Portal de Periódicos da CAPES

Total occlusion of the common carotid artery with a patent internalcarotid artery; identification by duplex ultrasonography: Report of acase

1989; Elsevier BV; Volume: 10; Issue: 4 Linguagem: Inglês

10.1016/0741-5214(89)90426-6

1097-6809

Andrew J. Bebry, George L. Hines,

Renal and Vascular Pathologies

Total occlusion of a carotid artery can be manifested as an asymptomatic event, a cerebrovascular accident with or without total recovery, or in rare cases, as recurrent transient ischemic events. Therapy of the latter situation is controversial and in part depends on accurate evaluation of the extracranial and intracranial cerebrovascular system. 1Jacobs NM Grant EG Schellinger D Byrd MC Richardson JD Cohan SL. Duplex carotid sonography: criteria for stenosis, accuracy, and pitfalls.Radiology. 1985; 154: 385-391PubMed Google Scholar, 2Newton TH Couch RSC. Possible errors in the arteriographic diagnosis of the internal carotid artery occlusion.Radiology. 1960; 75: 766-773PubMed Google Scholar, 3Riles TS Posner MP Cohen WS Pinto R Imparato AM Baumann FG. The totally occluded internal carotid artery.Arch Surg. 1982; 117: 1185-1188Crossref PubMed Scopus (11) Google Scholar, 4Roederer GO Folcarelli PH Dixon RD Riles TS Baumann FG Imparato AM. Non-invasive evaluation of carotid subclavian bypass grafts.Bruit. 1984; 8: 261-265Google Scholar Angiography may not accurately define the status of the internal carotid artery (ICA), especially with total occlusion of the common carotid artery (CCA) or proximal ICA.3Riles TS Posner MP Cohen WS Pinto R Imparato AM Baumann FG. The totally occluded internal carotid artery.Arch Surg. 1982; 117: 1185-1188Crossref PubMed Scopus (11) Google Scholar Duplex ultrasonography has been shown to accurately reflect the degree of stenosis at the carotid bifurcation. 1Jacobs NM Grant EG Schellinger D Byrd MC Richardson JD Cohan SL. Duplex carotid sonography: criteria for stenosis, accuracy, and pitfalls.Radiology. 1985; 154: 385-391PubMed Google Scholar, 4Roederer GO Folcarelli PH Dixon RD Riles TS Baumann FG Imparato AM. Non-invasive evaluation of carotid subclavian bypass grafts.Bruit. 1984; 8: 261-265Google Scholar A 65-year-old white man was referred to our vascular laboratory complaining of 10 episodes of transient blindness in his left eye in the previous month. Each episode lasted between 4 and 10 minutes and resolved spontaneously. The patient had a history of smoking and hypertension. Pertinent physical findings included bilateral carotid bruits, absence of a palpable left carotid artery, and markedly diminished pulsation of the left superficial temporal artery. A duplex ultrasound scan of the extracranial left carotid arteries revealed a totally occluded CCA; complicated plaque in the bifurcation with turbulent bidirectional low-velocity flow (19 cm/sec); stenotic proximal ICA with bidirectional flow, mainly antegrade (45 cm/sec.); antegrade flow more distal in the ICA, (39 cm/sec, 4.5 cm from the bifurcation); bidirectional flow in the proximal external carotid artery (ECA) and bidirectional, mainly retrograde flow more distal in the ECA (−55 cm/sec, 2 cm from the bifurcation) (Fig. 1).The right carotid arteries showed mild-to-moderate obstructive disease with no critical stenosis. A diagnosis was made of total occlusion of the left CCA to the level of the carotid bifurcation, with retrograde flow in the ECA and then filling of the ICA from the ECA. Bilateral carotid and aortic arch angiograms were obtained. The aortic study showed a complete occlusion of the left CCA 1 cm from its origin from the aorta. No filling of the left ICA or ECA was identified, Delayed films of the right carotid injection showed filling of the left ECA, bulb, and ICA via collateral flow from the superior thyroid branch of the right ECA to the superior thyroid branch of the left ECA (Fig. 2). The patient underwent bypass grafting of left subclavian to left internal carotid artery with 6 mm thin-walled polytetrafluoroethylene graft material. Operative findings revealed a complete occlusion of the left CCA. A large left superior thyroid artery measuring 5 mm in diameter, which was acting as a collateral, was found. The patient has had no symptoms since surgery. The clinical presentation and treatment of the stenotic CCA or the totally occluded CCA with a visualized patent distal CCA or ICA has been well described by Crawford et al.5Crawford ES Stowe CL Powers RW. Occlusion of the innominate, common carotid, and subclavian arteries: long-term results of surgical treatment.Surgery. 1983; 94: 781-791PubMed Google Scholar and many others. Our case is slightly different, because based on initial angiographic evaluation the left ICA appeared to be totally occluded. The results of direct operative treatment by standard carotid endarterectomy of a totally occluded ICA have been inconsistent. It has been suggested that this is so because an ICA may be occluded only at its origin with a patent distal vessel (type 1)3Riles TS Posner MP Cohen WS Pinto R Imparato AM Baumann FG. The totally occluded internal carotid artery.Arch Surg. 1982; 117: 1185-1188Crossref PubMed Scopus (11) Google Scholar or be completely thrombosed to its intracranial portion (type 2). Various methods have been used to avoid this problem of operating on a totally occluded ICA. These include isolated external carotid endarterectomy in those patients with total ICA occlusion and stenosis of the ECA and extracranial-intracranial bypass grafting. Riles et al. used rapid segmental computerized tomography to evaluate the ICA in 15 patients with angiographic total occlusion of the ICA. Four patients were thought to have patent distal arteries on rapid segmental computerized tomography.3Riles TS Posner MP Cohen WS Pinto R Imparato AM Baumann FG. The totally occluded internal carotid artery.Arch Surg. 1982; 117: 1185-1188Crossref PubMed Scopus (11) Google Scholar Surgical exploration was carried out on three of these patients, and all had patent internal carotid arteries and were treated with standard endarterectomy. Duplex scanning of the carotid bifurcation has repeatedly demonstrated its accuracy in predicting the hemodynamic significance of carotid bifurcation lesions. It also appears to be able to determine complete carotid occlusion. Whether or not it can accurately ascertain the anatomy distal to a common carotid or proximal internal carotid occlusion has not previously been shown. We believe this case to be instructive for two reasons. First, despite total occlusion of the CCA, the duplex scanner was able to accurately define the hemodynamics of the extracranial carotid system distal to the obstruction. Second, the decision to use multiple delayed studies of the left carotid system after right carotid injection was guided completely by the preangiographic noninvasive workup.