Siddiqui, Adnan H

Abstract We present a case of tandem stenosis of the great vessels (cervical internal carotid artery [ICA] and brachiocephalic trunk ostium [BTO]) treated with stenting and balloon angioplasty of both lesions under flow arrest. A 70-yr-old woman with a history of hypertension, hyperlipidemia, coronary artery disease, and previous strokes presented with recurrent transient ischemic attacks of the left upper and lower extremities over the last 6 mo. She underwent right cervical endarterectomy (CEA) 16 yr prior. Neurological examination was unremarkable. Carotid Doppler ultrasonography revealed severely increased velocities of the right ICA. Cervical magnetic resonance angiography demonstrated 80% right ICA stenosis and 50% BTO stenosis. Digital subtraction cerebral angiography showed 80% right ICA stenosis and 70% BTO stenosis. The patient was not a candidate for standard carotid artery stenting because the BTO precluded endovascular access or for CEA because of the previous CEA; therefore, direct carotid access and flow reversal was an alternative. Under general anesthesia and systemic heparinization, the patient underwent right carotid artery surgical exposure. Under flow reversal using the Enroute System (Silk Road Medical, Sunnyvale, California), anterograde right ICA stenting angioplasty and retrograde BTO stenting and angioplasty were performed. Successful revascularization of the right ICA and BTO was obtained. No procedure-related complications occurred. The patient was discharged home 2 d postprocedure, neurologically intact. Direct carotid access with flow reversal is a safe and effective therapeutic alternative for patients with ICA (or common carotid artery) stenosis who cannot undergo CEA or when endovascular access from the aortic arch is not possible. Patient consent was obtained prior to performing the procedure. Institutional board approval is not required for the report of a single case.

OBJECTIVE The overall risk of ischemic stroke from a chronically occluded internal carotid artery (COICA) is around 5%–7% per year despite receiving the best available medical therapy. Here, authors propose a radiographic classification of COICA that can be used as a guide to determine the technical success and safety of endovascular recanalization for symptomatic COICA and to assess the changes in systemic blood pressure following successful revascularization. METHODS The radiographic images of 100 consecutive subjects with COICA were analyzed. A new classification of COICA was proposed based on the morphology, location of occlusion, and presence or absence of reconstitution of the distal ICA. The classification was used to predict successful revascularization in 32 symptomatic COICAs in 31 patients, five of whom were female (5/31 [16.13%]). Patients were included in the study if they had a COICA with ischemic symptoms refractory to medical therapy. Carotid artery occlusion was defined as 100% cross-sectional occlusion of the vessel lumen as documented on CTA or MRA and confirmed by digital subtraction angiography. RESULTS Four types (A–D) of radiographic COICA were identified. Types A and B were more amenable to safe revascularization than types C and D. Recanalization was successful at a rate of 68.75% (22/32 COICAs; type A: 8/8; type B: 8/8; type C: 4/8; type D: 2/8). The perioperative complication rate was 18.75% (6/32; type A: 0/8 [0%]; type B: 1/8 [12.50%]; type C: 3/8 [37.50%], type D: 2/8 [25.00%]). None of these complications led to permanent morbidity or death. Twenty (64.52%) of 31 subjects had improvement in their symptoms at the 2–6 months’ follow-up. A statistically significant decrease in systolic blood pressure (SBP) was noted in 17/21 (80.95%) patients who had successful revascularization, which persisted on follow-up (p = 0.0001). The remaining 10 subjects in whom revascularization failed had no significant changes in SBP (p = 0.73). CONCLUSIONS The pilot study suggested that our proposed classification of COICA may be useful as an adjunctive guide to determine the technical feasibility and safety of revascularization for symptomatic COICA using endovascular techniques. Additionally, successful revascularization may lead to a significant decrease in SBP postprocedure. A Phase 2b trial in larger cohorts to assess the efficacy of endovascular revascularization using our COICA classification is warranted.

Abstract BACKGROUND Neck remnants are not uncommon after endovascular treatment of cerebral aneurysms. Critics of endovascular treatments for cerebral aneurysms cite neck remnants as evidence in favor of microsurgical clipping. However, studies have failed to evaluate the true clinical significance of aneurysm neck remnants following endovascular therapies. OBJECTIVE To assess the clinical significance of residual aneurysm necks and to determine the rate of subsequent rupture following coiling or stent-assisted coiling of cerebral aneurysms. METHODS We retrospectively reviewed the records of 1292 aneurysm cases that underwent endovascular treatment at 4 institutions. Aneurysms treated by primary coiling or stent-assisted coiling were included in the study; those treated by flow diversion were excluded Aneurysms with residual filling (i.e., Raymond–Roy Occlusion Classification II, neck remnant; or III, residual aneurysm filling) were assessed for their risk of subsequent rupture. RESULTS A total of 626 aneurysms were identified as having residual filling immediately posttreatment. Of these, 13 aneurysms (2.1%) ruptured during the follow-up period (mean 7.3 mo; range 1-84 mo). Eleven of the 13 (84.6%) were ruptured at presentation. Rupture at presentation, the size of the aneurysm, and the increasing age of the patient were predictive of posttreatment rupture. CONCLUSION We found that unruptured aneurysms with residual necks following endovascular treatment posed a very low risk of rupture (0.6%). However, patients presenting with ruptured aneurysms had a higher risk of rerupture from a neck remnant (3.4%). These results highlight the importance of achieving complete angiographic occlusion of ruptured aneurysms.

Abstract The University at Buffalo's neuroendovascular fellowship is one of the longest running fellowship programs in North America. The burgeoning neurointerventional workforce and the rapid growth in the neurointerventional space on the heels of groundbreaking clinical trials prompted us to assess the fellowship's academic impact and its graduates’ perceptions and productivity. An anonymized web-based survey was sent to all former neuroendovascular fellows with specific questions pertaining to current practice, research and funding, and perceptions about the fellowship's impact on their skills, competitiveness, and compensation. Additionally, the h -index was calculated to assess the academic productivity of each graduated fellow. Among 50 former fellows, 42 (84%) completed the survey. The fellows came from various countries, ethnic backgrounds, and specialties including neurosurgery (n = 39, 93%), neurology (n = 2, 5%), and neuroradiology (n = 1, 2%). Twenty (48%) respondents were currently chairs or directors of their practice. Most (n = 30, 71%) spent at least 10% of their time on research activities, with 27 (64%) receiving research funding. The median h -index of all 50 former fellows was 14. The biggest gains from the fellowship were reported to be improvement in endovascular skills (median = 10 on a scale of 0-10 [highest]) and increase in competitiveness for jobs in vascular neurosurgery (median = 10), followed by increase in academic productivity (median = 8), and knowledge of vascular disease (median = 8). In an era with open calls for moratoriums on endovascular fellowships, concerns over market saturation, and pleas to improve training, fellowship programs perhaps merit a more objective assessment. The effectiveness of a fellowship program may best be measured by the academic impact and leadership roles of former fellows.

Background: Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation. Methods: STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0–2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass. Results: A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients ( P <0.001). Clinical outcomes were better in the direct group, with 60.0% (299/498) achieving functional independence compared with 52.2% (213/408) in the transfer group (odds ratio, 1.38; 95% confidence interval, 1.06–1.79; P =0.02). Likewise, excellent outcome (modified Rankin Score 0–1) was achieved in 47.4% (236/498) of direct patients versus 38.0% (155/408) of transfer patients (odds ratio, 1.47; 95% confidence interval, 1.13–1.92; P =0.005). Mortality did not differ between the 2 groups (15.1% for direct, 13.7% for transfer; P =0.55). Intravenous tissue plasminogen activator did not impact outcomes. Hypothetical bypass modeling for all transferred patients suggested that intravenous tissue plasminogen activator would be delayed by 12 minutes, but MT would be performed 91 minutes sooner if patients were routed directly to endovascular-capable centers. If bypass is limited to a 20-mile radius from onset, then intravenous tissue plasminogen activator would be delayed by 7 minutes and MT performed 94 minutes earlier. Conclusions: In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02239640.

Limited data exist on clot composition and detailed characteristics of arterial thrombi associated with large vessel occlusion in acute ischemic stroke. Advances in endovascular thrombectomy and related imaging modalities have created a unique opportunity to analyze thrombi removed from cerebral arteries. Insights into thrombus composition, etiology, physical properties and neurovascular interactions may lead to future advancements in acute ischemic stroke treatment and improved clinical outcomes. Advances in imaging techniques may enhance clot characterization and inform therapeutic decision-making prior to treatment and reveal stroke etiology to guide secondary prevention. Current imaging techniques can provide some information about thrombi, but there remains much to evaluate about relationships that may exist among thrombus composition, occlusion characteristics and treatment outcomes. Improved pathophysiological characterization of clot types, their properties and how these properties change over time, together with clinical correlates from ongoing studies, may facilitate revascularization with thrombolysis and thrombectomy. Interdisciplinary approaches covering clinical, engineering and scientific aspects of thrombus research will be key to advancing the understanding of thrombi and improving acute ischemic stroke therapy. This consensus statement integrates recent research on clots and thrombi retrieved from cerebral arteries and provides a rationale for further analyses, including current opportunities and limitations.

Abstract BACKGROUND Neuroendovascular intervention has become a key treatment option for acute ischemic stroke. The Sofia (6F) PLUS catheter was designed for neurovascular access for diagnostic or therapeutic interventions. OBJECTIVE To report the first series describing use of the Sofia PLUS intermediate/distal access reperfusion catheter in the treatment of acute ischemic stroke. METHODS In this retrospective study, 41 stroke cases were identified in which the catheter was utilized for thrombolysis/thrombectomy. Mean preprocedure National Institutes of Health Stroke Scale score was 16.5 ± 5.2 (range 4-29). Occluded vessels included the M1 segment, M2 segment, internal carotid artery terminus, cervical internal carotid artery, and basilar artery. RESULTS Successful positioning of the Sofia PLUS catheter near the occlusion site was achieved in 38 (92.7%) of 41 cases in which thrombectomy or thrombolysis was attempted using intraarterial tissue plasminogen activator, a direct aspiration first-pass technique, and/or stent retrieval. A postprocedure thrombolysis in cerebral infarction (TICI) score of 2b/3 was achieved in 37 of 41 cases. Of 15 cases where the Sofia PLUS was used for a direct aspiration first-pass technique, TICI 2b/3 was achieved in 11 (73.3%). In one case where intra-arterial tissue plasminogen activator was used as the only treatment modality, TICI 2a was achieved. No device-related or catheter-related complications were observed. The mean 7-d-postprocedure National Institutes of Health Stroke Scale score among the 39 survivors was 8.5 ± 7.3 (range 0-23). CONCLUSION Initial results with use of the Sofia (6F) PLUS for endovascular treatment of acute ischemic stroke have been encouraging. Experience with a larger series is warranted to further evaluate the safety and efficacy of this device and compare it with other reperfusion catheters.

Abstract BACKGROUND: Early and mid-term safety and efficacy of aneurysm treatment with the Pipeline Embolization Device (PED) has been well demonstrated in prior studies. OBJECTIVE: To present 5-yr follow-up for patients treated in the Pipeline for Uncoilable or Failed Aneurysms clinical trial. METHODS: In our prospective, multicenter trial, 109 complex internal carotid artery (ICA) aneurysms in 107 subjects were treated with the PED. Patients were followed per a standardized protocol at 180 d and 1, 3, and 5 yr. Aneurysm occlusion, in-stent stenosis, modified Rankin Scale scores, and complications were recorded. RESULTS: The primary endpoint of complete aneurysm occlusion at 180 d (73.6%) was previously reported. Aneurysm occlusion for those patients with angiographic follow-up progressively increased over time to 86.8% (79/91), 93.4% (71/76), and 95.2% (60/63) at 1, 3, and 5 yr, respectively. Six aneurysms (5.7%) were retreated. New serious device-related events at 1, 3, and 5 yr were noted in 1% (1/96), 3.5% (3/85), and 0% (0/81) of subjects. There were 4 (3.7%) reported deaths in our trial. Seventy-eight (96.3%) of 81 patients with 5-yr clinical follow-up had modified Rankin Scale scores ≤2. No delayed neurological deaths or hemorrhagic or ischemic cerebrovascular events were reported beyond 6 mo. No recanalization of a previously occluded aneurysm was observed. CONCLUSION: Our 5-yr findings demonstrate that PED is a safe and effective treatment for large and giant wide-necked aneurysms of the intracranial ICA, with high rates of complete occlusion and low rates of delayed adverse events.