INTERVENTIONAL NEURORADIOLOGY
VOLUME 21 - No. 2 APRIL 2015 ISSN 1591-0199 Online ISSN 2385-2011
neuroradiology solutions www.abmedica.it
Volume 21, No. 2, Pages 141 - 284, 2015
ab medica s.p.a.
Via nerviano, 31 - 20020 Lainate (MI) tel +39 02 933051 - fax +39 02 93305400 [email protected]
Journal of Peritherapeutic Neuroradiology, Surgical Procedures and Related Neurosciences Official Journal of: WFITN - World Federation of Interventional and Therapeutic Neuroradiology AAFITN - Asian & Australasian Federation of Interventional & Therapeutic Neuroradiology SAWITN - South American Working Group in Interventional and Therapeutic Neuroradiology The Chinese INR Coordinating Committee of the Chinese Doctor Association INSHCM - Interventional Neuroradiology Society of HCM City, Viet Nam Journal sponsored by JSNET - Japanese Society of Neuro Endovascular Therapy FIO - Italian Federation of Ozone Therapy Interventional Neuroradiology is published in cooperation with the American Journal of Neuroradiology
Original Article
Transforaminal approach for cerebral dural arteriovenous fistula embolization
Interventional Neuroradiology 2015, Vol. 21(2) 240–243 ! The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1591019915581961 ine.sagepub.com
Ramsey Ashour, Sachin Pandey and Mohammad Ali Aziz-Sultan
Abstract A transverse sinus dural arteriovenous fistula (DAVF) not easily accessible by standard transfemoral (transarterial or transvenous) endovascular approaches is presented. An enlarged transosseous retromastoid foramen harboring the occipital artery branch feeding the lesion was identified on CT angiogram (CTA). Curative Onyx embolization was achieved via percutaneous CT-guided direct puncture of the transosseous occipital arterial branch followed by microcatheter navigation through the needle distally towards the site of the fistula.
Keywords Dural arteriovenous fistula, Onyx embolization, CT imaging
Introduction Recent improvements in catheter design, novel liquid embolic agents, and enhanced imaging capabilities have combined to allow most cerebral dural arteriovenous fistulas (DAVFs) to be effectively treated by endovascular means. Endovascular accessibility is a primary determinant of successful DAVF treatment and may be limited by arterial feeder tortuosity, unfavorable local venous anatomy, venous sinus occlusion, and lesion location/morphology, among other factors. We present a case of a transverse sinus DAVF not easily accessible by standard transfemoral endovascular approaches in which curative Onyx embolization was achieved via percutaneous CT-guided puncture of a transosseous occipital arterial branch.
Case report A middle-aged normotensive patient with a history of alcoholism-related coagulopathy presented with a non-traumatic acute headache, aphasia, and right hemiparesis. Brain CT showed a large left temporal hemorrhage. CT angiogram did not reveal an obvious intracerebral vascular malformation. Cerebral angiography (Figure 1) demonstrated a DAVF supplied exclusively by a transosseous branch of the left occipital artery fistulizing into a parallel venous channel alongside and subsequently draining into the left transverse sinus. Given the patient’s coagulopathy and the absence of cortical venous drainage, the fistula was considered incidental. Nevertheless, given the small chance that the hemorrhage itself might have hindered visualization
of cortical venous drainage, and in light of the low risk of curative treatment, endovascular intervention was offered. We anticipated that transfemoral transarterial endovascular access to the lesion would be challenging due to significant tortuosity of the occipital artery; also, the typical middle meningeal access was not present. Furthermore, the site of arteriovenous fistulization did not appear easily accessible via a transvenous approach, which would likely have required sacrifice of the transverse sinus. Alternative options included no treatment, craniotomy for open surgical treatment of the fistula, or surgically assisted endovascular access followed by embolization. In order to avoid the risks of the open surgical approaches in a coagulopathic patient, and in anticipation of the low likelihood of success using the transfemoral transarterial or transvenous approaches, we decided to embolize the lesion percutaneously as follows: A CT biopsy grid marker was secured alongside the patient’s head on the left side. A rotational noncontrast head CT was performed on our neurointerventional image-guided system. By using the CT to make measurements in relation to the biopsy grid, the enlarged left retromastoid foramen harboring the transosseous occipital arterial feeder to the lesion was localized (Figure 2[a]) and the overlying skin was marked. Of note, although not available in our
Departments of Radiology and Neurosurgery, Harvard Medical School/ Brigham and Women’s Hospital, USA Corresponding author: Ramsey Ashour, 75 Francis Street, PBB-311 Boston, MA 02115, USA. Email: [email protected]
Ashour et al.
241
Figure 1. (a) early lateral; (b) late lateral; (c) early anteroposterior and (d) late anteroposterior left external carotid artery angiograms demonstrating DAVF fed by transosseous occipital artery branch fistulizing into a venous channel alongside and subsequently draining into the left transverse sinus.
neuroangiography suite, newer CT image-guided systems exist that allow automated selection of entry/ target points while providing real-time needle-oriented fluoroscopic views for interventional procedures. A short 21-gauge needle was used to access the transosseous occipital arterial branch with ultrasound guidance (Figure 2(b)). A follow-up roadmap microangiogram (Figure 2(c)) through the needle was performed, demonstrating accurate placement of the needle within the intended transosseous arterial branch. Intravenous extension tubing was connected to the needle, which was secured in place with adhesive strips. The intravenous tubing was connected proximally to a rotating hemostatic valve (RHV), and kept under continuous heparinized saline flush. Roadmap guidance was then used to advance a Marathon (Covidien) microcatheter through the RHV, through the intravenous tubing, and subsequently through the percutaneous access needle over a Mirage (Covidien) microwire, distally into the inferior branch of the feeding arterial pedicle (Figure 2(d)). The DAVF was successfully embolized using 2 ml of Onyx 18 (Covidien), with immediate angiography demonstrating complete obliteration of the fistula (Figure 3). The patient tolerated the procedure well and has continued to recover neurologically from the effects of the presenting intracerebral hemorrhage. Follow-up angiography at 3 months demonstrated continued complete obliteration of the fistula.
Discussion Endovascular accessibility, whether via a transarterial or a transvenous route, is a primary determinant of successful DAVF embolization. In general, the ability to achieve a curative result improves if the microcatheter can be positioned closer to the point of arteriovenous shunting, because this increases the likelihood that the injected embolic agent will reach and occlude the site of pathologic fistulization, preventing future recruitment of arterial supply or re-routing of venous drainage after embolization. In the setting of a suspected DAVF, the presence of an enlarged transosseous ‘nutrient’ foramen on CT is a known diagnostic clue;1 however, the sensitivity and specificity of this finding are not well established.2 In the setting of a known DAVF, as suggested by the current case, an enlarged transosseous foramen can be used to plan and execute treatment as well. Rivet et al.3 previously reported a case of a transverse sigmoid DAVF treated by a combination of standard transfemoral transarterial polyvinyl alcohol particle embolization followed by direct puncture of a mastoid emissary vein, through which the venous pouch of the fistula was occluded with coils. More recently, Saura et al.4 reported five cases of curative DAVF Onyx embolization by direct transforaminal puncture (three parietal, one frontal, one occipital) using a 25-gauge butterfly needle. A key difference in our case is that we used a
242
Interventional Neuroradiology 21(2)
Figure 2. (a) axial CT demonstrating the enlarged transosseous foramen (white arrow). (b) axial CT showing advance into the transosseous foramen. (c) roadmap microangiogram delineating the DAVF and point of vascular access. (d) roadmap angiogram demonstrating the microcatheter being navigated over a microwire towards the fistula.
Figure 3. (a) post-embolization skull X-ray demonstrating the Onyx cast. (b) post-embolization left external carotid angiogram demonstrating obliteration of the fistula.
21-gauge micropuncture needle, allowing passage of a microcatheter through the needle and subsequent navigation distally up to the level of the fistula itself. This is a variant of the technique described by Chapot et al.,5
who previously reported four DAVF cases in which a microcatheter was navigated through an 18-gauge needle after direct transforaminal puncture to perform curative n-butyl cyanoacrylate (NBCA) glue
Ashour et al. embolization. The use of Onyx offers the advantages of a longer injection time with less risk of microcatheter retention, the ability to perform control angiography to monitor the progress of embolization, and deeper penetration of the injected agent as compared with NBCA. During transforaminal embolization, the surrounding transosseous channel may provide increased microcatheter stability and also act as a mechanical barrier to limit reflux of the injected embolic agent. However, care must be taken not to advance the access needle too deeply in order to avoid penetration into the subdural space, which could potentially result in significant hemorrhage. On the other hand, very superficial placement of the needle may result in tenuous access that is easily lost during seemingly minor manipulation of the needle hub. In order to mitigate some of these technical difficulties, the following points are emphasized:
243 ultimately able to achieve. Furthermore, a transfemoral transvenous approach would have resulted in a more complicated procedure, requiring a second groin puncture, a second set of catheters to be advanced through the venous system, and navigation into a narrow parallel venous channel, and ultimately appeared to carry a greater risk of inadvertent reflux of embolic material into the transverse sinus. It is possible that direct puncture of the proximal extraforaminal occipital artery would have allowed a simpler procedure while achieving the same distal access. Nevertheless, a direct percutaneous transforaminal approach using CT guidance proved to be an effective curative solution, allowing us to achieve precise microcatheter access as distally as possible, in a minimally invasive fashion, and should be considered as a treatment option in selected DAVFs, as detailed in our report. Funding
1. Even when using fluoroscopic/CT localization, we recommend also using ultrasound guidance to facilitate intravascular access to the transosseous branch, preferably with a short needle. Once intravascular access is achieved, no further advancement of the needle is required. 2. Once the needle is in place, sterile gauze or towels can be rolled up and secured strategically around the needle using adhesive strips in order to support and stabilize the position of the needle. 3. By carefully connecting intravenous extension tubing to the needle, and subsequently connecting an RHV to the tubing, the microcatheter can be introduced through the RHV in a ‘familiar’ fashion, without having to attempt direct injection through the needle or direct passage of the microcatheter through the needle hub. We believe this setup is inherently more stable than direct manipulation of the needle. Furthermore, radiation exposure to the hands of the operator is lessened by increasing the distance from the patient. In our case, had we utilized a standard transfemoral transarterial approach or a smaller needle for direct puncture/embolization without a microcatheter, feeding arterial tortuosity would have precluded us from reaching the distal embolization position that we were
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest Dr Aziz-Sultan is a proctor for Covidien (Mansfield, MA), the manufacturer of the liquid embolic agent Onyx. The other authors have no conflicts of interest to disclose.
References 1. Alatakis S, Koulouris G and Stuckey S. CT-demonstrated transcalvarial channels diagnostic of dural arteriovenous fistula. Am J Neuroradiol 2005; 26: 2393–2396. 2. Narvid J, Do HM, Blevins NH, et al. CT angiography as a screening tool for dural arteriovenous fistula in patients with pulsatile tinnitus: Feasibility and test characteristics. Am J Neuroradiol 2011; 32: 446–453. 3. Rivet DJ, Goddard JK 3rd, Rich KM, et al. Percutaneous transvenous embolization of a dural arteriovenous fistula through a mastoid emissary vein. Technical note. J Neurosurg 2006; 105: 636–639. 4. Saura P, Saura J, Perez-Higueras A, et al. Direct transforaminal Onyx embolization of intracranial dural arteriovenous fistulas: Technical note and report of five cases. J Neurointerv Surg 2014; 6: 500–504. 5. Chapot R, Saint-Maurice JP, Narata AP, et al. Transcranial puncture through the parietal and mastoid foramina for the treatment of dural fistulas. Report of four cases. J Neurosurg 2007; 106: 912–915.
Copyright of Interventional Neuroradiology is the property of Centauro srl 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.
VOLUME 21 - No. 2 APRIL 2015 ISSN 1591-0199 Online ISSN 2385-2011
neuroradiology solutions www.abmedica.it
Volume 21, No. 2, Pages 141 - 284, 2015
ab medica s.p.a.
Via nerviano, 31 - 20020 Lainate (MI) tel +39 02 933051 - fax +39 02 93305400 [email protected]
Journal of Peritherapeutic Neuroradiology, Surgical Procedures and Related Neurosciences Official Journal of: WFITN - World Federation of Interventional and Therapeutic Neuroradiology AAFITN - Asian & Australasian Federation of Interventional & Therapeutic Neuroradiology SAWITN - South American Working Group in Interventional and Therapeutic Neuroradiology The Chinese INR Coordinating Committee of the Chinese Doctor Association INSHCM - Interventional Neuroradiology Society of HCM City, Viet Nam Journal sponsored by JSNET - Japanese Society of Neuro Endovascular Therapy FIO - Italian Federation of Ozone Therapy Interventional Neuroradiology is published in cooperation with the American Journal of Neuroradiology
Original Article
Transforaminal approach for cerebral dural arteriovenous fistula embolization
Interventional Neuroradiology 2015, Vol. 21(2) 240–243 ! The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1591019915581961 ine.sagepub.com
Ramsey Ashour, Sachin Pandey and Mohammad Ali Aziz-Sultan
Abstract A transverse sinus dural arteriovenous fistula (DAVF) not easily accessible by standard transfemoral (transarterial or transvenous) endovascular approaches is presented. An enlarged transosseous retromastoid foramen harboring the occipital artery branch feeding the lesion was identified on CT angiogram (CTA). Curative Onyx embolization was achieved via percutaneous CT-guided direct puncture of the transosseous occipital arterial branch followed by microcatheter navigation through the needle distally towards the site of the fistula.
Keywords Dural arteriovenous fistula, Onyx embolization, CT imaging
Introduction Recent improvements in catheter design, novel liquid embolic agents, and enhanced imaging capabilities have combined to allow most cerebral dural arteriovenous fistulas (DAVFs) to be effectively treated by endovascular means. Endovascular accessibility is a primary determinant of successful DAVF treatment and may be limited by arterial feeder tortuosity, unfavorable local venous anatomy, venous sinus occlusion, and lesion location/morphology, among other factors. We present a case of a transverse sinus DAVF not easily accessible by standard transfemoral endovascular approaches in which curative Onyx embolization was achieved via percutaneous CT-guided puncture of a transosseous occipital arterial branch.
Case report A middle-aged normotensive patient with a history of alcoholism-related coagulopathy presented with a non-traumatic acute headache, aphasia, and right hemiparesis. Brain CT showed a large left temporal hemorrhage. CT angiogram did not reveal an obvious intracerebral vascular malformation. Cerebral angiography (Figure 1) demonstrated a DAVF supplied exclusively by a transosseous branch of the left occipital artery fistulizing into a parallel venous channel alongside and subsequently draining into the left transverse sinus. Given the patient’s coagulopathy and the absence of cortical venous drainage, the fistula was considered incidental. Nevertheless, given the small chance that the hemorrhage itself might have hindered visualization
of cortical venous drainage, and in light of the low risk of curative treatment, endovascular intervention was offered. We anticipated that transfemoral transarterial endovascular access to the lesion would be challenging due to significant tortuosity of the occipital artery; also, the typical middle meningeal access was not present. Furthermore, the site of arteriovenous fistulization did not appear easily accessible via a transvenous approach, which would likely have required sacrifice of the transverse sinus. Alternative options included no treatment, craniotomy for open surgical treatment of the fistula, or surgically assisted endovascular access followed by embolization. In order to avoid the risks of the open surgical approaches in a coagulopathic patient, and in anticipation of the low likelihood of success using the transfemoral transarterial or transvenous approaches, we decided to embolize the lesion percutaneously as follows: A CT biopsy grid marker was secured alongside the patient’s head on the left side. A rotational noncontrast head CT was performed on our neurointerventional image-guided system. By using the CT to make measurements in relation to the biopsy grid, the enlarged left retromastoid foramen harboring the transosseous occipital arterial feeder to the lesion was localized (Figure 2[a]) and the overlying skin was marked. Of note, although not available in our
Departments of Radiology and Neurosurgery, Harvard Medical School/ Brigham and Women’s Hospital, USA Corresponding author: Ramsey Ashour, 75 Francis Street, PBB-311 Boston, MA 02115, USA. Email: [email protected]
Ashour et al.
241
Figure 1. (a) early lateral; (b) late lateral; (c) early anteroposterior and (d) late anteroposterior left external carotid artery angiograms demonstrating DAVF fed by transosseous occipital artery branch fistulizing into a venous channel alongside and subsequently draining into the left transverse sinus.
neuroangiography suite, newer CT image-guided systems exist that allow automated selection of entry/ target points while providing real-time needle-oriented fluoroscopic views for interventional procedures. A short 21-gauge needle was used to access the transosseous occipital arterial branch with ultrasound guidance (Figure 2(b)). A follow-up roadmap microangiogram (Figure 2(c)) through the needle was performed, demonstrating accurate placement of the needle within the intended transosseous arterial branch. Intravenous extension tubing was connected to the needle, which was secured in place with adhesive strips. The intravenous tubing was connected proximally to a rotating hemostatic valve (RHV), and kept under continuous heparinized saline flush. Roadmap guidance was then used to advance a Marathon (Covidien) microcatheter through the RHV, through the intravenous tubing, and subsequently through the percutaneous access needle over a Mirage (Covidien) microwire, distally into the inferior branch of the feeding arterial pedicle (Figure 2(d)). The DAVF was successfully embolized using 2 ml of Onyx 18 (Covidien), with immediate angiography demonstrating complete obliteration of the fistula (Figure 3). The patient tolerated the procedure well and has continued to recover neurologically from the effects of the presenting intracerebral hemorrhage. Follow-up angiography at 3 months demonstrated continued complete obliteration of the fistula.
Discussion Endovascular accessibility, whether via a transarterial or a transvenous route, is a primary determinant of successful DAVF embolization. In general, the ability to achieve a curative result improves if the microcatheter can be positioned closer to the point of arteriovenous shunting, because this increases the likelihood that the injected embolic agent will reach and occlude the site of pathologic fistulization, preventing future recruitment of arterial supply or re-routing of venous drainage after embolization. In the setting of a suspected DAVF, the presence of an enlarged transosseous ‘nutrient’ foramen on CT is a known diagnostic clue;1 however, the sensitivity and specificity of this finding are not well established.2 In the setting of a known DAVF, as suggested by the current case, an enlarged transosseous foramen can be used to plan and execute treatment as well. Rivet et al.3 previously reported a case of a transverse sigmoid DAVF treated by a combination of standard transfemoral transarterial polyvinyl alcohol particle embolization followed by direct puncture of a mastoid emissary vein, through which the venous pouch of the fistula was occluded with coils. More recently, Saura et al.4 reported five cases of curative DAVF Onyx embolization by direct transforaminal puncture (three parietal, one frontal, one occipital) using a 25-gauge butterfly needle. A key difference in our case is that we used a
242
Interventional Neuroradiology 21(2)
Figure 2. (a) axial CT demonstrating the enlarged transosseous foramen (white arrow). (b) axial CT showing advance into the transosseous foramen. (c) roadmap microangiogram delineating the DAVF and point of vascular access. (d) roadmap angiogram demonstrating the microcatheter being navigated over a microwire towards the fistula.
Figure 3. (a) post-embolization skull X-ray demonstrating the Onyx cast. (b) post-embolization left external carotid angiogram demonstrating obliteration of the fistula.
21-gauge micropuncture needle, allowing passage of a microcatheter through the needle and subsequent navigation distally up to the level of the fistula itself. This is a variant of the technique described by Chapot et al.,5
who previously reported four DAVF cases in which a microcatheter was navigated through an 18-gauge needle after direct transforaminal puncture to perform curative n-butyl cyanoacrylate (NBCA) glue
Ashour et al. embolization. The use of Onyx offers the advantages of a longer injection time with less risk of microcatheter retention, the ability to perform control angiography to monitor the progress of embolization, and deeper penetration of the injected agent as compared with NBCA. During transforaminal embolization, the surrounding transosseous channel may provide increased microcatheter stability and also act as a mechanical barrier to limit reflux of the injected embolic agent. However, care must be taken not to advance the access needle too deeply in order to avoid penetration into the subdural space, which could potentially result in significant hemorrhage. On the other hand, very superficial placement of the needle may result in tenuous access that is easily lost during seemingly minor manipulation of the needle hub. In order to mitigate some of these technical difficulties, the following points are emphasized:
243 ultimately able to achieve. Furthermore, a transfemoral transvenous approach would have resulted in a more complicated procedure, requiring a second groin puncture, a second set of catheters to be advanced through the venous system, and navigation into a narrow parallel venous channel, and ultimately appeared to carry a greater risk of inadvertent reflux of embolic material into the transverse sinus. It is possible that direct puncture of the proximal extraforaminal occipital artery would have allowed a simpler procedure while achieving the same distal access. Nevertheless, a direct percutaneous transforaminal approach using CT guidance proved to be an effective curative solution, allowing us to achieve precise microcatheter access as distally as possible, in a minimally invasive fashion, and should be considered as a treatment option in selected DAVFs, as detailed in our report. Funding
1. Even when using fluoroscopic/CT localization, we recommend also using ultrasound guidance to facilitate intravascular access to the transosseous branch, preferably with a short needle. Once intravascular access is achieved, no further advancement of the needle is required. 2. Once the needle is in place, sterile gauze or towels can be rolled up and secured strategically around the needle using adhesive strips in order to support and stabilize the position of the needle. 3. By carefully connecting intravenous extension tubing to the needle, and subsequently connecting an RHV to the tubing, the microcatheter can be introduced through the RHV in a ‘familiar’ fashion, without having to attempt direct injection through the needle or direct passage of the microcatheter through the needle hub. We believe this setup is inherently more stable than direct manipulation of the needle. Furthermore, radiation exposure to the hands of the operator is lessened by increasing the distance from the patient. In our case, had we utilized a standard transfemoral transarterial approach or a smaller needle for direct puncture/embolization without a microcatheter, feeding arterial tortuosity would have precluded us from reaching the distal embolization position that we were
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest Dr Aziz-Sultan is a proctor for Covidien (Mansfield, MA), the manufacturer of the liquid embolic agent Onyx. The other authors have no conflicts of interest to disclose.
References 1. Alatakis S, Koulouris G and Stuckey S. CT-demonstrated transcalvarial channels diagnostic of dural arteriovenous fistula. Am J Neuroradiol 2005; 26: 2393–2396. 2. Narvid J, Do HM, Blevins NH, et al. CT angiography as a screening tool for dural arteriovenous fistula in patients with pulsatile tinnitus: Feasibility and test characteristics. Am J Neuroradiol 2011; 32: 446–453. 3. Rivet DJ, Goddard JK 3rd, Rich KM, et al. Percutaneous transvenous embolization of a dural arteriovenous fistula through a mastoid emissary vein. Technical note. J Neurosurg 2006; 105: 636–639. 4. Saura P, Saura J, Perez-Higueras A, et al. Direct transforaminal Onyx embolization of intracranial dural arteriovenous fistulas: Technical note and report of five cases. J Neurointerv Surg 2014; 6: 500–504. 5. Chapot R, Saint-Maurice JP, Narata AP, et al. Transcranial puncture through the parietal and mastoid foramina for the treatment of dural fistulas. Report of four cases. J Neurosurg 2007; 106: 912–915.
Copyright of Interventional Neuroradiology is the property of Centauro srl 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.
