title: Safety and feasibility of a novel transcervical access neuroprotection system for carotid artery stenting in the PROOF Study.
abstract: BACKGROUND
  Randomized controlled trials have shown that periprocedural rates of stroke and death are higher with carotid artery stenting (CAS) than with carotid endarterectomy (CEA) in the treatment of carotid artery stenosis. Diffusion-weighted magnetic resonance imaging (DW-MRI) has shown higher rates of clinically silent new ischemic brain lesions when CAS is performed as compared with CEA. The Silk Road Medical Embolic PROtectiOn System: First-In-Man (PROOF) Study is a single-arm first-in-man study using the MICHI Neuroprotection System (Silk Road Medical Inc, Sunnyvale, Calif), a novel transcervical access and cerebral embolic protection system. This system enables stent implantation under controlled blood flow reversal of the carotid artery, also known as Flow Altered Short Transcervical Carotid Artery Stenting (FAST-CAS).
  
  
  METHODS
  Between March 2009 and February 2010, a total of 44 subjects were enrolled into the study. The primary composite endpoint was major stroke, myocardial infarction, or death within 30 days. Forty-three patients (97.7%) completed the study through the 30-day endpoint. One patient was lost to follow-up. In a subgroup of consecutive subjects, DW-MRI examinations were performed preprocedure and within 24 to 48 hours after the stent implantation. Blinded independent neuroradiologists reviewed all DW-MRI studies and confirmed the absence or presence of new ischemic brain lesions.
  
  
  RESULTS
  All enrolled patients were successfully treated, and no major adverse events were seen through the follow-up period. Thirty-one subjects had DW-MRI examinations. Of these, five patients (16%) had evidence of new ischemic brain lesions but no clinical sequelae. Transient intolerance to reverse flow was reported in 9% of cases, but in all cases, a stent was successfully placed, and the intolerance was managed by minimizing the duration of reverse flow during the procedure.
  
  
  CONCLUSIONS
  In this first-in-man experience, FAST-CAS using the MICHI Neuroprotection System was shown to be a safe and feasible method for carotid revascularization. DW-MRI findings suggest controlled reverse flow provides cerebral embolic protection similar to that seen with CEA.
authors.affiliation: Department of Vascular Surgery and Endovascular Therapy, Augusta Hospital, Düsseldorf, Germany.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Pinter
authors.forename: Marc
authors.initials: M
authors.lastname: Ribo
authors.forename: Christopher
authors.initials: C
authors.lastname: Loh
authors.forename: Barton
authors.initials: B
authors.lastname: Lane
authors.forename: Tracy
authors.initials: T
authors.lastname: Roberts
authors.forename: Tony M
authors.initials: TM
authors.lastname: Chou
authors.forename: Ralf R
authors.initials: RR
authors.lastname: Kolvenbach
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000009:adverse effects / Q000295:instrumentation*; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D002560:Cerebrovascular Circulation; D038524:Diffusion Magnetic Resonance Imaging; D057505:Embolic Protection Devices; D005240:Feasibility Studies; D005260:Female; D005858:Germany; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D012720:Severity of Illness Index; D015607:Stents; D020521:Stroke / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex