Delayed Leukoencephalopathy: A Rare Complication after Coiling of Cerebral Aneurysms.

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?=?.009), along with indications suggesting that these procedures required larger median volumes of contrast medium (225 versus 175?mL, OR?=?5.5, P?=?.008) as well as a longer median fluoroscopy duration (123.6 versus 99.3?minutes, OR?=?3.0, P?=?.06). Our data did not suggest that delayed leukoencephalopathy was associated with the number of coils (P?=?.57), microguidewires (P?=?.35), and guiding systems (P?=?.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. Delayed leukoencephalopathy is a rare complication that occurs after endovascular coiling of cerebral aneurysms and is found in the literature with several different names, such as delayed leukoencephalopathy, delayed enhancing lesions, and delayed multiple white matter lesions. Its various suggested etiologies include granulation reaction caused by foreign body emboli from the hydrophilic coating of procedural devices, contrast-induced encephalopathy, and nickel or bioactive polyglycolic/polylactic acid coil sensitivity. The authors analyzed 1754 endovascular coiling procedures of 1594 aneurysms. Sixteen procedures demonstrated delayed leukoencephalopathy on follow-up FLAIR MR imaging examinations after a median period of 71.5 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. They found evidence of an association between delayed leukoencephalopathy and the number of microcatheters used per procedure, along with evidence suggesting that these procedures required larger median volumes of contrast medium and weak evidence regarding the need for a longer median fluoroscopy duration.