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.

Sequential Flow Diversion After Nitinol Stent Placement for a Large, Matricidal Cavernous Internal Carotid Artery Aneurysm: Technical Video.

The Surpass Evolve flow diverter is a novel 64-wire braided intravascular stent approved to treat unruptured large or giant saccular wide-neck or fusiform intracranial aneurysms of the intracranial internal carotid artery.1-3 Flow diverting stents have been used for the treatment of previously stented aneurysms, including residual aneurysms following prior flow diversion.5-8 This patient initially presented with a large symptomatic matricidal cavernous ICA aneurysm4 that was treated with stand-alone Neuroform Atlas stenting at an outside hospital. Here we present a video demonstrating the placement of sequential Surpass Evolve flow diverter stents within a Neuroform Atlas nitinol stent.

Double-Barrel (2-Donor-2-Recipient) Bypass as Rescue Treatment for Patient with Occluded Middle Cerebral Artery Intracranial Stent and Recurrent Ischemia.

Stent occlusion is a challenging complication following endovascular interventions that require intracranial stenting.1-4 Although there are small series describing revascularization for stenoocclusive disease failing best medical management,5-14 there are few reports in the literature regarding surgical bypass as a treatment for stent occlusion.5 We present the case of a 37-year-old man who presented with right-sided weakness, numbness, and difficulty with speech and ambulation. His history is notable for a left M1 (segment of middle cerebral artery) occlusion 6 months prior that was treated with mechanical thrombectomy requiring repeat thrombectomy and rescue acute middle cerebral artery (MCA) stent placement given vessel reocclusion. Diagnostic cerebral angiography demonstrated stent occlusion. Given his continued ischemic symptoms despite best medical management, the patient underwent a double-barrel superficial temporal artery-MCA direct bypass to revascularize the MCA territory. To our knowledge, there is no literature to date describing a 2-donor-2-recipient direct bypass for the rescue treatment of symptomatic intracranial stent occlusion with recurrent ischemia. We review the case presentation, angiographic findings, surgical nuances, and postoperative course with imaging. The patient provided informed consent for the procedure and verbal support for publishing his image and inclusion in this submission.

Direct, Indirect, and Combined Extracranial-to-Intracranial Bypass for Adult Moyamoya Disease: An Updated Systematic Review and Meta-Analysis.

BACKGROUND: Moyamoya disease is a chronic, progressive cerebrovascular disease involving occlusion or stenosis of the terminal portion of the internal carotid artery. We conducted an updated systematic review and meta-analysis to investigate clinical and angiographic outcomes comparing direct, combined, and indirect bypass for the treatment of moyamoya disease in adults. METHODS: Two independent authors performed Preferred Reporting Items for Systematic reviews and Meta-Analyses guided literature searches in December 2021 to identify articles reporting clinical/angiographic outcomes in adult moyamoya disease patients undergoing bypass. Primary end points used were ischemic and hemorrhagic strokes, clinical outcomes, and angiographic revascularization. Study quality was evaluated with Newcastle-Ottawa and the Oxford Center for Evidence-Based Medicine scales. RESULTS: Four thousand four hundred fifty seven articles were identified in the initial search; 143 articles were analyzed. There were 3827 direct, 3826 indirect, and 3801 combined bypasses. Average length of follow-up was 3.59±2.93 years. Pooled analysis significantly favored direct (odds ratio [OR], 0.62 [0.48-0.79]; P<0.0001; OR, 0.44 [0.32-0.59]; P<0.0001; OR, 0.56 [0.42-0.74]; P<0.0001; OR, 3.1 [2.5-3.8]; P=0.0001) and combined (OR, 0.53 [0.41-0.69]; P<0.0001; OR, 0.28 [0.2-0.41]; P<0.0001; OR, 0.41 [0.3-0.56]; P<0.0001; OR, 3.1 [2.8-4.3]; P=0.0001) over indirect bypass for early stroke, late stroke, late intracerebral hemorrhage, and favorable outcomes, respectively. Indirect bypass was favored over combined (OR, 3.1 [1.7-5.6]; P<0.0001) and direct (OR, 4.12 [2.34-7.25]; P<0.0001) for early intracerebral hemorrhage. The meta-analysis significantly favored direct (OR, 0.37 [0.23-0.60]; P<0.001; OR, 0.49 [0.31-0.77]; P=0.002) and combined (OR, 0.23 [0.12-0.43]; P<0.00001; OR, 0.30 [0.18-0.49]; P<0.00001) bypass over indirect bypass for late stroke and late hemorrhage, respectively. Combined bypass was favored over indirect bypass for favorable outcomes (OR, 2.06 [1.18-3.58]; P=0.01). CONCLUSIONS: Based on combined meta-analysis (43 articles) and pooled analysis (143 articles), the existing literature indicates that combined and direct bypasses have significant benefits for patients suffering from late stroke and hemorrhage versus indirect bypass. Combined bypass was favored over indirect bypass for favorable outcomes. This is a strong recommendation based on low-quality evidence when utilizing the Grades of Recommendation, Assessment, Development, and Evaluation system. These findings have important implications for bypass strategy selection.

Woven EndoBridge Embolized Aneurysm Clippings: 2-Dimensional Operative Video.

The Woven EndoBridge (WEB) device (MicroVention, Aliso Viejo, California) is an intrasaccular flow disruptor used for the treatment of both unruptured and ruptured intracranial aneurysms. WEB has been shown to have 54% complete and 85% adequate aneurysm occlusion rates at 1-yr follow-up.1 Residual and recurrent ruptured aneurysms have been shown to have a higher risk of re-rupture than completely occluded aneurysms.2 With increased utilization of WEB in the United States, optimizing treatment strategies of residual aneurysms previously treated with the WEB device is essential, including surgical clipping.3,4 Here, we present an operative video demonstrating the surgical clip occlusion of previously ruptured middle cerebral artery and anterior communicating artery aneurysms that had been treated with the WEB device and had sizable recurrence on follow-up angiography. Informed consent was obtained from both patients. Lessons learned include the following: (1) the WEB device is highly compressible, unlike coils; (2) proximal WEB marker may interfere with clip closure; (3) no evidence of WEB extrusion into the subarachnoid space; (4) no more scarring than expected in ruptured cases; and (5) clipping is a feasible option for treating WEB recurrent or residual aneurysms.

Implications of limiting mechanical thrombectomy to patients with emergent large vessel occlusion meeting top tier evidence criteria.

BACKGROUND: Recent guidelines for endovascular management of emergent large vessel occlusion (ELVO) award top tier evidence to the same selective criteria in recent trials. We aimed to understand how guideline adherence would have impacted treatment numbers and outcomes in a cohort of patients from a comprehensive stroke center. METHODS: A retrospective observational study was conducted using consecutive emergent endovascular patients. Mechanical thrombectomy (MT) was performed with stent retrievers or large bore clot aspiration catheters. Procedural outcomes were compared between patients meeting, and those failing to meet, top tier evidence criteria. RESULTS: 126 patients receiving MT from January 2012 to June 2015 were included (age 31-89 years, National Institutes of Health Stroke Scale (NIHSS) score 2-38); 62 (49%) patients would have been excluded if top tier criteria were upheld: pretreatment NIHSS score <6 (10%), Alberta Stroke Program Early CT score <6 (6.5%), premorbid modified Rankin Scale (mRS) score ≥2 (27%), M2 occlusion (10%), posterior circulation (32%), symptom to groin puncture >360 min (58%). 26 (42%) subjects had more than one top tier exclusion. Symptomatic intracerebral hemorrhage (sICH) and systemic hemorrhage rates were similar between the groups. 3 month mortality was 45% in those lacking top tier evidence compared with 26% (p=0.044), and 3 month mRS score 0-2 was 33% versus 46%, respectively (NS). After adjusting for potential confounders, top tier treatment was not associated with neurological improvement during hospitalization (ß -8.2; 95% CI -24.6 to -8.2; p=0.321), 3 month mortality (OR=0.38; 95% CI 0.08 to 1.41), or 3 month favorable mRS (OR=0.97; 95% CI 0.28 to 3.35). CONCLUSIONS: Our study showed that with strict adherence to top tier evidence criteria, half of patients may not be considered for MT. Our data indicate no increased risk of sICH and a potentially higher mortality that is largely due to treatment of patients with basilar occlusions and those treated at an extended time window. Despite this, good functional recovery is possible, and consideration of MT in patients not meeting top tier evidence criteria may be warranted.

A safe and effective management strategy for blunt cerebrovascular injury: Avoiding unnecessary anticoagulation and eliminating stroke.

BACKGROUND: Few injuries have produced as much debate with respect to management as have blunt cerebrovascular injuries (BCVIs). Recent work (American Association for the Surgery of Trauma 2013) from our institution suggested that 64-channel multidetector computed tomographic angiography (CTA) could be the primary screening tool for BCVI. Consequently, our screening algorithm changed from digital subtraction angiography (DSA) to CTA, with DSA reserved for definitive diagnosis of BCVI following CTA-positive study results or unexplained neurologic findings. The current study was performed to evaluate outcomes, including the potential for missed clinically significant BCVI, since this new management algorithm was adopted. METHODS: Patients who underwent DSA (positive CTA finding or unexplained neurologic finding) over an 18-month period subsequent to the previous study were identified. Screening and confirmatory test results, complications, and BCVI-related strokes were reviewed and compared. RESULTS: A total of 228 patients underwent DSA: 64% were male, with mean age and Injury Severity Score (ISS) of 43 years and 22, respectively. A total of 189 patients (83%) had a positive screening CTA result. Of these, DSA confirmed injury in 104 patients (55%); the remaining 85 patients (45%) (false-positive results) were found to have no injury on DSA. Five patients (4.8%) experienced BCVI-related strokes, unchanged from the previous study (3.9%, p = 0.756); two were symptomatic at trauma center presentation, and three occurred while receiving appropriate therapy. No patient with a negative screening CTA result experienced a stroke. CONCLUSION: This management scheme using 64-channel CTA for screening coupled with DSA for definitive diagnosis was proven to be safe and effective in identifying clinically significant BCVIs and maintaining a low stroke rate. Definitive diagnosis by DSA led to avoidance of potentially harmful anticoagulation in 45% of CTA-positive patients (false-positive results). No strokes resulted from injuries missed by CTA. LEVEL OF EVIDENCE: Diagnostic study, level III.

Prevention of stent thrombosis with reduced dose of prasugrel in two patients undergoing treatment of cerebral aneurysms with pipeline embolisation devices.

Prevention of intracranial stent thrombosis with dual-antiplatelet therapy is widely used in neuroendovascular procedures. However, the rising incidence of inadequate platelet inhibition with clopidogrel may increase complications following stent placement, especially with newer devices that possess a larger total metal surface area. While there are recent reports of prasugrel as an alternative to clopidogrel, there is no clinical evidence in neurointerventional patients regarding the use of a lower maintenance dose as an alternative strategy to gain adequate platelet inhibition while possibly reducing the risk of bleeding. We present 6-month efficacy and safety outcomes of two patients undergoing elective pipeline embolisation that were found to have inadequate platelet response to clopidogrel and subsequently transitioned to prasugrel 5 mg daily for the prevention of stent thrombosis.

Prevention of stent thrombosis with reduced dose of prasugrel in two patients undergoing treatment of cerebral aneurysms with pipeline embolisation devices.

Prevention of intracranial stent thrombosis with dual-antiplatelet therapy is widely used in neuroendovascular procedures. However, the rising incidence of inadequate platelet inhibition with clopidogrel may increase complications following stent placement, especially with newer devices that possess a larger total metal surface area. While there are recent reports of prasugrel as an alternative to clopidogrel, there is no clinical evidence in neurointerventional patients regarding the use of a lower maintenance dose as an alternative strategy to gain adequate platelet inhibition while possibly reducing the risk of bleeding. We present 6-month efficacy and safety outcomes of two patients undergoing elective pipeline embolisation that were found to have inadequate platelet response to clopidogrel and subsequently transitioned to prasugrel 5 mg daily for the prevention of stent thrombosis.

Aneurysm inflow-angle as a discriminant for rupture in sidewall cerebral aneurysms: morphometric and computational fluid dynamic analysis.

BACKGROUND AND PURPOSE: The ability to discriminate between ruptured and unruptured cerebral aneurysms on a morphological basis may be useful in clinical risk stratification. The objective was to evaluate the importance of inflow-angle (IA), the angle separating parent vessel and aneurysm dome main axes. METHODS: IA, maximal dimension, height-width ratio, and dome-neck aspect ratio were evaluated in sidewall-type aneurysms with respect to rupture status in a cohort of 116 aneurysms in 102 patients. Computational fluid dynamic analysis was performed in an idealized model with variational analysis of the effect of IA on intra-aneurysmal hemodynamics. RESULTS: Univariate analysis identified IA as significantly more obtuse in the ruptured subset (124.9 degrees+/-26.5 degrees versus 105.8 degrees+/-18.5 degrees, P=0.0001); similarly, maximal dimension, height-width ratio, and dome-neck aspect ratio were significantly greater in the ruptured subset; multivariate logistic regression identified only IA (P=0.0158) and height-width ratio (P=0.0017), but not maximal dimension or dome-neck aspect ratio, as independent discriminants of rupture status. Computational fluid dynamic analysis showed increasing IA leading to deeper migration of the flow recirculation zone into the aneurysm with higher peak flow velocities and a greater transmission of kinetic energy into the distal portion of the dome. Increasing IA resulted in higher inflow velocity and greater wall shear stress magnitude and spatial gradients in both the inflow zone and dome. CONCLUSIONS: Inflow-angle is a significant discriminant of rupture status in sidewall-type aneurysms and is associated with higher energy transmission to the dome. These results support inclusion of IA in future prospective aneurysm rupture risk assessment trials.

Stent graft treatment of cerebrovascular wall defects: intermediate-term clinical and angiographic results.

OBJECTIVE: Endovascular stent graft (SG) deployment offers a useful vessel-preserving strategy for vascular wall lesions such as pseudoaneurysms and fistulae. Although deployment of expanded polytetrafluoro-ethylene-covered SGs within the carotid and vertebral arteries is technically feasible, data on long-term efficacy, safety, and patency rate remain sparse. METHODS: Six patients with traumatic (n = 4), iatrogenic (n = 1), or spontaneous (n = 1) internal carotid and vertebral artery injuries (direct carotid-cavernous fistula, n = 2; pseudoaneurysms, n = 4) were treated with nine balloon-mounted coronary expanded polytetrafluoro-ethylene SGs. Angiographic (mean, 2.3 yr; range, 1.7-4.2 yr) and neurological follow-up (mean, 2.7 yr) was performed for all patients. RESULTS: Complete angiographic exclusion of the lesion was achieved by the initial procedure in five of the six patients; one ruptured cavernous carotid aneurysm leading to a direct carotid-cavernous fistula showed persistent slow shunting despite tandem deployment of two SGs. All six patients revealed complete and persistent angiographic obliteration at delayed follow-up, with minimal in-stent stenosis (<20%) seen in two instances. Difficulty with SG navigation was encountered in five patients, resulting in one instance of guide catheter-induced intimal dissection. Type I endoleak was observed in five patients, requiring secondary angioplasty in four patients and deployment of an additional tandem SG in three. CONCLUSION: Technical challenges in current-generation SG deployment include sizing, navigation, positioning, and propensity for endoleak. When managed successfully, stent grafting provides a valuable approach for the treatment of vascular wall defects for which vessel preservation is preferred. Intermediate-term safety is satisfactory, with no delayed complications and minimal in-stent stenosis in follow-up periods of more than 2 years.

Angiographic detection of carotid and vertebral arterial injury in the high-energy blunt trauma patient.

BACKGROUND AND OBJECTIVE: Injury to the carotid and vertebral arteries is an identified risk to patients after blunt high-energy cranio-cervical trauma with an associated risk of thromboembolic stroke. We sought to determine the incidence, features, and risk factors of arterial injury using selective cerebral angiography in a high-risk trauma patient subset. METHODS: Blunt trauma patients with a high-energy mechanism were selected to undergo screening cerebral angiography if they met one of the following criteria: (1) cervical spine hyperextension/hyperflexion injury, (2) skull-base or facial fracture, (3) lateralizing neurologic deficit, ischemic deficit, or cerebral infarction, or (4) hemorrhage of arterial origin. RESULTS: Of 69 screened patients 20 were found to have a vascular injury (28.9%), including 13 carotid and 15 vertebral; 9 of the 20 patients with vascular injury were symptomatic (45%). The most frequent injuries were intimal dissections (8/28), pseudoaneurysms (6/28), and vessel occlusions (5/28); 8 lesions were intracranial and 20 cervical. Displaced facial fractures (P<0.02) but not skull-base fracture were predictive of carotid injury; multilevel cervical spine fractures (P<0.001) and transverse foraminal fractures (P<0.02) were associated with vertebral injury. CONCLUSIONS: Cerebral angiography in a selected group of trauma patients was found to yield a significant rate of carotid and vertebral arterial injury, a finding that had implications to subsequent clinical management.

Iatrogenic vasospasm in carotid artery stent angioplasty with distal protection devices.

OBJECT: Distal protection devices (DPDs) have decreased the risk of embolic stroke among patients with carotid artery (CA) disease undergoing CA stent placement. The FilterWire EX is a first-generation fixed-basket DPD with a filter rigidly attached to a guidewire. Second-generation mobile-basket DPDs (RX Accunet or SpiderFX) allow movement of the filter relative to the guidewire and can thus reduce the potential for vessel irritation, vasospasm, or intimal injury during CA stent placement. METHODS: Stent angioplasty was attempted in 40 CAs (37 patients) using the fixed-basket FilterWire DPD, a second-generation mobile-basket DPD, or no protection in 12, 6, and 22 arteries, respectively. Clinical presentation, angiographic details relating to the incidence of vasospasm or dissection, and clinical outcome data were recorded and analyzed. RESULTS: Vasospasm was associated with use of the fixed-basket FilterWire device (8 [67%] of 12 cases) compared with the bare unfiltered guidewire group (3 [14%] of 22) and the second-generation mobile-basket DPD group (1 [17%] of 6, p < 0.004). Secondary angioplasty was also associated with intraprocedural vasospasm. In a multivariate analysis, FilterWire use was an independent risk factor for vasospasm (p < 0.0003). CONCLUSIONS: A high incidence of vasospasm was observed following CA stent placement procedures in which the fixed-basket FilterWire EX DPD was used but not in unprotected CA stent placement or procedures in which a second-generation mobile-basket DPD was used. Although this phenomenon was self-limited in all instances, vasospasm should be considered a risk of these devices and may predispose to more serious vascular injury. Coronary artery stent placement should be performed with a second-generation mobile-basket DPD to minimize the risks of embolic complications and iatrogenic vascular injury.

Decompressive hemicraniectomy for the treatment of intractable intracranial hypertension after aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Decompressive hemicraniectomy and duroplasty (DHCD) can improve survival in patients with severe cerebral edema. We present our clinical experience with DHCD for the treatment of refractory elevated intracranial pressure (ICP) in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: DHCD was performed in 16 patients (11 female; median age, 49.5 years) with aSAH (11 Hunt-Hess grade 4 to 5) for sustained ICP >250 mm H(2)O refractory to maximal medical treatment and cerebrospinal fluid drainage at a median of 2 days from admission. Half of the patients were treated with endovascular coiling and the other half with surgical clipping. RESULTS: DHCD (mean flap size, 8536 mm(2)) reduced ICP from 350+/-157 to 147+/-124 mm H(2)O. Eleven patients survived (69%), and at latest follow-up (median, 450 days), 7 (64%) had a modified Rankin score of 0 to 3 and 4 (36%) a score of 4 to 5. Peak herniated brain volume was inversely associated with good outcome (P<0.005). Early craniectomy performed within 48 hours after the aSAH was associated with better outcome: 6 of 8 patients had good outcomes (75%) compared with 1 of 8 patients in whom late decompression was performed (P<0.01). Midline shift, Hunt-Hess grade, presence of hemorrhage, hematoma volume, craniectomy area, peak ICP, and relative ICP reduction were not associated with outcome in this patient population. CONCLUSIONS: DHCD is a useful adjunct modality for management of refractory intracranial hypertension in patients with high-grade aSAH, even in the absence of large intraparenchymal hemorrhage. In our series, long-term outcome was better in patients who underwent early intervention.

Preoperative embolization of hypervascular spinal metastases using percutaneous direct injection with n-butyl cyanoacrylate: technical case report.

OBJECTIVE: Intraoperative blood loss constitutes a major cause of perioperative morbidity in surgical decompression and reconstruction of highly vascular spinal metastatic tumors. We propose a technique for embolization of highly vascular vertebral metastases using percutaneous direct injection using n-butyl cyanoacrylate (NBCA) instead of polymethylmethacrylate to complement preoperative transarterial embolization and to minimize operative blood loss. METHODS: Five patients with renal cell carcinoma metastases to the spine (one cervical, one thoracic, and three lumbar) underwent embolization by percutaneous direct injection of the affected vertebrae with a mixture of NBCA and iodized oil to supplement transarterial embolization with polyvinyl alcohol particles and fibered platinum coils. This was achieved via a transpedicular approach in four cases and by direct vertebral body puncture in one case. RESULTS: The percutaneous NBCA direct injection procedure was technically successful in all cases and was not associated with neurological or medical complications. All patients underwent subsequent vertebrectomy and spinal instrumentation. Surgical resection was performed with lower than expected blood loss and with a subjective improvement in tumor tissue handling and dissection. CONCLUSION: The extent of tumor devascularization can be improved by supplementing transarterial embolization with NBCA direct injection to decrease operative blood loss and increase the safety of surgical resection and stabilization of highly vascular spinal metastases.