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Endovascular Treatment for Recurrent Carotid Stenosis in a Patient with Proatlantal Intersegmental Artery
Letters to the Editor
Endovascular Treatment for Recurrent Carotid Stenosis in a Patient with Proatlantal Intersegmental Artery From: Marcia Morales, MD, Alexandre Anacleto, MD, Murilo Berbert, MD, Milton Mello, MD, Cresceˆncio Ceˆntola, MD, Carlos Eli Piccinato, MD, PhD, and Joa˜o Carloss Anacleto, MD Departments of Vascular Surgery (M.Morales, A.A., M.B., M.Mello, J.C.A.) and Interventional Radiology (C.C.) Hospital Beneficeˆncia Portuguesa Sa˜o Jose´ do Rio Preto; and Department of Vascular Surgery and Anatomy (C.E.P.) Faculdade de Medicina de Ribeira˜o Preto–USP Ribeira˜o Preto, Brazil Editor: The proatlantal intersegmental artery is a remnant of one of the primitive channels that provide communication between the carotid system and vertebrobasilar system for a short period of time during embryonic life. The persistence of these embryonic arteries, although rare (1), may be essential for irrigation of the posterior cerebral region. When obstructive disease of the carotid artery is associated with the occurrence of a proatlantal intersegmental artery, tactical changes in the treatment for the carotid stenosis need to be made, independent of the technique adopted. Two types of proatlantal artery have been described. Both originate from the carotid artery and enter the cranium via the foramen magnum. Type 1 proatlantal arteries originates from the caudal portion of the internal carotid artery and go up to the occipital–atlantal space without going through any transversal cervical foramen. Type 2 proatlantal arteries originate from the external carotid artery, present a lateralized pathway, and join the horizontal portion of the vertebral artery before going into the foramen magnum. Such arteries with primitive anastomoses that are treated by means of endarterectomy are also subject to recurrent stenosis. The present communication reports the case of a 65-year-old man who was admitted to the emergency service with a history of multiple episodes of dizziness during the preceding 5 days and a 2-hour bout of decreased muscle power in the upper right limb that took place 24 hours before admission. On admission examination, the patient was found to be alert and aware, normotensive, without neurologic deficits, and with a cervical murmur on the left side. The patient had undergone endarterectomy of the left carotid at the same institution 10 years earlier without any outpatient follow-up in the past 8 years. His medical records showed that he had a type 1 proatlantal intersegmental artery that caused communication between the left internal carotid artery and left vertebral artery. Duplex mapping and digital subtraction angiography were performed, which
DOI: 10.1097/01.RVI.0000196319.48140.D7
demonstrated stenosis of more than 90% in the left common carotid artery, with occlusion of the left external carotid artery and presence of a left proatlantal intersegmental artery (Figure, part a). The vertebral arteries were found to be hypoplastic and had no communication with the basilar artery. Endovascular treatment was chosen. The procedure was performed with the patient under moderate sedation. Vascular access was achieved via the right femoral artery. The EPI Filter Wire carotid artery protection system (Boston Scientific, Natick, MA) was positioned in the internal carotid artery distal to the origin of the proatlantal artery. Predilation with use of a 3-mm ⫻ 15-mm angioplasty balloon was performed before the release of a self-expanding Monorail Wallstent (Boston Scientific) 9 mm in diameter by 50 mm in length. The stent was then dilated with use of a 6-mm angioplasty balloon. Immediately after dilation, with the flow to the posterior fossa reestablished and the cerebral protection device still in position, the patient became moderately unresponsive and had a slight decrease in muscle power in the upper right limb. Control angiography (Figure, part b) showed good positioning of the stent and a lack of alterations in the left hemispheric circulation and posterior fossa circulation. There was complete remission of the neurologic deficit within 24 hours, and computed tomography of the brain showed no alterations. In conventional surgery for the treatment of restenosis associated with a proatlantal artery, clamping of the carotid artery must be avoided by means of the use of routine shunts (2). There has even been a description of the use of two shunts during the period of clamping the common carotid artery, one to supply the anterior region and the other for the posterior region (3). Today, one therapeutic option for the treatment of such a restenosis is endovascular stent implantation (4). In this case, the concern was not limited to preservation of flow to the posterior fossa, but also whether to use cerebral protection devices in anterior and posterior vessels. In our case, the cerebral protection system was positioned in the internal carotid artery whereas the posterior circulation relating to the region of the proatlantal artery remained without protection. During the procedure, the patient presented symptoms that may have been consequences of ischemia in the region irrigated by the proatlantal artery or may have been caused by the presence of the filter wire in the left carotid artery compromising the blood flow to the cerebral hemisphere. We believe it was more likely that the transitory neurologic deficit was provoked by embolism as a result of the absence of a protection device in the proatlantal region. We now believe this patient may have benefited from the use of two cerebral protection filters. References 1. Ouriel K, Green RM, DeWeese JA. Anomalous carotid-basilar anastomoses in cerebrovascular surgery. J Vasc Surg 1988; 7:774– 777. 2. Fantini GA, Reilly LM, Stoney RJ. Persistent hypoglossal artery: diagnostic and therapeutic considerations concerning carotid thromboendarterectomy. J Vasc Surg 1994; 20:995–999. 3. Grego F, Stramana´ R, Lepidi S, et al. Primitive proatlantal intersegmental artery and carotid endarterectomy. J Vasc Surg 2004; 39:691. 4. Hobson RW, Goldstein JE, Jamil Z, et al. Carotid restenosis: operative and endovascular management. J Vasc Surg 1999; 9:228–238.
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Letters to the Editor
Figure. (a) Digital subtraction arteriography shows the proatlantal intersegmental artery (solid arrow) yielding communication between the left internal carotid artery and the left vertebral artery. (b) Selective arteriogram after carotid angioplasty and implantation of a 9-mm ⫻ 50-mm carotid Wallstent.
February 2006
JVIR
Endovascular Treatment for Recurrent Carotid Stenosis in a Patient with Proatlantal Intersegmental Artery From: Marcia Morales, MD, Alexandre Anacleto, MD, Murilo Berbert, MD, Milton Mello, MD, Cresceˆncio Ceˆntola, MD, Carlos Eli Piccinato, MD, PhD, and Joa˜o Carloss Anacleto, MD Departments of Vascular Surgery (M.Morales, A.A., M.B., M.Mello, J.C.A.) and Interventional Radiology (C.C.) Hospital Beneficeˆncia Portuguesa Sa˜o Jose´ do Rio Preto; and Department of Vascular Surgery and Anatomy (C.E.P.) Faculdade de Medicina de Ribeira˜o Preto–USP Ribeira˜o Preto, Brazil Editor: The proatlantal intersegmental artery is a remnant of one of the primitive channels that provide communication between the carotid system and vertebrobasilar system for a short period of time during embryonic life. The persistence of these embryonic arteries, although rare (1), may be essential for irrigation of the posterior cerebral region. When obstructive disease of the carotid artery is associated with the occurrence of a proatlantal intersegmental artery, tactical changes in the treatment for the carotid stenosis need to be made, independent of the technique adopted. Two types of proatlantal artery have been described. Both originate from the carotid artery and enter the cranium via the foramen magnum. Type 1 proatlantal arteries originates from the caudal portion of the internal carotid artery and go up to the occipital–atlantal space without going through any transversal cervical foramen. Type 2 proatlantal arteries originate from the external carotid artery, present a lateralized pathway, and join the horizontal portion of the vertebral artery before going into the foramen magnum. Such arteries with primitive anastomoses that are treated by means of endarterectomy are also subject to recurrent stenosis. The present communication reports the case of a 65-year-old man who was admitted to the emergency service with a history of multiple episodes of dizziness during the preceding 5 days and a 2-hour bout of decreased muscle power in the upper right limb that took place 24 hours before admission. On admission examination, the patient was found to be alert and aware, normotensive, without neurologic deficits, and with a cervical murmur on the left side. The patient had undergone endarterectomy of the left carotid at the same institution 10 years earlier without any outpatient follow-up in the past 8 years. His medical records showed that he had a type 1 proatlantal intersegmental artery that caused communication between the left internal carotid artery and left vertebral artery. Duplex mapping and digital subtraction angiography were performed, which
DOI: 10.1097/01.RVI.0000196319.48140.D7
demonstrated stenosis of more than 90% in the left common carotid artery, with occlusion of the left external carotid artery and presence of a left proatlantal intersegmental artery (Figure, part a). The vertebral arteries were found to be hypoplastic and had no communication with the basilar artery. Endovascular treatment was chosen. The procedure was performed with the patient under moderate sedation. Vascular access was achieved via the right femoral artery. The EPI Filter Wire carotid artery protection system (Boston Scientific, Natick, MA) was positioned in the internal carotid artery distal to the origin of the proatlantal artery. Predilation with use of a 3-mm ⫻ 15-mm angioplasty balloon was performed before the release of a self-expanding Monorail Wallstent (Boston Scientific) 9 mm in diameter by 50 mm in length. The stent was then dilated with use of a 6-mm angioplasty balloon. Immediately after dilation, with the flow to the posterior fossa reestablished and the cerebral protection device still in position, the patient became moderately unresponsive and had a slight decrease in muscle power in the upper right limb. Control angiography (Figure, part b) showed good positioning of the stent and a lack of alterations in the left hemispheric circulation and posterior fossa circulation. There was complete remission of the neurologic deficit within 24 hours, and computed tomography of the brain showed no alterations. In conventional surgery for the treatment of restenosis associated with a proatlantal artery, clamping of the carotid artery must be avoided by means of the use of routine shunts (2). There has even been a description of the use of two shunts during the period of clamping the common carotid artery, one to supply the anterior region and the other for the posterior region (3). Today, one therapeutic option for the treatment of such a restenosis is endovascular stent implantation (4). In this case, the concern was not limited to preservation of flow to the posterior fossa, but also whether to use cerebral protection devices in anterior and posterior vessels. In our case, the cerebral protection system was positioned in the internal carotid artery whereas the posterior circulation relating to the region of the proatlantal artery remained without protection. During the procedure, the patient presented symptoms that may have been consequences of ischemia in the region irrigated by the proatlantal artery or may have been caused by the presence of the filter wire in the left carotid artery compromising the blood flow to the cerebral hemisphere. We believe it was more likely that the transitory neurologic deficit was provoked by embolism as a result of the absence of a protection device in the proatlantal region. We now believe this patient may have benefited from the use of two cerebral protection filters. References 1. Ouriel K, Green RM, DeWeese JA. Anomalous carotid-basilar anastomoses in cerebrovascular surgery. J Vasc Surg 1988; 7:774– 777. 2. Fantini GA, Reilly LM, Stoney RJ. Persistent hypoglossal artery: diagnostic and therapeutic considerations concerning carotid thromboendarterectomy. J Vasc Surg 1994; 20:995–999. 3. Grego F, Stramana´ R, Lepidi S, et al. Primitive proatlantal intersegmental artery and carotid endarterectomy. J Vasc Surg 2004; 39:691. 4. Hobson RW, Goldstein JE, Jamil Z, et al. Carotid restenosis: operative and endovascular management. J Vasc Surg 1999; 9:228–238.
399
400
•
Letters to the Editor
Figure. (a) Digital subtraction arteriography shows the proatlantal intersegmental artery (solid arrow) yielding communication between the left internal carotid artery and the left vertebral artery. (b) Selective arteriogram after carotid angioplasty and implantation of a 9-mm ⫻ 50-mm carotid Wallstent.
February 2006
JVIR