. The authors present the historical progression of their understanding of AVM pathogenesis. They focus on the foundation laid by early pioneers, discussing embryological anatomy and vasculogenesis, the prominent theories of AVM development that have emerged over time, and culminate in an overview of the most current understanding of the pathogenesis of these complex vascular lesions and the clinical implications of our scientific progress.

The Promise, Mystery, and Perils of Stenting for Symptomatic Internal Jugular Vein Stenosis: A Case Series.

BACKGROUND AND OBJECTIVES: Cerebral venous outflow disorders (CVDs) secondary to internal jugular vein (IJV) stenosis are becoming an increasingly recognized cause of significant cognitive and functional impairment in patients. There are little published data on IJV stenting for this condition. This study aims to report on procedural success. METHODS: A single-center retrospective analysis was performed on patients with CVD that underwent IJV stenting procedures. RESULTS: From 2019 to 2023, 29 patients with CVD underwent a total of 33 IJV stenting procedures. Most patients (20; 69%) had an underlying connective tissue disorder diagnosis. The mean age of the included patients was 36.3 years (SD 12.4), 24 were female (82.8%), and all were Caucasian except for 2 patients (27; 93.0%). Twenty-eight procedures (85%) involved isolated IJV stenting under conscious sedation, whereas 5 procedures (15%) involved IJV stenting and concomitant transverse sinus stenting under general anesthesia. Thirteen (39%) patients underwent IJV stenting after open IJV decompression and styloidectomy. Three patients had stents placed for stenosis below the C1 tubercle, one of which was for carotid compression. Periprocedural complications occurred in 11 (33%), including intracardiac stent migration in 1 patient, temporary shoulder pain/weakness in 5 (15%), and persistent and severe shoulder pain/weakness in 2 patients (6%). Approximately 75% of patients demonstrated improvement after stenting although only 12 patients (36%) had durable improvement over a mean follow-up of 4.5 months (range 6 weeks-3.5 years). CONCLUSION: Our experience, along with early published studies, suggests that there is significant promise to IJV revascularization techniques in these patients; however, stenting carries a high complication rate, and symptom recurrence is common. Most neurointerventionalists should not be performing IJV stenting unless they have experience with these patients and understand technical nuances (stent sizing, anatomy, patient selection), which can maximize benefit and minimize risk.

Superior cortical venous anatomy for endovascular device implantation: a systematic review.

Endovascular electrode arrays provide a minimally invasive approach to access intracranial structures for neural recording and stimulation. These arrays are currently used as brain-computer interfaces (BCIs) and are deployed within the superior sagittal sinus (SSS), although cortical vein implantation could improve the quality and quantity of recorded signals. However, the anatomy of the superior cortical veins is heterogenous and poorly characterised. MEDLINE and Embase databases were systematically searched from inception to December 15, 2023 for studies describing the anatomy of the superior cortical veins. A total of 28 studies were included: 19 cross-sectional imaging studies, six cadaveric studies, one intraoperative anatomical study and one review. There was substantial variability in cortical vein diameter, length, confluence angle, and location relative to the underlying cortex. The mean number of SSS branches ranged from 11 to 45. The vein of Trolard was most often reported as the largest superior cortical vein, with a mean diameter ranging from 2.1 mm to 3.3 mm. The mean vein of Trolard was identified posterior to the central sulcus. One study found a significant age-related variability in cortical vein diameter and another identified myoendothelial sphincters at the base of the cortical veins. Cortical vein anatomical data are limited and inconsistent. The vein of Trolard is the largest tributary vein of the SSS; however, its relation to the underlying cortex is variable. Variability in cortical vein anatomy may necessitate individualized pre-procedural planning of training and neural decoding in endovascular BCI. Future focus on the relation to the underlying cortex, sulcal vessels, and vessel wall anatomy is required.

Patients' perceptions on outcomes after mechanical thrombectomy in acute ischemic stroke.

BACKGROUND: The modified Rankin Scale (mRS) is a clinician-reported scale that measures the degree of disability in patients who suffered a stroke. Patients' perception of a meaningful recovery from severe stroke, expected value of a stroke intervention, and the effect of disparities are largely unknown. METHODS: We conducted a survey of patients, their family members, and accompanying visitors to understand their personal preferences and expectations for acute strokes potentially eligible for acute endovascular intervention using a hypothetical scenario of a severe stroke in a standardized questionnaire. RESULTS: Of 164 survey respondents, 65 (39.6%) were the patient involved, 93 (56.7%) were a family member, and six (3.7%) were accompanied visitors (friends, other). Minimally acceptable disability after a stroke intervention was considered as mRS 2 by 42 respondents (25.6%), as mRS 3 by 79 (48.2%), and as mRS 4 by 43 (26.2%) respondents. Race was associated with different views on this question (p < 0.001; Hispanic and Black patients being more likely to accept disability than Caucasian and Asian patients), while sex (p = 0.333) and age (p = 0.560) were not. Sixty-three respondents (38.4%) viewed minimally acceptable probability of improvement with an intervention as over 50%, 57 (34.8%) as 10-50%, and 44 (26.8%) as less than 10%. CONCLUSIONS: A wide range of acceptable outcomes were reported regardless of gender or age. However, race was associated with different acceptable outcome. This is an important finding to demonstrate because of the persistent racial and ethnic disparities in the utilization of endovascular therapy for acute stroke in the United States.

Repeat thrombectomy after large vessel re-occlusion: a propensity score matched analysis of technical and clinical outcomes.

BACKGROUND: Endovascular thrombectomy (EVT) remains the standard of care for acute large vessel occlusion (LVO) stroke. However, the safety and efficacy of repeat thrombectomy (rEVT) in recurrent LVO remains unclear. This study uses a large real-world patient cohort to study technical and clinical outcomes after rEVT. METHODS: This is a retrospective cohort study including patients who underwent thrombectomy between January 2013 and December 2022. Data were included from 21 comprehensive stroke centers globally through the Stroke Thrombectomy and Aneurysm Registry (STAR). Patients undergoing single EVT or rEVT within 30 days of LVO stroke were included in the study. Propensity score matching was used to compare patients undergoing single EVT versus rEVT. RESULTS: Out of a total of 7387 patients who underwent thrombectomy for LVO stroke, 90 (1.2%) patients underwent rEVT for the same vascular territory within 30 days. The median (IQR) time to re-occlusion was 2 (1-7) days. Compared with a matched cohort of patients undergoing a single EVT procedure, patients undergoing rEVT had a comparable rate of good functional outcome and mortality rate, but a higher rate of symptomatic intracranial hemorrhage (sICH). There was a significant reduction in the National Institutes of Health Stroke Scale (NIHSS) score of patients who underwent rEVT at discharge compared with baseline (-4.8±11.4; P=0.006). The rate of successful recanalization was similar in the single thrombectomy and rEVT groups (78% vs 80%, P=0.171) and between index and rEVT performed on the same patient (79% vs 80%; P=0.593). CONCLUSION: Short-interval rEVT is associated with an improvement in the NIHSS score following large vessel re-occlusion. Compared with single thrombectomy, there was a higher rate of sICH with rEVT, but without a significant impact on rates of functional independence or mortality.

Intensive care unit admission is not necessary after venous sinus stenting.

BACKGROUND: Venous sinus stenting (VSS) has emerged as a safe and effective treatment option for idiopathic intracranial hypertension. Many physicians routinely admit patients to the intensive care unit (ICU) for close monitoring, but little data exists on whether this is necessary. METHODS: Electronic medical records of consecutive patients who underwent VSS by the senior author from 2016 to 2022 at a single center were reviewed. RESULTS: 214 patients were included. The mean (SD) age was 35.5 (11.6) and 196 (91.6%) patients were female. A total of 166 (77.6%) patients underwent transverse sinus stenting alone; 9 (4.2%) underwent superior sagittal sinus (SSS) stenting alone, 37 (17.3) concomitant transverse and SSS stenting, and 2 (0.9%) underwent stenting at alternate sites. All patients were planned admission to the regular ward (27.6%) or day hospital (72.4%). Twenty (9.3%) patients were discharged to home the same day as the procedure and 182 (85%) patients were discharged the following day. Major periprocedural complications were identified in 2 (0.93%) patients and minor complications were identified in 16 (7.4%). Only one patient with a subdural hematoma identified in the post-anesthesia care unit (PACU) had care escalated to the ICU. No severe complications were identified after the PACU stay. During the next 48 hours after discharge, 4 (1.9%) patients returned to any emergency room to be evaluated without requiring readmission. CONCLUSION: Routine ICU admission following uncomplicated VSS is unnecessary. Overnight admission to a low-acuity ward, or even same-day discharge in select patients, appears to be a safe and cost-effective strategy.

Coil embolization alone appears sufficient for middle meningeal artery embolization.

BACKGROUND: Middle meningeal artery embolization (MMAE) has shown promise as an alternative treatment for chronic subdural hematoma (cSDH); however, the most effective procedural technique is debated. We sought to assess the safety and efficacy of coil embolization as a stand-alone technique for MMAE in cSDH. METHODS: A single-center retrospective analysis was performed of patients who underwent MMAE for chronic SDH with coil embolization alone. RESULTS: Forty-five patients were included in the study. All underwent successful stand-alone coil MMAE, of which 51.1% were bilateral. Indications for MMAE were varied, but 13.3% of patients required ongoing anticoagulation and another 11.1% had severe thrombocytopenia. Conscious sedation or no sedation was used in 73.2% of patients; 10 patients (22.2%) were scheduled electively and discharged same day. There were no severe or minor procedural complications identified. Of the 45 patients, only 3 (6.6%) underwent unplanned repeat surgical intervention: one patient developed a large recurrence at eight weeks after MMAE and underwent burr hole drainage; the second patient received burr hole drainage prior to MMAE but needed repeat burr hole drainage two weeks later due to residual; the third patient received two burr hole drainages at two and three weeks post MMAE due to persistent disease. CONCLUSION: Stand-alone MMAE with coiling can be performed under conscious sedation as an outpatient procedure and may be sufficient to prevent cSDH recurrence in most cases without the need for particle penetration of cSDH microvascular beds. Larger confirmatory studies are necessary.

Comprehensive analysis of the impact of procedure time and the 'golden hour' in subpopulations of stroke thrombectomy patients.

OBJECTIVE: To evaluate the effect of procedure time on thrombectomy outcomes in different subpopulations of patients undergoing endovascular thrombectomy (EVT), given the recently expanded indications for EVT. METHODS: This multicenter study included patients undergoing EVT for acute ischemic stroke at 35 centers globally. Procedure time was defined as time from groin puncture to successful recanalization (Thrombolysis in Cerebral Infarction score ≥2b) or abortion of procedure. Patients were stratified based on stroke location, use of IV tissue plasminogen activator (tPA), Alberta Stroke Program Early CT score, age group, and onset-to-groin time. Primary outcome was the 90-day modified Rankin Scale (mRS) score, with scores 0-2 designating good outcome. Secondary outcome was postprocedural symptomatic intracranial hemorrhage (sICH). Multivariate analyses were performed using generalized linear models to study the impact of procedure time on outcomes in each subpopulation. RESULTS: Among 8961 patients included in the study, a longer procedure time was associated with higher odds of poor outcome (mRS score 3-6), with 10% increase in odds for each 10 min increment. When procedure time exceeded the 'golden hour', poor outcome was twice as likely. The golden hour effect was consistent in patients with anterior and posterior circulation strokes, proximal or distal occlusions, in patients with large core infarcts, with or without IV tPA treatment, and across age groups. Procedures exceeding 1 hour were associated with a 40% higher sICH rate. Posterior circulation strokes, delayed presentation, and old age were the variables most sensitive to procedure time. CONCLUSIONS: In this work we demonstrate the universality of the golden hour effect, in which procedures lasting more than 1 hour are associated with worse clinical outcomes and higher rates of sICH across different subpopulations of patients undergoing EVT.

Management of intracranial arterial stenosis during mechanical thrombectomy: Survey of neuro-interventionalists.

BACKGROUND: The optimal management of emergent large vessel occlusion due to underlying intracranial stenosis (intracranial stenosis related large vessel occlusion) remains unknown. The primary aim of this survey analysis was to measure variation in the clinical management of intracranial stenosis related large vessel occlusion during mechanical thrombectomy. METHODS: A survey was designed using a web-based survey-building platform and distributed via the Society of NeuroInterventional Surgery (SNIS) and the Society of Vascular and Interventional Neurology (SVIN) websites for a response. Predictors of respondents' level of comfortability stenting were estimated using a binomial logistic regression model. RESULTS: We received 105 responses to the survey. Most respondents (54.3%) practiced at an academic Stroke Center. Nearly half of the respondents (49%) had been practicing for 5 or more years independently after fellowship. An average of 54 mechanical thrombectomies were performed by each respondent annually. There was variation in the definition of intracranial stenosis related large vessel occlusion, number of passes performed before pursuing rescue stenting, as well as intra and post-procedural antiplatelet management. Of respondents, 58% felt rescue stenting was very risky, and 55.7% agreed that there was equipoise regarding emergent angioplasty and/or stenting versus medical therapy for intracranial stenosis related large vessel occlusion. Respondents who encountered intracranial stenosis related large vessel occlusion more frequently thought that rescue stenting was less risky. CONCLUSION: There is notable variability in the diagnosis and management of intracranial stenosis related large vessel occlusion during mechanical thrombectomy. While most respondents felt rescue stenting was risky, the majority believed the benefit could outweigh the risk. The majority of respondents agreed that equipoise exists regarding the management of intracranial stenosis related large vessel occlusion, highlighting the need for clinical trials in this rare patient population.

Venous Pathologies and Interventions of the Head.

Intracranial venous pathologies are a historically underrecognized group of disorders that can have a devastating impact on patients. Despite advancements in peripheral venous disorders and arterial neurointerventions, intracranial venous pathologies have received comparatively little attention. Understanding the anatomy, physiology, clinical relevance, and treatment options of intracranial venous pathologies is fundamental to evolving therapies and research priorities. This article provides an overview of major intracranial venous pathologies, the respective pathophysiologies, and treatment options.

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".].

Incidence and outcome of perforations during medium vessel occlusion compared with large vessel occlusion thrombectomy.

BACKGROUND: Vessel perforation during thrombectomy is a severe complication and is hypothesized to be more frequent during medium vessel occlusion (MeVO) thrombectomy. The aim of this study was to compare the incidence and outcome of patients with perforation during MeVO and large vessel occlusion (LVO) thrombectomy and to report on the procedural steps that led to perforation. METHODS: In this multicenter retrospective cohort study, data of consecutive patients with vessel perforation during thrombectomy between January 1, 2015 and September 30, 2022 were collected. The primary outcomes were independent functional outcome (ie, modified Rankin Scale 0-2) and all-cause mortality at 90 days. Binomial test, chi-squared test and t-test for unpaired samples were used for statistical analysis. RESULTS: During 25 769 thrombectomies (5124 MeVO, 20 645 LVO) in 25 stroke centers, perforation occurred in 335 patients (1.3%; mean age 72 years, 62% female). Perforation occurred more often in MeVO thrombectomy (2.4%) than in LVO thrombectomy (1.0%, p<0.001). More MeVO than LVO patients with perforation achieved functional independence at 3 months (25.7% vs 10.9%, p=0.001). All-cause mortality did not differ between groups (overall 51.6%). Navigation beyond the occlusion and retraction of stent retriever/aspiration catheter were the two most common procedural steps that led to perforation. CONCLUSIONS: In our cohort, perforation was approximately twice as frequent in MeVO than in LVO thrombectomy. Efforts to optimize the procedure may focus on navigation beyond the occlusion site and retraction of stent retriever/aspiration catheter. Further research is necessary in order to identify thrombectomy candidates at high risk of intraprocedural perforation and to provide data on the effectiveness of endovascular countermeasures.

World federation of interventional and therapeutic neuroradiology (WFITN) federation assembly neurointerventional surgery safety checklist.

Over the last 10 years, there has been a rise in neurointerventional case complexity, device variety and physician distractions. Even among experienced physicians, this trend challenges our memory and concentration, making it more difficult to remember safety principles and their implications. Checklists are regarded by some as a redundant exercise that wastes time, or as an attack on physician autonomy. However, given the increasing case and disease complexity along with the number of distractions, it is even more important now to have a compelling reminder of safety principles that preserve habits that are susceptible to being overlooked because they seem mundane. Most hospitals have mandated a pre-procedure neurointerventional time-out checklist, but often it ends up being done in a cursory fashion for the primary purpose of 'checking off boxes'. There may be value in iterating the checklist to further emphasize safety and communication. The Federation Assembly of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) decided to construct a checklist for neurointerventional cases based on a review of the literature and insights from an expert panel.