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Bilateral suboccipital approach for a giant vertebral artery aneurysm
Journal of Clinical Neuroscience xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Technical note
Bilateral suboccipital approach for a giant vertebral artery aneurysm Yasuo Murai ⇑, Toshimasa Yamada, Eitaro Ishisaka, Shun Sato, Fumihiro Matano, Akio Morita Department of Neurological Surgery, Nippon Medical School, Tokyo, Japan
a r t i c l e
i n f o
Article history: Received 14 May 2017 Accepted 10 August 2017 Available online xxxx Keywords: Cerebral aneurysm Complication Suboccipital approach Vertebral artery
a b s t r a c t Giant thrombosed aneurysms of the vertebral artery (VA) are difficult to treat. Moreover, marked tortuosity of the parent VA complicates determination of the surgical approach. We report the case of a 71year-old male patient who presented with gait disturbance. Magnetic resonance imaging revealed a giant thrombosed aneurysm of approximately 4 cm in diameter located in the ventral region and to the right of the medulla oblongata. Computed tomography angiography showed that the right VA had extreme tortuosity, and that the VA union was in contact with the left 7th and 8th cranial nerves. Given that the aneurysm was thrombosed and causing a mass effect, we sought to trap it. In this case, because of the tortuous VA, intravascular team considered intravascular therapy to be too difficult. We made a question mark-shaped skin incision and used a wide bilateral suboccipital approach. The VA proximal to the aneurysm was occluded with an aneurysm clip using an approach from the right of the brainstem, while the VA distal to the aneurysm was occluded using a lateral suboccipital approach. When the VA and basilar artery are atherosclerotic and extremely tortuous, the distal and proximal aspects of the aneurysm can exist on both sides of the midline. In difficult cases such as that reported here, in which a giant VA aneurysm exceeded the midline of the anterior surface of the medulla, we believe that it is useful to employ a bilateral approach from both sides of the brainstem. Ó 2017 Elsevier Ltd. All rights reserved.
1. Introduction Vertebral artery (VA) aneurysms are mainly treated using a lateral suboccipital approach [1]. In cases of markedly tortuous aneurysms due to arteriosclerosis of the VA, surgical occlusion of the distal end of the aneurysm is difficult, and an endovascular approach also is challenging [2]. We treated a patient with a giant thrombosed aneurysm of the right VA, in which the course from the VA was extremely tortuous, and the distal end of the aneurysm were on the contralateral side. We used a bilateral suboccipital approach in order to trap the aneurysm proximally from the right side of the medulla and distally from the left side of the medulla. Here, we describe this case and present the bilateral suboccipital approach.
2. Case presentation The patient was a 71-year-old man who developed a gait disturbance 2 months before. He had a history of hypertension and hyperlipidemia. A giant thrombosed vertebral aneurysm, approxi⇑ Corresponding author at: Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-86, Japan. E-mail address: [email protected] (Y. Murai).
mately 4.2 cm in diameter, was observed (Fig. 1) on magnetic resonanse imaging (MRI). On digital subtraction angiography, the vertebral and basilar arteries were tortuous toward the midline (Fig. 2). However, the right anterior spinal artery bifurcation was unclear. The aneurysm was located distal to the right side of the medulla, crossed the midline, and was present on the left side, while the basilar artery was medial to the 7th and 8th cranial nerves. The right PICA bifurcated from the basilar artery. The right VA balloon occlusion test was conducted and neurologic findings were observed for 30 min, but no changes were noted. In this case, because of the tortuous VA, intravascular team considered intravascular therapy to be too difficult. In order to effectively reduce compression, we found it absolutely essential to trap the aneurysm. However, when using an approach from one side, it is difficult to trap the aneurysm. Therefore, we decided to use an approach from both sides of the posterior fossa. After distal clipping, if abnormal signs appeared in motor evoked potential (MEP) or auditory brainstem response, we intended to perform proximal clipping only. The patient was placed in the prone position (Video and Fig. 3). The surgeon was positioned on the patient’s right side. In order to perform a C1 laminectomy and extensive bone removal in the posterior fossa, a question mark-shaped skin incision was made, extending bilaterally from the height of C2, with the superior pole
http://dx.doi.org/10.1016/j.jocn.2017.08.019 0967-5868/Ó 2017 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019
2
Y. Murai et al. / Journal of Clinical Neuroscience xxx (2017) xxx–xxx
Fig. 2. Angiographic image of the right vertebral artery (VA), showing a giant thrombosed aneurysm and tourtuous right VA. Fig. 1. Noncontrast-enhanced T1-weighted magnetic resonance image, showing a giant thrombosed aneurysm located on the ventral medulla.
at the superior nuchal line. The occipital muscles were separated from the skin flap on the right side and midline, moving toward the right side, in order to preserve blood flow of the skin flap. In addition, the lateral skin flap and muscle layers on the left side were removed en bloc. At the height of the superior nuchal line, a T-shaped incision was made, and the muscle layers were dissected bilaterally.
Fig. 3. Schematic drawing of intraoperative findings using a bilateral suboccipital approach.
Video. This short video was made to introduce the technique of the bilateral suboccipital approach for trapping a vertebral artery aneurysm.
After the bilateral occipital bone removal, a C1 laminectomy was performed. After a Y-shaped incision was made in the dura, the proximal VA was confirmed between the right cerebellar tonsil and medulla. There was no change in MEP amplitude after proxi-
mal occlusion with Yasargil FT 740T clip. Next, we rotated the surgical bed by 15° and moved the patient so that his left side was facing upwards. Then, the cerebellum was retracted, and the VA union was confirmed medial to the 7th and 8th cranial nerves. The distal end of the aneurysm in the right VA was occluded with a Yasargil FT 750 T clip. There was no change in MEP amplitude after this subsequent occlusion. CT showed a small high-density area within the aneurysm, which was thought to be due to thrombosis. Fiv days after surgery, left hemiplegia was noted, which was probably due to mild dehydration after surgery associated with heart failure. The following day, diffusion-weighted MRI showed a small cerebral infarction in the medulla (Fig. 4), and the patient was transferred to another hospital for rehabilitation. His hemiparesis, although improved, remained at 12 months after rehabilitation.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019
Y. Murai et al. / Journal of Clinical Neuroscience xxx (2017) xxx–xxx
Fig. 4. Postoperative diffusion-weighted image on day 5, showing a high-intensity area in the medulla.
3. Discussion We were able to trap a highly tortuous giant VA aneurysm from both sides of the brainstem without cranial nerve injury or cerebeller contusion. We believe this is a valuable option when treating difficult lesions such as this. During surgical treatment of cerebral aneurysms, it is important to preserve the proximal and distal ends of the parent artery [2]. When an aneurysm is found in the VA, and the distal end is located anterior to the brainstem due to tortuosity, retraction of the brainstem or movement of the cranial nerves is required, which carries a substantial risk of injury [2]. Various approaches, including endovascular surgery, have been investigated for complex VA aneurysms [2,3]. In this case, because symptoms of brainstem compression already had appeared, there was risk for traction of the aneurysm and the surrounding brain tissue. According to several reports, when one end of the aneurysm is located on the contralateral side, exceeding the midline, a contralateral approach can enable successful clipping [2]. We believe, however, that a contralateral suboccipital approach is effective only when the aneurysm is relatively small. We decided to use the method described here because both the proximal and distal ends of the aneurysm could be reached using a normal lateral suboccipital approach. In the actual surgical field, the proximal and distal ends were visualized easily without lower cranial nerve injury. However, in each case, the locations of the proximal and distal necks are different, and the appropriate craniotomy range must be considered; MRI using fast imaging employing steadystate acquisition seems to be useful for that. Because craniotomy on both sides was the first experience, we performed an extensive craniotomy, considering the possibility of decompression of the cerebellum. However, in actuality, because the distal neck was on the medial side of the 7th and 8th cranial nerves, and the proximal neck was on the left side of the medulla in the cisterna magna, we could have completed the trapping by craniotomy using bilateral ordinary LSA. A midline skin incision and midline suboccipital approach can be used. However, this surgical approach is used for medial cerebellar or brainstem lesions [1,2]. Moreover, the microscopic surgical field narrows when viewing the vertebral artery in front of the
3
brainstem from the lateral side. To solve this problem, we evaluated a surgical approach where a midline incision is expanded into a T shape above the superior nuchal line. However, we did not use this approach because of an extremely wide towing of the skin flap on both lateral sides, considering the risk of blood flow failure into the middle region where the three flap positions intersected. In contrast, our method of choice provided a sufficient lateral and caudal surgical field of view without blood flow failure into the flap. We did not perform a thrombectomy to decrease the mass effect after aneurysm trapping. Parent vessel occlusion with or without bypass surgery is considered to be effective for cranial nerve palsy and other compression symptoms due to a large cavernous internal carotid artery aneurysm [4,5]. In addition, even after coiling, internal carotid artery and posterior communicating artery aneurysms will relieve third nerve palsy [6]. In the present case, endovascular treatment has to be abandoned due to atherosclerotic tortuous parent VA. Despite the remarkable progress of devices for endovascular surgery, in cases of giant thrombosed aneurysms in the vertebrobasilar system, satisfactory results have not been obtained, even with methods that concomitantly use a stent [7]. In other words, ischemic complications and worsening of compressive symptoms have been reported after endovascular surgery [3,7]. Flow diversion has potential as a future alternative, but high rates of hemorrhagic complications have been reported [7]. In addition, based on previous reports, we believe it is necessary to trap and occlude the parent artery from outside the vessel for the following reasons [4]. First, there may be residual blood flow into the aneurysm or vasa vasorum if the parent artery is incompletely embolized. Second, growth of the aneurysm, which may be associated with the vasa vasorum, occasionally occurs. Thus, if the procedure is definitely safe, aneurysmectomy may be a recommendable therapeutic option, particularly when the mass effect is severe [3]. In conclusion, in the present case, we used the method described here because we determined with certainty that it was possible to trap the aneurysm. However, we should have considered prescribing an antiplatelet drug before surgery as well as adequate hydration after surgery in order to prevent ischemic changes to perforators from the VA leading to the brain stem. Conflicts of interest statement The content of this manuscript in full has not been published elsewhere in any form. I, (Yasuo Murai), certify that this manuscript is a unique submission and is not being considered for publication with any other source in any medium. All authors have read the manuscript and have approved this submission. Financial support for this study was not provided. The authors report no conflicts of interest. Additional informed consent was obtained from all individual participants for whom identifying information is included in this article. References [1] Sundt Thoralf M. In: Surgical techniques for saccular and giant intracranial aneurysms. Williams & Wilkin; 1990. p. 213–346. [2] Bragg TM, Duckworth EA. Contralateral far-lateral approach for clipping of a ruptured vertebral artery-posterior inferior cerebellar artery aneurysm. Neurosurg Focus 2008;25(6):E9. [3] Siddiqui Adnan H, Abla Adib A, Kan Peter, Dumont Travis M, Jahshan Shady, Britz Gavin W, et al. Panacea or problem: flow diverters in the treatment of symptomatic large or giant fusiform vertebrobasilar aneurysms. J Neurosurg 2012;116:1258–66. [4] Iihara K, Murao K, Sakai N, Soeda A, Ishibashi-Ueda H, Yutani C, et al. Continued growth of and increased symptoms from a thrombosed giant aneurysm of the vertebral artery after complete endovascular occlusion and trapping: the role of vasa vasorum. Case Rep J Neurosurg 2003;98:407–13.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019
4
Y. Murai et al. / Journal of Clinical Neuroscience xxx (2017) xxx–xxx
[5] Matano F, Murai Y, Mizunari T, Tamaki T, Tateyama K, Koketsu K, et al. Recovery of visual and ophthalmologic symptoms after treating large or giant internal carotid artery aneurysm by high-flow bypass with cervical ligation. World Neurosurg 2016. http://dx.doi.org/10.1016/j.wneu.2016.10.082 [Epub ahead of print]. [6] van Rooij WJ, Sluzewski M. Unruptured large and giant carotid artery aneurysms presenting with cranial nerve palsy: comparison of clinical
recovery after selective aneurysm coiling and therapeutic carotid artery occlusion. AJNR Am J Neuroradiol 2008;29:997–1002. [7] Rouchaud A, Brinjikji W, Lanzino G, Cloft HJ, Kadirvel R, Kallmes DF. Delayed hemorrhagic complications after flow diversion for intracranial aneurysms: a literature overview. Neuroradiology 2016;58:171–7.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Technical note
Bilateral suboccipital approach for a giant vertebral artery aneurysm Yasuo Murai ⇑, Toshimasa Yamada, Eitaro Ishisaka, Shun Sato, Fumihiro Matano, Akio Morita Department of Neurological Surgery, Nippon Medical School, Tokyo, Japan
a r t i c l e
i n f o
Article history: Received 14 May 2017 Accepted 10 August 2017 Available online xxxx Keywords: Cerebral aneurysm Complication Suboccipital approach Vertebral artery
a b s t r a c t Giant thrombosed aneurysms of the vertebral artery (VA) are difficult to treat. Moreover, marked tortuosity of the parent VA complicates determination of the surgical approach. We report the case of a 71year-old male patient who presented with gait disturbance. Magnetic resonance imaging revealed a giant thrombosed aneurysm of approximately 4 cm in diameter located in the ventral region and to the right of the medulla oblongata. Computed tomography angiography showed that the right VA had extreme tortuosity, and that the VA union was in contact with the left 7th and 8th cranial nerves. Given that the aneurysm was thrombosed and causing a mass effect, we sought to trap it. In this case, because of the tortuous VA, intravascular team considered intravascular therapy to be too difficult. We made a question mark-shaped skin incision and used a wide bilateral suboccipital approach. The VA proximal to the aneurysm was occluded with an aneurysm clip using an approach from the right of the brainstem, while the VA distal to the aneurysm was occluded using a lateral suboccipital approach. When the VA and basilar artery are atherosclerotic and extremely tortuous, the distal and proximal aspects of the aneurysm can exist on both sides of the midline. In difficult cases such as that reported here, in which a giant VA aneurysm exceeded the midline of the anterior surface of the medulla, we believe that it is useful to employ a bilateral approach from both sides of the brainstem. Ó 2017 Elsevier Ltd. All rights reserved.
1. Introduction Vertebral artery (VA) aneurysms are mainly treated using a lateral suboccipital approach [1]. In cases of markedly tortuous aneurysms due to arteriosclerosis of the VA, surgical occlusion of the distal end of the aneurysm is difficult, and an endovascular approach also is challenging [2]. We treated a patient with a giant thrombosed aneurysm of the right VA, in which the course from the VA was extremely tortuous, and the distal end of the aneurysm were on the contralateral side. We used a bilateral suboccipital approach in order to trap the aneurysm proximally from the right side of the medulla and distally from the left side of the medulla. Here, we describe this case and present the bilateral suboccipital approach.
2. Case presentation The patient was a 71-year-old man who developed a gait disturbance 2 months before. He had a history of hypertension and hyperlipidemia. A giant thrombosed vertebral aneurysm, approxi⇑ Corresponding author at: Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-86, Japan. E-mail address: [email protected] (Y. Murai).
mately 4.2 cm in diameter, was observed (Fig. 1) on magnetic resonanse imaging (MRI). On digital subtraction angiography, the vertebral and basilar arteries were tortuous toward the midline (Fig. 2). However, the right anterior spinal artery bifurcation was unclear. The aneurysm was located distal to the right side of the medulla, crossed the midline, and was present on the left side, while the basilar artery was medial to the 7th and 8th cranial nerves. The right PICA bifurcated from the basilar artery. The right VA balloon occlusion test was conducted and neurologic findings were observed for 30 min, but no changes were noted. In this case, because of the tortuous VA, intravascular team considered intravascular therapy to be too difficult. In order to effectively reduce compression, we found it absolutely essential to trap the aneurysm. However, when using an approach from one side, it is difficult to trap the aneurysm. Therefore, we decided to use an approach from both sides of the posterior fossa. After distal clipping, if abnormal signs appeared in motor evoked potential (MEP) or auditory brainstem response, we intended to perform proximal clipping only. The patient was placed in the prone position (Video and Fig. 3). The surgeon was positioned on the patient’s right side. In order to perform a C1 laminectomy and extensive bone removal in the posterior fossa, a question mark-shaped skin incision was made, extending bilaterally from the height of C2, with the superior pole
http://dx.doi.org/10.1016/j.jocn.2017.08.019 0967-5868/Ó 2017 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019
2
Y. Murai et al. / Journal of Clinical Neuroscience xxx (2017) xxx–xxx
Fig. 2. Angiographic image of the right vertebral artery (VA), showing a giant thrombosed aneurysm and tourtuous right VA. Fig. 1. Noncontrast-enhanced T1-weighted magnetic resonance image, showing a giant thrombosed aneurysm located on the ventral medulla.
at the superior nuchal line. The occipital muscles were separated from the skin flap on the right side and midline, moving toward the right side, in order to preserve blood flow of the skin flap. In addition, the lateral skin flap and muscle layers on the left side were removed en bloc. At the height of the superior nuchal line, a T-shaped incision was made, and the muscle layers were dissected bilaterally.
Fig. 3. Schematic drawing of intraoperative findings using a bilateral suboccipital approach.
Video. This short video was made to introduce the technique of the bilateral suboccipital approach for trapping a vertebral artery aneurysm.
After the bilateral occipital bone removal, a C1 laminectomy was performed. After a Y-shaped incision was made in the dura, the proximal VA was confirmed between the right cerebellar tonsil and medulla. There was no change in MEP amplitude after proxi-
mal occlusion with Yasargil FT 740T clip. Next, we rotated the surgical bed by 15° and moved the patient so that his left side was facing upwards. Then, the cerebellum was retracted, and the VA union was confirmed medial to the 7th and 8th cranial nerves. The distal end of the aneurysm in the right VA was occluded with a Yasargil FT 750 T clip. There was no change in MEP amplitude after this subsequent occlusion. CT showed a small high-density area within the aneurysm, which was thought to be due to thrombosis. Fiv days after surgery, left hemiplegia was noted, which was probably due to mild dehydration after surgery associated with heart failure. The following day, diffusion-weighted MRI showed a small cerebral infarction in the medulla (Fig. 4), and the patient was transferred to another hospital for rehabilitation. His hemiparesis, although improved, remained at 12 months after rehabilitation.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019
Y. Murai et al. / Journal of Clinical Neuroscience xxx (2017) xxx–xxx
Fig. 4. Postoperative diffusion-weighted image on day 5, showing a high-intensity area in the medulla.
3. Discussion We were able to trap a highly tortuous giant VA aneurysm from both sides of the brainstem without cranial nerve injury or cerebeller contusion. We believe this is a valuable option when treating difficult lesions such as this. During surgical treatment of cerebral aneurysms, it is important to preserve the proximal and distal ends of the parent artery [2]. When an aneurysm is found in the VA, and the distal end is located anterior to the brainstem due to tortuosity, retraction of the brainstem or movement of the cranial nerves is required, which carries a substantial risk of injury [2]. Various approaches, including endovascular surgery, have been investigated for complex VA aneurysms [2,3]. In this case, because symptoms of brainstem compression already had appeared, there was risk for traction of the aneurysm and the surrounding brain tissue. According to several reports, when one end of the aneurysm is located on the contralateral side, exceeding the midline, a contralateral approach can enable successful clipping [2]. We believe, however, that a contralateral suboccipital approach is effective only when the aneurysm is relatively small. We decided to use the method described here because both the proximal and distal ends of the aneurysm could be reached using a normal lateral suboccipital approach. In the actual surgical field, the proximal and distal ends were visualized easily without lower cranial nerve injury. However, in each case, the locations of the proximal and distal necks are different, and the appropriate craniotomy range must be considered; MRI using fast imaging employing steadystate acquisition seems to be useful for that. Because craniotomy on both sides was the first experience, we performed an extensive craniotomy, considering the possibility of decompression of the cerebellum. However, in actuality, because the distal neck was on the medial side of the 7th and 8th cranial nerves, and the proximal neck was on the left side of the medulla in the cisterna magna, we could have completed the trapping by craniotomy using bilateral ordinary LSA. A midline skin incision and midline suboccipital approach can be used. However, this surgical approach is used for medial cerebellar or brainstem lesions [1,2]. Moreover, the microscopic surgical field narrows when viewing the vertebral artery in front of the
3
brainstem from the lateral side. To solve this problem, we evaluated a surgical approach where a midline incision is expanded into a T shape above the superior nuchal line. However, we did not use this approach because of an extremely wide towing of the skin flap on both lateral sides, considering the risk of blood flow failure into the middle region where the three flap positions intersected. In contrast, our method of choice provided a sufficient lateral and caudal surgical field of view without blood flow failure into the flap. We did not perform a thrombectomy to decrease the mass effect after aneurysm trapping. Parent vessel occlusion with or without bypass surgery is considered to be effective for cranial nerve palsy and other compression symptoms due to a large cavernous internal carotid artery aneurysm [4,5]. In addition, even after coiling, internal carotid artery and posterior communicating artery aneurysms will relieve third nerve palsy [6]. In the present case, endovascular treatment has to be abandoned due to atherosclerotic tortuous parent VA. Despite the remarkable progress of devices for endovascular surgery, in cases of giant thrombosed aneurysms in the vertebrobasilar system, satisfactory results have not been obtained, even with methods that concomitantly use a stent [7]. In other words, ischemic complications and worsening of compressive symptoms have been reported after endovascular surgery [3,7]. Flow diversion has potential as a future alternative, but high rates of hemorrhagic complications have been reported [7]. In addition, based on previous reports, we believe it is necessary to trap and occlude the parent artery from outside the vessel for the following reasons [4]. First, there may be residual blood flow into the aneurysm or vasa vasorum if the parent artery is incompletely embolized. Second, growth of the aneurysm, which may be associated with the vasa vasorum, occasionally occurs. Thus, if the procedure is definitely safe, aneurysmectomy may be a recommendable therapeutic option, particularly when the mass effect is severe [3]. In conclusion, in the present case, we used the method described here because we determined with certainty that it was possible to trap the aneurysm. However, we should have considered prescribing an antiplatelet drug before surgery as well as adequate hydration after surgery in order to prevent ischemic changes to perforators from the VA leading to the brain stem. Conflicts of interest statement The content of this manuscript in full has not been published elsewhere in any form. I, (Yasuo Murai), certify that this manuscript is a unique submission and is not being considered for publication with any other source in any medium. All authors have read the manuscript and have approved this submission. Financial support for this study was not provided. The authors report no conflicts of interest. Additional informed consent was obtained from all individual participants for whom identifying information is included in this article. References [1] Sundt Thoralf M. In: Surgical techniques for saccular and giant intracranial aneurysms. Williams & Wilkin; 1990. p. 213–346. [2] Bragg TM, Duckworth EA. Contralateral far-lateral approach for clipping of a ruptured vertebral artery-posterior inferior cerebellar artery aneurysm. Neurosurg Focus 2008;25(6):E9. [3] Siddiqui Adnan H, Abla Adib A, Kan Peter, Dumont Travis M, Jahshan Shady, Britz Gavin W, et al. Panacea or problem: flow diverters in the treatment of symptomatic large or giant fusiform vertebrobasilar aneurysms. J Neurosurg 2012;116:1258–66. [4] Iihara K, Murao K, Sakai N, Soeda A, Ishibashi-Ueda H, Yutani C, et al. Continued growth of and increased symptoms from a thrombosed giant aneurysm of the vertebral artery after complete endovascular occlusion and trapping: the role of vasa vasorum. Case Rep J Neurosurg 2003;98:407–13.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019
4
Y. Murai et al. / Journal of Clinical Neuroscience xxx (2017) xxx–xxx
[5] Matano F, Murai Y, Mizunari T, Tamaki T, Tateyama K, Koketsu K, et al. Recovery of visual and ophthalmologic symptoms after treating large or giant internal carotid artery aneurysm by high-flow bypass with cervical ligation. World Neurosurg 2016. http://dx.doi.org/10.1016/j.wneu.2016.10.082 [Epub ahead of print]. [6] van Rooij WJ, Sluzewski M. Unruptured large and giant carotid artery aneurysms presenting with cranial nerve palsy: comparison of clinical
recovery after selective aneurysm coiling and therapeutic carotid artery occlusion. AJNR Am J Neuroradiol 2008;29:997–1002. [7] Rouchaud A, Brinjikji W, Lanzino G, Cloft HJ, Kadirvel R, Kallmes DF. Delayed hemorrhagic complications after flow diversion for intracranial aneurysms: a literature overview. Neuroradiology 2016;58:171–7.
Please cite this article in press as: Murai Y et al. Bilateral suboccipital approach for a giant vertebral artery aneurysm. J Clin Neurosci (2017), http://dx.doi. org/10.1016/j.jocn.2017.08.019