Total brain volume is associated with severity of transverse sinus stenosis in idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a complex neurological condition characterized by symptoms of increased intracranial pressure of unclear etiology. While transverse sinus stenosis (TSS) is often present in patients with IIH, how and why it occurs remains unclear. METHODS: IIH patients and a set of age-matched normal controls were identified from our single-center tertiary care institution from 2016 to 2024. Brain MRIs before treatment were computationally segmented and parcellated using FreeSurfer software. Extent of TSS on MR venograms was graded using the Farb scoring system. Relationship between normalized brain volume, normalized brain-to-CSF volume, and TSS was investigated. Multiple linear regression was conducted to investigate the association between continuous variables, accounting for the covariates body mass index, sex, and age. RESULTS: In total, 84 IIH patients (mean age, 29.8 years; 87% female) and 15 normal controls (mean age, 28.1 years) were included. Overall, increasing/worsening TSS was found to be significantly associated with normalized total brain volume (p=0.018, R=0.179) and brain-to-CSF ratio volume (p=0.026, R=0.184). Additionally, there was a significant difference between controls and IIH patients with mild and severe stenosis regarding normalized total brain volume (ANCOVA, p=0.023) and brain-to-CSF ratio volume (ANCOVA, p=0.034). Likewise, IIH patients with severe TSS had a significantly higher brain-to-CSF volume compared with controls (p=0.038) and compared with IIH patients with mild TSS (p=0.038). CONCLUSIONS: These findings suggest that total brain volume is associated with extent of TSS, which may reflect extramural venous compression due to enlarged brain and/or venous hypertension with associated cerebral congestion/swelling.

Early cerebral venous drainage associated with focal seizures: a correlation of digital subtraction angiography and electroencephalography. Illustrative case.

BACKGROUND: Early venous drainage is a critical diagnostic feature of arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). However, other conditions associated with early venous drainage can mimic AVMs and AVFs and mislead the treating physician team. OBSERVATIONS: The authors present a unique case of a 56-year-old man with new left hemianopsia. Workup with magnetic resonance imaging and magnetic resonance angiography had revealed cortical enhancement and early venous drainage, possibly caused by an AVF or AVM. Catheter angiography confirmed the presence of early venous drainage of specifically the right occipital lobe. The early venous drainage occurred as the result of local hyperperfusion limited to the right occipital lobe. Subsequent electroencephalography confirmed focal seizure activity in the right occipital lobe. After seizure control with multiple antiepileptic medications, the patient regained his vision. Repeat digital subtraction angiography revealed restoration of normal cerebral blood flow. LESSONS: Early venous drainage observed during catheter angiography can be associated with seizure activity. Differentiation from other conditions, such as AVM, AVF, or ischemic stroke, is critical to facilitate prompt and appropriate treatment.

Vein of Galen malformations in the newborn: case series.

BACKGROUND: Vein of Galen malformations (VoGMs) in newborns often represent life-threatening emergencies. Outcome is difficult to predict. The authors review 50 VoGM cases to correlate anatomical types with treatment and outcome. OBSERVATIONS: Four distinct types of VoGMs are identified: mural simple (type I), mural complex (type II), choroidal (type III), and choroidal with deep venous drainage (type IV). Seven patients presented with mural simple VoGMs with a "single hole" fistula supplied by only one large feeder. These patients were treated electively at >6 months; development was normal. Fifteen patients presented with complex mural VoGMs. Multiple large feeders joined a single fistulous point within the wall of the varix. Patients typically presented with congestive heart failure (CHF) and required emergent transarterial intervention. Mortality was 7.7% with less than two-thirds developing normally. Twenty-five patients presented with choroidal VoGMs. Multiple large arterial feeders joined at multiple fistulous sites. Severe CHF in most patients required emergent transarterial and sometimes transvenous intervention. Mortality was 9.5%; two-thirds of the patients had a normal development. Three babies presented with choroidal VoGMs with deep intraventricular venous drainage. This phenomenon caused fatal "melting brain syndrome" in all three patients. LESSONS: Recognition of the specific VoGM type determines treatment options and sets outcome expectations.

Tricuspid regurgitation and left ventricular eccentricity as a measure of heart failure in the newborn patient with a vein of Galen malformation: illustrative case.

BACKGROUND: Successful management of a vein of Galen malformation (VoGM) in the newborn patient requires a highly coordinated team approach involving neonatologists, pediatric cardiologists, pediatric neurologists, neurosurgeons, and interventionalists. Indication and timing of catheter intervention are topics of ongoing debate. OBSERVATIONS: The authors highlighted two key echocardiographic markers believed to be practical indicators regarding the need for urgent catheter embolization in neonates with a VoGM. The first and preferred parameter was the tricuspid valve regurgitation (TR) gradient, an estimate of pulmonary artery hypertension. If the TR gradient exceeds systolic blood pressure (suprasystemic pulmonary hypertension [PH], i.e., >60 mm Hg), urgent intervention should be considered in eligible newborns. The second parameter was the left ventricular end-systolic eccentricity index (EI), a newly emerging echocardiographic marker and indirect correlate of PH. As an alternative to the TR gradient, an increased eccentricity index (>1.6) suggests severe right heart compromise, requiring emergency catheter embolization of the malformation. Postoperatively, the progressive reduction of both the TR gradient and the EI correlated with recovery. LESSONS: In eligible newborns, urgent embolization of a VoGM is recommended in the presence of suprasystemic TR gradients and/or increased EI >1.6.

Moyamoya syndrome in a young person with Down syndrome: diagnostic and therapeutic considerations.

An 18-year-old woman with a history of Down syndrome (DS) presented with left upper extremity weakness. Neurological examination revealed moderate hypotonia throughout, with mild spasticity of the left ankle. She had 2/5 left upper and lower extremity strength, mild pronation with drift in the left arm and 3+ deep tendon reflexes in the left biceps, brachioradialis, patellar and Achilles. Strength was 5/5 in the right upper and lower extremities. A CT angiography of the head and neck with contrast demonstrated severe narrowing of the bilateral supraclinoid internal carotid arteries (ICAs), suggestive of moyamoya pattern. A diagnostic angiography confirmed stenosis in the right and left supraclinoid ICAs. The patient was started on aspirin therapy and underwent an indirect bypass procedure via encephaloduroarteriosynangiosis 6 weeks after initial presentation. DS is associated with a high risk of congenital heart disease, which in turn increases risk of stroke, namely cardioembolic events, including moyamoya disease. Intellectual disability is nearly ubiquitous in DS, thus adding to the challenges of making a diagnosis of moyamoya in this population.

A Case Report on the Progressive Hunterian Ligation of an Intracranial Aneurysm by Flow Diversion: The Endovascular Selverstone Clamp.

Proximal Hunterian ligation remains a treatment option for select complex brain aneurysms. Progressive occlusion over time (as accomplished with Selverstone clamping) can enable collateral flow to develop while the aneurysm regresses or occludes. A 50-year-old woman presented with an unruptured 16-mm posterior inferior cerebellar artery (PICA) aneurysm. The aneurysm was located 4 mm distal to the PICA origin. It was bilobed, incorporating the PICA. The PICA inflow and outflow zone orientation prevented direct stent reconstruction. Surgical clipping with bypass was considered. Alternatively, an attempt at proximal ligation of the PICA via flow-diverting stents was offered. After extensive counseling, the patient decided to proceed with endovascular treatment. Two overlapping pipeline embolization devices (PED) were placed into the vertebral artery, covering the PICA origin. The one-year follow-up angiography demonstrated flow reduction within the aneurysm and the distal PICA. A de novo (previously not opacified) accessory PICA collateral had developed, partially taking over the arterial supply of the PICA territory. The newly established accessory PICA originated from the vertebral artery 8 mm distal to the PICA origin. After two years, the aneurysm was fully obliterated, and the true PICA was occluded and functionally replaced by the accessory PICA. The current case suggests that progressive Hunterian ligation via endovascular flow diversion can be an effective treatment strategy for true PICA aneurysms. However, this strategy should only be considered if no immediate aneurysm occlusion is required or if all alternative methods are associated with substantial risk.

Surgical treatment of brainstem cavernous malformations: an international Delphi consensus.

OBJECTIVE: Indication for surgery in brainstem cavernous malformations (BSCMs) is based on many case series, few comparative studies, and no randomized controlled trials. The objective of this study was to seek consensus about surgical management aspects of BSCM. METHODS: A total of 29 experts were invited to participate in a multistep Delphi consensus process on the surgical treatment of BSCM. RESULTS: Twenty-two (76%) of 29 experts participated in the consensus. Qualitative analysis (content analysis) of an initial open-ended question survey resulted in 99 statements regarding surgical treatment of BSCM. By using a multistep survey with 100% participation in each round, consensus was reached on 52 (53%) of 99 statements. These were grouped into 4 categories: 1) definitions and reporting standards (7/14, 50%); 2) general and patient-related aspects (11/16, 69%); 3) anatomical-, timing of surgery-, and BSCM-related aspects (22/37, 59%); and 4) clinical situation-based decision-making (12/32, 38%). Among other things, a consensus was reached for surgical timing, handling of associated developmental venous anomalies, handling of postoperative BSCM remnants, assessment of specific anatomical BSCM localizations, and treatment decisions in typical clinical BSCM scenarios. CONCLUSIONS: A summary of typical clinical scenarios and a catalog of various BSCM- and patient-related aspects that influence the surgical treatment decision have been defined, rated, and interpreted.

Flow diversion of fusiform intracranial aneurysms.

Fusiform aneurysms are less common than saccular aneurysms, but have higher associated mortality and rebleeding rates. Recently, flow diversion has emerged as a possible treatment option. The purpose of this study was to determine the safety and efficacy of the Pipeline Embolization Device (PED) for the treatment of ruptured and unruptured fusiform aneurysms. This was a retrospective analysis of patients with fusiform intracranial aneurysms treated with a PED at a quaternary care center between January 2012 and September 2019. Occlusion rates, neurologic morbidity/mortality, and other clinical variables were analyzed. Twenty-nine patients with 30 fusiform aneurysms were treated with a PED. Sixteen aneurysms (53%) were located in the anterior circulation and 14 aneurysms (47%) were in the posterior circulation. The mean maximal diameter of the aneurysms was 10.1 ± 5.6 mm (range 2.3-25 mm). Angiographic and clinical follow-up were available for 28 aneurysms (93%). The median follow-up was 17.4 months (IQR 4.8 to 28 months) and occlusion rates were graded according to the O'Kelly-Marotta (OKM) scale. Of patients with DSA follow-up, 15 aneurysms (60%) were completely occluded (OKM D) and 19 aneurysms (76%) had a favorable occlusion result (OKM C1-3 and D). The overall complication rate was 26.7% with a neurological morbidity rate of 6.7% and neurological mortality rate of 3.4%. Flow diversion can be an effective treatment for both ruptured and unruptured fusiform aneurysms. Nevertheless, complete occlusion rates are lower than for saccular aneurysms. Therefore, flow diversion should be considered only if other more direct treatment options, such as clipping or stent/coiling are not applicable. Flow diversion should be used cautiously in patients presenting with rupture.

Decompressive craniectomy in aneurysmal subarachnoid hemorrhage: Who and when? - A systematic review and meta-analysis.

OBJECTIVE: Decompressive craniectomy (DC) is a standard neurosurgical procedure against intractable intracranial hypertension. Patients with severe aneurysmal subarachnoid hemorrhage (aSAH) are prone to intracranial hypertension, necessitating DC in certain cases. However, the clinical utility of DC after aSAH remains unclear. Hereby we present a systematic review and meta-analysis summarizing the published studies on DC in aSAH patients. MATERIAL AND METHODS: We systematically searched PubMed, Scopus, Web of Science and Cochrane Library for articles published before Jul 10, 2019 reporting on rates, outcome, indications, timing and complications of SAH patients undergoing DC. RESULTS: Of 1085 identified unique records, 28 observational studies published between 1993 and 2018 were included. In total, data of 2788 aSAH patients was extracted including 2014 patients with DC. The mean DC rate was 10.9 % (range 3.3%-25.6%). Good initial clinical condition (p = 0.01; odds ratio (OR) = 2.93; confidence interval (95 % CI) 1.30-6.61) and younger patients' age (p = 0.02; mean difference (MD) = -4.50; 95 % CI -8.36 - -0.64) increased the chance of good outcome after DC. Overall, patients with primary DC showed a tendency towards better outcome than those that underwent secondary DC (p = 0.08; OR = 1.50; 95 % CI 0.96-2.35). Younger age (p < 0.00001; MD = -3.63; 95 % CI -5.20 to -2.06), presence of intracerebral hemorrhage (ICH; p < 0.00001; OR = 6.63; 95 % CI 3.98-11.03), poor initial clinical condition (p < 0.00001; OR = 4.81; 95 % CI 2.88-8.03) and treatment modality (coiling, p < 0.00001; OR = 0.19; 95 % CI 0.10-0.35) were associated with the indication to DC. CONCLUSIONS: Around 10 % of aSAH individuals undergo DC. Younger individuals, with poor initial clinical condition, additional ICH and aneurysm clipping are more likely to be selected for DC. Due to expected outcome benefit, younger individuals with good-grade aSAH should be considered for early decompression in case of increased intracranial pressure.

Impact of active dose management on radiation exposure and image quality in computed tomography: An observational study in 1315 patients.

PURPOSE: To determine the clinical impact of CT dose management team on radiation exposure and image quality. METHODS: 2026 clinical routine CT examinations of 1315 patients were evaluated retrospectively. A CT dose management team was established as an integral part of the radiological department. It identified 5 CT protocols (A-E), where national reference values were exceeded the most. Those reference values included specifically the mean volumetric CT dose index (CTDIvol) and the mean dose-length product (DLP). Baseline data (period 1) and follow up data (period 2) were obtained after reduction of tube voltage and increase of pitch or noise index. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated to compare image quality. Two-sided t-tests were performed. RESULTS: Mean CTDIvol and mean DLP of the chest protocol (A) decreased after reduction of tube voltage (P < 0.01). In the chest/abdomen/pelvis protocol (B), the increase of noise index resulted in a significant mean CTDIvol decrease (P < 0.02) without statistical significance of mean DLP (P < 0.12). In the abdomen/pelvis protocol (C), mean CTDIvol (P = 0.01) and mean DLP (P < 0.01) were significantly lower after noise index increase. In the staging of hepatocellular carcinoma (D), mean CTDIvol and mean DLP were significantly lower after increase of pitch and noise index (P < 0.01). The lung protocol (E) yielded no significant changes after modulation (P > 0.05). SNR (protocol A) was significantly higher in period 2 (P < 0.04). Protocol D showed significantly lower selected SNR and CNR (P < 0.02). CONCLUSIONS: Establishing an operating dose management team as a standard for good clinical practice helps to considerably reduce CT radiation dose while preserving image quality.

Chronic Thromboembolic Pulmonary Hypertension Perioperative Monitoring Using Phase-Resolved Functional Lung (PREFUL)-MRI.

BACKGROUND: The translation of phase-resolved functional lung (PREFUL)-MRI to routine practice in monitoring chronic thromboembolic pulmonary hypertension (CTEPH) still requires clinical corresponding imaging biomarkers of pulmonary vascular disease. PURPOSE: To evaluate successful pulmonary endarterectomy (PEA) via PREFUL-MRI with pulmonary pulse wave transit time (pPTT). STUDY TYPE: Retrospective. POPULATION: Thirty CTEPH patients and 12 healthy controls were included. FIELD STRENGTH/SEQUENCE: For PREFUL-MRI a 2D spoiled gradient echo sequence and for DCE-MRI a 3D time-resolved angiography with stochastic trajectories (TWIST) sequence were performed on 1.5T. ASSESSMENT: Eight coronal slices of PREFUL-MRI were obtained on consecutive 13 days before and 14 days after PEA. PREFUL quantitative lung perfusion (PREFULQ ) phases over the whole cardiac cycle were calculated to quantify pPTT, the time the pulmonary pulse wave travels from the central pulmonary arteries to the pulmonary capillaries. Also, perfusion defect percentage based on pPTT (QDPpPTT ), PREFULQ (QDPPREFUL ), and V/Q match were calculated. For DCE-MRI, pulmonary blood flow (PBF) and QDPPBF were computed as reference. For clinical correlation, mean pulmonary arterial pressure (mPAP) and 6-minute walking distance were evaluated preoperatively and after PEA. STATISTICAL TESTS: The Shapiro-Wilk test, paired two-sided Wilcoxon rank sum test, Dice coefficient, and Spearman's correlation coefficient (ρ) were applied. RESULTS: Median pPTT was significantly lower post PEA (139 msec) compared to pre PEA (193 msec), P = 0.0002. Median pPTT correlated significantly with the mPAP post PEA (r = 0.52, P < 0.008). Median pPTT was distributed more homogeneously after PEA: IQR pPTT decreased from 336 to 281 msec (P < 0.004). Median PREFULQ (P < 0.0002), QDPpPTT (P < 0.0478), QDPPREFUL (P < 0.0001) and V/Q match (P < 0.0001) improved significantly after PEA. Percentage change of PREFULQ correlated significantly with percentage change of 6-minute walking distance (ρ = 0.61; P = 0.0031) 5 months post PEA. DATA CONCLUSION: Perioperative perfusion changes in CTEPH can be detected and quantified by PREFUL-MRI. Normalization of pPTT reflects surgical success and improvement of PREFULQ predicts 6-minute walking distance changes. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:610-619.

Inferolateral thalamic ischemia secondary to PCA P2 perforator occlusion mimics MCA stroke syndrome.

Paramedian thalamic strokes following occlusion of the posterior medial (paramedian) thalamic perforators have been previously described in great detail. However, the stroke syndrome associated with occlusion of posterior lateral (inferolateral) thalamic perforators is less commonly known. We present an illustrative case of an inferolateral thalamic perforator stroke mimicking a middle cerebral artery (MCA) syndrome and provide a review of the literature. A 62-year-old male presented with dysarthria, contralateral hemisensory loss, and contralateral weakness, concerning for possible MCA stroke. However, close examination revealed the hemiparesis to be ataxic in nature. Imaging revealed a left PCA P2 segment occlusion and lacunar infarction of the ventral lateral (VL) and ventral posterior (VP) thalamus, the main thalamic destination of cerebellar and sensory pathways. The case is unique because the P1 segment and posterior communicating artery (Pcom) remained patent, resulting in selective occlusion of only the posterior lateral (inferolateral) thalamic perforators at the P2 level. Acute loss of the posterior lateral (inferolateral) thalamic perforators at the proximal P2 segment results in a ventral lateral and ventral posterior thalamic stroke characterized by contralateral hemisensory loss, contralateral ataxic hemiparesis, and dysarthria. It is important to recognize the inferolateral thalamic stroke syndrome, as it may be mistaken clinically for an MCA occlusion. The benefit of mechanical thrombectomy for this type of stroke is not well established and should be considered carefully.

Prospective Trial of Cerebrospinal Fluid Filtration After Aneurysmal Subarachnoid Hemorrhage via Lumbar Catheter (PILLAR).

Background and Purpose- The PILLAR (Extracorporeal Filtration of Subarachnoid Hemorrhage via Spinal Catheter) study is a first-in-human trial of cerebrospinal fluid (CSF) filtration in aneurysmal subarachnoid hemorrhage. The study evaluates the safety and feasibility of a novel filtration system to rapidly remove blood and blood breakdown products from CSF after securement of a ruptured aneurysm. Methods- Patients with aneurysmal subarachnoid hemorrhage had a dual-lumen lumbar, intrathecal catheter placed after aneurysm securement and received up to 24 hours of CSF filtration (neurapheresis therapy). The catheter aspirated blood-contaminated CSF from the lumbar cistern and returned filtered CSF to the thoracic subarachnoid space. Neuro checks were performed q2 hours, and CSF samples were collected for cell counts, total protein, and gram stain. Computed tomography scans were acquired at baseline and post-filtration. Clinical follow-up occurred at 2 weeks and 30 days. Results- Thirteen patients had a catheter placed (mean time 24:13 hours after ictus). The system processed 632.0 mL (180.6-1447.6 mL) CSF in 15:07 hours (5:32-24:00 hours) of filtration. The mean initial CSF red blood cell count, 2.78×105 cells/µL, reduced to 1.17×105 cells/µL after filtration (52.9% reduction), and total protein reduced 71%. Independent analysis of baseline and postfiltration computed tomographies found notable cisternal blood decrease, with 46.5% mean Hijdra Score reduction. Three mild, anticipated adverse events were reported. Conclusions- The initial safety and feasibility of Neurapheresis therapy in aneurysmal subarachnoid hemorrhage demonstrated the potential to safely filter CSF and remove blood and blood byproducts. Future studies are warranted. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT0287263.

Predictors of Clinical Outcome After Treatment of Intracranial Aneurysms with the Pipeline Embolization Device.

BACKGROUND: Flow-diverting stents have revolutionized the endovascular treatment of intracranial aneurysms. The purpose of this study is to identify predictors of adverse outcomes associated with the pipeline embolization device (PED). METHODS: A retrospective analysis of all patients treated with PED at a single high-volume center from January 2014 to September 2018. Patient outcomes, neurologic morbidity/mortality, and other clinical variables were analyzed. RESULTS: We treated 204 aneurysms in 170 patients with PED. Mean length of follow-up was 11 months. Most (181) aneurysms (89%) were located in the anterior circulation, and 23 (11%) were found in the posterior circulation. Most aneurysms were saccular (82%), followed by fusiform (11%), blister (4%), and dissecting pseudoaneurysms (3%). Mean aneurysm size was 8.2 + 5.7 mm with 145 (71%) small aneurysms (≤10 mm), 53 (26%) large aneurysms (between 10 and 25 mm), and 6 (3%) giant aneurysms (≥25 mm). Ninety-two percent of aneurysms were unruptured, and 8% were ruptured. The overall major neurologic morbidity/mortality was 4.7% and 1.8%, respectively. The all-cause mortality was 2.9%. Predictors of neurologic morbidity/mortality included the baseline modified Rankin Scale (P = 0.001), aneurysm neck size (P = 0.003), aneurysm size (P = 0.006), anterior versus posterior location (P = 0.02), and rupture at presentation (0.006). The P2Y12 Reactivity Unit, parent vessel diameter, and patient age did not correlate with adverse events. CONCLUSIONS: The PED has a satisfactory safety profile in both on- and off-label indications. A poor clinical patient baseline, wider aneurysm neck or larger size, and rupture predict an increased risk of an unfavorable outcome.

Endovascular repair of an acute symptomatic carotid artery dissection through the false dissecting carotid lumen.

A 48-year-old woman presented with an acute ischemic stroke (National Institutes of Health Stroke Scale (NIHSS) 21) six hours after symptom onset. Workup revealed a left cervical internal carotid artery (ICA) occlusive dissection, which was emergently reconstructed with a flow-diverting stent. A routine Duplex scan one hour later suggested reocclusion of the ICA, confirmed by angiography. The true lumen of the ICA could not be accessed and therefore the "false lumen" of the ICA dissection was entered proximally. The true lumen and ultimately the flow-diverting stent were accessed via the false lumen. In analogy to the subintimal arterial flossing with antegrade-retrograde intervention technique described for peripheral vascular disease, several stents were placed in telescoping fashion from the true common carotid lumen through the "false dissecting" lumen of the proximal ICA into the distal true lumen. The stent construct remained patent, and the patient recovered clinically to an NIHSS of 1.

Treatment of direct carotid-cavernous fistulas with flow diversion - does it work?

Direct carotid-cavernous fistulas (CCFs) are high flow lesions that can be challenging to treat. A number of recent reports suggest that flow diversion may be a viable treatment option. We present a case of a post-traumatic CCF successfully treated with flow diversion and provide a review of the literature. Our results suggest that flow diversion is a potentially effective treatment option for CCFs and is most successful when used as an adjunctive therapy.

Thromboembolic Events with Enterprise Versus Pipeline: Porcine In Vivo Experiment.

BACKGROUND: Thromboembolic complications are serious adverse events associated with stenting of intracranial aneurysms. For the development of novel devices, currently no practical model exists to evaluate distal embolic events. The purpose of the current study was 2-fold: 1) assess the feasibility of a porcine carotid bifurcation model for in vivo testing of stent thrombogenicity and 2) compare the thrombogenicity of the Enterprise vascular reconstruction device versus the Pipeline embolization device (PED). METHODS: Six Yorkshire pigs underwent implantation of size-matched devices across the carotid bifurcation. Each animal received 1 Enterprise and 1 PED contralaterally. Baseline and 2-week follow-up angiography were performed. Images were analyzed including detailed measurements of the rete mirabile, a small-vessel conglomerate supplied by branches of the common carotid artery. RESULTS: In the absence of thromboembolic events at 2 weeks (n = 8), the perfused rete area measured 134.4 ± 6.9 mm2. In the presence of thromboembolic events (n = 4), the perfused rete was reduced to an area covering 37.1 ± 8.6 mm2 (P < 0.01). There was no difference in thrombogenicity between Enterprise and PED with a thromboembolic event rate of 33.3% for both devices (P > 0.99). CONCLUSION: The swine carotid stent model allows in vivo analysis of device-related thrombogenicity and distal embolic event rates. Size reduction of the perfused rete mirabile indicates the presence of thromboembolic events. Both Enterprise and PED were associated with similar thrombogenicity in this experiment.

Infundibular Dilations and Subarachnoid Hemorrhage: to Treat or Not to Treat?

BACKGROUND: Infundibular dilations are funnel-shaped widenings at the origin of a cerebral artery, most commonly the posterior communicating artery. Controversy exists as to whether an infundibulum represents a normal anatomic variant or a lesion with the potential for rupture and subarachnoid hemorrhage (SAH). METHODS: We reviewed all reported cases of infundibular dilations and SAH in the world literature and present an illustrative case. RESULTS: Most infundibula in the context of SAH were associated with an aneurysm either on or near an infundibulum. However, there have been 7 reports in which the infundibulum could have been the primary site of rupture and no associated aneurysm was identified. Close review reveals significant limitations of those 7 reports. CONCLUSIONS: The literature, and our own experience, do not support the treatment of infundibula, even in SAH patients. Treatment should be directed toward an associated aneurysm, not the infundibulum.

Onyx embolization of a pial AV fistula with a giant venous varix using a flow-directed Scepter balloon catheter: Technical note.

BACKGROUND AND IMPORTANCE: Pial arteriovenous fistulas (AVFs) of the brain are treacherous lesions that can be challenging to treat because of high risk of hemorrhage. We report on a rare case of a pial AVF with a giant venous varix as a draining vein treated successfully with flow-directed balloon-assisted Onyx embolization. CLINICAL PRESENTATION: A 56-year-old female with headaches underwent brain magnetic resonance imaging, which demonstrated a 4 cm aneurysmal malformation in the right temporal lobe. A diagnostic cerebral angiogram demonstrated a right temporal pial AVF fed by an enlarged right posterior cerebral artery with drainage into a giant venous varix. Onyx embolization was curative using a flow-directed Scepter balloon catheter. CONCLUSION: Flow-directed balloon-assisted Onyx embolization can be highly successful for the curative embolization of pial AVFs. Balloon application changes the nature of the lesion from high-flow-high risk to no-flow-low-risk. Using a flow-directed technique with balloon microcatheters may help minimize the risk of intracranial vascular injury.