Faculty Bibliography

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.

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: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.

The anatomy of vertebrobasilar perforators has been widely studied in human cadavers, with most reports found in the neurosurgical literature. These arterial perforators are extremely hard to visualize consistently with traditional two-dimensional digital subtraction angiography, but are reliably visible with cross sectional cone beam CT techniques. A clear understanding of this specific neurovascular anatomy and pathology is essential for informed treatment decisions. This review analyzes the anatomy of vertebrobasilar perforators with a focus on practical implications for aneurysm treatment, particularly flow diversion.

Dural arteriovenous fistulas (dAVFs) can occur as complications after surgical procedures, especially following the resection of meningiomas near the dural sinus. This case report presents a 74-year-old male who developed a recurrent sigmoid dAVF following meningioma resection. Initially treated with transvenous embolization and middle meningeal artery embolization, the dAVF recurred with worsening clinical symptoms. Conventional treatment options, including sinus sacrifice and transarterial embolization, were unsuitable due to the critical role of the patient's dominant right sigmoid sinus in cerebral venous drainage. Consequently, a reconstructive approach was employed using a pipeline embolization device (PED) construct. The PED successfully occluded the dAVF while preserving the function of the sigmoid sinus. A follow-up angiogram confirmed stable occlusion and normalization of intracranial venous drainage. This case underscores the potential of flow diversion as a viable treatment option for dAVFs, particularly in scenarios where preserving venous sinus function is paramount.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Superficial temporal artery to middle cerebral artery (STA-MCA) bypass is the workhorse for flow augmentation surgery. Although either interrupted or running sutures can be used to complete the anastomosis with high intraoperative patency rates, no previous study in the cranial bypass literature has compared long-term patency and maturity of end-to-side STA-MCA anastomoses. We compared STA-MCA anastomoses performed with running vs interrupted sutures by evaluating bypass flow and anastomotic maturation on follow-up vascular imaging. METHODS:Ninety-six STA-MCA anastomoses were performed from 1/2019 to 6/2024. Forty-seven anastomoses (40 patients) with long-term vascular imaging were retrospectively analyzed. All anastomoses were intraoperatively patent on initial revascularization. Patient demographics, clinical course, and imaging were reviewed. All images were reviewed by a neuroradiologist or a cerebrovascular neurosurgeon. RESULTS:Twenty-five anastomoses were performed with interrupted sutures and compared with 22 anastomoses performed with running sutures. All patients underwent a preoperative perfusion assessment confirming a significant hypoperfusion state. There were no significant differences between cohorts in demographics, bypass indication, or time to follow-up. Formal digital subtraction angiography was performed for 35 anastomoses (21 interrupted, 14 running). On digital subtraction angiography follow-up, there was no difference in STA caliber between cohorts (P = .204), but there was a difference in anastomotic growth (P = .014), with 5/21 (23.8%) anastomoses stable or enlarged in the interrupted cohort vs 9/14 (64.3%) stable or enlarged in the running cohort. Notably, of the 47 total anastomoses, there was no difference in long-term bypass patency between interrupted and running anastomoses (22/25 (88.0%) vs 22/22 (100.0%), respectively, P = .380). CONCLUSION/CONCLUSIONS:No significant differences in patency or STA caliber on follow-up imaging were observed between STA-MCA anastomoses performed with interrupted vs running sutures although a difference in anastomotic maturity was observed, with the running suture cohort having a higher proportion of enlarged or stable anastomoses. Further studies are needed for validation.

BACKGROUND:Subdural hematoma is a rare manifestation of hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu disease. Here, the authors present a patient with HHT and a large chronic subdural hematoma, for whom nonsurgical management was pursued. OBSERVATIONS/METHODS:A 49-year-old right-handed male with a history of hypertension and familial HHT presented with complaints of mild confusion and left hemiparesis over several days. Noncontrast head computed tomography images demonstrated a large chronic right hemisphere subdural hematoma compressing the right cerebral hemisphere and causing a 1.3-cm midline shift. Due to concerns about surgical complications arising from hemorrhages of cryptic telangiectasias, the patient was treated conservatively with middle meningeal artery embolization and adjuvant tranexamic acid. There was clinical and radiological resolution several months later. LESSONS/CONCLUSIONS:This case highlights the rarity of a subdural hematoma as a manifestation of HHT and the nonsurgical treatment strategy as a mechanism to avoid hemorrhagic complications of surgical evacuation. https://thejns.org/doi/10.3171/CASE24483.

BACKGROUND:Hypoglossal canal dural arteriovenous fistulas (HCDAVFs) are a relatively rare subtype of dural arteriovenous fistula (dAVF), representing 3%-5% of all dAVFs. The complex angio- and venous architecture predisposed to numerous anastomoses and nearby anatomical structures, including the posterior fossa sinuses and cranial nerves, can complicate both the diagnosis and treatment of these lesions. OBSERVATIONS/METHODS:The authors describe the case of HCDAVF in a 74-year-old male who presented with pulsatile tinnitus (PT) lasting 3 months and significant fatigue, headaches, and dizziness. Diagnostic cerebral angiography demonstrated a left-sided HCDAVF with bilateral supply from the ascending pharyngeal arteries and fistulous connection at the level of the left anterior condylar vein (ACV). This lesion was consistent with a Cognard and Borden type I dAVF. LESSONS/CONCLUSIONS:The authors present a case in which transvenous embolization (TVE) with detachable coils via the ipsilateral internal jugular vein successfully occluded the previously visualized shunt to the left ACV and provided a clinical cure for the patient's PT and headaches without complication. Selecting the appropriate treatment strategy for the successful treatment of HCDAVFs is predicated on a comprehensive understanding of the anatomical features of the lesion, namely arterial feeders, venous drainage pattern, and location of the fistulous connection. TVE is a safe and efficacious treatment option for HCDAVFs. https://thejns.org/doi/10.3171/CASE24606.

BACKGROUND:Aspiration thrombectomy is one of the mainstays for stroke interventions. The Zoom 71 (Z71) aspiration catheter is unique with its angled tip. This study describes the orientation of the angled tip as it is navigated around the carotid siphon in relation to trackability. METHOD/METHODS:Prospectively collected cases involving large vessel occlusions of the anterior circulation intervened upon using the Z71 were retrospectively analyzed. 71 passes in 50 patients were analyzed with respect to Z71 tip orientation. 3 anatomical "turns" were defined as follows: "1": proximal cavernous, "2"- ophthalmic turn, and "3"-ICA terminus to M1. The tip was described as "Toward" Vs "Away" with respect to the inner curve of each turn. The tip getting "caught" was also analyzed. RESULTS:There was no preferential angled tip orientation of the Z71 as it was navigated around "Turn 1", 51 % "Away" vs 44 % "Toward", p= 0.54; "2", 46.5 % "Away" vs 53.5 % "Toward", p= 0.55; and "3", 43.7 % "Away" vs 46.5 % "Toward", p=0.63. The tip was not caught in Turn 1. It was caught up in "2" in 15.5 % of passes. "Away" at "2" got caught up in 21 % of passes vs 10.5 % for "Toward", p= 0.22. Z71 got caught up in "3" in 4.7 % of passes. "Away" was associated with getting caught in 6.5 % of passes vs 3 % for "Toward", p=0.52. Zoom 88 (Z88) usage as guide catheter may be associated with Z71 getting caught less in "2" compared to "Others", 9.3 % for Z88 vs 25 %, p= 0.07. This also applied to Turn 3, 0 % for Z88 vs 11.1 %, p=0.038. CONCLUSION/CONCLUSIONS:There is no preferential angled tip orientation of the Z71 as it navigates around the carotid siphon. The tip orientation does not appear to significantly affect navigation. Usage of Z88 as guide catheter helps with Z71 trackability around the siphon.