Novel Insights from Clinical Practice Pediatr Neurosurg 2014–15;50:216–219 DOI: 10.1159/000430845 Received: January 28, 2015 Accepted after revision: April 21, 2015 Published online: July 14, 2015 Endovascular Treatment of Two High-Flow Brain Arteriovenous Fistulas with a Combination of Detachable Coils and Onyx in an Infant: Case Report and Review of Literature Qihong Wang a Zhe Quan b ZhiQiang Li b a Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, and b Department of Neurosurgery, Fengxian District Central Hospital, Shanghai Jiaotong University, Shanghai, China Established Facts • Onyx has been widely adopted for the treatment of arteriovenous malformations. • BAVFs are more frequent in younger patients and frequently lead to intracranial hemorrhage. Novel Insights • Endovascular treatment of high-flow BAVFs with detachable coils and Onyx is feasible. Abstract Congenital brain arteriovenous fistulas (BAVFs) are rare neurovascular lesions of the brain, and few cases have been reported of their treatment with a combination of detachable coils and Onyx, especially in infants. Here, we present a case of 2 high-flow BAVFs occurring in a 12-month-old boy. Standard techniques of digital subtraction angiography were used, and dimethyl sulfoxide-compatible microcatheters were delivered and entered into a distal feeding artery as closely as possible to the fistulas. Then, a combination of detachable coils and Onyx was used. After the treatment of the 2 high-flow BAVFs, a complete percutaneous emboliza- © 2015 S. Karger AG, Basel 1016–2291/15/0504–0216$39.50/0 E-Mail karger@karger.com www.karger.com/pne tion of the fistulas was obtained. The fistulas remained closed, as ascertained by follow-up angiograms. No new neurological deficit related to the procedure was detected, and the infant was asymptomatic and in good health 4 years after the surgery. Our case shows that the endovascular treatment of high-flow BAVFs with a combination of detachable coils and Onyx in an infant is safe and effective. © 2015 S. Karger AG, Basel Introduction As rare neurovascular lesions of the brain, congenital brain arteriovenous fistulas (BAVFs) account for 1.6– 4.7% of all brain arteriovenous malformations [1, 2]. BAVFs are defined as an abrupt brain vascular transition Zhe Quan or ZhiQiang Li Department of Neurosurgery, Fengxian District Central Hospital 6600 Nanfeng Road, Nanqiao Town, Fengxian District Shanghai 201400 (China) E-Mail zhequanzq @ 163.com or lzq_999 @ 163.com Downloaded by: Chinese University of Hong Kong 198.143.53.33 - 1/27/2016 12:31:14 AM Key Words Embolization · Brain arteriovenous fistulas · Coil · Onyx from the arterial feeder to a draining vein, with an immediate increase in vessel caliber and absence of a plexiform nidus. This disease poses a severe treatment challenge, and few cases have been reported of their treatment with a combination of detachable coils and Onyx, especially in infants. A precise anatomic and pathophysiologic evaluation with magnetic resonance imaging and angiography should be performed prior to determining the appropriate treatment [3, 4]. As endovascular technologies are developing rapidly, endovascular treatment has become the therapy of choice for these cases. However, despite the small amount of contrast medium used in infants, due to the complexity of this disease, the detailed preoperative assessment and the high requirements for the operation on infants, the endovascular treatment of high-flow BAVFs with detachable coils and onyx in infants is extremely rare. In this report, we present the case of a 12-month-old infant with 2 separate high-flow BAVFs on angiography, who underwent treatment with a combination of detachable coils and Onyx. tained. The coils served as a template for the deposition of the Onyx (Onyx Liquid Embolic System; ev3). Then, the fistula was gradually occluded using the arterial feeder with the detachable coils and Onyx. After the procedure, low-molecular-weight heparin was medicated subcutaneously for 24 h. The mean arterial pressure was 75 mm Hg after 48 h of embolization. A control angiogram of the right internal carotid injection was then performed after 3 months of treatment. A routine cranial computed tomography revealed a high-density mass in the left frontal lobe (fig. 1a). Magnetic resonance images showed that the intracerebral varix was associated with a high-flow pial arteriovenous fistula (fig. 1b, c). A diagnostic cerebral angiography showed that the 2 high-flow arteriovenous fistulas were accompanied by a venous aneurysm, fed into the left MCA at the M2 segment, left the ACA at the A2 segment and drained into the left sigmoid sinus (fig. 1d–h). In addition, an arteriovenous fistula was exhibited through a microcatheter from the left ACA to the right ACA and by superselective angiography (fig. 1i). The fistula at the left M2 segment was embolized by using coils and Onyx-34 (fig. 1j, k). The control angiogram of the anteroposterior and lateral views after the placement of 8 coils and after a 3.5-ml Onyx-34 injection showed that the 2 fistulas were completely obliterated (fig. 1l, m). The fistulas remained closed, and no new neurological deficit was identified during a follow-up time of 12–48 months. Four years after the surgery, the infant was asymptomatic and in good health. Case Report Discussion BAVFs are composed of ≥1 abnormal artery connected to a single venous channel without any intervening nidus of capillaries or vessels [6]. The treatment of these lesions depends on the age at which they become active and interfere with postnatal brain development [7]. BAVFs are extremely rare neurovascular lesions of the brain, and few cases have been reported of their treatment with a combination of detachable coils and Onyx, especially in infants. We thus summarized, in this study, the therapeutic effect on an infant with 2 separate high-flow BAVFs using a combination of detachable coils and Onyx. After a 48-month follow-up, we found that the infant was asymptomatic and in good health. As the neurocognitive prognosis is worse with conservative management, the key treatment in cortical AVFs in young children is the rapid control of the lesion [1]. The aim of treating BAVFs is to interrupt all the feeding arter- Fig. 1. Cranial computed tomography revealed a high-density mass in the left frontal (a). T1-/T2-weighted axial magnetic resonance images demonstrated the enlarged draining veins (b, c). Diagnostic cerebral angiography showed 2 high-flow AVFs with a venous aneurysm. The lesion drained into the left sigmoid sinus via the left ACA at the A2 segment and the left MCA at the M2 segment (d–h). An arteriovenous fistula was shown through a microcatheter (i). The fistula at the left M2 segment was embolized using coils and Onyx-34 (j, k). The control angiogram of the right internal carotid showed that the 2 fistulas were completely obliterated (l, m). (For figure see next page.) Treatment of BAVFs with Coils and Onyx Pediatr Neurosurg 2014–15;50:216–219 DOI: 10.1159/000430845 217 Downloaded by: Chinese University of Hong Kong 198.143.53.33 - 1/27/2016 12:31:14 AM A 2-year-old boy presenting with seizures and macrocrania since the age of 12 months was admitted to the Huashan Hospital. No neurologic deficit was palpable at the physical examination. Auscultation failed to reveal any bruit. He had no history of trauma. No personal (or familial) sign of systemic disease or collagen disease was found. The patient underwent angiography and 2 endovascular treatments under ordinary anesthesia through a femoral approach. The standard technique of digital subtraction angiography with road mapping was used, and a diagnosis of 2 separate arteriovenous fistulas from the left anterior cerebral artery (ACA) and the left middle cerebral artery (MCA) was made. Then, the fistulas of the left ACA and left MCA were embolized in 2 procedures. Dimethyl sulfoxidecompatible microcatheters (Rebar-14, MTI, Irvine, Calif., USA), guided by a 0.014-in Transcend soft-tip EX (Boston Scientific, Natick, Mass., USA), were delivered and advanced into a distal feeding artery as closely as possible to the fistulas, as previously described [5]. After that, the guidewire was pulled out, and a biplane superselective arteriogram was performed through the microcatheter. Three detachable coils including Guglielmi detachable coils (Boston Scientific), Microples (Microvention, Aliso Viejo, Calif., USA) and NXT fiber coils (ev3, Irvine, Calif., USA) were delivered and repositioned carefully until a safe and stable position was ob- a b c d e f g h i j k 1 218 Pediatr Neurosurg 2014–15;50:216–219 DOI: 10.1159/000430845 Wang/Quan/Li Downloaded by: Chinese University of Hong Kong 198.143.53.33 - 1/27/2016 12:31:14 AM m l ies as closely as possible to the fistula, leaving the venous drainage intact [1]. Although surgery has been the traditional approach to clip the feeding pedicles, with intraand postoperative hypotension, it is technically difficult because the feeding pedicles are often found to be numerous and the fistula to be deep. Endovascular applications have been found successful in disconnecting AVFs with a number of different agents like coils [8], Onyx [9] and balloons [10]. By preventing normal perfusion pressure breakthrough in high-flow lesions, endovascular applications could be implemented in a deep or inaccessible location and may reduce the risk of postoperative bleeding. Onyx has been verified as a feasible and safe treatment in the embolization of brain arteriovenous malformations [11]. In addition, highly concentrated Onyx has been used to occlude large arteriovenous shunts or pial arteriovenous fistulas in a more controlled way [11, 12]. However, because of the risk of retained microcatheters, a simple Onyx injection is not always feasible in the treatment of brain arteriovenous malformations. For example, Onyx may migrate through the fistula into the distal draining veins in some high-flow shunts [6]. Onyx could be combined with balloons or coils to slow down the flow within the fistula and stop it from entering into the veins [13, 14]. Detachable coils are available for repositioning till a safe and stable position is reached and may thus eliminate the distal embolization. Besides, they could act as a template to deposit other embolic materials, like Onyx, by reducing the flow in the fistula and creating turbulence to accelerate the polymerization of the Onyx at the fistula site. In this study, detachable coils were used as an adjunct to Onyx embolization and were inserted at the distal feeding artery of the fistula to reduce the flow and promote the injection of Onyx, which was consistent with the study of Wang et al. [9] who studied patients with congenital BAVFs at ages from 2 to 48 years. However, a balloon could not be used in this infant because of a tortuous artery. The fistula could recur, and a new lesion might develop, hence it was important to observe this patient over a long period of time. Studies are still underway to investigate the long-term efficacy of Onyx. Glue may become recanalized, and we advocate a periodic radiological re-evaluation of the BAVFs after the embolization, like in this patient. In conclusion, high-flow BAVFs, especially 2 or more, are rare in infants and are characterized by the absence of a nidus and by their high-flow nature. Endovascular treatment of high-flow BAVFs with a combination of detachable coils and Onyx in an infant is safe and effective. Acknowledgments Our contract grant sponsor is the National Natural Science Foundation of China (contract grant number 81271304). Disclosure Statement All authors declare that they have no conflict of interests to state. 1 Weon YC, Yoshida Y, Sachet M, Mahadevan J, Alvarez H, Rodesch G, Lasjaunias P: Supratentorial cerebral arteriovenous fistulas (AVFs) in children: review of 41 cases with 63 non choroidal single-hole AVFs. Acta Neurochir (Wien) 2005;147:17–31. 2 Hung P-C, Wang H-S: Successful endovascular treatment of cerebral arteriovenous fistula. 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