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Stenting for Internal Carotid Artery Stenosis Associated with Persistent Primitive Hypoglossal Artery Using Proximal Flow Blockade and Distal Protection System: A Technical Case Report and Literature Review
ARTICLE IN PRESS
Case Studies
Stenting for Internal Carotid Artery Stenosis Associated with Persistent Primitive Hypoglossal Artery Using Proximal Flow Blockade and Distal Protection System: A Technical Case Report and Literature Review Satoshi Murai, MD, Noboru Kusaka, MD, Michiari Umakoshi, MD, Hisakazu Itami, MD, Shinji Otsuka, MD, Tsukasa Nishiura, MD, and Kotaro Ogihara, MD
We report a very rare case of internal carotid artery (ICA) stenosis associated with persistent primitive hypoglossal artery (PPHA) treated by stenting using a proximal flow blockade and distal filter protection system. A 77-year-old man with a medical history of repeated cerebral infarction was referred to our hospital for treatment of progressive ICA stenosis. Cerebral angiography revealed that the degree of stenosis was 50% and the PPHA branched just distal to the stenosis at the C2 vertebral level. Black-blood magnetic resonance imaging indicated vulnerable plaque. The stenosis was at a high location, so carotid artery stenting was employed. Under the proximal flow blockade system with occlusion of the external and common carotid artery, distal filter protection was placed in the ICA to prevent distal embolization. A self-expanding stent was successfully deployed and the patient was discharged without any neurological deficits. In stenting for the ICA stenosis associated with PPHA, the combination of a proximal flow blockade and distal protection system is reasonable and safe. Key Words: Persistent primitive hypoglossal artery—internal carotid artery stenosis—carotid artery stenting—protection system. © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Introduction Persistent primitive hypoglossal artery (PPHA) is a type of carotid–basilar anastomosis with an estimated incidence of .02%-.26%. The hypoglossal artery originates from
From the Department of Neurosurgery, National Hospital Organization Iwakuni Clinical Center, Iwakuni, Japan. Received February 9, 2016; accepted March 15, 2016. Address correspondence to Satoshi Murai, MD, Department of Neurosurgery, National Hospital Organization Iwakuni Clinical Center, 1-1-1 Atago-machi Iwakuni-shi, Yamaguchi, 740-8510 Japan. E-mail: [email protected]. 1052-3057/$ - see front matter © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2016.03.026
the internal carotid artery (ICA) at the C1-C3 vertebral level and courses dorsally and laterally toward the hypoglossal nerve and then through the hypoglossal canal.1 PPHA is associated with ICA stenosis, cerebral aneurysm, moyamoya disease, arteriovenous malformation, and brain tumor.2 In the case of ICA stenosis associated with PPHA, posterior circulation is dependent on the PPHA. As such, the progression of ICA stenosis can induce flow reduction of the ICA and PPHA, resulting in severe ischemic stroke in both the anterior and posterior circulations. We report a very rare case of ICA stenosis associated with PPHA treated by a proximal flow blockade system using the Mo.Ma Ultra Proximal Protection System (Medtronic Invatec, Frauenfeld, Switzerland) and distal filter protection. The literature pertaining to ICA stenosis with PPHA is also reviewed.
Journal of Stroke and Cerebrovascular Diseases, Vol. ■■, No. ■■ (■■), 2016: pp ■■–■■
1
ARTICLE IN PRESS S. MURAI ET AL.
2
Case Presentation A 77-year-old man with a medical history of diabetes mellitus and hypertension was referred to our institute for the treatment of progressive ICA stenosis. Although the patient suffered from right cerebral infarction 4 times between 2007 and 2014, he was neurologically intact. The etiology of cerebral infarction was considered to be arteryto-artery embolisms. The patient was treated with clopidogrel (75 mg) and cilostazol (200 mg). Magnetic resonance imaging (MRI) showed multiple infarctions in the watershed area (Fig 1, A). MR angiography and 3-dimensional computed tomographic angiography showed right ICA stenosis and PPHA branching distal to the stenosis at the C2 vertebral level, coursing through the right hypoglossal canal (Fig 1, B-E). Three-dimensional computed tomographic angiography revealed that the degree of stenosis was 50%, as measured by the North American Symptomatic Carotid Endarterectomy Trial criteria, and the lesion length was approximately 20 mm. The right vertebral artery (VA) was aplastic and the left VA was hypoplastic. The anterior communicating artery and right posterior communicating artery (PcomA) were not visualized; therefore, we speculated that the PPHA served as the main supply for posterior circulation. On blackblood MRI, the carotid plaque showed hyperintensity, which indicated vulnerability (Fig 1, F). Single-photon emission computed tomography revealed slight hypoperfusion
in the watershed area. As the stenosis was at a high location, carotid endarterectomy (CEA) was considered difficult. Carotid artery stenting (CAS) with a proximal flow blockade system and distal filter protection was chosen instead.
Procedure The procedure was performed under general anesthesia. A 9-Fr long sheath was placed in the right common femoral artery. A .035-mm-long wire was inserted in the right external carotid artery (ECA) and then exchanged for Mo.Ma Ultra. FilterWire EZ (Boston Scientific, Natick, MA) was first placed in the PPHA as distal protection. Angiography with balloon occlusion of the ECA and common carotid artery (CCA) resulted in retrograde flow from the left VA to the ICA so FilterWire EZ was replaced in the ICA (Fig 2, A-C). Under proximal flow blockade, direct stenting was used to shorten the occlusion time. A Carotid Wallstent 10 × 24 mm (Boston Scientific) was deployed into the distal ICA at a site just proximal to the origin of the PPHA. Postdilatation was subsequently performed using a 5.5 × 30 mm Sterling balloon catheter (Boston Scientific, Natick). The blood was suctioned from the Mo.Ma Ultra and aspiration catheter; however, there was no plaque debris. The FilterWire Ez was removed and final angiography of the ICA showed ideal dilatation of the stenosis area and intracranial flow (Fig 2, D,E).
Figure 1. (A) MRI reveals cerebral infarction in the watershed area. (B and C) Magnetic resonance angiography reveals right internal carotid artery stenosis (arrowhead) and PPHA branching distal to the stenosis (white arrow). (D and E) Three-dimensional computed tomographic angiography reveals PPHA (black arrow) coursing through the right hypoglossal canal (white arrow). (F) On black-blood MRI, the carotid plaque shows high intensity (double arrow), which indicates vulnerability. Abbreviations: MRI, magnetic resonance imaging; PPHA, persistent primitive hypoglossal artery.
ARTICLE IN PRESS STENTING FOR ICA STENOSIS ASSOCIATED WITH PPHA
3
Figure 2. (A) Cerebral angiography reveals that the degree of stenosis is 50% and the lesion length is approximately 20 mm. (B) Under the occlusion of external carotid artery and CCA, distal filter protection is initially placed in the PPHA. (C) Distal filter protection is replaced in the ICA because of the retrograde flow from the PPHA to the internal carotid artery. (D) A self-expandable stent is deployed between the origin of the PPHA and the CCA and postdilatation is initiated. (E) Final angiography reveals an ideal dilatation of the stenosis area. (F) Cerebral angiography 1 year after carotid artery stenting reveals good patency. Abbreviations: CCA, common carotid artery; PPHA, persistent primitive hypoglossal artery.
The patient’s postoperative clinical course was good and MRI revealed no complications. Follow-up angiography 1 year after CAS revealed good patency (Fig 2, F).
Discussion ICA Stenosis Associated with PPHA The anatomical criteria for diagnosing PPHA are as follows: (1) the artery arises from the cervical ICA at the C1-C3 level; (2) the artery passes through the hypoglossal canal and not through the foramen magnum; (3) the basilar artery is filled only beyond the point of junction with the PPHA; and (4) the PcomAs are absent. In addition, the VAs are either aplastic on the ipsilateral side and hypoplastic on the contralateral side, or hypoplastic bilaterally.3 While the diseases associated with PPHA, such as cerebral aneurysms, arteriovenous malformations, or brain tumors, are explained by congenital factors, the cause of ICA stenosis is considered to be hemodynamic stress. The posterior circulation is maintained
primarily by the PPHA because the PcomA and VA tend to be hypoplastic or aplastic. The cerebral blood flow in the ipsilateral ICA associated with PPHA may be greater than the contralateral flow, resulting in intimal injury and stenosis.4 The progression of ICA stenosis can induce flow reduction of the ICA and PPHA, resulting in ischemic stroke in both anterior and posterior circulations.
Treatment for ICA Stenosis Associated with PPHA In previous reports, CEA was selected for the treatment of ICA stenosis associated with PPHA; however, several recent reports have described successful treatment with CAS. To the best of our knowledge, 4 cases of CAS for ICA stenosis associated with PPHA have been reported (Table 1). In all cases, the stenosis was at a high location (C1 and C2 vertebral levels). The PPHA arises from the ICA at the C1-C3 vertebral levels and the stenosis area is also at a high location in most cases, so CAS is more reasonable than CEA. All cases of CAS were
ARTICLE IN PRESS S. MURAI ET AL.
None None None None None 68/M 62/M 63/F 47/M 77/M Kanazawa et al5 Nii et al4 Silva et al6 Zhang et al7 Our case
Abbreviations: CAS, carotid artery stenting; F, female; ICA, internal carotid artery; M, male; PPHA, persistent primitive hypoglossal artery.
8 11 — 13 11 Reversal None None Blockade Blockade Balloon Balloon Balloon None Filter General General General General General C2 C2 C2 C1 C1/2
Age/sex
— 75 75 80 50
Proximal flow control
performed under general anesthesia. General anesthesia is appropriate for the placement of distal protection in the PPHA to avoid body motion due to brainstem ischemia. However, if distal protection is necessary for the ICA alone, local anesthesia may be acceptable.
Selection of the Protection Device
Case reports
Degree (%)
Location
Anesthesia
Distal protection
Protection Stenosis
Table 1. Summary of previous reports of CAS for ICA stenosis associated with PPHA
Occlusion time (min)
Complications
4
The key to successful CAS for ICA stenosis associated with PPHA is the protection of both the ICA and the PPHA. The ipsilateral and contralateral VAs as well as the PcomA are usually hypoplastic or aplastic.3 Therefore, both anterior and posterior circulations depend on the ICA. Distal embolization during the procedure may result in serious infarction of the brain stem. In 4 cases of CAS, two had distal protection alone, one had proximal protection, and one had a combination of proximal and distal protection. Silva et al6 reported 1 case using double distal protection to both the ICA and the PPHA. Silva et al placed 2 balloon protection devices in the right ICA and PPHA, respectively.6 As this procedure needs to cross severely stenotic lesions with 2 separate protective devices, in the case of severe stenosis or vulnerable plaque, the risk of embolism may be high. Nii et al4 reported 1 case treated by CAS with single distal balloon protection. Because the distance between the distal end of ICA stenosis and the origin of PPHA was long enough to place the balloon, a single balloon could prevent embolisms in both the ICA and the PPHA.4 Single balloon protection may be useful when the distance between the distal end of the ICA stenosis and the origin of the PPHA is sufficiently long. Two cases with proximal protection have been reported. Zhang et al7 reported a case with proximal protection using the Mo.Ma device. The ICA stenosis extended to the origin of the ipsilateral PPHA, so predilatation of the ICA and PPHA stenosis was initiated sequentially with occlusion of the ECA and CCA. A self-expandable stent was then deployed in the initial segment of the PPHA extending to the ICA.7 Kanazawa et al5 reported that they underwent CAS under flow reversal protection with occlusion of the ECA and CCA and distal balloon protection in the PPHA. Kanazawa et al report that the occlusion of 3 arteries resulted in a feeble reverse flow in the ICA.5 Proximal flow blockade with balloon occlusion of the ECA and CCA is a safe procedure that prevents embolic complication. However, unlike flow reversal protection, the retrograde flow remains from the ICA to the PPHA or from the PPHA to the ICA in the case of ICA stenosis associated with PPHA. The Parodi antiembolism system is the ideal protection with balloon occlusion of the ECA and CCA and an arteriovenous shunt, providing continuous reverse flow.8 However, this system is not currently available. Therefore, the combination of proximal
ARTICLE IN PRESS STENTING FOR ICA STENOSIS ASSOCIATED WITH PPHA
5 9
collateral anterior-to-vertebrobasilar flow. According to Thayer et al’s reports, greater than expected retrograde flow in the PPHA can be achieved. Therefore, preoperative BTO is useful to determine where to place distal protection. We propose that the combination with distal protection is necessary for the successful treatment of ICA stenosis associated with PPHA using proximal flow blockade.
Conclusion We report a very rare case of ICA stenosis associated with PPHA treated by stenting using a proximal flow blockade and a distal filter protection system.
References Figure 3. The scheme shows the direction of the retrograde flow and the placement of distal filter protection. (A) If the retrograde flow goes from the ICA to the PPHA, distal protection should be placed in the ICA. (B) On the other hand, if the retrograde flow goes from the PPHA to the ICA as in our case, distal protection should be placed in the PPHA. Abbreviations: ICA, internal carotid artery; PPHA, persistent primitive hypoglossal artery.
and distal protection may be safer than proximal protection alone. We attempt to simplify the procedures using Mo.Ma Ultra for proximal flow blockade and FilterWire EZ for distal protection. Mo.Ma Ultra is a double-occlusion balloon system that uses a guide catheter to provide full-time proximal protection during lesion crossing. Proximal protection reduces embolic complications, especially for lipid-rich or hemorrhagic plaque. In our case, the contralateral VA was hypoplastic and collateral flow in the PPHA was thought to be low, so we placed distal filter protection in the PPHA first. However, the balloon test occlusion unexpectedly revealed the retrograde flow from the PPHA to the ICA, so distal filter protection was replaced in the ICA (Fig 3, A,B). Thayer et al9 reported CEA for ICA stenosis associated with PPHA. When the CCA-to-distal ICA shunt was opened, pulsatile back bleeding was noted from the PPHA. Thayer et al reported that the ipsilateral PcomA might be patent or the leptomeningeal perforators might supply
1. Ouriel K, Green RM, DeWeese JA. Anomalous carotidbasilar anastomoses in cerebrovascular surgery. J Vasc Surg 1988;7:774-777. 2. Hatayama T, Yamane K, Shima T, et al. Persistent primitive hypoglossal artery associated with cerebral aneurysm and cervical internal carotid artery stenosis—case report. Neurol Med Chir (Tokyo) 1999;39:372-375. 3. Lie TA. Persistent carotid-basilar carotid-vertebral anastomosis, in congenital anomalies of the carotid arteries. Amsterdam: Excerpta Medica, 1968:76-84. 4. Nii K, Aikawa H, Tsutsumi M, et al. Carotid artery stenting in a patient with internal carotid artery stenosis and ipsilateral persistent primitive hypoglossal artery presenting with transient ischemia of the vertebrobasilar system: case report. Neurol Med Chir (Tokyo) 2010;50:921-924. 5. Kanazawa R, Ishihara S, Okawara M, et al. Successful treatment with carotid arterial stenting for symptomatic internal carotid artery severe stenosis with ipsilateral persistent primitive hypoglossal artery: case report and review of the literature. Minim Invasive Neurosurg 2008;51:298-302. 6. Silva CF, Hou SY, Kühn AL, et al. Double embolic protection during carotid artery stenting with persistent hypoglossal artery. J Neurointerv Surg 2014;6:e23. 7. Zhang L, Song G, Chen L, et al. Concomitant asymptomatic internal carotid artery and persistent primitive hypoglossal artery stenosis treated by endovascular stenting with proximal embolic protection. J Vasc Surg 2016;63:237-240. 8. Parodi JC, Ferreira LM, Sicard G, et al. Cerebral protection during carotid stenting using flow reversal. J Vasc Surg 2005;41:416-422. 9. Thayer WP, Gaughen JR, Harthun NL. Surgical revascularization in the presence of a preserved primitive carotid-basilar communication. J Vasc Surg 2005;41:10661069.
Case Studies
Stenting for Internal Carotid Artery Stenosis Associated with Persistent Primitive Hypoglossal Artery Using Proximal Flow Blockade and Distal Protection System: A Technical Case Report and Literature Review Satoshi Murai, MD, Noboru Kusaka, MD, Michiari Umakoshi, MD, Hisakazu Itami, MD, Shinji Otsuka, MD, Tsukasa Nishiura, MD, and Kotaro Ogihara, MD
We report a very rare case of internal carotid artery (ICA) stenosis associated with persistent primitive hypoglossal artery (PPHA) treated by stenting using a proximal flow blockade and distal filter protection system. A 77-year-old man with a medical history of repeated cerebral infarction was referred to our hospital for treatment of progressive ICA stenosis. Cerebral angiography revealed that the degree of stenosis was 50% and the PPHA branched just distal to the stenosis at the C2 vertebral level. Black-blood magnetic resonance imaging indicated vulnerable plaque. The stenosis was at a high location, so carotid artery stenting was employed. Under the proximal flow blockade system with occlusion of the external and common carotid artery, distal filter protection was placed in the ICA to prevent distal embolization. A self-expanding stent was successfully deployed and the patient was discharged without any neurological deficits. In stenting for the ICA stenosis associated with PPHA, the combination of a proximal flow blockade and distal protection system is reasonable and safe. Key Words: Persistent primitive hypoglossal artery—internal carotid artery stenosis—carotid artery stenting—protection system. © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Introduction Persistent primitive hypoglossal artery (PPHA) is a type of carotid–basilar anastomosis with an estimated incidence of .02%-.26%. The hypoglossal artery originates from
From the Department of Neurosurgery, National Hospital Organization Iwakuni Clinical Center, Iwakuni, Japan. Received February 9, 2016; accepted March 15, 2016. Address correspondence to Satoshi Murai, MD, Department of Neurosurgery, National Hospital Organization Iwakuni Clinical Center, 1-1-1 Atago-machi Iwakuni-shi, Yamaguchi, 740-8510 Japan. E-mail: [email protected]. 1052-3057/$ - see front matter © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2016.03.026
the internal carotid artery (ICA) at the C1-C3 vertebral level and courses dorsally and laterally toward the hypoglossal nerve and then through the hypoglossal canal.1 PPHA is associated with ICA stenosis, cerebral aneurysm, moyamoya disease, arteriovenous malformation, and brain tumor.2 In the case of ICA stenosis associated with PPHA, posterior circulation is dependent on the PPHA. As such, the progression of ICA stenosis can induce flow reduction of the ICA and PPHA, resulting in severe ischemic stroke in both the anterior and posterior circulations. We report a very rare case of ICA stenosis associated with PPHA treated by a proximal flow blockade system using the Mo.Ma Ultra Proximal Protection System (Medtronic Invatec, Frauenfeld, Switzerland) and distal filter protection. The literature pertaining to ICA stenosis with PPHA is also reviewed.
Journal of Stroke and Cerebrovascular Diseases, Vol. ■■, No. ■■ (■■), 2016: pp ■■–■■
1
ARTICLE IN PRESS S. MURAI ET AL.
2
Case Presentation A 77-year-old man with a medical history of diabetes mellitus and hypertension was referred to our institute for the treatment of progressive ICA stenosis. Although the patient suffered from right cerebral infarction 4 times between 2007 and 2014, he was neurologically intact. The etiology of cerebral infarction was considered to be arteryto-artery embolisms. The patient was treated with clopidogrel (75 mg) and cilostazol (200 mg). Magnetic resonance imaging (MRI) showed multiple infarctions in the watershed area (Fig 1, A). MR angiography and 3-dimensional computed tomographic angiography showed right ICA stenosis and PPHA branching distal to the stenosis at the C2 vertebral level, coursing through the right hypoglossal canal (Fig 1, B-E). Three-dimensional computed tomographic angiography revealed that the degree of stenosis was 50%, as measured by the North American Symptomatic Carotid Endarterectomy Trial criteria, and the lesion length was approximately 20 mm. The right vertebral artery (VA) was aplastic and the left VA was hypoplastic. The anterior communicating artery and right posterior communicating artery (PcomA) were not visualized; therefore, we speculated that the PPHA served as the main supply for posterior circulation. On blackblood MRI, the carotid plaque showed hyperintensity, which indicated vulnerability (Fig 1, F). Single-photon emission computed tomography revealed slight hypoperfusion
in the watershed area. As the stenosis was at a high location, carotid endarterectomy (CEA) was considered difficult. Carotid artery stenting (CAS) with a proximal flow blockade system and distal filter protection was chosen instead.
Procedure The procedure was performed under general anesthesia. A 9-Fr long sheath was placed in the right common femoral artery. A .035-mm-long wire was inserted in the right external carotid artery (ECA) and then exchanged for Mo.Ma Ultra. FilterWire EZ (Boston Scientific, Natick, MA) was first placed in the PPHA as distal protection. Angiography with balloon occlusion of the ECA and common carotid artery (CCA) resulted in retrograde flow from the left VA to the ICA so FilterWire EZ was replaced in the ICA (Fig 2, A-C). Under proximal flow blockade, direct stenting was used to shorten the occlusion time. A Carotid Wallstent 10 × 24 mm (Boston Scientific) was deployed into the distal ICA at a site just proximal to the origin of the PPHA. Postdilatation was subsequently performed using a 5.5 × 30 mm Sterling balloon catheter (Boston Scientific, Natick). The blood was suctioned from the Mo.Ma Ultra and aspiration catheter; however, there was no plaque debris. The FilterWire Ez was removed and final angiography of the ICA showed ideal dilatation of the stenosis area and intracranial flow (Fig 2, D,E).
Figure 1. (A) MRI reveals cerebral infarction in the watershed area. (B and C) Magnetic resonance angiography reveals right internal carotid artery stenosis (arrowhead) and PPHA branching distal to the stenosis (white arrow). (D and E) Three-dimensional computed tomographic angiography reveals PPHA (black arrow) coursing through the right hypoglossal canal (white arrow). (F) On black-blood MRI, the carotid plaque shows high intensity (double arrow), which indicates vulnerability. Abbreviations: MRI, magnetic resonance imaging; PPHA, persistent primitive hypoglossal artery.
ARTICLE IN PRESS STENTING FOR ICA STENOSIS ASSOCIATED WITH PPHA
3
Figure 2. (A) Cerebral angiography reveals that the degree of stenosis is 50% and the lesion length is approximately 20 mm. (B) Under the occlusion of external carotid artery and CCA, distal filter protection is initially placed in the PPHA. (C) Distal filter protection is replaced in the ICA because of the retrograde flow from the PPHA to the internal carotid artery. (D) A self-expandable stent is deployed between the origin of the PPHA and the CCA and postdilatation is initiated. (E) Final angiography reveals an ideal dilatation of the stenosis area. (F) Cerebral angiography 1 year after carotid artery stenting reveals good patency. Abbreviations: CCA, common carotid artery; PPHA, persistent primitive hypoglossal artery.
The patient’s postoperative clinical course was good and MRI revealed no complications. Follow-up angiography 1 year after CAS revealed good patency (Fig 2, F).
Discussion ICA Stenosis Associated with PPHA The anatomical criteria for diagnosing PPHA are as follows: (1) the artery arises from the cervical ICA at the C1-C3 level; (2) the artery passes through the hypoglossal canal and not through the foramen magnum; (3) the basilar artery is filled only beyond the point of junction with the PPHA; and (4) the PcomAs are absent. In addition, the VAs are either aplastic on the ipsilateral side and hypoplastic on the contralateral side, or hypoplastic bilaterally.3 While the diseases associated with PPHA, such as cerebral aneurysms, arteriovenous malformations, or brain tumors, are explained by congenital factors, the cause of ICA stenosis is considered to be hemodynamic stress. The posterior circulation is maintained
primarily by the PPHA because the PcomA and VA tend to be hypoplastic or aplastic. The cerebral blood flow in the ipsilateral ICA associated with PPHA may be greater than the contralateral flow, resulting in intimal injury and stenosis.4 The progression of ICA stenosis can induce flow reduction of the ICA and PPHA, resulting in ischemic stroke in both anterior and posterior circulations.
Treatment for ICA Stenosis Associated with PPHA In previous reports, CEA was selected for the treatment of ICA stenosis associated with PPHA; however, several recent reports have described successful treatment with CAS. To the best of our knowledge, 4 cases of CAS for ICA stenosis associated with PPHA have been reported (Table 1). In all cases, the stenosis was at a high location (C1 and C2 vertebral levels). The PPHA arises from the ICA at the C1-C3 vertebral levels and the stenosis area is also at a high location in most cases, so CAS is more reasonable than CEA. All cases of CAS were
ARTICLE IN PRESS S. MURAI ET AL.
None None None None None 68/M 62/M 63/F 47/M 77/M Kanazawa et al5 Nii et al4 Silva et al6 Zhang et al7 Our case
Abbreviations: CAS, carotid artery stenting; F, female; ICA, internal carotid artery; M, male; PPHA, persistent primitive hypoglossal artery.
8 11 — 13 11 Reversal None None Blockade Blockade Balloon Balloon Balloon None Filter General General General General General C2 C2 C2 C1 C1/2
Age/sex
— 75 75 80 50
Proximal flow control
performed under general anesthesia. General anesthesia is appropriate for the placement of distal protection in the PPHA to avoid body motion due to brainstem ischemia. However, if distal protection is necessary for the ICA alone, local anesthesia may be acceptable.
Selection of the Protection Device
Case reports
Degree (%)
Location
Anesthesia
Distal protection
Protection Stenosis
Table 1. Summary of previous reports of CAS for ICA stenosis associated with PPHA
Occlusion time (min)
Complications
4
The key to successful CAS for ICA stenosis associated with PPHA is the protection of both the ICA and the PPHA. The ipsilateral and contralateral VAs as well as the PcomA are usually hypoplastic or aplastic.3 Therefore, both anterior and posterior circulations depend on the ICA. Distal embolization during the procedure may result in serious infarction of the brain stem. In 4 cases of CAS, two had distal protection alone, one had proximal protection, and one had a combination of proximal and distal protection. Silva et al6 reported 1 case using double distal protection to both the ICA and the PPHA. Silva et al placed 2 balloon protection devices in the right ICA and PPHA, respectively.6 As this procedure needs to cross severely stenotic lesions with 2 separate protective devices, in the case of severe stenosis or vulnerable plaque, the risk of embolism may be high. Nii et al4 reported 1 case treated by CAS with single distal balloon protection. Because the distance between the distal end of ICA stenosis and the origin of PPHA was long enough to place the balloon, a single balloon could prevent embolisms in both the ICA and the PPHA.4 Single balloon protection may be useful when the distance between the distal end of the ICA stenosis and the origin of the PPHA is sufficiently long. Two cases with proximal protection have been reported. Zhang et al7 reported a case with proximal protection using the Mo.Ma device. The ICA stenosis extended to the origin of the ipsilateral PPHA, so predilatation of the ICA and PPHA stenosis was initiated sequentially with occlusion of the ECA and CCA. A self-expandable stent was then deployed in the initial segment of the PPHA extending to the ICA.7 Kanazawa et al5 reported that they underwent CAS under flow reversal protection with occlusion of the ECA and CCA and distal balloon protection in the PPHA. Kanazawa et al report that the occlusion of 3 arteries resulted in a feeble reverse flow in the ICA.5 Proximal flow blockade with balloon occlusion of the ECA and CCA is a safe procedure that prevents embolic complication. However, unlike flow reversal protection, the retrograde flow remains from the ICA to the PPHA or from the PPHA to the ICA in the case of ICA stenosis associated with PPHA. The Parodi antiembolism system is the ideal protection with balloon occlusion of the ECA and CCA and an arteriovenous shunt, providing continuous reverse flow.8 However, this system is not currently available. Therefore, the combination of proximal
ARTICLE IN PRESS STENTING FOR ICA STENOSIS ASSOCIATED WITH PPHA
5 9
collateral anterior-to-vertebrobasilar flow. According to Thayer et al’s reports, greater than expected retrograde flow in the PPHA can be achieved. Therefore, preoperative BTO is useful to determine where to place distal protection. We propose that the combination with distal protection is necessary for the successful treatment of ICA stenosis associated with PPHA using proximal flow blockade.
Conclusion We report a very rare case of ICA stenosis associated with PPHA treated by stenting using a proximal flow blockade and a distal filter protection system.
References Figure 3. The scheme shows the direction of the retrograde flow and the placement of distal filter protection. (A) If the retrograde flow goes from the ICA to the PPHA, distal protection should be placed in the ICA. (B) On the other hand, if the retrograde flow goes from the PPHA to the ICA as in our case, distal protection should be placed in the PPHA. Abbreviations: ICA, internal carotid artery; PPHA, persistent primitive hypoglossal artery.
and distal protection may be safer than proximal protection alone. We attempt to simplify the procedures using Mo.Ma Ultra for proximal flow blockade and FilterWire EZ for distal protection. Mo.Ma Ultra is a double-occlusion balloon system that uses a guide catheter to provide full-time proximal protection during lesion crossing. Proximal protection reduces embolic complications, especially for lipid-rich or hemorrhagic plaque. In our case, the contralateral VA was hypoplastic and collateral flow in the PPHA was thought to be low, so we placed distal filter protection in the PPHA first. However, the balloon test occlusion unexpectedly revealed the retrograde flow from the PPHA to the ICA, so distal filter protection was replaced in the ICA (Fig 3, A,B). Thayer et al9 reported CEA for ICA stenosis associated with PPHA. When the CCA-to-distal ICA shunt was opened, pulsatile back bleeding was noted from the PPHA. Thayer et al reported that the ipsilateral PcomA might be patent or the leptomeningeal perforators might supply
1. Ouriel K, Green RM, DeWeese JA. Anomalous carotidbasilar anastomoses in cerebrovascular surgery. J Vasc Surg 1988;7:774-777. 2. Hatayama T, Yamane K, Shima T, et al. Persistent primitive hypoglossal artery associated with cerebral aneurysm and cervical internal carotid artery stenosis—case report. Neurol Med Chir (Tokyo) 1999;39:372-375. 3. Lie TA. Persistent carotid-basilar carotid-vertebral anastomosis, in congenital anomalies of the carotid arteries. Amsterdam: Excerpta Medica, 1968:76-84. 4. Nii K, Aikawa H, Tsutsumi M, et al. Carotid artery stenting in a patient with internal carotid artery stenosis and ipsilateral persistent primitive hypoglossal artery presenting with transient ischemia of the vertebrobasilar system: case report. Neurol Med Chir (Tokyo) 2010;50:921-924. 5. Kanazawa R, Ishihara S, Okawara M, et al. Successful treatment with carotid arterial stenting for symptomatic internal carotid artery severe stenosis with ipsilateral persistent primitive hypoglossal artery: case report and review of the literature. Minim Invasive Neurosurg 2008;51:298-302. 6. Silva CF, Hou SY, Kühn AL, et al. Double embolic protection during carotid artery stenting with persistent hypoglossal artery. J Neurointerv Surg 2014;6:e23. 7. Zhang L, Song G, Chen L, et al. Concomitant asymptomatic internal carotid artery and persistent primitive hypoglossal artery stenosis treated by endovascular stenting with proximal embolic protection. J Vasc Surg 2016;63:237-240. 8. Parodi JC, Ferreira LM, Sicard G, et al. Cerebral protection during carotid stenting using flow reversal. J Vasc Surg 2005;41:416-422. 9. Thayer WP, Gaughen JR, Harthun NL. Surgical revascularization in the presence of a preserved primitive carotid-basilar communication. J Vasc Surg 2005;41:10661069.