title: Angioplasty and stenting for intracranial atherosclerotic stenosis with nitinol stent:  factors affecting technical success and patient safety.
abstract: BACKGROUND
  Angioplasty and stenting using nitinol stents is a recognized treatment option for intracranial atherosclerosis.
  
  
  OBJECTIVE
  To identify procedure-related factors that may affect patient safety and technical outcome.
  
  
  METHODS
  In this prospective study of 57 consecutive patients, the primary end points were intraprocedural technical problems, periprocedure morbidity, and complications. Major periprocedure complication was defined as all stroke or death at 30 days. Technical failure was defined as the inability to complete the procedure because of technical or safety problems. Procedure failure was defined as a procedure outcome of technical failure or major periprocedure complication. Secondary end points were procedure-related factors that may affect patient safety and technical outcome.
  
  
  RESULTS
  Procedure failure rate was 12.3% (7/57) (major periprocedure complication rate, 5.3% [3/57]; technical failure rate, 7% [4/57]). Initial failure in tracking of balloon or stent occurred in 20 patients, other technical problems occurred in 11 patients, including kinking or trapping of balloon catheter (2 cases), difficulty in unsheathing of stent (3 cases), forward migration of stent during deployment (4 cases), trapping of nose cone after stent deployment (1 case), fracture of delivery system (2 cases), and guidewire fracture (1 case). Unfavorable vascular morphology signified by the presence of 2 or more reverse curves along the access path was found to associate with initial failure in the tracking of instruments (OR = ∞), and occurrence of other technical problems (OR = 25).
  
  
  CONCLUSIONS
  Procedure-related factors could be identified and lead to improvements in patient safety and technical outcome. Tortuous vascular morphology is a key factor to be overcome.
authors.affiliation: Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, The New Territories, Hong Kong. simonyu@cuhk.edu.hk
authors.forename: Simon Chun Ho
authors.initials: SC
authors.lastname: Yu
authors.forename: Thomas Wai Hong
authors.initials: TW
authors.lastname: Leung
authors.forename: Esther Hiu Yee
authors.initials: EH
authors.lastname: Hung
authors.forename: Kwok Tung
authors.initials: KT
authors.lastname: Lee
authors.forename: Lawrence Ka Sing
authors.initials: LK
authors.lastname: Wong
mesh_terms: D000368:Aged; D000497:Alloys / Q000627:therapeutic use*; D017130:Angioplasty / Q000295:instrumentation* / Q000379:methods* / Q000401:mortality; D000800:Angioplasty, Balloon / Q000295:instrumentation / Q000379:methods / Q000401:mortality; D002536:Cerebral Arteries / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D004868:Equipment Failure; D005260:Female; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D061214:Patient Safety; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D017064:Process Assessment, Health Care / Q000379:methods; D011446:Prospective Studies; D011859:Radiography; D015607:Stents / Q000009:adverse effects / Q000592:standards*; D016896:Treatment Outcome
chemical_list: D000497:Alloys; C013616:nitinol