title: Carotid duplex velocity criteria revisited for the diagnosis of carotid in-stent restenosis.
abstract: Carotid percutaneous transluminal angioplasty/stenting has become an accepted treatment modality for carotid artery stenosis in high-risk patients. There has been an ongoing debate regarding which duplex ultrasound (DUS) criteria to use to determine the rate of in-stent restenosis. This prospective study revisits DUS criteria for determining the rate of in-stent restenosis. In analyzing a subset of 12 patients (pilot study) who had both completion carotid angiography and DUS within 30 days, 10 patients with normal post-stenting carotid angiography (< 30% residual stenosis) had peak systolic velocities (PSVs) of the stented internal carotid artery (ICA) of < or = 155 cm/s and two patients with > or = 30% residual stenosis had internal carotid artery (ICA) PSVs of > 155 cm/s. Eighty-three patients who underwent carotid stenting as part of clinical trials were analyzed. All patients underwent post-stenting carotid DUS that was done at 1 month and every 6 months thereafter. PSVs and end-diastolic velocities of the ICA and common carotid artery were recorded. Patients with PSVs of the ICA of > 140 cm/s underwent carotid computed tomographic (CT) angiography. The perioperative stroke rate was 1.2%. When the old DUS velocity criteria for nonstented carotid arteries were applied, 54% of patients had > or = 30% restenosis (PSV of > 120 cm/s), but when our new proposed DUS velocity criteria for stented arteries were applied (PSV of > 155 cm/s), 33% had > or = 30% restenosis at a mean follow-up of 18 months (p = .007). The mean PSVs for patients with normal stented carotid arteries based on CT angiography, were 122 cm/s versus 243 cm/s for > or = 30% restenosis and 113 cm/s versus 230 cm/s for > or = 30% restenosis based on our new criteria. The mean PSVs of in-stent restenosis of 30 to < 50%, 50 to < 70%, and 70 to 99%, based on CT angiography, were 205 cm/s, 264 cm/s, and 435 cm/s, respectively. Receiver operating curve analysis demonstrated that an ICA PSV of > 155 cm/s was optimal for detecting > or = 30% in-stent restenosis, with a sensitivity of 100%, a specificity of 90%, a positive predictive value of 74%, and a negative predictive value of 100%. The currently used carotid DUS velocity criteria overestimated the incidence of in-stent restenosis. We propose new velocity criteria for the ICA PSV of > 155 cm/s to define > or = 30% in-stent restenosis.
authors.affiliation: Department of Surgery, West Virginia University, Charleston Area Medical Center, WV 25304, USA. ali.aburahma@camc.org
authors.forename: Ali F
authors.initials: AF
authors.lastname: AbuRahma
authors.forename: Damian
authors.initials: D
authors.lastname: Maxwell
authors.forename: Kris
authors.initials: K
authors.lastname: Eads
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Flaherty
authors.forename: Tabitha
authors.initials: T
authors.lastname: Stutler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000379:methods; D001783:Blood Flow Velocity / Q000502:physiology; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012008:Recurrence; D012680:Sensitivity and Specificity; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000379:methods; D014463:Ultrasonography