The Neuroradiology Journal 19: 348-354, 2006
www. centauro. it
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection A Case Report S. KERVANCIOGLU*, A. SIRIKCI*, R. YIGITER**, Y. CAKIR*, M. METIN BAYRAM* * Department of Radiology; ** Department of Neurology, University of Gaziantep, Faculty of Medicine; Gaziantep, Turkey
Key words: common carotid artery, dissection, stenting
SUMMARY – Isolated spontaneous common carotid artery (CCA) dissection is rare. So far, surgical or medical treatment have only been reported in a few cases in the literature. We report a 39year-old man, diagnosed as isolated spontaneous CCA dissection one year ago, who experienced a new minor stroke despite medical treatment. Because of the presence of new ischemic lesions on new magnetic resonance imaging despite medical treatment, and critical narrowing of internal carotid artery (ICA) orifice with jet and turbulence flow pattern at the bulbar portion of the ICA, endovascular management was performed with carotid stent deployment. To the best of our knowledge, this is the first case of spontaneous isolated CCA dissection treated with stenting of the carotid artery reported in literature. ÖZET – İzole spontan common carotid arter (CCA) diseksiyonu nadirdir. Literatürde sadece birkaç adet, medikal veya cerrahi tedavi uygulanan, CCA diseksiyonu olgusu bildirilmiştir. Bildirimizde, bir yıl önce izole spontan CCA diseksiyonu tanısı almış ve medikal tedavi altında iken yeni minor strok geçiren 39 yaşında erkek olguyu sunuyoruz. Olgunun yeni magnetik rezonans görüntülemesinde (MRG), sol posterior frontal ve pariyetal loblarda yeni iskemik lezyonların ortaya çıktığı görüldü. Renkli Doppler ultrasonografi (RDUS) incelemesinde eski incelemesine gore darlığın arttığı izlendi. Karotis anjiografide de internal karotis arter başlangıcında jet ve türbülans akıma neden olan kritik darlık saptanması üzerine endovasküler tedavi planlandı. Femoral girişimle koruyucu filtre kullanılarak self ekspandıbl stent yerleştirildi ve postdilatasyon balon uygulandı. Işlemden 24 saat sonra alınan difüzyon MRG incelemesinde yeni iskemik alan görülmedi. Birinci ve 3. ay kontrollerinde, nörolojik muayenesinde yeni bulgu saptanmadı. RDUS incelemelerinde stentin açık olduğu görüldü. Karotis artere stent yerleştirimesi cerrahiye alternatif bir tedavi olup daha az invazivdir. Stent uygulaması, spontan ve travmatik internal karotis arter darlıklarında kullanılmış, ancak izole spontan CCA diseksiyonunda kullanılmamıştır. Olgumuz nadir görülen izole spontan CCA diseksiyonu olgularından biri olup stent yerleştirilerek tedavi edilmiştir. Sonuç olarak, medikal tedaviye rağmen tekrarlayan semptomları olan izole spontan CCA diseksiyonu olgularda tromboemboli kaynağının kontrol altına alınması ve yeterli karotis akımının sağlanması için stent yerleştirilmesi gerekebilir.
Introduction Spontaneous dissection of the extracranial carotid artery is a major cause of stroke in young adults and frequently develops in the internal 348
carotid artery (ICA) 1. Dissection of the common carotid artery (CCA) is uncommon and almost always traumatic and can result either from direct trauma or extension of dissection of the aorta or the innominate artery 2. Among them,
S. Kervancioglu
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
A
B
Figure 1 A) Axial cranial MRI fluid-attenuated inversion recovery (FLAIR) sequence obtained one year ago shows scattered cortical-subcortical hyperintensity involving the posterior left frontal and parietal lobes. B) Axial FLAIR image obtained after one year during acute relapse of neurological compromise shows new lesions (arrows) in the posterior left frontal and parietal lobes.
349
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
S. Kervancioglu
Figure 2 Contrast-enhanced MR angiography shows a slender left CCA from midportion to the bifurcation (arrows).
➞ isolated spontaneous CCA dissection is rare. So far, only a few cases have been reported in the literature 3. To the best of our knowledge, endovascular management of isolated CCA dissection has not been achieved using percutaneous stent angioplasty. Here, we report the treatment of a spontaneous isolated CCA dissection with stenting of the carotid artery. Case Report A 39-year-old man was referred to our hospital for further evaluation and management of CCA dissection with complaints of sudden onset of right upper extremity numbness and 350
dysarthria arising suddenly one year ago without any remarkable cervical trauma in his history, and forgetfulness for the last month. He had been undergoing medical treatment for carotid artery dissection associated with scattered ischemic areas in the left posterior frontal and parietal lobes determined by magnetic resonance imaging (MRI) before admission to our hospital (figure 1A). Carotid Doppler ultrasonography disclosed a semicircular intramural hematoma extending from the midportion of the CCA to the bifurcation with increasing velocity (peak systolic velocity: 170 cm/s, end-diastolic velocity: 64 cm/s). Neurological examination revealed right arm hypoesthesia and dysphasia on admission to our hospital. His family’s his-
www. centauro. it
The Neuroradiology Journal 19: 348-354, 2006
B
Figure 3 Left carotid angiography reveals (A) diffuse stenosis of the CCA causing (B) jet and turbulence flow pattern in the bulbar portion of the ICA (arrow).
A
tory was unremarkable. The usual blood tests and studies including erythrocyte sedimentation rate, antinuclear antibody, fibrinogen, serology tests for syphilis, homocysteine, anticardiolipin antibody and lupus anticoagulant all yielded normal results. The results of chest x-ray and electrocardiography were negative. MRI showed new focal ischemic areas in the left posterior frontal and parietal lobes when compared with the former MRI study (figure 1B). Contrast-enhanced magnetic resonance angiography showed narrowing of the distal half of the left CCA (figure 2). Carotid Doppler ultrasonography revealed progression of the stenosis with increasing velocity (peak systolic velocity: 230 cm/s; end-di-
astolic velocity: 84 cm/s). Digital subtraction angiography showed a slender left CCA from the midportion to the bifurcation that caused jet and turbulence flow pattern in the bulbar portion (figure 3). Because of the presence of new ischemic lesions on MRI despite medical treatment, and critical narrowing of the ICA orifice causing a jet and turbulence flow pattern, endovascular management was decided. Endovascular treatment was performed while the patient was awake. At the beginning of the procedure heparin administration was begun with a 5000-unit intravenous bolus and positioning of a 7F guiding catheter into the beginning of left CCA, a cerebral protection device mounted on a 0.014’’ wire (FiltreWire EZ, Bos351
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
S. Kervancioglu
Figure 4 A completion angiogram shows successful reconstitution of the carotid system and flow pattern with deployment of a Wallstent.
ton Scientific) was advanced across the target lesion and deployed in a straight segment of the ICA under assistance of road map imaging. After filter opening, a 7.0×50-mm self expanding stent (Wallstent, Boston Scientific) was positioned across the lesion and deployed. The stent extended from the midportion of CCA to the proximal ICA. After stent placement, 0.5 mg of atropin was administered intravenously as prophylaxis against reflex bradycardia, and postdilatation with a 6×20 mm balloon (Gazelle, Boston Scientific) was performed. A completion angiogram showed patency of the carotid system, and the protection device was re-sheathed and deployed. Ipsilateral cervical and intracranial carotid angiography demon352
strated technical success and excluded distal cerebral embolization (figure 4). After the procedure, the patient was monitored in the neurointensive care unit for overnight observation. Intravenous heparin infusion of 1000 U/h was stopped eight hours later and low molecular weight heparin 6000 IU was given twice a day for two days. During the observation, neurological evaluation did not reveal a new neurologic deficit, and postprocedural diffusion-weighted MRI did not show a new ischemic area the next day. At discharge, oral aspirin 300 mg/day was advised to be continued indefinitely and clopidogrel 75 mg daily for six months. Following duplex sonographic examinations revealed patency of the carotid stent without any new find-
www. centauro. it
ings in his neurological examination at the first and third months after stenting (at the third month, peak systolic velocity: 88 cm/s; end-diastolic velocity: 29 cm/s) Discussion Spontaneous dissection of the extracranial carotid artery is a major cause of stroke in young adults 1. Spontaneous dissections can be associated with fibromuscular dysplasia, cystic medial necrosis, Marfan’s syndrome, type IV Ehlers-Darlos syndrome, aortic root dilatation, intracranial aneurysms and hypertension 1,4. In the pathogenesis of spontaneous carotid artery dissection, an underlying arteriopathy related to a generalized extracellular matrix defect could be mentioned. Furthermore, abnormal elastic properties of carotid arteries have been found in spontaneous carotid artery dissection. Higher stiffness of the carotid wall material and circumferential wall stress could increase the risk of dissection in these patients 1. However in most cases the pathogenesis remains unknown. Extracranial carotid artery dissection develops frequently in the ICA. Spontaneous dissection of the CCA is rare and frequently associated with aortic dissection 2. Isolated CCA dissection is also rare and frequently associated with cervical trauma, angiographic examination or endovascular interventions 5. Isolated spontaneous CCA dissection is very rare and has been reported as case reports in the English language literature. The clinical presentations included neck pain or headache, cerebral ischemia, cranial nerve palsy and monocular blindness 3. Digital subtraction angiography is considered the gold standard for detecting arterial dissection. Angiographic findings may include double lumen with intimal flap, smooth or slightly irregular luminal narrowing, or distal branch occlusions secondary to embolization. DSA fails to show intramural hematomas which are readily demonstrated by ultrasonography, computed tomography (CT) or MRI. Findings of CT and MRI include intimal flap or an eccentric rim of mural thickening surrounding a narrowed lumen. Sonographic findings may include double lumen with echogenic intimal flap or echogenic thrombus, and Doppler waveforms may show changes in blood flow. Doppler sonography is especially helpful for follow-up examinations to control extension of residual stenosis or formation of aneurysm.
The Neuroradiology Journal 19: 348-354, 2006
The formation of a false channel and associated anatomic disruption of the endothelial monolayer results in conditions favoring local thrombus formation. This thrombus formation may then embolize distally, and results in brain infarction 6. This thromboembolism is the most likely mechanism of cerebral infarction in carotid artery dissection and can occur up to one month after dissection 7,8. We thought that this mechanism could not explain the thromboembolism in our case, because of the repeated embolism that occurred in the chronic period of dissection (nearly one year after the dissection). The peculiarity of our case is that the dissection ended at the ICA orifice resulting in severe stenosis and poststenotic flow changes. Holme et al. concluded that severely stenosed arteries as in our case activate platelets and produce platelet-derived microparticles 9. In addition, the bulbar portion acted as a pseudo outpouching sac at the end of the dissection in our case. This action of pseudo out-pouching sac at the bulbar portion caused poststenotic disturbance and swirling flow pattern, and all those might have resulted in platelet aggregation and thrombus formation. According to the current conception of the relationship between the mechanism of infarction and stroke patterns, cortical-subcortical infarcts as seen in our case are more likely to be of embolic origin. This acknowledgement supports the thromboembolism more than the homodynamic infarct in our case as we thought in the mechanism of infarction. The optimal management of isolated spontaneous CCA dissection cannot be determined from the few reported cases. As thromboembolism is the most likely mechanism of cerebral infarction, prevention of arterioarterial embolism is the main therapeutic goal in carotid artery dissection. Surgery and medical treatment with anticoagulant or antiplatelet therapy have been reported 3. To date stenting of the carotid artery in isolated spontaneous CCA dissection has not been reported in the literature. The aims of the therapies for carotid dissection are prevention of embolism from thrombosis, and/or removal of thromboembolic sources, and/or establishment of adequate carotid flow. Conservative therapy with anticoagulation or antiplatelet medication may be recommended to prevent thromboembolic events in asymptomatic patients, or to prevent further neurological deterioration in symptomatic patients. In spite of medical management, complete recovery is achieved in less than one third of patients with carotid artery dissection 10. More 353
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
aggressive therapy including stenting and surgical repair may be required to remove or control the resistant thromboembolic sources and/ or improve cerebral perfusion. It is also necessary if conservative therapy is contraindicated or if symptoms are progressing under medical treatment. Among them, surgical management can be complicated by perioperative stroke that occurs in 10% of patients with carotid artery dissection 11. Stenting of the carotid artery is an attractive alternative management to surgical treatment, with a less invasive procedure. Recently, stents have been used for the treatment of spontaneous and posttraumatic dissection of the ICA, but not in isolated spontaneous dissection of CCA. Some authors favor stenting of the carotid artery only in chronic cases 12. Most of the reported cases of ICA dissection treated with stenting of the carotid artery were in the chronic stage of the disease. The patient presented underwent stent placement after he had experienced failure of medical therapy. Restoration of the vessel lumen with stenting should improve cerebral perfusion and control the dissection and the thromboembolism as in our case. Potential
S. Kervancioglu
complications of carotid artery stenting consist of thromboembolic events, thrombosis, and intimal hyperplasia. Thromboembolic events can be seen at each stage of the endovascular procedure for atherosclerotic stenosis. As the lesion is more compliant in dissection, stent deployment is less traumatic accompanied by lower pressure angioplasty in contrast with atherosclerotic stenosis. The risk of stent thrombosis is too low because of the relatively high artery diameter with accurate placement of the stent over dissection and supplementary medical treatment. Clinically significant stenosis of stent has been reported with a rate of 6.4% in atherosclerosis 13. This intimal hyperplasia is linked to an underlying inflammatory process in atherosclerosis 14. Depending on the different mechanism of the arterial stenosis (dissection), re-stenosis of the stent in the current patient is expected to be less than the atherosclerotic lesion. In conclusion, isolated spontaneous CCA dissection is rare, and carotid artery stenting may be required to control the thromboembolic sources and establish adequate carotid flow in patients with recurring symptoms despite medical treatment.
References 1 Calvet D, Boutouyrie P, Touze E et Al: Increased stiffness of the carotid wall material in patients with spontaneous cervical artery dissection. Stroke 35: 20782082, 2004. 2 Hirst AE, Johns VJ Jr, Kime SW Jr: Dissecting aneurysm of the aorta: a review of 505 cases. Medicine (Baltimore) 37: 217-219, 1958. 3 Chen YC, Lee TH, Chen CJ et Al: Spontaneous common carotid artery dissection: A case report and review of the literature. Eur Neurol 50: 58-60, 2003. 4 Robertson DI, Stuckey SL: Isolated intrapetrous carotid canal atraumatic internal carotid artery dissection: MRI and digital subtraction angiography findings. Australas Radiol 47: 462-464, 2003. 5 Hart RG, Easton JD: Dissection of cervical and cerebral arteries. Neurol Clin 1: 155-182, 1983. 6 Malek AM, Higashida RT, Phatouros CC et Al: Endovascular management of extracranial carotid artery dissection achieved using stent angioplasty. Am J Neuroradiol 21: 1280-1292, 2000. 7 Benninger DH, Georgiadis D, Kremer C et Al: Mechanism of ischemic infarct in spontaneous carotid dissection. Stroke 35: 482-485, 2004. 8 Vazquez Rodriguez C, Lemaire V, Renard F et Al: Primary stenting for the acute treatment of carotid artery dissection. Eur J Vasc Endovasc Surg 29: 350-352, 2005. 9 Holme PA, Orvim U, Hamers MJ et Al: Shear-induced platelet activation and platelet microparticle formation at blood flow conditions as in arteries with a severe stenosis. Arterioscler Thromb Vasc Biol 17: 646-653, 1997. 10 Bassi P, Lattuada P, Gomitoni A: Cervical cerebral ar-
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11
12
13
14
tery dissection: a multicenter prospective study (preliminary report). Neurol Sci 24: S4-S7, 2003. Schievink WI, Piepgras DG, McCaffrey TV et Al: Surgical treatment of extracranial internal carotid artery dissecting aneurysms. Neurosurgery 35: 809-816, 1994. Coric D, Wilson JA, Regan JD et Al: Primary stenting of the extracranial internal carotid artery in a patient with multiple cervical dissections: technical case report. Neurosurgery 43: 956-959, 1998. Lal BK, Hobson RW 2nd, Goldstein J et Al: In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance. J Vasc Surg 38: 11621169, 2003. Cipollone F, Ferri C, Desideri G et Al: Preprocedural level of soluble CD40L is predictive of enhanced inflammatory response and restenosis after coronary angioplasty. Circulation 108: 2776-2782, 2003.
Selim Kervancioglu, M.D. University of Gaziantep Faculty of Medicine Department of Radiology 27310 Sahinbey/Gaziantep - Turkey E-mail: [email protected]
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Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection A Case Report S. KERVANCIOGLU*, A. SIRIKCI*, R. YIGITER**, Y. CAKIR*, M. METIN BAYRAM* * Department of Radiology; ** Department of Neurology, University of Gaziantep, Faculty of Medicine; Gaziantep, Turkey
Key words: common carotid artery, dissection, stenting
SUMMARY – Isolated spontaneous common carotid artery (CCA) dissection is rare. So far, surgical or medical treatment have only been reported in a few cases in the literature. We report a 39year-old man, diagnosed as isolated spontaneous CCA dissection one year ago, who experienced a new minor stroke despite medical treatment. Because of the presence of new ischemic lesions on new magnetic resonance imaging despite medical treatment, and critical narrowing of internal carotid artery (ICA) orifice with jet and turbulence flow pattern at the bulbar portion of the ICA, endovascular management was performed with carotid stent deployment. To the best of our knowledge, this is the first case of spontaneous isolated CCA dissection treated with stenting of the carotid artery reported in literature. ÖZET – İzole spontan common carotid arter (CCA) diseksiyonu nadirdir. Literatürde sadece birkaç adet, medikal veya cerrahi tedavi uygulanan, CCA diseksiyonu olgusu bildirilmiştir. Bildirimizde, bir yıl önce izole spontan CCA diseksiyonu tanısı almış ve medikal tedavi altında iken yeni minor strok geçiren 39 yaşında erkek olguyu sunuyoruz. Olgunun yeni magnetik rezonans görüntülemesinde (MRG), sol posterior frontal ve pariyetal loblarda yeni iskemik lezyonların ortaya çıktığı görüldü. Renkli Doppler ultrasonografi (RDUS) incelemesinde eski incelemesine gore darlığın arttığı izlendi. Karotis anjiografide de internal karotis arter başlangıcında jet ve türbülans akıma neden olan kritik darlık saptanması üzerine endovasküler tedavi planlandı. Femoral girişimle koruyucu filtre kullanılarak self ekspandıbl stent yerleştirildi ve postdilatasyon balon uygulandı. Işlemden 24 saat sonra alınan difüzyon MRG incelemesinde yeni iskemik alan görülmedi. Birinci ve 3. ay kontrollerinde, nörolojik muayenesinde yeni bulgu saptanmadı. RDUS incelemelerinde stentin açık olduğu görüldü. Karotis artere stent yerleştirimesi cerrahiye alternatif bir tedavi olup daha az invazivdir. Stent uygulaması, spontan ve travmatik internal karotis arter darlıklarında kullanılmış, ancak izole spontan CCA diseksiyonunda kullanılmamıştır. Olgumuz nadir görülen izole spontan CCA diseksiyonu olgularından biri olup stent yerleştirilerek tedavi edilmiştir. Sonuç olarak, medikal tedaviye rağmen tekrarlayan semptomları olan izole spontan CCA diseksiyonu olgularda tromboemboli kaynağının kontrol altına alınması ve yeterli karotis akımının sağlanması için stent yerleştirilmesi gerekebilir.
Introduction Spontaneous dissection of the extracranial carotid artery is a major cause of stroke in young adults and frequently develops in the internal 348
carotid artery (ICA) 1. Dissection of the common carotid artery (CCA) is uncommon and almost always traumatic and can result either from direct trauma or extension of dissection of the aorta or the innominate artery 2. Among them,
S. Kervancioglu
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
A
B
Figure 1 A) Axial cranial MRI fluid-attenuated inversion recovery (FLAIR) sequence obtained one year ago shows scattered cortical-subcortical hyperintensity involving the posterior left frontal and parietal lobes. B) Axial FLAIR image obtained after one year during acute relapse of neurological compromise shows new lesions (arrows) in the posterior left frontal and parietal lobes.
349
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
S. Kervancioglu
Figure 2 Contrast-enhanced MR angiography shows a slender left CCA from midportion to the bifurcation (arrows).
➞ isolated spontaneous CCA dissection is rare. So far, only a few cases have been reported in the literature 3. To the best of our knowledge, endovascular management of isolated CCA dissection has not been achieved using percutaneous stent angioplasty. Here, we report the treatment of a spontaneous isolated CCA dissection with stenting of the carotid artery. Case Report A 39-year-old man was referred to our hospital for further evaluation and management of CCA dissection with complaints of sudden onset of right upper extremity numbness and 350
dysarthria arising suddenly one year ago without any remarkable cervical trauma in his history, and forgetfulness for the last month. He had been undergoing medical treatment for carotid artery dissection associated with scattered ischemic areas in the left posterior frontal and parietal lobes determined by magnetic resonance imaging (MRI) before admission to our hospital (figure 1A). Carotid Doppler ultrasonography disclosed a semicircular intramural hematoma extending from the midportion of the CCA to the bifurcation with increasing velocity (peak systolic velocity: 170 cm/s, end-diastolic velocity: 64 cm/s). Neurological examination revealed right arm hypoesthesia and dysphasia on admission to our hospital. His family’s his-
www. centauro. it
The Neuroradiology Journal 19: 348-354, 2006
B
Figure 3 Left carotid angiography reveals (A) diffuse stenosis of the CCA causing (B) jet and turbulence flow pattern in the bulbar portion of the ICA (arrow).
A
tory was unremarkable. The usual blood tests and studies including erythrocyte sedimentation rate, antinuclear antibody, fibrinogen, serology tests for syphilis, homocysteine, anticardiolipin antibody and lupus anticoagulant all yielded normal results. The results of chest x-ray and electrocardiography were negative. MRI showed new focal ischemic areas in the left posterior frontal and parietal lobes when compared with the former MRI study (figure 1B). Contrast-enhanced magnetic resonance angiography showed narrowing of the distal half of the left CCA (figure 2). Carotid Doppler ultrasonography revealed progression of the stenosis with increasing velocity (peak systolic velocity: 230 cm/s; end-di-
astolic velocity: 84 cm/s). Digital subtraction angiography showed a slender left CCA from the midportion to the bifurcation that caused jet and turbulence flow pattern in the bulbar portion (figure 3). Because of the presence of new ischemic lesions on MRI despite medical treatment, and critical narrowing of the ICA orifice causing a jet and turbulence flow pattern, endovascular management was decided. Endovascular treatment was performed while the patient was awake. At the beginning of the procedure heparin administration was begun with a 5000-unit intravenous bolus and positioning of a 7F guiding catheter into the beginning of left CCA, a cerebral protection device mounted on a 0.014’’ wire (FiltreWire EZ, Bos351
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
S. Kervancioglu
Figure 4 A completion angiogram shows successful reconstitution of the carotid system and flow pattern with deployment of a Wallstent.
ton Scientific) was advanced across the target lesion and deployed in a straight segment of the ICA under assistance of road map imaging. After filter opening, a 7.0×50-mm self expanding stent (Wallstent, Boston Scientific) was positioned across the lesion and deployed. The stent extended from the midportion of CCA to the proximal ICA. After stent placement, 0.5 mg of atropin was administered intravenously as prophylaxis against reflex bradycardia, and postdilatation with a 6×20 mm balloon (Gazelle, Boston Scientific) was performed. A completion angiogram showed patency of the carotid system, and the protection device was re-sheathed and deployed. Ipsilateral cervical and intracranial carotid angiography demon352
strated technical success and excluded distal cerebral embolization (figure 4). After the procedure, the patient was monitored in the neurointensive care unit for overnight observation. Intravenous heparin infusion of 1000 U/h was stopped eight hours later and low molecular weight heparin 6000 IU was given twice a day for two days. During the observation, neurological evaluation did not reveal a new neurologic deficit, and postprocedural diffusion-weighted MRI did not show a new ischemic area the next day. At discharge, oral aspirin 300 mg/day was advised to be continued indefinitely and clopidogrel 75 mg daily for six months. Following duplex sonographic examinations revealed patency of the carotid stent without any new find-
www. centauro. it
ings in his neurological examination at the first and third months after stenting (at the third month, peak systolic velocity: 88 cm/s; end-diastolic velocity: 29 cm/s) Discussion Spontaneous dissection of the extracranial carotid artery is a major cause of stroke in young adults 1. Spontaneous dissections can be associated with fibromuscular dysplasia, cystic medial necrosis, Marfan’s syndrome, type IV Ehlers-Darlos syndrome, aortic root dilatation, intracranial aneurysms and hypertension 1,4. In the pathogenesis of spontaneous carotid artery dissection, an underlying arteriopathy related to a generalized extracellular matrix defect could be mentioned. Furthermore, abnormal elastic properties of carotid arteries have been found in spontaneous carotid artery dissection. Higher stiffness of the carotid wall material and circumferential wall stress could increase the risk of dissection in these patients 1. However in most cases the pathogenesis remains unknown. Extracranial carotid artery dissection develops frequently in the ICA. Spontaneous dissection of the CCA is rare and frequently associated with aortic dissection 2. Isolated CCA dissection is also rare and frequently associated with cervical trauma, angiographic examination or endovascular interventions 5. Isolated spontaneous CCA dissection is very rare and has been reported as case reports in the English language literature. The clinical presentations included neck pain or headache, cerebral ischemia, cranial nerve palsy and monocular blindness 3. Digital subtraction angiography is considered the gold standard for detecting arterial dissection. Angiographic findings may include double lumen with intimal flap, smooth or slightly irregular luminal narrowing, or distal branch occlusions secondary to embolization. DSA fails to show intramural hematomas which are readily demonstrated by ultrasonography, computed tomography (CT) or MRI. Findings of CT and MRI include intimal flap or an eccentric rim of mural thickening surrounding a narrowed lumen. Sonographic findings may include double lumen with echogenic intimal flap or echogenic thrombus, and Doppler waveforms may show changes in blood flow. Doppler sonography is especially helpful for follow-up examinations to control extension of residual stenosis or formation of aneurysm.
The Neuroradiology Journal 19: 348-354, 2006
The formation of a false channel and associated anatomic disruption of the endothelial monolayer results in conditions favoring local thrombus formation. This thrombus formation may then embolize distally, and results in brain infarction 6. This thromboembolism is the most likely mechanism of cerebral infarction in carotid artery dissection and can occur up to one month after dissection 7,8. We thought that this mechanism could not explain the thromboembolism in our case, because of the repeated embolism that occurred in the chronic period of dissection (nearly one year after the dissection). The peculiarity of our case is that the dissection ended at the ICA orifice resulting in severe stenosis and poststenotic flow changes. Holme et al. concluded that severely stenosed arteries as in our case activate platelets and produce platelet-derived microparticles 9. In addition, the bulbar portion acted as a pseudo outpouching sac at the end of the dissection in our case. This action of pseudo out-pouching sac at the bulbar portion caused poststenotic disturbance and swirling flow pattern, and all those might have resulted in platelet aggregation and thrombus formation. According to the current conception of the relationship between the mechanism of infarction and stroke patterns, cortical-subcortical infarcts as seen in our case are more likely to be of embolic origin. This acknowledgement supports the thromboembolism more than the homodynamic infarct in our case as we thought in the mechanism of infarction. The optimal management of isolated spontaneous CCA dissection cannot be determined from the few reported cases. As thromboembolism is the most likely mechanism of cerebral infarction, prevention of arterioarterial embolism is the main therapeutic goal in carotid artery dissection. Surgery and medical treatment with anticoagulant or antiplatelet therapy have been reported 3. To date stenting of the carotid artery in isolated spontaneous CCA dissection has not been reported in the literature. The aims of the therapies for carotid dissection are prevention of embolism from thrombosis, and/or removal of thromboembolic sources, and/or establishment of adequate carotid flow. Conservative therapy with anticoagulation or antiplatelet medication may be recommended to prevent thromboembolic events in asymptomatic patients, or to prevent further neurological deterioration in symptomatic patients. In spite of medical management, complete recovery is achieved in less than one third of patients with carotid artery dissection 10. More 353
Endovascular Angioplasty-Stenting as a Definitive Treatment for Isolated Spontaneous Common Carotid Artery Dissection
aggressive therapy including stenting and surgical repair may be required to remove or control the resistant thromboembolic sources and/ or improve cerebral perfusion. It is also necessary if conservative therapy is contraindicated or if symptoms are progressing under medical treatment. Among them, surgical management can be complicated by perioperative stroke that occurs in 10% of patients with carotid artery dissection 11. Stenting of the carotid artery is an attractive alternative management to surgical treatment, with a less invasive procedure. Recently, stents have been used for the treatment of spontaneous and posttraumatic dissection of the ICA, but not in isolated spontaneous dissection of CCA. Some authors favor stenting of the carotid artery only in chronic cases 12. Most of the reported cases of ICA dissection treated with stenting of the carotid artery were in the chronic stage of the disease. The patient presented underwent stent placement after he had experienced failure of medical therapy. Restoration of the vessel lumen with stenting should improve cerebral perfusion and control the dissection and the thromboembolism as in our case. Potential
S. Kervancioglu
complications of carotid artery stenting consist of thromboembolic events, thrombosis, and intimal hyperplasia. Thromboembolic events can be seen at each stage of the endovascular procedure for atherosclerotic stenosis. As the lesion is more compliant in dissection, stent deployment is less traumatic accompanied by lower pressure angioplasty in contrast with atherosclerotic stenosis. The risk of stent thrombosis is too low because of the relatively high artery diameter with accurate placement of the stent over dissection and supplementary medical treatment. Clinically significant stenosis of stent has been reported with a rate of 6.4% in atherosclerosis 13. This intimal hyperplasia is linked to an underlying inflammatory process in atherosclerosis 14. Depending on the different mechanism of the arterial stenosis (dissection), re-stenosis of the stent in the current patient is expected to be less than the atherosclerotic lesion. In conclusion, isolated spontaneous CCA dissection is rare, and carotid artery stenting may be required to control the thromboembolic sources and establish adequate carotid flow in patients with recurring symptoms despite medical treatment.
References 1 Calvet D, Boutouyrie P, Touze E et Al: Increased stiffness of the carotid wall material in patients with spontaneous cervical artery dissection. Stroke 35: 20782082, 2004. 2 Hirst AE, Johns VJ Jr, Kime SW Jr: Dissecting aneurysm of the aorta: a review of 505 cases. Medicine (Baltimore) 37: 217-219, 1958. 3 Chen YC, Lee TH, Chen CJ et Al: Spontaneous common carotid artery dissection: A case report and review of the literature. Eur Neurol 50: 58-60, 2003. 4 Robertson DI, Stuckey SL: Isolated intrapetrous carotid canal atraumatic internal carotid artery dissection: MRI and digital subtraction angiography findings. Australas Radiol 47: 462-464, 2003. 5 Hart RG, Easton JD: Dissection of cervical and cerebral arteries. Neurol Clin 1: 155-182, 1983. 6 Malek AM, Higashida RT, Phatouros CC et Al: Endovascular management of extracranial carotid artery dissection achieved using stent angioplasty. Am J Neuroradiol 21: 1280-1292, 2000. 7 Benninger DH, Georgiadis D, Kremer C et Al: Mechanism of ischemic infarct in spontaneous carotid dissection. Stroke 35: 482-485, 2004. 8 Vazquez Rodriguez C, Lemaire V, Renard F et Al: Primary stenting for the acute treatment of carotid artery dissection. Eur J Vasc Endovasc Surg 29: 350-352, 2005. 9 Holme PA, Orvim U, Hamers MJ et Al: Shear-induced platelet activation and platelet microparticle formation at blood flow conditions as in arteries with a severe stenosis. Arterioscler Thromb Vasc Biol 17: 646-653, 1997. 10 Bassi P, Lattuada P, Gomitoni A: Cervical cerebral ar-
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12
13
14
tery dissection: a multicenter prospective study (preliminary report). Neurol Sci 24: S4-S7, 2003. Schievink WI, Piepgras DG, McCaffrey TV et Al: Surgical treatment of extracranial internal carotid artery dissecting aneurysms. Neurosurgery 35: 809-816, 1994. Coric D, Wilson JA, Regan JD et Al: Primary stenting of the extracranial internal carotid artery in a patient with multiple cervical dissections: technical case report. Neurosurgery 43: 956-959, 1998. Lal BK, Hobson RW 2nd, Goldstein J et Al: In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance. J Vasc Surg 38: 11621169, 2003. Cipollone F, Ferri C, Desideri G et Al: Preprocedural level of soluble CD40L is predictive of enhanced inflammatory response and restenosis after coronary angioplasty. Circulation 108: 2776-2782, 2003.
Selim Kervancioglu, M.D. University of Gaziantep Faculty of Medicine Department of Radiology 27310 Sahinbey/Gaziantep - Turkey E-mail: [email protected]
