Oishi Yumiko, Akiyama Takenori, Mizutani Katsuhiro, Horiguchi Takashi, Imanishi Nobuaki, Yoshida Kazunari
Department of Neurosurgery, Keio University School of Medicine, Shinjukuku, Tokyo, Japan.
Department of Neurosurgery, Keio University School of Medicine, Shinjukuku, Tokyo, Japan.
Clin Neurol Neurosurg. 2018 Nov;174:207-213. doi: 10.1016/j.clineuro.2018.09.033. Epub 2018 Sep 24.
The venous outlet of anterior condylar arteriovenous fistulas (AC-AVFs) often empties into the anterior condylar vein (ACV). Hypoglossal nerve palsy is one of the major complications after transvenous embolization (TVE) for the AC-AVF within the hypoglossal canal. However, no studies have investigated the route of the hypoglossal nerve within the hypoglossal canal in AC-AVF. The aim of the current study is to retrospectively verify the anatomical route of the hypoglossal nerve within its canal using dynamic computed tomography angiography (CTA) in order to facilitate the safe TVE for AC-AVF.
We included five patients with AC-AVF from 2011 to 2017. Dynamic CTA was performed on all patients. When the ACV was well-visualized by dynamic CTA, the hypoglossal nerve could be recognized as a less-intense structure within the surrounding enhanced vasculatures and the nerve route within the canal was analyzed. We also analyzed the location of the fistulas by digital subtraction angiography and cone-beam computed tomography.
In all five patients, the filling defect of the hypoglossal nerve ran through the most caudal portion of the hypoglossal canal. The fistulous pouches were located in the hypoglossal canal in three cases, and in the jugular tubercle venous complex in two cases. In all three cases with AC-AVF in the hypoglossal canal, the fistulous pouches were located in the superior wall of the hypoglossal canal, which means superior to the ACV. We performed TVE in four patients and none developed post-therapeutic hypoglossal nerve palsy.
In the current study, dynamic CTA is useful for detecting the hypoglossal nerve within the hypoglossal canal. The hypoglossal nerve usually ran the bottom of its canal and the fistulous pouches were usually located at the superior aspect of the canal opposite side to the hypoglossal nerve. Accordingly, the selective embolization within the fistulous pouch located in the superior aspect of the ACV including jugular tubercle venous complex can reduce the risk of hypoglossal nerve palsy.
髁前动静脉瘘（AC - AVF）的静脉引流通常汇入髁前静脉（ACV）。舌下神经麻痹是舌下神经管内AC - AVF经静脉栓塞术（TVE）后的主要并发症之一。然而，尚无研究探讨AC - AVF时舌下神经管内舌下神经的走行路径。本研究的目的是利用动态计算机断层血管造影（CTA）回顾性验证舌下神经管内舌下神经的解剖路径，以便为AC - AVF的安全TVE提供便利。
我们纳入了2011年至2017年间5例AC - AVF患者。对所有患者均进行了动态CTA检查。当动态CTA清晰显示ACV时，舌下神经可被识别为周围强化血管内密度较低的结构，并对管内神经走行进行分析。我们还通过数字减影血管造影和锥形束计算机断层扫描分析了瘘口的位置。
所有5例患者中，舌下神经的充盈缺损均穿过舌下神经管的最尾端部分。瘘囊位于舌下神经管内3例，位于颈静脉结节静脉复合体2例。在所有3例舌下神经管内有AC - AVF的病例中，瘘囊均位于舌下神经管的上壁，即ACV的上方。我们对4例患者进行了TVE，无一例出现治疗后舌下神经麻痹。
在本研究中，动态CTA有助于检测舌下神经管内的舌下神经。舌下神经通常走行于神经管底部，瘘囊通常位于舌下神经对侧的神经管上侧。因此，对位于ACV上侧包括颈静脉结节静脉复合体的瘘囊进行选择性栓塞可降低舌下神经麻痹的风险。
