Characteristics of Duplex Sonographic Parameters Over Time After Successful Carotid Artery Stenting

Abstract

Objectives Carotid duplex sonography is the primary tool for surveillance after carotid artery stenting, but the course of sonographic velocities over time after successful stenting is unclear. The purpose of this study was to describe carotid duplex sonographic velocity parameters after successful carotid artery stenting and to determine the predictors of poststent sonographic velocities. Methods We queried institutional carotid stent and noninvasive vascular laboratory databases for internal carotid artery stents placed between January 2004 and June 2007. We included patients with stenosis of 20% or less on completion angiograms who had carotid duplex sonography within 30 days before and 7 days after stenting. The prestent peak systolic velocity (PSV), end‐diastolic velocity (EDV), internal‐to‐common carotid artery PSV ratio, contralateral internal carotid artery velocities, stent type, open‐ versus closed‐cell stent design, and days of follow‐up were tested as potential predictors of poststent velocities. Results Eighty‐two of 498 patients met inclusion criteria. The mean PSV and PSV ratio decreased from 423.6 cm/s and 7.1 before stenting to 98.5 cm/s and 1.3 after stenting (both P < .001). During a median follow‐up of 370 days, poststent velocities remained stable. All poststent velocities (PSV, EDV, and PSV ratio) were dependent on prestent ipsilateral and contralateral velocities. The poststent EDV was dependent on the type of stent. The upper range for 0% to 20% stenosis in the stented internal carotid artery was a PSV of 141 cm/s, an EDV of 42 cm/s, and a PSV ratio of 2.1 or lower. Conclusions With a median follow‐up of 1 year, the PSV and PSV ratio remained stable over time in successfully stented carotid arteries. Deviations in sonographic parameters after initial poststent carotid duplex sonography should prompt an investigation for possible in‐stent restenosis.

Neurosonological Diagnosis in the Acute Phase of Stroke is a Sign of Qualified Care

“…The reason for the increased flow rates in the stent-supplied ICA appears to be, in addition to the reduction of vessel diameter after introduction of the stent, reduced arterial compliance [26,31] and altered geometry of the blood vessel [32]. Longitudinal ultrasound examinations of 82 patients with stent-supplied ICA showed that postinterventional moderately increased flow velocities in the stent (PSV 98.5 ± 21 cm/s, EDV 25.5 ± 8.1 cm/s) remained stable for more than 1 year, contradicting the idea that initial hyperperfusion after CAS causes increased flow velocities [33]. Pragmatically, an early baseline ultrasound examination is recommended in the first days after stent implantation, which can then be used for the follow-up observations in order to quantify later complications such as a hyperplasia of the neointima or formation of neoartherosclerosis.…”

Neurosonologische Diagnostik in der Akutphase des Schlaganfalls ist Merkmal einer qualifizierten Versorgung

“…Ursächlich für die erhöhten Flussgeschwindigkeiten in der stentversorgten ACI scheinen neben der Verringerung des Gefäßdurchmessers nach Einbringung des Stents vor allem auch eine verminderte Compliance [26,31] und eine veränderte Geometrie des Gefäßes zu sein [32]. Longitudinale Ultraschalluntersuchungen von 82 Patienten mit stentversorgter ACI zeigten, dass postinterventionell moderat erhöhte Flussgeschwindigkeiten im Stent (PSV 98,5 ± 21 cm/s, EDV 25,5 ± 8,1 cm/s) über 1 Jahr stabil blieben, was gegen eine initiale Hyperperfusion nach CAS als Ursache für die erhöhten Flussgeschwindigkeiten spricht [33]. Pragmatisch empfiehlt sich eine frühe Basis-Ultraschalluntersuchung in den ersten Tagen nach Stent-Implantation, die für die Verlaufsbeobachtungen herangezogen werden kann, um dann auch spätere Komplikationen wie eine Hyperplasie der Neointima oder die Ausbildung einer Neoartherosklerose zu quantifizieren.…”

Extrakranielle Farbduplexsonografie hirnversorgender Arterien

“…Nach einer Karotisendarteriektomie oder interventionellen Behandlung mit Dilatation und Stentimplantation in der Stenose kann der lokale Befund nach der Intervention und im weiteren Verlauf mit dem Farbduplex gut beurteilt werden (19,20) (▶Abb. 7).…”