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Carotid Endarterectomy in the Face of a Persistent Hypoglossal Artery
Accepted Manuscript Carotid Endarterectomy in the Face of a Persistent Hypoglossal Artery Issam Koleilat, M.D., Tod Hanover, M.D. PII:
S0890-5096(15)00615-9
DOI:
10.1016/j.avsg.2015.05.032
Reference:
AVSG 2499
To appear in:
Annals of Vascular Surgery
Received Date: 4 April 2015 Revised Date:
27 May 2015
Accepted Date: 28 May 2015
Please cite this article as: Koleilat I, Hanover T, Carotid Endarterectomy in the Face of a Persistent Hypoglossal Artery, Annals of Vascular Surgery (2015), doi: 10.1016/j.avsg.2015.05.032. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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ACCEPTED MANUSCRIPT
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Carotid Endarterectomy in the Face of a Persistent Hypoglossal Artery
Department of Vascular Surgery Greenville Health Systems 701 Grove Road Greenville, SC 29605 864.455.7886 (p) 864.455.1320 (f)
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Issam Koleilat,1,2 M.D and Tod Hanover, 1 M.D.
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Corresponding Author
ACCEPTED MANUSCRIPT Koleilat and Hanover 2 ABSTRACT
CASE REPORT
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A 68 year-old woman presented with signs and symptoms suggestive of a cerebrovascular accident. Her workup revealed left internal carotid artery stenosis, consistent with her presentation of a left middle cerebral artery distribution stroke. Imaging also incidentally revealed a persistent hypoglossal artery. She underwent carotid endarterectomy. Our intraoperative strategy for management of this persistent fetal anomaly is reviewed.
M AN U
SC
A 68 year-old woman presented to the emergency department with a one-day history of right arm weakness and expressive aphasia. Her history was significant for 30 pack-years of tobacco abuse prior to cessation about five years ago, and hypertension. She was neither taking any medications prior to presentation nor was she seeing a physician regularly. On physical examination, she had a mild decrease in right arm strength with pronator drift, as well as an expressive aphasia. Her blood pressure was elevated at 157/82 on presentation. Her examination was otherwise unremarkable. Computed tomography (CT) revealed left middle cerebral artery [MCA] territory frontal cortical subacute stroke. Carotid duplex was consistent with right internal carotid artery (ICA) 50-69% stenosis, left ICA 70-99% stenosis and left vertebral artery occlusion.
TE D
Aspirin, atorvastatin and metoprolol were initiated for the acute medical management of her stroke. Further workup included magnetic resonance imaging (MRI) which confirmed the recent left frontal cortical and subcortical white matter stroke. Utilizing NASCET (North American Symptomatic Carotid Endarterectomy Trial) criteria, CT angiography of the head and neck found right ICA 57% stenosis, left ICA 71% stenosis, left vertebral artery absence or occlusion, right vertebral artery hypoplasia, and a patent persistent left hypoglossal artery serving as the predominant vascular supply to the basilar system (Figure 1). Her symptoms over her hospitalization began to improve.
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EP
A left carotid endarterectomy was performed under general anesthesia on hospital day four. Intraoperatively, identification of the hypoglossal artery was accomplished by division of the digastric muscle (Figure 2), which allowed proper identification of shunt location during carotid clamping. A Sundt shunt allowed continued perfusion of the left ICA as well as the hypoglossal artery during the endarterectomy by positioning the distal end of the shunt just caudal to the takeoff of the hypoglossal artery. The endarterectomy was unremarkable and the arteriotomy was closed with a bovine patch. Postoperatively, the patient remained at her neurologic baseline and was discharged to a rehabilitation facility two days later. Follow-up at two months reveals resolution of her right arm weakness with mild improvement of the aphasia. The patient gave consent to the use of her deidentified patient data for research and educational purposes. Our institutional policy on obtaining consent from patients encompasses use of deidentified data for research and educational purposes, including publishing of case reports. DISCUSSION
ACCEPTED MANUSCRIPT Koleilat and Hanover 3
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Persistent fetal carotid-basilar anastomoses are rare, occurring in less than 1% of the general population (1). Women are more likely to exhibit these anomalies (2). A persistent hypogloassl artery (PHA) is the second most common persistent fetal variant behind a persistent trigeminal artery with a prevalence of 0.02 – 0.1% in the general population (3). A PHA, as with most of the persistent fetal vascular anomalies, is usually found on CT or MRI as the typical carotid duplex interrogation does not image portions of the cervical carotid sufficiently cranial to visualize this variant anatomy.
SC
Embryologically, the internal carotid artery develops from the dorsal aorta and the third fetal aortic arch (4). Failure of regression of the fetal carotid-basilar anastomoses may lead to any of several variant anatomies. These include not only a PHA but also a persistent trigeminal artery, proatlantal intersegmental artery, persistent otic artery, persistent dorsal ophthalmic artery or persistent primitive olfactory artery (1). Of these, the only one that may complicate carotid endarterectomy is the PHA (5).
M AN U
A PHA originates from the ICA, usually at the level of the first through third cervical vertebrae, and courses through the hypoglossal canal (not the foramen magnum) to anastomose with the basilar artery (1, 6). Frequently, the vertebral arteries and posterior cerebral arteries may be hypoplastic or absent, especially ipsilateral to the PHA (7, 8). There is increased incidence in patients with PHA of associated vascular malformations or aneurysmal formation at the origin of persistent fetal vessels or of other intracranial vessels (1, 2, 8). Additionally, ischemic insults may cause clinical diagnostic confusion due to the common origin of both anterior and posterior vascular supply (9, 10).
EP
TE D
The presence of a fetal anatomic variant should prompt intracranial cerebral vascular imaging and as a result may uncover other vascular anomalies. In patients with isolated posterior circulation symptoms, imaging of the cervical and cerebral circulation is useful regardless of the underlying suspicion for persistent fetal anomalies, although certainly this imaging would detect any carotid-vertebral anastomosis. If discovered intraoperatively incidentally, consideration should be given to obtaining postoperative cross-sectional imaging with CT or MRI of the intracranial circulation due to the risk of associated vascular abnormalities such as arteriovenous malformations or aneurysms.
AC C
Intraoperative management may be rather simple, as in the case presented here, or complex. If the plaque ends caudal to the origin of the PHA as in this patient, a shunt may be easily positioned proximally to perfuse both the PHA and the distal ICA. If the plaque extends into the distal ICA beyond the PHA or into the PHA itself, the PHA may be endarterectomized by eversion or the arteriotomy may need to be extended. Management of this scenario may be akin to management of the superficial and profunda femoral arteries during femoral endarterectomy. Angioplasty with patch closure may need to extend into either one or both the ICA or PHA. In these more complex situations it may be logistically more advantageous to the surgeon if the patient can tolerate the procedure without use of a shunt. A carotid-vertebrobasilar anastomosis such as a PHA may encourage shunt use during carotid endarterectomy due to the dependence of not only the ipsilateral cerebral hemisphere but also the posterior circulation (9). Should use of a shunt be required, there are several
ACCEPTED MANUSCRIPT Koleilat and Hanover 4
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options. One may choose to shunt only the more critical of the two vessels. If the ICA stump pressure is adequate, shunting the PHA may be all that is needed. Alternatively, multiple shunts may be used. Two shunts side-by-side may be possible but this may produce inadequate hemostasis at the more proximal shunt site. One may consider placing one shunt from the CCA to the ICA and another from the ICA into PHA, thereby shunting both vessels serially, although this would not be feasible if arteriotomy extension to the origin of the PHA or beyond was required. Shunts in the shape of a ‘Y’ are also available (e.g. PruittInahara, LeMaitre Vascular, Inc., Burlington, MA) although modification by attachment to tubing and a needle inserted in the PHA to maintain perfusion may be required.
M AN U
SC
While others have described some of these approaches to the open management of a PHA in the face of carotid stenosis (5, 11), Eller et al describe endovascular management using flow reversal and interestingly stenting of tandem lesions of the ICA and mid-PHA (12). Conceivably, adding distal embolic protection in either the distal ICA, distal PHA or both to this strategy may be useful in cases where significant concern for embolism intraprocedurally is present.
TE D
Overall, PHA is usually an incidental finding. Once discovered, though, it is important to understand the aberrant anatomy to avoid potential complications. Adequate operative planning is important to avoid pitfalls both in open endarterectomy and during carotid stenting. There is no clear data to guide the decision to approach a lesion by endovascular or open means, and this remains a clinical decision based on the patient’s physiology, whether the lesion is symptomatic, the appearance of the lesion and vessels and the ability to adequately expose and treat them, etc. While rare, patients with persistent carotid-basilar anastomoses may prove to be interesting albeit challenging cases. DISCLOSURES
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The authors have no conflicts of interests or financial disclosures. No extramural funding was required for this report.
ACCEPTED MANUSCRIPT Koleilat and Hanover 5 FIGURES
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Figure 1: Computed tomographic angiogram (CTA) 3-D reconstruction depicting left common carotid artery bifurcation with persistent hypoglossal artery (red arrow) originating from the distal internal carotid artery (blue arrow) and traversing through the hypoglossal foramen to anastomose with the basilar system. The external carotid artery at the carotid bulb is depicted by the yellow arrow.
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Figure 2: Intraoperative image showing the carotid bifurcation. The blue vessel loop is on the common carotid artery. The black arrow identifies the vessel loop to the internal carotid artery as it continues into the cranium. The white arrow designates the vessel loop around the persistent hypoglossal artery.
ACCEPTED MANUSCRIPT Koleilat and Hanover 6 REFERENCES
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1. Dimmick SJ, Faulder KC. Normal variants of the cerebral circulation at multidetector CT angiography. Radiographics. 2009 Jul-Aug;29(4):1027-43. 2. Uchino A, Saito N, Watadani T, Okada Y, Kozawa E, Nishi N, et al. Vertebral artery variations at the C1-2 level diagnosed by magnetic resonance angiography. Neuroradiology. 2012 Jan;54(1):19-23. 3. Oelerich M, Schuierer G. Primitive hypoglossal artery: demonstration with digital subtraction-, MR- and CT angiography. European radiology. 1997;7(9):1492-4. 4. AG O. Diagnostic Cerebral Angiography. Philadelphia, PA: Lippincott Williams and Wilkins; 1999. 5. Megyesi JF, Findlay JM, Sherlock RA. Carotid endarterectomy in the presence of a persistent hypoglossal artery: case report. Neurosurgery. 1997 Sep;41(3):669-72. 6. Hahnel S, Hartmann M, Jansen O, Sartor K. Persistent hypoglossal artery: MRI, MRA and digital subtraction angiography. Neuroradiology. 2001 Sep;43(9):767-9. 7. Agnoli AL. Vascular anomalies and subarachnoid haemorrhage associated with persisting embryonic vessels. Acta neurochirurgica. 1982;60(3-4):183-99. 8. Clerici AM, Craparo G, Cafasso G, Micieli C, Bono G. De-novo headache with transient vertebro-basilar symptoms: role of embryonic hypoglossal artery. The journal of headache and pain. 2011 Dec;12(6):639-43. 9. Fantini GA, Reilly LM, Stoney RJ. Persistent hypoglossal artery: diagnostic and therapeutic considerations concerning carotid thromboendarterectomy. Journal of vascular surgery. 1994 Dec;20(6):995-9. 10. Ghandehari K, Ghandehari K. Interesting basis of vertebrobasilar arterial territory. Iranian journal of neurology. 2012;11(3):111-4. 11. Thayer WP, Gaughen JR, Harthun NL. Surgical revascularization in the presence of a preserved primitive carotid-basilar communication. Journal of vascular surgery. 2005 Jun;41(6):1066-9. 12. Eller JL, Jahshan S, Dumont TM, Kan P, Siddiqui AH. Tandem symptomatic internal carotid artery and persistent hypoglossal artery stenosis treated by endovascular stenting and flow reversal. Journal of neurointerventional surgery. 2014 May;6(4):e25.
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ACCEPTED MANUSCRIPT
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ACCEPTED MANUSCRIPT
S0890-5096(15)00615-9
DOI:
10.1016/j.avsg.2015.05.032
Reference:
AVSG 2499
To appear in:
Annals of Vascular Surgery
Received Date: 4 April 2015 Revised Date:
27 May 2015
Accepted Date: 28 May 2015
Please cite this article as: Koleilat I, Hanover T, Carotid Endarterectomy in the Face of a Persistent Hypoglossal Artery, Annals of Vascular Surgery (2015), doi: 10.1016/j.avsg.2015.05.032. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
RI PT
ACCEPTED MANUSCRIPT
SC
Carotid Endarterectomy in the Face of a Persistent Hypoglossal Artery
Department of Vascular Surgery Greenville Health Systems 701 Grove Road Greenville, SC 29605 864.455.7886 (p) 864.455.1320 (f)
TE D
1
M AN U
Issam Koleilat,1,2 M.D and Tod Hanover, 1 M.D.
AC C
EP
2
Corresponding Author
ACCEPTED MANUSCRIPT Koleilat and Hanover 2 ABSTRACT
CASE REPORT
RI PT
A 68 year-old woman presented with signs and symptoms suggestive of a cerebrovascular accident. Her workup revealed left internal carotid artery stenosis, consistent with her presentation of a left middle cerebral artery distribution stroke. Imaging also incidentally revealed a persistent hypoglossal artery. She underwent carotid endarterectomy. Our intraoperative strategy for management of this persistent fetal anomaly is reviewed.
M AN U
SC
A 68 year-old woman presented to the emergency department with a one-day history of right arm weakness and expressive aphasia. Her history was significant for 30 pack-years of tobacco abuse prior to cessation about five years ago, and hypertension. She was neither taking any medications prior to presentation nor was she seeing a physician regularly. On physical examination, she had a mild decrease in right arm strength with pronator drift, as well as an expressive aphasia. Her blood pressure was elevated at 157/82 on presentation. Her examination was otherwise unremarkable. Computed tomography (CT) revealed left middle cerebral artery [MCA] territory frontal cortical subacute stroke. Carotid duplex was consistent with right internal carotid artery (ICA) 50-69% stenosis, left ICA 70-99% stenosis and left vertebral artery occlusion.
TE D
Aspirin, atorvastatin and metoprolol were initiated for the acute medical management of her stroke. Further workup included magnetic resonance imaging (MRI) which confirmed the recent left frontal cortical and subcortical white matter stroke. Utilizing NASCET (North American Symptomatic Carotid Endarterectomy Trial) criteria, CT angiography of the head and neck found right ICA 57% stenosis, left ICA 71% stenosis, left vertebral artery absence or occlusion, right vertebral artery hypoplasia, and a patent persistent left hypoglossal artery serving as the predominant vascular supply to the basilar system (Figure 1). Her symptoms over her hospitalization began to improve.
AC C
EP
A left carotid endarterectomy was performed under general anesthesia on hospital day four. Intraoperatively, identification of the hypoglossal artery was accomplished by division of the digastric muscle (Figure 2), which allowed proper identification of shunt location during carotid clamping. A Sundt shunt allowed continued perfusion of the left ICA as well as the hypoglossal artery during the endarterectomy by positioning the distal end of the shunt just caudal to the takeoff of the hypoglossal artery. The endarterectomy was unremarkable and the arteriotomy was closed with a bovine patch. Postoperatively, the patient remained at her neurologic baseline and was discharged to a rehabilitation facility two days later. Follow-up at two months reveals resolution of her right arm weakness with mild improvement of the aphasia. The patient gave consent to the use of her deidentified patient data for research and educational purposes. Our institutional policy on obtaining consent from patients encompasses use of deidentified data for research and educational purposes, including publishing of case reports. DISCUSSION
ACCEPTED MANUSCRIPT Koleilat and Hanover 3
RI PT
Persistent fetal carotid-basilar anastomoses are rare, occurring in less than 1% of the general population (1). Women are more likely to exhibit these anomalies (2). A persistent hypogloassl artery (PHA) is the second most common persistent fetal variant behind a persistent trigeminal artery with a prevalence of 0.02 – 0.1% in the general population (3). A PHA, as with most of the persistent fetal vascular anomalies, is usually found on CT or MRI as the typical carotid duplex interrogation does not image portions of the cervical carotid sufficiently cranial to visualize this variant anatomy.
SC
Embryologically, the internal carotid artery develops from the dorsal aorta and the third fetal aortic arch (4). Failure of regression of the fetal carotid-basilar anastomoses may lead to any of several variant anatomies. These include not only a PHA but also a persistent trigeminal artery, proatlantal intersegmental artery, persistent otic artery, persistent dorsal ophthalmic artery or persistent primitive olfactory artery (1). Of these, the only one that may complicate carotid endarterectomy is the PHA (5).
M AN U
A PHA originates from the ICA, usually at the level of the first through third cervical vertebrae, and courses through the hypoglossal canal (not the foramen magnum) to anastomose with the basilar artery (1, 6). Frequently, the vertebral arteries and posterior cerebral arteries may be hypoplastic or absent, especially ipsilateral to the PHA (7, 8). There is increased incidence in patients with PHA of associated vascular malformations or aneurysmal formation at the origin of persistent fetal vessels or of other intracranial vessels (1, 2, 8). Additionally, ischemic insults may cause clinical diagnostic confusion due to the common origin of both anterior and posterior vascular supply (9, 10).
EP
TE D
The presence of a fetal anatomic variant should prompt intracranial cerebral vascular imaging and as a result may uncover other vascular anomalies. In patients with isolated posterior circulation symptoms, imaging of the cervical and cerebral circulation is useful regardless of the underlying suspicion for persistent fetal anomalies, although certainly this imaging would detect any carotid-vertebral anastomosis. If discovered intraoperatively incidentally, consideration should be given to obtaining postoperative cross-sectional imaging with CT or MRI of the intracranial circulation due to the risk of associated vascular abnormalities such as arteriovenous malformations or aneurysms.
AC C
Intraoperative management may be rather simple, as in the case presented here, or complex. If the plaque ends caudal to the origin of the PHA as in this patient, a shunt may be easily positioned proximally to perfuse both the PHA and the distal ICA. If the plaque extends into the distal ICA beyond the PHA or into the PHA itself, the PHA may be endarterectomized by eversion or the arteriotomy may need to be extended. Management of this scenario may be akin to management of the superficial and profunda femoral arteries during femoral endarterectomy. Angioplasty with patch closure may need to extend into either one or both the ICA or PHA. In these more complex situations it may be logistically more advantageous to the surgeon if the patient can tolerate the procedure without use of a shunt. A carotid-vertebrobasilar anastomosis such as a PHA may encourage shunt use during carotid endarterectomy due to the dependence of not only the ipsilateral cerebral hemisphere but also the posterior circulation (9). Should use of a shunt be required, there are several
ACCEPTED MANUSCRIPT Koleilat and Hanover 4
RI PT
options. One may choose to shunt only the more critical of the two vessels. If the ICA stump pressure is adequate, shunting the PHA may be all that is needed. Alternatively, multiple shunts may be used. Two shunts side-by-side may be possible but this may produce inadequate hemostasis at the more proximal shunt site. One may consider placing one shunt from the CCA to the ICA and another from the ICA into PHA, thereby shunting both vessels serially, although this would not be feasible if arteriotomy extension to the origin of the PHA or beyond was required. Shunts in the shape of a ‘Y’ are also available (e.g. PruittInahara, LeMaitre Vascular, Inc., Burlington, MA) although modification by attachment to tubing and a needle inserted in the PHA to maintain perfusion may be required.
M AN U
SC
While others have described some of these approaches to the open management of a PHA in the face of carotid stenosis (5, 11), Eller et al describe endovascular management using flow reversal and interestingly stenting of tandem lesions of the ICA and mid-PHA (12). Conceivably, adding distal embolic protection in either the distal ICA, distal PHA or both to this strategy may be useful in cases where significant concern for embolism intraprocedurally is present.
TE D
Overall, PHA is usually an incidental finding. Once discovered, though, it is important to understand the aberrant anatomy to avoid potential complications. Adequate operative planning is important to avoid pitfalls both in open endarterectomy and during carotid stenting. There is no clear data to guide the decision to approach a lesion by endovascular or open means, and this remains a clinical decision based on the patient’s physiology, whether the lesion is symptomatic, the appearance of the lesion and vessels and the ability to adequately expose and treat them, etc. While rare, patients with persistent carotid-basilar anastomoses may prove to be interesting albeit challenging cases. DISCLOSURES
AC C
EP
The authors have no conflicts of interests or financial disclosures. No extramural funding was required for this report.
ACCEPTED MANUSCRIPT Koleilat and Hanover 5 FIGURES
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Figure 1: Computed tomographic angiogram (CTA) 3-D reconstruction depicting left common carotid artery bifurcation with persistent hypoglossal artery (red arrow) originating from the distal internal carotid artery (blue arrow) and traversing through the hypoglossal foramen to anastomose with the basilar system. The external carotid artery at the carotid bulb is depicted by the yellow arrow.
AC C
EP
TE D
M AN U
SC
Figure 2: Intraoperative image showing the carotid bifurcation. The blue vessel loop is on the common carotid artery. The black arrow identifies the vessel loop to the internal carotid artery as it continues into the cranium. The white arrow designates the vessel loop around the persistent hypoglossal artery.
ACCEPTED MANUSCRIPT Koleilat and Hanover 6 REFERENCES
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1. Dimmick SJ, Faulder KC. Normal variants of the cerebral circulation at multidetector CT angiography. Radiographics. 2009 Jul-Aug;29(4):1027-43. 2. Uchino A, Saito N, Watadani T, Okada Y, Kozawa E, Nishi N, et al. Vertebral artery variations at the C1-2 level diagnosed by magnetic resonance angiography. Neuroradiology. 2012 Jan;54(1):19-23. 3. Oelerich M, Schuierer G. Primitive hypoglossal artery: demonstration with digital subtraction-, MR- and CT angiography. European radiology. 1997;7(9):1492-4. 4. AG O. Diagnostic Cerebral Angiography. Philadelphia, PA: Lippincott Williams and Wilkins; 1999. 5. Megyesi JF, Findlay JM, Sherlock RA. Carotid endarterectomy in the presence of a persistent hypoglossal artery: case report. Neurosurgery. 1997 Sep;41(3):669-72. 6. Hahnel S, Hartmann M, Jansen O, Sartor K. Persistent hypoglossal artery: MRI, MRA and digital subtraction angiography. Neuroradiology. 2001 Sep;43(9):767-9. 7. Agnoli AL. Vascular anomalies and subarachnoid haemorrhage associated with persisting embryonic vessels. Acta neurochirurgica. 1982;60(3-4):183-99. 8. Clerici AM, Craparo G, Cafasso G, Micieli C, Bono G. De-novo headache with transient vertebro-basilar symptoms: role of embryonic hypoglossal artery. The journal of headache and pain. 2011 Dec;12(6):639-43. 9. Fantini GA, Reilly LM, Stoney RJ. Persistent hypoglossal artery: diagnostic and therapeutic considerations concerning carotid thromboendarterectomy. Journal of vascular surgery. 1994 Dec;20(6):995-9. 10. Ghandehari K, Ghandehari K. Interesting basis of vertebrobasilar arterial territory. Iranian journal of neurology. 2012;11(3):111-4. 11. Thayer WP, Gaughen JR, Harthun NL. Surgical revascularization in the presence of a preserved primitive carotid-basilar communication. Journal of vascular surgery. 2005 Jun;41(6):1066-9. 12. Eller JL, Jahshan S, Dumont TM, Kan P, Siddiqui AH. Tandem symptomatic internal carotid artery and persistent hypoglossal artery stenosis treated by endovascular stenting and flow reversal. Journal of neurointerventional surgery. 2014 May;6(4):e25.
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ACCEPTED MANUSCRIPT
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