British Journal of Neurosurgery, August 2014; 28(4): 539–540 © 2014 The Neurosurgical Foundation ISSN: 0268-8697 print / ISSN 1360-046X online DOI: 10.3109/02688697.2013.865707
SHORT REPORT
The graft kinking of high-flow bypass for internal carotid artery aneurysm due to elongated styloid process: A case report Makoto Katsuno1, Rokuya Tanikawa2, Naoto Izumi1 & Masaaki Hashimoto1 1Department of Neurosurgery, Abashiri Neurosurgical and Rehabilitation Hospital, Abashiri, Hokkaido, Japan, and 2Department of Neurosurgery, Teishinkai Hospital, Sapporo, Hokkaido, Japan
high-flow graft. Right after the operation, three-dimensional computed tomographic angiography (Fig. 1A) and magnetic resonance (MR) angiography (Fig. 1B) demonstrated the disappearance of the aneurysm and good patency of the superficial temporal artery to middle cerebral artery bypass and high-flow bypass, but a segment of the graft was kinked due to an Elongated styloid process (ESP) that length was 35 mm (Fig. 2A). The kinked graft was found to be occluded and the left middle cerebral artery (MCA) tended to disappear due to low perfusion pressure at the follow-up MR angiography (Fig. 1C); besides, the patient showed gradual increase of spatial disorientation and slight right hemiparesis after the operation. We speculated her condition was due to low perfusion pressure in the left MCA territory. A new graft route by the new saphenous vein graft that passed lateral to the styloid process was immediately created (Fig. 2B). Intraoperatively, the thrombus was filled at the kinking graft but did not exist at both edges of anastomotic sites. Postoperatively, her condition promptly improved without causing a cerebral infarction.
Abstract Elongated styloid process is an often-caused symptom due to the compression of neighboring structures. We present a case of a graft kink of high-flow bypass due to an elongated styloid process and describe the technical pitfalls encountered when creating a graft route from the standpoint of the anatomical site. Keywords: aneurysm; elongated styloid process; high flow bypass
Case report The patient was a 76-year-old woman who suffered leftside blindness due to a large left ICA-ophthalmic unclippable aneurysm. We trapped the ICA between its cervical segment and immediately after the bifurcation of the ophthalmic artery with the combined low- and high-flow bypass at the preauricular infratemporal fossa. During the operation, we did not detect abnormal responses of motor evoked potentials nor abnormal Doppler sounds in the
Fig. 1. The postoperative three-dimensional computed tomography angiography (3DCTA) (A) and magnetic resonance (MR) angiography (B) showed the disappearance of the aneurysm and good patency of the high-flow bypass (white arrowhead). The follow-up MR angiography (C) demonstrated graft occlusion and disappearance of left middle cerebral artery due to low perfusion pressure.
Correspondence: Makoto Katsuno, Department of Neurosurgery, Abashiri Neurosurgical and Rehabilitation Hospital, 4-1-7, Katsuramachi, Abashiri, Hokkaido 093-0041, Japan. Tel: ⫹ 81-152-45-1311. Fax: ⫹ 81-152-44-5503. E-mail: [email protected] Received for publication 7 August 2013; accepted 10 November 2013
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Fig. 2. The 3DCTA of the postoperative (A) and post-reoperative (B) are shown. The graft (black arrow) is kinked due to the elongated styloid process. The new graft (black arrowhead) is improved the kink by created the new graft route that passed lateral to the styloid process.
Discussion ESP is an anatomical variant that has been described as the cause of Eagle syndrome. Symptoms most commonly manifest as pain in the face due to compression of neighboring structures. Therefore, it is necessary to carefully create the graft route for a high-flow bypass around the styloid process in the case of ESP. To perform a high-flow bypass safely and successfully for parent vessel occlusion in patients with complex ICA aneurysms, it is imperative to assess and prevent perioperatively the graft problems that might cause severe ischemic complications. Therefore, the high-flow grafting technique requires certain manipulation to avoid a graft kink. Of the three conventional graft routes,1–3 we used the preauricular infratemporal fossa as the graft route to prevent graft kinking because this route is more natural from the anatomical viewpoint than the pre-2 or postauricular subcutaneous3 routes. Nevertheless, it is necessary to create the graft route with extreme care because the process is blind and involves blunt dissection. Accordingly, every possible effort must be made to confirm the anatomical structures to reduce the blind range. First, we confirmed the gaps between the temporal muscle and the lateral pterygoid muscle at the cranial end and between the posterior belly of the digastric muscle and the hypoglossal nerve at the cervical end. Second, the surgeon inserted a finger from the gap at the cervical end and moved the finger toward the medial part of the stylohyoid muscle after palpating the tip of the styloid process. Third, the surgeon directed his/her finger toward the gap between the stylohyoid muscle and the styloglossus muscle to confirm the position of the tip of the forceps that was inserted from the gap at the cranial end. Fourth, we passed a thoracostomy tube guided by the finger and pulled it up toward the cranial end using the forceps. Thus a graft route that passed between the stylohyoid muscle and the
styloglossus muscle, the same as the natural course of the external carotid artery, was established by the thoracostomy tube. Finally, the surgeon inserted the graft into the tube from cranial to cervical end and removed the tube. In patients with an EPS, the graft route must be changed because the gap between the stylohyoid muscle and the styloglossus muscle is too narrow. The graft route has to pass lateral to the stylohyoid muscle after the styloid process is fractured toward the medial line when the styloid process is too long, as in our patient. However, it is also possible to perform the bypass under intraoperative angiography or by alterating other graft routes such as subcutaneous routes2,3 to reduce the incidence of perioperative graft troubles. To our knowledge, this is the first report about the relationship between the structure around styloid process and the manufacturing process of high-flow graft. In conclusion, this case suggests that an evaluation of the styloid process length before the operation and modification of the graft route during the surgery are necessary to achieve a high-flow bypass with low surgical morbidity. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Houkin K, Kamiyama H, Kuroda S, et al. Long-term patency of radial artery graft bypass for reconstruction of the internal carotid artery. J Neurosurg 1999;90:786–90. 2. Quiñones-Hinojosa A , Du R, Lawton MT. Revascularization with saphenous vein bypasses for complex intracranial aneurysms. Skull Base 2005;15:119–32. 3. Sekher LN, Bucur SD, Bank WO, Wright DC. Vernous and arterial bypass grafts for difficult tumors, aneurysms, and occlusive vascular lesions: evolution of surgical treatment and improved graft results. Neurosurgery 1999;44:1207–24.
Copyright of British Journal of Neurosurgery is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
SHORT REPORT
The graft kinking of high-flow bypass for internal carotid artery aneurysm due to elongated styloid process: A case report Makoto Katsuno1, Rokuya Tanikawa2, Naoto Izumi1 & Masaaki Hashimoto1 1Department of Neurosurgery, Abashiri Neurosurgical and Rehabilitation Hospital, Abashiri, Hokkaido, Japan, and 2Department of Neurosurgery, Teishinkai Hospital, Sapporo, Hokkaido, Japan
high-flow graft. Right after the operation, three-dimensional computed tomographic angiography (Fig. 1A) and magnetic resonance (MR) angiography (Fig. 1B) demonstrated the disappearance of the aneurysm and good patency of the superficial temporal artery to middle cerebral artery bypass and high-flow bypass, but a segment of the graft was kinked due to an Elongated styloid process (ESP) that length was 35 mm (Fig. 2A). The kinked graft was found to be occluded and the left middle cerebral artery (MCA) tended to disappear due to low perfusion pressure at the follow-up MR angiography (Fig. 1C); besides, the patient showed gradual increase of spatial disorientation and slight right hemiparesis after the operation. We speculated her condition was due to low perfusion pressure in the left MCA territory. A new graft route by the new saphenous vein graft that passed lateral to the styloid process was immediately created (Fig. 2B). Intraoperatively, the thrombus was filled at the kinking graft but did not exist at both edges of anastomotic sites. Postoperatively, her condition promptly improved without causing a cerebral infarction.
Abstract Elongated styloid process is an often-caused symptom due to the compression of neighboring structures. We present a case of a graft kink of high-flow bypass due to an elongated styloid process and describe the technical pitfalls encountered when creating a graft route from the standpoint of the anatomical site. Keywords: aneurysm; elongated styloid process; high flow bypass
Case report The patient was a 76-year-old woman who suffered leftside blindness due to a large left ICA-ophthalmic unclippable aneurysm. We trapped the ICA between its cervical segment and immediately after the bifurcation of the ophthalmic artery with the combined low- and high-flow bypass at the preauricular infratemporal fossa. During the operation, we did not detect abnormal responses of motor evoked potentials nor abnormal Doppler sounds in the
Fig. 1. The postoperative three-dimensional computed tomography angiography (3DCTA) (A) and magnetic resonance (MR) angiography (B) showed the disappearance of the aneurysm and good patency of the high-flow bypass (white arrowhead). The follow-up MR angiography (C) demonstrated graft occlusion and disappearance of left middle cerebral artery due to low perfusion pressure.
Correspondence: Makoto Katsuno, Department of Neurosurgery, Abashiri Neurosurgical and Rehabilitation Hospital, 4-1-7, Katsuramachi, Abashiri, Hokkaido 093-0041, Japan. Tel: ⫹ 81-152-45-1311. Fax: ⫹ 81-152-44-5503. E-mail: [email protected] Received for publication 7 August 2013; accepted 10 November 2013
539
540
M. Katsuno et al.
Fig. 2. The 3DCTA of the postoperative (A) and post-reoperative (B) are shown. The graft (black arrow) is kinked due to the elongated styloid process. The new graft (black arrowhead) is improved the kink by created the new graft route that passed lateral to the styloid process.
Discussion ESP is an anatomical variant that has been described as the cause of Eagle syndrome. Symptoms most commonly manifest as pain in the face due to compression of neighboring structures. Therefore, it is necessary to carefully create the graft route for a high-flow bypass around the styloid process in the case of ESP. To perform a high-flow bypass safely and successfully for parent vessel occlusion in patients with complex ICA aneurysms, it is imperative to assess and prevent perioperatively the graft problems that might cause severe ischemic complications. Therefore, the high-flow grafting technique requires certain manipulation to avoid a graft kink. Of the three conventional graft routes,1–3 we used the preauricular infratemporal fossa as the graft route to prevent graft kinking because this route is more natural from the anatomical viewpoint than the pre-2 or postauricular subcutaneous3 routes. Nevertheless, it is necessary to create the graft route with extreme care because the process is blind and involves blunt dissection. Accordingly, every possible effort must be made to confirm the anatomical structures to reduce the blind range. First, we confirmed the gaps between the temporal muscle and the lateral pterygoid muscle at the cranial end and between the posterior belly of the digastric muscle and the hypoglossal nerve at the cervical end. Second, the surgeon inserted a finger from the gap at the cervical end and moved the finger toward the medial part of the stylohyoid muscle after palpating the tip of the styloid process. Third, the surgeon directed his/her finger toward the gap between the stylohyoid muscle and the styloglossus muscle to confirm the position of the tip of the forceps that was inserted from the gap at the cranial end. Fourth, we passed a thoracostomy tube guided by the finger and pulled it up toward the cranial end using the forceps. Thus a graft route that passed between the stylohyoid muscle and the
styloglossus muscle, the same as the natural course of the external carotid artery, was established by the thoracostomy tube. Finally, the surgeon inserted the graft into the tube from cranial to cervical end and removed the tube. In patients with an EPS, the graft route must be changed because the gap between the stylohyoid muscle and the styloglossus muscle is too narrow. The graft route has to pass lateral to the stylohyoid muscle after the styloid process is fractured toward the medial line when the styloid process is too long, as in our patient. However, it is also possible to perform the bypass under intraoperative angiography or by alterating other graft routes such as subcutaneous routes2,3 to reduce the incidence of perioperative graft troubles. To our knowledge, this is the first report about the relationship between the structure around styloid process and the manufacturing process of high-flow graft. In conclusion, this case suggests that an evaluation of the styloid process length before the operation and modification of the graft route during the surgery are necessary to achieve a high-flow bypass with low surgical morbidity. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Houkin K, Kamiyama H, Kuroda S, et al. Long-term patency of radial artery graft bypass for reconstruction of the internal carotid artery. J Neurosurg 1999;90:786–90. 2. Quiñones-Hinojosa A , Du R, Lawton MT. Revascularization with saphenous vein bypasses for complex intracranial aneurysms. Skull Base 2005;15:119–32. 3. Sekher LN, Bucur SD, Bank WO, Wright DC. Vernous and arterial bypass grafts for difficult tumors, aneurysms, and occlusive vascular lesions: evolution of surgical treatment and improved graft results. Neurosurgery 1999;44:1207–24.
Copyright of British Journal of Neurosurgery is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
