title: What is the real risk of dislodging thrombi during endovascular revascularization of a proximal internal carotid artery occlusion?
abstract: BACKGROUND
  There is a theoretical concern that a thrombus may be dislodged distally when crossing the occluded segment during recanalization of a complete occlusion.
  
  
  OBJECTIVE
  To assess the immediate postprocedural brain diffusion-weighted image (DWI) findings following endovascular recanalization using an embolic protection device for proximal internal carotid artery (ICA) occlusion.
  
  
  METHODS
  We retrospectively identified 12 patients who underwent stent implantation for sudden symptomatic occlusion of the proximal ICA. In 8 patients, no additional intracranial occlusions were identified. In 4 patients, an additional intracerebral thrombus was detected in the middle cerebral artery. Distal protection devices were used in all cases. We evaluated the presence and amount of retrieved embolic fragments in the distal protection devices. The incidence and location of postprocedural emboli were determined using DWI.
  
  
  RESULTS
  Recanalization of the proximal ICA was achieved in all patients. After complete occlusion of the proximal ICA was demonstrated, primary passage of the embolic protection device through the occluded ICA was gently navigated in 7 patients. However, this was not possible in 5 patients. Three patients developed new lesions on postprocedural DWI. Of the 12 patients in which distal protection devices were used, debris was detected in 7 patients.
  
  
  CONCLUSIONS
  In endovascular revascularization of proximal ICA occlusion, postprocedural emboli occur less frequently than reported in a systematic review of the DWI literature. The real risk of dislodging thrombi appears to be from plaque fragment mobilization by angioplasty, rather than from crossing an occluded segment.
authors.affiliation: Department of Diagnostic Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Korea. skbaik9@gmail.com
authors.forename: Seung Kug
authors.initials: SK
authors.lastname: Baik
authors.forename: Ungbae
authors.initials: U
authors.lastname: Jeon
authors.forename: Ki Seok
authors.initials: KS
authors.lastname: Choo
authors.forename: Yong-Woo
authors.initials: YW
authors.lastname: Kim
authors.forename: Kyung
authors.initials: K
authors.lastname: Pil-Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D002548:Cerebral Revascularization / Q000009:adverse effects*; D057510:Endovascular Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D015912:Thrombolytic Therapy / Q000009:adverse effects; D013927:Thrombosis / Q000000981:diagnostic imaging / Q000601:surgery*; D014656:Vascular Surgical Procedures / Q000009:adverse effects