Early versus Delayed Extracranial-Intracranial Bypass Surgery in Symptomatic Atherosclerotic Occlusion

Application of individual brain connectome in chronic ischemia: mapping symptoms before and after reperfusion

How brain functions in the distorted ischemic state before and after reperfusion is unclear. It is also uncertain whether there are any indicators within ischemic brain that could predict surgical outcomes. To alleviate these issues, we applied individual brain connectome in chronic steno-occlusive vasculopathy (CSOV) to map both ischemic symptoms and their postbypass changes. A total of 499 bypasses in 455 CSOV patients were collected and followed up for 47.8 ± 20.5 months. Using multimodal parcellation with connectivity-based and pathological distortion-independent approach, areal MR features of brain connectome were generated with three measurements of functional connectivity (FC), structural connectivity, and PageRank centrality at the single-subject level. Thirty-three machine-learning models were then trained with clinical and areal MR features to obtain acceptable classifiers for both ischemic symptoms and their postbypass changes, among which, 11 were deemed acceptable (AUC > 0.7). Notably, the FC feature-based model for long-term neurological outcomes performed very well (AUC > 0.8). Finally, a Shapley additive explanations plot was adopted to extract important individual features in acceptable models to generate "fingerprints" of brain connectome. This study not only establishes brain connectomic fingerprint databases for brain ischemia with distortion, but also provides informative insights for how brain functions before and after reperfusion.

Advances in Atherosclerosis Theranostics Harnessing Iron Oxide-Based Nanoparticles

Atherosclerosis, a multifaceted chronic inflammatory disease, has a profound impact on cardiovascular health. However, the critical limitations of atherosclerosis management include the delayed detection of advanced stages, the intricate assessment of plaque stability, and the absence of efficacious therapeutic strategies. Nanotheranostic based on nanotechnology offers a novel paradigm for addressing these challenges by amalgamating advanced imaging capabilities with targeted therapeutic interventions. Meanwhile, iron oxide nanoparticles have emerged as compelling candidates for theranostic applications in atherosclerosis due to their magnetic resonance imaging capability and biosafety. This review delineates the current state and prospects of iron oxide nanoparticle-based nanotheranostics in the realm of atherosclerosis, including pivotal aspects of atherosclerosis development, the pertinent targeting strategies involved in disease pathogenesis, and the diagnostic and therapeutic roles of iron oxide nanoparticles. Furthermore, this review provides a comprehensive overview of theranostic nanomedicine approaches employing iron oxide nanoparticles, encompassing chemical therapy, physical stimulation therapy, and biological therapy. Finally, this review proposes and discusses the challenges and prospects associated with translating these innovative strategies into clinically viable anti-atherosclerosis interventions. In conclusion, this review offers new insights into the future of atherosclerosis theranostic, showcasing the remarkable potential of iron oxide-based nanoparticles as versatile tools in the battle against atherosclerosis.

Extracranial-Intracranial Cerebral Revascularization for Atherosclerotic Vessel Occlusion: An Updated Systematic Review of the Literature

BACKGROUND

Atherosclerotic steno-occlusive cerebrovascular disease includes extracranial carotid occlusive and intracranial atherosclerotic disease. Despite the negative findings in Carotid Occlusion Surgery Study (COSS), many large centers continue to report favorable results for revascularization surgery in select groups of patients. The aim of our study was to perform an updated systematic review to investigate the role of revascularization surgery for atherosclerotic steno-occlusive patients in the modern era.

METHODS

Five independent reviewers performed Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided literature searches in October 2022 to identify articles reporting clinical outcomes in adult patients undergoing bypass for atherosclerotic steno-occlusive disease. Primary endpoints used were perioperative and long-term ischemic strokes, intracerebral hemorrhage, bypass patency, and favorable clinical outcomes. Study quality was evaluated with Newcastle-Ottawa, JADAD, and the Oxford Center for Evidence-Based Medicine scales.

RESULTS

A total of 6709 articles were identified in the initial search. Of these articles, 50 met the inclusion criteria and were included in the systematic review. A notable increase in the proportion of articles published over the past 10 years was observed. There were 6046 total patients with 4447 bypasses performed over the period from 1978 to 2022. The average length of follow-up was 2.75 ± 2.71 years. The average Newcastle-Ottawa was 6.23 out of 9 stars. There was a significant difference in perioperative stroke (odds ratio [OR], 0.65 [0.48-0.87]; P = 0.004), long-term ischemia (OR, 0.32 [0.23-0.44]; P < 0.0001), overall ischemia (OR, 0.36 [0.28-0.44]; P < 0.0001), and favorable outcomes (OR, 3.63 [2.84-4.64]; P < 0.0001) when comparing pre-COSS to post-COSS time frames in favor of post-COSS.

CONCLUSIONS

Based on a systematic review of 50 articles, the existing literature indicates that long-term stroke rates and favorable outcomes for surgical revascularization for steno-occlusive disease have improved over time and are lower than previously reported. Improved patient selection, perioperative care, and surgical techniques may contribute to improved outcomes.

The Natural History of Carotid Artery Occlusions Diagnosed on Duplex Ultrasound

BACKGROUND

There is a paucity of literature on the natural history of extracranial carotid artery occlusion (CAO). This study reviews the natural history of this patient cohort.

METHODS

This single-institution retrospective analysis studied patients with CAO diagnosed by duplex ultrasound between 2010 and 2021. Patients were identified by searching our office-based Intersocietal Accreditation Commission accredited vascular laboratory database. Imaging and clinical data were obtained via our institutional electronic medical record. Outcomes of interest included ipsilateral stroke, attributable neurologic symptoms, and ipsilateral intervention after diagnosis.

RESULTS

The full duplex database consisted of 5,523 patients who underwent carotid artery duplex examination during the study period. The CAO cohort consisted of 139 patients; incidence of CAO was 2.5%. Mean age at diagnosis was 69.7 years; 31.4% were female. Hypertension (72.7%), hyperlipidemia (64.7%), and prior smoking (43.9%) were the most common comorbid conditions. Of the CAO cohort, 61.3% (n = 85) of patients were asymptomatic at diagnosis; 38.8% (n = 54) were diagnosed after a stroke or transient ischemic attack occurring within 6 months prior to diagnosis, with 21.6% occurring ipsilateral to the CAO and 10.1% occurring contralateral to the CAO. 7.2% (n = 10) had unclear symptoms or laterality at presentation. Of the CAO cohort, 95 patients (68.3%) had duplex imaging follow-up (mean 42.7 ± 31.3 months). Of those with follow-up studies, 7 patients (5.0%) developed subsequent stroke ipsilateral to the CAO with mean occurrence 27.8 ± 39.0 months postdiagnosis. In addition, 5 patients (3.6%) developed other related symptoms, including global hypoperfusion (2.4%) and transient ischemic attack (1.2%). Of those, 95 patients with follow-up duplex ultrasound imaging, 6 (4.3%) underwent eventual ipsilateral intervention, including carotid endarterectomy (n = 4), transfemoral carotid artery stent (n = 1), and carotid bypass (n = 1), with mean occurrence 17.7 ± 23.7 months postdiagnosis. The aggregate rate of ipsilateral cerebrovascular accident, attributable neurologic symptoms, or ipsilateral intervention was 11.5%. Of 95 patients with follow-up duplex ultrasound imaging, 5 underwent subsequent duplex studies demonstrating ipsilateral patency, resulting in a 5.3% discrepancy rate between sequential duplex studies. All 6 patients undergoing intervention received periprocedural cross-sectional imaging (magnetic resonance angiography or computed tomography angiography). In 5 of these 6 patients, cross-sectional demonstrated severe stenosis rather than CAO, disputing prior duplex ultrasound findings.

CONCLUSIONS

In this large, institutional cohort of patients with a CAO diagnosis on duplex ultrasound, a clinically meaningful subset of patients experienced cerebrovascular accident, related symptoms, or intervention. We also found a notable rate of temporal duplex discrepancies among patients with CAO diagnoses and discrepancies between CAO diagnosis per duplex ultrasound and findings on cross-sectional imaging for those patients who underwent intervention. These results suggest that use of a single duplex ultrasound as a sole diagnostic tool in CAO may not be sufficient and that physicians should consider close duplex ultrasound surveillance of these patients, potentially in conjunction with additional confirmatory imaging modalities. Further investigation into optimal workup and surveillance protocols for CAO is needed.

Diagnosis and treatment of acute isolated proximal internal carotid artery occlusions: a narrative review

The clinical manifestations of proximal (extracranial) internal carotid artery occlusions (pICAOs) may range from asymptomatic to acute, large, and devastating ischemic strokes. The etiology and pathophysiology of the occlusion, intracranial collateral status and patient's premorbid status are among the factors determining the clinical presentation and outcome of pICAOs. Rapid and accurate diagnosis is crucial and may be assisted by the combination of carotid and transcranial duplex sonography, or a computed tomography/magnetic resonance angiography (CTA/MRA). It should be noted that with either imaging modalities, the discrimination of a pseudo-occlusion of the extracranial internal carotid artery (ICA) from a true pICAO may not be straightforward. In the absence of randomized data, the management of acute, symptomatic pICAOs remains individualized and relies largely on expert opinion. Administration of intravenous thrombolysis is reasonable and probably beneficial in the settings of acute ischemic stroke with early presentation. Unfortunately, rates of recanalization are rather low and acute interventional reperfusion therapies emerge as a potentially powerful therapeutic option for patients with persistent and severe symptoms. However, none of the pivotal clinical trials on mechanical thrombectomy for acute ischemic stroke randomized patients with isolated extracranial large vessel occlusions. On the contrary, several lines of evidence from non-randomized studies have shown that acute carotid endarterectomy, or endovascular thrombectomy/stenting of the ICA are feasible and safe, and pοtentially beneficial. The heterogeneity in the pathophysiology and clinical presentation of acute pICAOs renders patient selection for an acute interventional treatment a complicated decision-making process. The present narrative review will outline the pathophysiology, clinical presentation, diagnostic challenges, and possible treatment options for pICAOs.

Efficacy of Emergent STA–MCA Bypass for Acute Atherosclerotic ICA Stenosis/Occlusion with Concomitant Chronic Contralateral ICA Occlusion/Stenosis: Two Case Reports

Recombinant tissue-type plasminogen activator with/without endovascular regimen is sometimes not effective for the treatment of acute hemodynamic stroke. Emergent superficial temporal artery-middle cerebral artery (STA–MCA) bypass has been reportedly effective in patients with progressive hemodynamic stroke; however, the effectiveness of urgent STA–MCA bypass for acute internal carotid artery (ICA) stenosis/occlusion with concomitant contralateral chronic ICA stenosis/occlusion, that is considered the worst hemodynamic situations, is unclear. Two cases of acute left ICA stenosis with concomitant right chronic ICA occlusion wherein both developed hemodynamic infarction and were initially treated by maximal medical treatment. Nevertheless, the patients' symptoms had gradually worsened, thus we performed emergency STA–MCA bypass for both cases. Postoperatively, deterioration of imaging and neurological findings was successfully stopped and the patients' condition gradually stabilized. An urgent STA–MCA bypass can be considered as a last resort to prevent progressive neurological deterioration for patients with progressive infarction due to ICA stenosis/occlusion concomitant with contralateral ICA stenosis/occlusion.

Leaving the day behind: endovascular therapy beyond 24 h in acute stroke of the anterior and posterior circulation

Background:

There is little evidence of endovascular therapy (EVT) being performed in acute ischemic stroke beyond 24 h, and that evidence is limited to anterior circulation stroke.

Objective:

To extend evidence of efficacy and safety of EVT after more than 24 h in both anterior and posterior circulation stroke.

Methods:

Local, prospectively collected registries were screened for patients with acute ischemic stroke and large-vessel occlusion who had received either EVT > 24 h after last-seen-well but <24 h after symptom recognition (EVT_>24LSW) or EVT > 24 h since first (definitive) symptom recognition (EVT_>24DEF). Patients treated <24 h served as a group for comparison. Favorable outcome was defined as modified Rankin scale (mRS) 0–2 or return to prestroke mRS at 3 months.

Results:

Between January 2014 and August 2021, N = 2347 were treated with EVT at our comprehensive stroke center, of whom n = 43 met the inclusion criteria (EVT_>24LSW, n = 16, EVT_>24DEF, n = 27). EVT_>24LSW patients were treated at a median of 28.7 h [interquartile range (IQR) = 27.3–32.8] after last-seen-well and 7.3 h (IQR = 2.8–14.3) after symptom recognition; EVT_>24DEF patients were treated 52.5 h (IQR = 26.5–94.2) after first symptoms. Favorable outcome was achieved by 23.3% (10/43) in the EVT > 24 compared with 39.4% (886/2250) in the EVT < 24 group (p = 0.04). Bleeding rates were similar across groups. Mortality was also similar [EVT > 24, 27.9% (12/43) versus EVT < 24, 25.7% (584/2264), p = 0.727; posterior circulation, EVT > 24, 41.7% (5/12) versus EVT < 24, 36.5% (92/252) p = 0.764].

Conclusion:

In selected patients, EVT seems effective and safe beyond 24 h for both anterior and posterior circulation stroke.

Endovascular recanalization for symptomatic intracranial internal carotid and middle cerebral artery occlusion lasting longer than 72 h: Experience in a single center

OBJECTIVE

The objective of this study was to assess the safety, feasibility, and outcomes of endovascular recanalization for symptomatic intracranial internal carotid and middle cerebral artery occlusion lasting longer than 72 h.

METHODS

Thirty-nine consecutive patients with symptomatic occlusion of the anterior circulation and failure of medical therapy underwent endovascular recanalization and were included in this retrospective study. Patient characteristics, atherosclerotic risk factors, successful recanalization rates, and angiographic data were collected.

RESULTS

Recanalization was successful in 37 cases (94.9%). The average residual stenosis immediately after intervention was 11.6 ± 4.3%. The patients who underwent balloon angioplasty alone had similar residual stenosis to those who also underwent stent placement (15.6 ± 7.3% vs. 9.0 ± 6.4%, P = 0.184). Intra- and perioperative complications occurred in three cases (7.69%). One patient (2.7%) developed severe in-stent restenosis with transient ischemic attack symptoms at 1-year follow-up.

CONCLUSIONS

Endovascular recanalization is feasible for symptomatic occlusion of the anterior circulation lasting longer than 72 h. Recanalization provides a higher success rate when performed within 6 months of the qualifying event.

One-donor, two-recipient extracranial-intracranial bypass series for moyamoya and cerebral occlusive disease: rationale, clinical and angiographic outcomes, and intraoperative blood flow analysis

OBJECTIVE

Cerebral extracranial-intracranial (EC-IC) direct bypass is a commonly used procedure for ischemic vasculopathy. A previously described variation of this technique is to utilize one donor artery to supply two recipient arteries, which the authors designate as 1D2R. The purpose of this study is to present a single surgeon's series of 1D2R direct bypasses for moyamoya and ischemia using detailed clinical, angiographic, and intraoperative blood flow measurement data. To the authors' knowledge, this is the largest series reported to date.

METHODS

Hospital, office, and radiographic imaging records for all patients who underwent cerebral revascularization using a 1D2R bypass by the senior author were reviewed. The patients' demographic information, clinical presentation, associated medical conditions, intraoperative information, and postoperative course were obtained from reviewing the medical records.

RESULTS

A total of 21 1D2R bypasses were performed in 19 patients during the study period. Immediate bypass patency was 100% and was 90% on delayed follow-up. The mean initial cut flow index (CFI(i)) was 0.64 ± 0.33 prior to the second anastomosis and the mean final value (CFI(f)) was 0.94 ± 0.38 after the second anastomosis (p < 0.001). The overall bypass flow increased on average by 50% (mean 17.9 ml/min, range -10 to 40 ml/min) with the addition of the second anastomosis. There was no significant difference in the overall flow measurements when the end-to-side anastomosis or side-to-side anastomosis was performed first. There was a statistically significant difference in the proportion of patients with a modified Rankin Scale (mRS) score of 0 or 1 postoperatively compared to preoperatively (p < 0.01). Through the application of Poiseuille's law, the authors analyzed flow dynamics, deduced the component vascular resistances based on an analogy to electrical circuits and Ohm's law, and introduced the new concepts of "second anastomosis relative augmentation" and "second anastomosis sink index" in the evaluation of 1D2R bypasses.

CONCLUSIONS

The application of the 1D2R technique in a series of 19 consecutive patients undergoing direct EC-IC bypass for flow augmentation demonstrated high patency rates, statistically significantly higher CFIs compared to 1D1R, and improved mRS scores at last clinical follow-up. Additionally, the technique allows a shorter dissection time and preserves blood flow to the scalp. The routine utilization of intraoperative volumetric flow measurements in such surgeries allows a deeper understanding of the hemodynamic impact on individual patients.

Superficial Temporal Artery to Middle Cerebral Artery Cranial Bypass for Nonmoyamoya Steno-Occlusive Disease in Patients Who Failed Optimal Medical Treatment: A Case Series

BACKGROUND

In the post-Carotid Occlusion Surgery Study (COSS) era, multiple reviews suggested subset groups of patients as potential candidates for superficial temporal artery to middle cerebral artery (STA-MCA) bypass. Among them are patients with recurrent strokes despite optimal medical therapy. There is a paucity of data on the outcome of bypass in these specific patients.

OBJECTIVE

To examine the safety and efficacy of direct STA-MCA bypass in patients with nonmoyamoya, symptomatic steno-occlusive disease with impaired distal perfusion, who failed optimal medical management or endovascular treatment.

METHODS

A retrospective review was performed to identify patients with cerebrovascular steno-occlusive disease who underwent bypass after symptomatic recurrent or rapidly progressive strokes, despite optimal conservative or endovascular treatment.

RESULTS

A total of 8 patients (mean age 60 ± 6 yr) underwent direct or combined direct/indirect STA-MCA bypass between 2016 and 2019. All anastomoses were patent. One bypass carried slow flow. There were no procedure-related permanent deficits. One patient developed seizures which were controlled by medications. A total of 7 out of 8 patients were stable or improved clinically at last follow-up (mean 27.3 ± 13.8 mo) without recurrent strokes. One patient did not recover from their presenting stroke, experienced severe bilateral strokes 4 mo postoperatively, and subsequently expired. Modified Rankin Scale (mRS) improved in 6 patients (75%), remained stable in 1 patient (12.5%), and deteriorated in 1 (12.5%). Good long-term functional outcome was achieved in 5 patients (63%, mRS ≤ 2).

CONCLUSION

Patients with symptomatic, hypoperfused steno-occlusive disease who fail optimal medical or endovascular treatment may benefit from cerebral revascularization. Direct or combined STA-MCA bypass was safe and provided favorable outcomes in this small series.

A 1-Donor 2-Recipient Superficial Temporal Artery-Middle Cerebral Artery Bypass for Moyamoya Syndrome: 2-Dimensional Operative Video

We present the case of a 34-yr-old male who suffered repeated ischemic events resulting in right-sided weakness. He was found to have left M1 segment near occlusion on angiography with a large area of uncompensated hypoperfusion. The patient underwent a direct superficial temporal artery-middle cerebral artery (STA-MCA) bypass. Direct bypass in the acute setting of ischemia has been previously described.1-5 Moyamoya ischemic disease can be treated with either direct or indirect surgical revascularization. There have been several techniques developed for direct bypasses in moyamoya ischemic disease. These include the standard 1-donor 1-recipient (1D1R) end-to-side (ES) bypass, the "double-barrel" 2-donor 2-recipient (2D2R) ES bypass, and the more recently developed 1-donor 2-recipient (1D2R)6,7 utilizing both an ES and a side-to-side (SS) bypass with a 1-donor vessel. The case presentation, surgical anatomy, decision-making, operative nuances, and postoperative course and outcome are reviewed. The patient gave verbal consent for participating in the procedure and surgical video.

Impact of Extracranial-Intracranial Bypass on Cognitive Function in a Patient with Chronic Cerebral Ischemia

Extracranial–intracranial (EC-IC) arterial bypass surgery was developed to prevent subsequent stroke by improving hemodynamics distal to the occluded intracranial artery, but its utilization has been decreasing due to the development in medical treatment. However, EC-IC bypass surgery may be effective for arresting or reversing cognitive decline in patients with cerebral ischemia. A 69-year-old man with the left internal carotid artery occlusion that manifested as scattered cerebral infarction of the left hemisphere presented with dysarthria and transient right hemiparesis. Hemodynamic condition was impaired in the left side, and therefore, EC-IC bypass surgery was performed to prevent recurrence of cerebral infarction. Neuropsychological examination at 6 months after the surgery showed marked improvement as compared to the preoperative examination and there was no recurrence of stroke in the patient. EC-IC bypass may contribute to the improvement of cognitive function as well as the prevention of recurrence of cerebral infarction in patients with hemodynamic insufficiency, but there might be a threshold of hemodynamic impairment with respect to the reversibility of cognitive performance. Investigation of the target and timing can identify cases in which the cognitive function is improved by surgery.

Timing and Outcomes of Intracranial Stenting in the Post-SAMMPRIS Era: A Systematic Review

Objective: To investigate the impact of timing on the safety and efficacy of stenting for ICAS, we reviewed high-volume randomized controlled trials or prospective cohort studies of stenting for intracranial atherosclerotic artery stenosis (ICAS) after the SAMMPRIS trial.

Methods: We included randomized controlled trials or prospective cohort studies since 2011 (the publication of the SAMMPRIS trial), evaluating the outcomes of intracranial stenting for ICAS patients. The primary outcomes were perioperative and 1-year stroke or death rate. The interaction of timing and outcomes were shown on trend plots. Overall meta-analysis and subgroup analysis by timing of intracranial stenting were conducted.

Results: Fourteen studies with a total of 1,950 patients were included. The perioperative and post-operative stroke or death rates decreased with the time of stenting to the qualifying events. The perioperative stroke rate was significantly higher in patients treated within 21 days after the qualifying events, compared to those beyond 21 days (IRR = 1.60, 95%CI: 1.10–2.33; p = 0.014), similar relationships were obtained for both post-procedural (IRR = 1.61, 95%CI: 1.02–2.55; p = 0.042) and 1-year (IRR = 1.51, 95%CI: 1.10–2.08; p = 0.012) stroke or death rate.

Conclusions: The timing of intracranial stenting may influence the safety and efficacy outcomes of stenting. Intracranial stenting within 21 days from the qualifying events may confer a higher risk of stroke or death. More studies are needed to confirm the impact of timing and the proper cut-off value.

Efficacy and Safety of Timely Urgent Superficial Temporal Artery-to-Middle Cerebral Artery Bypass Surgery in Patients with Acute Ischemic Stroke: A Single-Institutional Prospective Study and a Pooled Analysis

BACKGROUND

Clinical outcome in patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) is not satisfactory if reperfusion treatment fails or is not tried.

AIMS

We aimed to assess the efficacy and safety of urgent superficial temporal-to-middle cerebral artery (STA-MCA) bypass surgery in selected patients.

METHODS

Patients who were diagnosed with LVO-induced AIS in the anterior circulation but had a failed intra-arterial thrombectomy (IAT) or were not tried due to IAT contraindications were prospectively enrolled. Timely urgent STA-MCA bypass surgery was performed if they showed perfusion-diffusion mismatch or symptom-diffusion mismatch in the acute phase of disease. Clinical and radiological data of these patients were assessed to demonstrate the safety and efficacy of urgent bypass procedures. A pooled analysis of published data on urgent bypass surgery in acute stroke patients was conducted and analyzed.

RESULTS

In 18 patients who underwent timely bypass, the National Institutes of Health Stroke Scale (NIHSS) score improved from 12.11 ± 4.84 to 9.89 ± 6.52, 1 week after surgery. Three-month and long-term (9.72 ± 5.00 months) favorable outcomes (modified Rankin Scale [mRS] scores 0-2) were achieved in 50 and 75% of the patients, respectively. The pooled analysis (117 patients from 10 articles, including ours) identified favorable mRS scores in 71.79% patients at 3 months. A significant NIHSS score improvement from 11.51 ± 4.89 to 7.59 ± 5.50 was observed after surgery with significance. Major complications occurred in 3 patients (2.6%, 3/117) without mortality.

CONCLUSIONS

Urgent STA-MCA bypass surgery can be regarded as a safe optional treatment to prevent cerebral infarct expansion and to improve clinical and radiological outcomes in highly selected patients.

Flow-augmentation bypass in the treatment of acute ischemic stroke

INTRODUCTION

Results of two randomized trials did not show benefit of revascularization with extracranial-intracranial (EC-IC) flow augmentation bypass in patients with symptomatic occlusion of internal carotid artery (ICA). However, patients with acute stroke were not included in these studies. Herein, we systematically analyze and discuss the literature about flow augmentation bypass for treatment of acute ischemic stroke.

EVIDENCE ACQUISITION

This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. MEDLINE, Web of Science and EMBASE were independently searched by two reviewers for published series to identify literature relating to EC-IC bypass in the surgical management of acute ischemic stroke up to June 2020. Studies were categorized according to their level of evidence.

EVIDENCE SYNTHESIS

Nineteen studies met the inclusion criteria for the systematic literature review, including 16 level IV studies (ten case series and six6 case reports) and three level III studies (retrospective cohort case-control studies). Occurrence of fatal or non-fatal ischemic or hemorrhagic postoperative stroke, as well as clinical functional outcome at follow-up were considered as primary and secondary endpoints, respectively.

CONCLUSIONS

The literature about flow augmentation bypass for treatment of acute ischemic stroke is scarce and heterogenous, with only 19 studies. The results of the present systematic review encourage further study to explore and validate the use of EC-IC bypass in the treatment of anterior circulation acute ischemic stroke in highly selected patients (symptomatic and with persistent penumbra despite best medical/endovascular treatment).

Surgical procedures including carotid-carotid crossover bypass and ring-stripping hybrid operation for Rile's type 1A common carotid artery occlusion: an experience of 6 cases

Background

At present, there is no consensus on the treatment of common carotid artery occlusion (CCAO). We explored the surgical indications and observed the therapeutic effects of carotid-carotid crossover bypass and ring-stripping hybrid operation for treatment of Rile’s type 1A CCAO.

Methods

The imaging data, clinical manifestations, surgical complications and postoperative ischemic events were retrospectively collected from the 6 cases with Rile’s type 1A CCAO that underwent surgery in our department from 2011 to 2018. Of the 6 cases, 4 received carotid-carotid crossover bypass and 2 ring-stripping hybrid operation.

Results

Of the 6 cases, 4 were male and 2 females, with a mean age of 62.7 years. All cases had the left CCAO combined with decreased computed tomography perfusion (CTP) in the left internal carotid artery blood supply area. In the 4 cases receiving carotid-carotid crossover bypass, the mean operation time was 186±13 min, the mean hospital stay was 17±1 d, postoperative CTP improved, one case had swallowing foreign body sensation, synthetic vascular grafts were patent and no ischemic events occurred during the mean follow-up of 62.3±26.3 months. In the 2 cases receiving ring-stripping hybrid operation, the mean operation time was 118±11 min, the mean hospital stay was 5.5±0.7 d, postoperative CTP improved, and the opened common carotid arteries (CCA) were patent and no ischemic events occurred during the mean follow-up of 17.5±3.5 months.

Conclusions

Rile’s type 1A CCAO with related symptoms and decreased CTP should be treated by revascularization. The carotid-carotid crossover bypass is a good choice in bypass schemes because of its easy operation and good long-term patency. The ring-stripping hybrid operation may be an ideal surgical scheme for Rile’s type 1A CCAO.

Early versus delayed stenting for intracranial atherosclerotic artery stenosis with ischemic stroke

OBJECTIVE

To evaluate the clinical outcomes of early stenting (≤14 days) or late stenting (>14 days) in patients who underwent intracranial stent placement.

METHODS

Patients with ischemic stroke caused by 70-99% intracranial atherosclerotic stenosis combined with poor collaterals were enrolled. The early stenting group, who underwent stenting within 14 days of last ischemic symptoms, were compared with the late stenting group who underwent stenting >14 days from last ischemic symptom. The patients were treated either with a balloon-mounted stent or a self-expanding stent as determined by the operators following a guideline. The baseline characteristics and clinical outcomes were evaluated and compared.

RESULTS

One hundred and fifteen stroke patients were recruited into the study. Four patients (4/41) in the early stenting group and two patients (2/74) in the late stenting group were diagnosed with a cerebral vascular event associated with stenting within 3 days (p=0.184). In the long-term follow-up, eight patients in the early stenting group had restenosis ≥50%, which was higher than patients in the late stenting group (8/41 vs 4/74, p=0.018). The total rates of any ischemic stroke, transient ischemic attack, hemorrhagic stroke, and death in the early stenting group were higher than in the late stenting group (9/41 vs 6/74, p=0.035). The recurrence rate of ischemic stroke in the early stenting group was higher than in the late stenting group (5/41 vs 2/74, p=0.041).

CONCLUSIONS

Stent placement in the setting of ischemic stroke caused by intracranial artery stenosis within 14 days may confer a higher risk of long-time cerebral vascular events and lead to a higher risk of restenosis.

CLINICAL TRIAL REGISTRATION

NCT01968122.

Utilization and safety of extracranial-intracranial bypass surgery in symptomatic steno-occlusive disorders

OBJECTIVE:

The objective of this study was to investigate patterns of utilization and safety of extracranial–intracranial (EC-IC) bypass in patients with symptomatic cerebrovascular steno-occlusive disorders.

METHODS:

Patients with one of the steno-occlusive conditions (defined as symptomatic intracranial stenosis, extracranial stenosis, and moyamoya disease) were identified using all nonfederal hospitalizations in New York (2005–2014) and Florida (2005–2015). EC-IC bypass surgery was defined using the corresponding procedure codes. Patients were included if there was a prior history of ischemic stroke or transient ischemic attack. Patients were excluded for any preceding diagnosis of cerebral hemorrhage, aneurysm, or trauma. The primary outcome was perioperative ischemic stroke, cerebral hemorrhage, or mortality occurring within 30 days of surgery. We also determined yearly trends for the volume of EC-IC bypass procedures in the study period.

RESULTS:

Among 346 patients with steno-occlusive disease treated with EC-IC bypass, median age was 52.5 years and 52.5% were female. Rates of EC-IC bypass surgery procedure increased until 2011 and then decreased coinciding with the publication of the Carotid Occlusion Surgery Study trial. Thirty-day event rates of stroke, hemorrhage, or death decreased in patients treated with EC-IC bypass (odds ratio: 0.2, confidence interval: 0.0.4–0.99; P = 0.03) over the 10-year study period.

CONCLUSIONS:

Overall utilization of EC-IC bypass procedure is relatively low, whereas the 30-day complication rates for patients with steno-occlusive conditions appear to be relatively low and improving. Further research is needed to confirm these findings and to determine the subset of patients who would most likely benefit from this intervention.

Clinical importance of the superficial temporal artery in neurovascular diseases: A PRISMA-compliant systematic review

The superficial temporal artery (STA) plays a very important role in neurovascular diseases and procedures. However, until now, no comprehensive review of the role of STA in neurovascular diseases from a neurosurgical perspective has ever been published. To review research on the clinical importance of STA in neurovascular diseases, a literature search was performed using the PubMed database. Articles were screened for suitability and data relevance. This paper was organized following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. According to the literature, STA is one of the terminal branches of the external carotid artery and can give off scalp, muscle, and transosseous branches. STA-middle cerebral artery (MCA) bypass is very useful for intracranial ischemic diseases, including moyamoya disease, chronic ICA and MCA insufficiency, and even acute ischemic stroke. For intracranial complex aneurysms, STA bypass remains a major option that can serve as flow replacement bypass during aneurysmal trapping or insurance bypass during temporary parent artery occlusion. Occasionally, the STA can also be involved in dural AVFs (DAVFs) via to its transosseous branches. In addition, the STA can be used as an intraoperative angiography path and the path to provide endovascular treatments. Therefore, STA is a very important artery in neurovascular diseases.