Faculty Bibliography

BACKGROUND AND IMPORTANCE/BACKGROUND:Rhino-orbital cerebral mucormycosis (ROCM) is an aggressive fungal infection involving the paranasal sinuses, orbit, and intracranial cavity, with a propensity for vascular invasion. This can lead to complications such as internal carotid artery (ICA) thrombosis and occlusion, presenting major neurosurgical challenges. Although surgical debridement and antifungal therapy are the mainstays of treatment, cases with significant neurovascular involvement require specialized intervention. We report a case of ROCM with severe flow-limiting ICA stenosis treated by direct extracranial-intracranial bypass. CLINICAL PRESENTATION/METHODS:tA 65-year-old man with diabetes presented with progressive left-sided blindness and facial numbness. Imaging revealed a left orbital mass extending into the paranasal sinuses and intracranially. Empiric antifungal therapy was started. Pathology confirmed Rhizopus species. Despite extensive surgical debridement and antifungal therapy, the patient developed progressive severe cavernous ICA stenosis, leading to watershed territory strokes. To restore cerebral perfusion, protect from distal emboli, and prepare for potential aggressive debridement, a flow-replacing direct (superficial temporal artery-middle cerebral artery (M2)) bypass was performed, and the supraclinoid carotid was trapped. Intraoperative angiography confirmed robust flow through the bypass. The patient was discharged on antifungal therapy and aspirin. At 6-month follow-up, the patient was neurologically intact with an modified Rankin Scale score of 1. Computed tomography angiography and transcranioplasty Doppler ultrasonography confirmed good flow through the bypass. CONCLUSION/CONCLUSIONS:In addition to antifungal therapy and surgical debridement, superficial temporal artery-middle cerebral artery bypass can be a lifesaving intervention in the management of ROCM with severe cerebrovascular compromise. This case highlights the critical role of cranial bypass in preserving cerebral perfusion in patients with flow-limiting ROCM-associated ICA invasion.

BACKGROUND:Flow-diverter stents (FDS) have become the standard of care for a wide range of intracranial aneurysms, but their efficacy/safety in the context of recurrent/recanalized aneurysms following stent-assisted coiling (SAC) is not well established. We evaluate the outcomes of FDS retreatment in a large multicenter cohort. METHODS:We retrospectively analyzed data from 118 patients across 22 institutions who underwent FDS retreatment for recurrent/persistent aneurysms after SAC (2008-22). The primary outcome was angiographic occlusion status at last follow-up, categorized as complete (100%), near-complete (90-99%), or incomplete (<90%) occlusion. Secondary outcomes included procedural complications and clinical outcomes measured by the modified Rankin Scale (mRS). RESULTS:A total of 118 patients (median age 57, 74.6% female) with median follow-up of 15.3 months were identified. Complete occlusion was achieved in 62.5% and near-complete occlusion in 25%. FDS deployment within the pre-existing stent was successful in 98.3% of cases. Major complications occurred in 3.4% of cases, including postoperative aneurysmal rupture with resultant mortality (1.6%) and thromboembolic events with long-term disability (1.6%). Favorable clinical outcomes (mRS 0-2) were observed in 95.1% of patients. Wider aneurysm neck diameter was a significant predictor of incomplete occlusion (adjusted OR (aOR) 1.23 per mm, P=0.044), with male sex trending towards association with non-occlusion (aOR 3.2, P=0.07), while baseline hypertension was associated with complete occlusion (aOR 0.32, P=0.048). CONCLUSIONS:FDS treatment for recurrent/residual aneurysms after SAC represents a viable treatment option for these challenging cases with acceptable safety and reasonable occlusion rates, although lower than de novo FDS occlusion rates.

While the Woven EndoBridge (WEB) device has transformed the treatment of wide-neck intracranial aneurysms, incomplete occlusion remains a significant challenge requiring better understanding of contributing factors. A retrospective analysis was conducted on multicenter data from patients who underwent WEB device treatment for intracranial aneurysms between January 2011 and December 2022. Using machine learning models, Cox regression, and time-stratified analyses, we evaluated factors associated with persistent incomplete occlusion, defined as non-improving Raymond-Roy Occlusion Classification grade 2 or 3 at final follow-up. Among 813 patients (607 with < 24 months follow-up, 206 with ≥ 24 months), machine learning analysis identified aneurysm height, Acom location, neck diameter, and pretreatment mRS as predictors of persistent incomplete occlusion. On Cox regression. larger aneurysm neck diameter (HR 1.13, 95% CI 1.01-1.27, p = 0.027) and height (HR 1.14, 95% CI 1.02-1.26, p = 0.017), and radial access (HR 2.68, 95% CI 1.76-4.07, p < 0.001) increased, while posterior circulation location (HR 0.56, 95% CI 0.37-0.84, p = 0.005) decreased the risk of persistent incomplete occlusion. Time-stratified analysis revealed that in short-term follow-up (< 24 months), larger aneurysm neck diameter (OR 1.28, 95% CI 1.08-1.52, p = 0.004) increased the risk of incomplete occlusion. In long-term follow-up (≥ 24 months), smoking (OR 2.69, 95% CI 1.04-7.00, p = 0.04), higher pre-treatment mRS (OR 1.78, 95% CI 1.15-2.76, p = 0.009), and immediate flow stagnation (OR 0.33, 95% CI 0.11-0.96, p = 0.04) increased, while older age (OR 0.94, 95% CI 0.90-0.98, p = 0.002) and WEB-DL (OR 0.06, p < 0.001) and SLS devices (OR 0.02, p = 0.003) decreased the risk of persistent incomplete occlusion. Aneurysm characteristics and device type significantly influence long-term WEB treatment outcomes.

The Woven EndoBridge (WEB) device is FDA-approved for the treatment of bifurcation aneurysms. Despite its wide popularity, it has been under scrutiny for its association with potential aneurysm recanalization and retreatment due to device shape modification. This study aims to analyze the shape modification rate of WEB devices and identify factors associated with this phenomenon, as well as its correlation with aneurysm retreatment. We conducted a retrospective review of the WorldWide WEB Consortium database, including adult patients treated for intracranial aneurysms with the WEB device. We assessed aneurysm occlusion using the WEB Occlusion Scale and defined WEB shape modification as a percentage reduction in the distance between two WEB markers. Logistic regression and Cox proportional hazards models were utilized to evaluate predictors of shape modification and retreatment. Kaplan-Meier curves were used to estimate the time-dependent probability of no or minor shape modification. A total of 405 patients were analyzed, with minor and major shape modification occurring in 31.4% and 10.1% of cases, respectively. Major shape modification was associated with lower rates of adequate occlusion (70.7%) compared to no or minor shape modification (86.6%) and a higher rate of retreatment (26.8% vs. 8.1%). Predictors of major shape modification included the presence of daughter sac, bifurcation aneurysms, absence of immediate flow stagnation, and a WEB width minus aneurysm width ratio ≤ 0.5. The probability of no or minor shape modification declined within the first 25 months and stabilized thereafter. WEB device shape modification is a significant predictor of aneurysm occlusion efficacy and retreatment. Recognizing the factors influencing shape modification can guide treatment decisions and follow-up protocols to improve patient outcomes.

Typical carotid webs are nonatherosclerotic shelf-like projections of fibromyxoid tissue extending from the posterior wall of the proximal internal carotid artery (ICA). Carotid webs may precipitate acute embolic stroke, especially in younger patients. We describe our experience with pathology-proven carotid webs of atypical appearance, or atypical carotid webs (ACWs), a subset of carotid webs exhibiting abnormal location, morphology, or association with atherosclerotic changes. Our electronic medical record database was queried for all imaging impressions containing "carotid web," "shelf," or "protrusion" from 2018-2024. Imaging was reviewed by an experienced neuroradiologist and neurosurgeon. Patients with typical carotid webs or those with different diagnoses (e.g. dissection/thrombus) were excluded. Twenty-seven patients were treated for typical carotid webs; 24 were treated with carotid endarterectomy (CEA) and had pathology-confirmed webs. Five patients (three male) were identified to have ACWs and included in this report. Mean age was 43.6 years. All ACWs were identified by computed tomography angiography (CTA). All patients presented with acute ischemic stroke or transient ischemic attack (TIA). One web was located on the anterior ICA wall, three were of abnormal morphology different from a "shelf-like" projection, and one was associated with atherosclerotic change. No patients experienced a further stroke or TIA following CEA. ACWs may precipitate ischemic stroke and can be treated and definitively diagnosed with CEA. Due to their unusual appearance, ACWs may evade radiographic identification or be misdiagnosed. As ACWs have not been previously reported in the literature, awareness of their existence must be raised to increase their detection and treatment.

BACKGROUND:Underlying intracranial stenosis is the most common cause of failed mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusion. Adjunct emergent stenting is sometimes performed to improve or maintain reperfusion, despite limited data regarding its safety or efficacy. METHODS:We conducted a prospective multicenter observational international cohort study. Patients were enrolled between January 2022 and December 2023 at 25 thrombectomy capable centers in North America, Europe, and Asia. Consecutive patients treated with mechanical thrombectomy were included if they were identified as having underlying intracranial stenosis, defined as 50-99% residual stenosis of the target vessel or intra-procedural re-occlusion. The primary outcome was functional independence, defined as modified Rankin Scale of 0-2 at 90 days. After applying inverse probability of treatment weighting (IPTW) based on propensity scores, we compared outcomes among patients who underwent adjunct emergent intracranial stenting (stenting) versus those who received mechanical thrombectomy alone. RESULTS:A total of 417 patients were included; 218 patients treated with mechanical thrombectomy alone (168 anterior circulation) and 199 with mechanical thrombectomy plus stenting (144 anterior circulation). Patients in the stenting group were less likely to be non-Hispanic White (51.8% vs 62.4%, p=0.03), and less likely to have diabetes (33.2% vs 43.1%, p=0.037) or hyperlipidemia (43.2% vs 56%, p= 0.009). In addition, there was a lower rate of IV thrombolysis use in the stenting group (18.6% vs 27.5%, p=0.03). There was a higher rate of successful reperfusion (modified Treatment In Cerebral Infarction score ≥ 2B) in the stenting versus mechanical thrombectomy alone group (90.9% vs 77.9%, p<0.001) and a higher rate of a 24-hour infarct volume of <30 mL (n=260, 67.9% vs 50.3%, p=0.005). The overall complication rate was higher in the stenting group (12.6% vs 5%, p=0.006), but there was not a significant difference in the rate of symptomatic hemorrhage (9% vs 5.5%, p=0.162). Functional independence at 90 days was significantly higher in the stenting group (42.2% vs. 28.4%, adjusted odds ratio 2.67; 95% CI, 1.66-4.32). CONCLUSIONS:In patients with underlying stenosis who achieved reperfusion with mechanical thrombectomy, adjunct emergent stenting was associated with better functional outcome without a significantly increased risk of symptomatic hemorrhage. REGISTRATION/BACKGROUND:https://clinicaltrials.gov/study/NCT05403593.

OBJECTIVE:Tobacco smoking is among the factors known to significantly augment the risk of untreated intracranial aneurysm (IA) growth and rupture. Smoking appears to have a variable effect on different endovascular treatment modalities. The impact of smoking on the safety, efficacy, and outcomes of Woven EndoBridge (WEB) device use for wide-neck IAs has not been evaluated. This study aimed to investigate the outcomes of WEB devices by smoking status. METHODS:A retrospective multicenter analysis was conducted on the data of patients from 36 sites worldwide treated with the WEB device for intracranial saccular aneurysms. Patients were stratified based on smoking status (current, former, and never smokers). The Student t-test and chi-square test were performed for continuous and categorical variables, respectively. Multivariable logistic regression was used to adjust for confounders. RESULTS:Of 1376 patients with available smoking status, 504 were current smokers, 358 were former smokers, and 514 were never smokers. Upon adjusting for significant confounders, no association was found between smoking and recurrence outcomes (OR 1.39, 95% CI 0.69-2.80; p = 0.36), thromboembolic and hemorrhagic complications, and mortality among IAs treated with the WEB device. There was no statistically significant difference in outcomes between former and never smokers (OR 1.23, 95% CI 0.70-2.18; p = 0.46). The location of aneurysms differed between smoking groups, with former smokers having more anterior circulation aneurysms compared with current and never smokers (99.0% vs 96.9% vs 95.3%; p = 0.01). In terms of clinical symptoms, headache and dizziness were more common in the never smokers compared with current and former smokers (13.9% vs 8.9% vs 7.7%, p = 0.01). CONCLUSIONS:This large-scale study suggests no significant correlation between smoking and the recurrence of IAs treated with the WEB device. Biological studies are warranted to better understand the biological impact of smoking on the growth and rupture of treated IAs.

BACKGROUND:Data about the safety and the efficacy of flow diversion for distal anterior cerebral artery (DACA) aneurysms are limited. We present the largest multicenter analysis evaluating the outcomes of flow diversion in unruptured DACA aneurysm treatment. METHODS:Databases from 39 centers were retrospectively reviewed for unruptured DACA aneurysms treated with flow-diverting stents. Demographics, clinical presentation, radiographic characteristics, procedural complications, and outcomes were assessed. RESULTS:A total of 168 patients with 168 unruptured DACA aneurysms were treated between January 2018 and December 2022. One hundred and twenty-five were women (74.4%) and the median age was 61 (IQR 52-67) years. The most common morphology was saccular (91.7%), with branch involvement in 61.9% of cases. Median parent vessel diameter was 1.9 mm (IQR 1.7-2.2) and stents were successfully deployed in 99.4% of cases. In 96.4% a single stent was implanted, while 3.6% of cases required two stents. Median imaging follow-up was 16.5 (IQR 7-24) months. At last follow-up the rate of occlusion (O'Kelly-Marotta scale C or D) was 82.1%. Symptomatic thromboembolic or hemorrhagic complications occurred in 5.3% of patients and the mortality rate was 0.6%. The rate of retreatment was 1.2%. CONCLUSIONS:Flow-diverting stents are a reasonably safe and effective treatment option for unruptured DACA aneurysms.

BACKGROUND:The Woven EndoBridge (WEB) device is frequently used for the treatment of intracranial aneurysms. Postoperative management, including the use of aspirin, varies among clinicians and institutions, but its impact on the outcomes of the WEB has not been thoroughly investigated. METHODS:This was a retrospective, multicenter study involving 30 academic institutions in North America, South America, and Europe. Data from 1492 patients treated with the WEB device were included. Patients were categorized into two groups based on their postoperative use of aspirin (aspirin group: n=1124, non-aspirin group: n=368). Data points included patient demographics, aneurysm characteristics, procedural details, complications, and angiographic and functional outcomes. Propensity score matching (PSM) was applied to balance variables between the two groups. RESULTS:Prior to PSM, the aspirin group exhibited significantly higher rates of modified Rankin scale (mRS) mRS 0-1 and mRS 0-2 (89.8% vs 73.4% and 94.1% vs 79.8%, p<0.001), lower rates of mortality (1.6% vs 8.6%, p<0.001), and higher major compaction rates (13.4% vs 7%, p<0.001). Post-PSM, the aspirin group showed significantly higher rates of retreatment (p=0.026) and major compaction (p=0.037) while maintaining its higher rates of good functional outcomes and lower mortality rates. In the multivariable regression, aspirin was associated with higher rates of mRS 0-1 (OR 2.166; 95% CI 1.16 to 4, p=0.016) and mRS 0-2 (OR 2.817; 95% CI 1.36 to 5.88, p=0.005) and lower rates of mortality (OR 0.228; 95% CI 0.06 to 0.83, p=0.025). However, it was associated with higher rates of retreatment (OR 2.471; 95% CI 1.11 to 5.51, p=0.027). CONCLUSIONS:Aspirin use post-WEB treatment may lead to better functional outcomes and lower mortality but with higher retreatment rates. These insights are crucial for postoperative management after WEB procedures, but further studies are necessary for validation.