Delayed neurological deficits after endovascular placement of a pipeline embolisation device: clinical manifestation and treatment

Abstract

Endovascular treatment has been the mainstay of therapy for repair of both ruptured and unruptured cerebral aneurysms. Flow diverter devices offer a new option for the treatment of complex aneurysms that were previously not amenable to coiling. Procedural adverse effects include intracranial haemorrhage and ischaemic stroke, which usually occur on the same day. Delayed complications are rare. We report a case of a patient who underwent placement of a pipeline embolisation device and developed delayed neurological deficits, which were thought to be an inflammatory reaction to the hydrophilic coating used in guidewires and microcatheters. Our patient was treated with a course of steroids, with improvement of her neurological deficits and resolution of MRI findings. As the use of flow diverter devices has increased, variable and delayed complications of such therapy are increasingly being reported in the literature.

Hydrophilic polymer embolization following flow diversion of cerebral aneurysms

“…Data about this phenomenon in neurointervention is limited to small cases series and case reports. 1,3,4,7,[20][21][22] The true incidence of HPE is unknown because MRI is not systematically obtained after endovascular procedures and there may be asymptomatic cases that go unnoticed. Clinical, histopathologic and radiological manifestations of HPE are secondary to small-sized distal cerebral vessel occlusion evolving into subacute granulomatous angiitis.…”

“…HPE has been reported after placement of flow diverter devices [1][2][3][4]20,21,[23][24][25] (Table 1). To our knowledge, this is the first case of HPE after an aborted flow diversion.…”

“…Data about this phenomenon in neurointervention is limited to small cases series and case reports. 1,3,4,7,20–22…”

“…Hydrophilic polymer embolism has been reported as a potential complication of endovascular flow diversion in the treatment of intracranial aneurysms. [1][2][3] Particulates of the hydrophilic device coatings may strip off secondary to mechanical friction/abrasion and embolize to downstream vascular territories causing a granulomatous inflammatory reaction with a wide spectrum of clinical and radiological manifestations. 4,5 Commonly reported complications of flow diversion include hemorrhagic and ischemic complications.…”

“…[6][7][8][9][10] Recently, hydrophilic polymer embolism has been reported as an additional potential complication of flow diversion of cerebral aneurysms. [1][2][3] This rare and potentially under-recognized complication should be considered in the differential diagnosis of new neurological findings following neurovascular interventions, particularly if there is a delay in the development of clinical symptoms after the procedure.…”