BACKGROUND AND PURPOSE:Recently we published a novel method of thrombus preparation for use in a swine model for evaluation of thrombectomy designs. The clot (fibrin rich clot) is characterized by its similarity in histologic characteristics to the thromboemboli recovered from stroke patients. The purpose of this latest study was to evaluate if the performance of a mechanical thrombectomy device was affected by the histologic characteristics of thromboembolus. Erythrocyte rich clot, which was created using exogenous thrombin, and the novel experimental clot with abundance of fibrin/cellular component were used for comparison. The Merci clot retriever was used for the evaluation and the angiographic outcomes were analyzed.

BACKGROUND AND PURPOSE: Delayed leukoencephalopathy is a rare complication that occurs after endovascular coiling of cerebral aneurysms. We aimed to describe a clinical picture of delayed leukoencephalopathy and explore potential associations with procedural characteristics. MATERIALS AND METHODS: We considered endovascular coiling procedures for cerebral aneurysms performed between January 2006 and December 2017 in our institution with follow-up MRIs. We used logistic regression models to estimate the ORs of delayed leukoencephalopathy for each procedural characteristic. RESULTS: We reviewed 1754 endovascular coiling procedures of 1594 aneurysms. Sixteen of 1722 (0.9%) procedures demonstrated delayed leukoencephalopathy on follow-up FLAIR MR imaging examinations after a median period of 71.5 days (interquartile range, 30-101 days) in the form of high-signal changes in the white matter at locations remote from the coil mass. Seven patients had headaches or hemiparesis, and 9 patients were asymptomatic. All imaging-associated changes improved subsequently. We found indications suggesting an association between delayed leukoencephalopathy and the number of microcatheters used per procedure (P 4 .009), along with indications suggesting that these procedures required larger median volumes of contrast medium (225 versus 175 mL, OR 4 5.5, P 4 .008) as well as a longer median fluoroscopy duration (123.6 versus 99.3 minutes, OR 4 3.0, P 4 .06). Our data did not suggest that delayed leukoencephalopathy was associated with the number of coils (P 4 .57), microguidewires (P 4 .35), and guiding systems (P 4 .57). CONCLUSIONS: Delayed leukoencephalopathy after coiling of cerebral aneurysms may have multiple etiologies such as foreign body emboli, contrast-induced encephalopathy, or hypersensitivity reaction to foreign bodies. ABBREVIATION: DL 4 delayed leukoencephalopathy E ndovascular coiling is an effective procedure for preventing rupture of cerebral aneurysms or treating ruptured aneurysms. 1,2 However, a small percentage of patients experience complications, 3 which include thromboembolic events (incidence rate of 4.7%-12.5%) and aneurysm rupture (incidence rate of 2.0%-8.8%), 3 along with posterior reversible encephalopathy

Tailor-made shaping of microcatheters may facilitate easier and safer procedures in coil embolization of intracranial aneurysm.

CFD, computational fluid dynamicsMCA, middle cerebral arteryPave, average pressurePD, pressure differencePmax, maximum pressureTWR, thin-walled regionWSS, wall shear stress.