Summary
Background
Carotid duplex ultrasonography is the prime investigation used to grade carotid artery stenosis in clinical routine. We compared the carotid ultrasound (US) scans performed externally with our results.
Materials and methods
This retrospective study included 288 patients who had been referred to our outpatient department and initially presented with an external carotid duplex scan report indicating carotid atherosclerosis. The external scans were analyzed and compared with our scans in respect of the accuracy of identification and quantification of stenosis, the criteria used to grade stenosis and the duplex criteria used. Weighted Kappa coefficients (K) were computed to quantify the agreement between internal and external findings.
Results
The majority of the external reports had been performed by radiologists [70.8 % (n = 204)], followed by specialists of internal medicine [19.4 (n = 56)] and by neurologists [9.8 % (n = 28)]. Only slight agreement was registered between the external reports and those performed at our institution with regard to the identification of stenosis (K = 0.2 for the left and K = 0.12 for the right side). Greater agreement was observed in respect of the level of stenosis (K = 0.42 for the right and K = 0.54 for the left side). Overestimation of the level of stenosis was registered for 45 % in the left internal carotid artery (ICA) and 36 % in the right ICA; the overestimation was most pronounced for occlusions and high-grade stenoses, which is a source of great concern for decision-making.
Conclusions
The present data indicate only a slight agreement between carotid duplex US imaging performed at medical offices and our results.
Zusammenfassung
Hintergrund
Die Duplexsonographie der Arteria carotis ist die Grundlage für die Stenosequantifizierung in der klinischen Routine. Diese Untersuchung wird zunehmend im niedergelassenen Bereich durchgeführt.
Patienten und Methoden
In dieser retrospektiven Studie wurden 288 konsekutive, ambulante Patienten der Abteilung Angiologie, die mit einem auswärtigen Befund einer Carotis-Duplexsonographie vorstellig wurden, inkludiert. Die Untersuchung wurde in unserem diagnostischen Speziallabor wiederholt. Die auswärtigen Befunde wurden in Hinblick auf die Identifikation einer Stenose, die Parameter zur Stenosequantifizierung analysiert und mit den an unserer Abteilung erstellten Befunden verglichen. Zu diesem Zweck wurden gewichtete Kappa -Koeffizienten (K) berechnet.
Ergebnisse
Die Mehrzahl der auswärtigen Untersuchungen wurden von Radiologen [70,8 % (n = 204)], gefolgt von Internisten [19,4 % (n = 56)] und Neurologen [9,8 % (n = 28)] durchgeführt.
Es zeigte sich nur eine geringe Konkordanz betreffend der Identifikation von Carotisstenosen (K = 0,2 für die linke und K = 0,12 für die rechte Seite) und eine etwas bessere Übereinstimmung in Bezug auf die Quantifizierung von Stenosen (K = 0,42 für die linke und K = 0,54 für die rechte Seite). Der Stenosegrad wurde in den auswärtig erstellten Befunden in 45 % betreffend die linke und in 36 % betreffend die rechte Arteria carotis überschätzt. Eine solche Überschätzung fand sich gehäuft im Fall von hochgradigen Stenosen.
Schlussfolgerungen
Das Management von Carotisstenosen, basierend auf auswärtig durchgeführte duplexsonographische Untersuchungen, birgt ein hohes Risiko für unnötige invasive Eingriffe zum einen, aber auch für mangelhafte therapeutische Konsequenzen zum anderen.
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References
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991;325:445–53.
European Carotid Surgery Trialists Collaborative Group. MRC European carotid surgery trial: interim results for symptomatic patients with severe (70–99 %) or mild (0–29 %) carotid stenosis. Lancet. 1991;337:1235–43.
Bogousslavsky J, Van Melle G, Regli F. The Lausanne stroke registry: analysis of 1,000 consecutive patients with first stroke. Stroke. 1988;19:1083–92.
Foulkes MA, Wolf PA, Price TR, et al. The stroke data bank: design, methods, and baseline characteristics. Stroke. 1988;19:547–54.
Roederer GO, Langlois YE, Jager KA, et al. The natural history of carotid arterial disease in asymptomatic patients with cervical bruits. Stroke. 1984;15:605–13.
Lewis RF, Abrahamowicz M, Côté R, et al. Predictive power of duplex ultrasonography in asymptomatic carotid disease. Ann Intern Med. 1997;127:13–20.
Sabeti S, Exner M, Mlekusch W, et al. Prognostic impact of fibrinogen in carotid atherosclerosis: nonspecific indicator of inflammation or independent predictor of disease progression? Stroke. 2005;36:1400–4.
Kaufmann TJ, Huston J 3rd, Mandrekar JN, et al. Complications of diagnostic cerebral angiography: evaluation of 19,826 consecutive patients. Radiology. 2007;243:812–9.
Davies KN, Humphrey PR. Complications of cerebral angiography in patients with symptomatic carotid territory ischaemia screened by carotid ultrasound. J Neurol Neurosurg Psychiatry. 1993;56:967–72.
Koelemay MJ, Nederkoorn PJ, Reitsma JB, et al. Systematic review of computed tomographic angiography for assessment of carotid artery disease. Stroke. 2004;35:2306–12.
Nederkoorn PJ, Van Der Graaf Y, Hunink MG. Duplex ultrasound and magnetic resonance angiography compared with digital subtraction angiography in carotid artery stenosis: a systematic review. Stroke. 2003;34:1324–32.
Chappell FM, Wardlaw JM, Young GR, et al. Carotid artery stenosis: accuracy of noninvasive tests—individual patient data meta-analysis. Radiology. 2009;251:493–502.
Dawson DL, Zierler RE, Strandness DE, et al. The role of duplex scanning and arteriography before carotid endarterectomy (a prospective study). J Vasc Surg. 1993;18:673–80.
Khaw KT. Does carotid duplex imaging render angiography redundant before carotid endarterectomy? Br J Radiol. 1997;70:235–8.
Huston J, James EM, Brown RD, et al. Redefined duplex ultrasonographic criteria for diagnosis of carotid artery stenosis. Mayo Clin Proc. 2000;75:1133–40.
Moneta GL, Edwards JM, Papanicolaou G, et al. Screening for asymptomatic internal carotid artery stenosis (duplex criteria for discriminating 60–99 % stenosis). J Vasc Surg. 1995;21:989–94.
Filis KA, Arko FR, Johnson BL, et al. Duplex ultrasound criteria for defining the severity of carotid stenosis. Ann Vasc Surg. 2002;16:413–21.
Ranger WR, Glover JL, Bendick PJ. Carotid endarterectomy based on preoperative duplex ultrasound. Am Surg. 1995;61:548–54.
Grant EG, Benson CB, Moneta GL, et al. Carotid artery stenosis: Gray-scale and Doppler US diagnosis—society of radiologists in ultrasound consensus conference. Radiology. 2003;229:340–6.
Sabeti S, Schillinger M, Mlekusch W, et al. Quantification of internal carotid artery stenosis with duplex US: comparative analysis of different flow velocity criteria. Radiology. 2004;232:431–9.
Nicolaides AN, Shifrin EG, Bradbury A, et al. Angiographic and duplex grading of internal carotid stenosis: can we overcome the confusion? J Endovasc Surg. 1996;3:158–65.
de Bray JM, Glatt B. Quantification of atheromatous stenosis in the extracranial internal carotid artery. Cerebrovasc Dis. 1995;5:414–26.
Crew JR, Dean M, Johnson JM, et al. Carotid surgery without angiography. Am J Surg. 1984;148(2):217–20.
Elmore JR, Franklin DP, Thomas DD, et al. Carotid endarterectomy: the mandate for high quality duplex. Ann Vasc Surg. 1998;12:156–62.
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Giurgea, GA., Lilaj, I., Gschwandtner, M. et al. Poor agreement in carotid artery stenosis detection by ultrasound between external offices and a vascular center. Wien Klin Wochenschr 124, 769–774 (2012). https://doi.org/10.1007/s00508-012-0259-1
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DOI: https://doi.org/10.1007/s00508-012-0259-1