椎骨動脈解離性病変に対する瘤様拡張部塞栓術  [in Japanese] Embolization of Aneurysmal Dilatations for Vertebral Artery Dissections  [in Japanese]

椎骨動脈解離性病変の治療としてわが国で最も多く行われている治療は近位側椎骨動脈閉塞術である. しかし近位側椎骨動脈閉塞術後に再出血や瘤増大が報告されており, 病変部分をtrappingするほうが根治性が高い. 一方, 血管内手術法でも近位側椎骨動脈塞栓術では開頭手術と同様に再出血の危険がある. 出血発症例では高率に再出血が生じるが, 未破裂例でも瘤様拡張部が大きければ出血の危険がある. 根治性を高めるために解離腔である瘤様拡張部より塞栓術を開始してエントリーおよび正常椎骨動脈まで閉塞することを目的とした血管内治療を行った. 症例と方法 症例 2001年12月より2003年12月までに血管内治療を行った椎骨動脈解離性病変の9症例を対象とした. 自験例は左右椎骨動脈合流部(以下, VA union)近傍病変や病変部が長いなど治療困難症例を紹介されて塞栓術を行った症例が大部分である. 両側性病変を1症例に認め病変数は10であった.

Our treatment strategy for vertebral artery dissection is to embolize the aneurysmal dilatation as a part of the dissecting pseudolumen, followed by obliteration of the entry and proximal true lumen of the vertebral artery. We report on 9 patients with a total of 10 vertebral artery dissections. The patients comprised 6 men and 3 women, ranging in age from 31 to 72 (mean, 49.7). Six patients presented with subarachnoid hemorrhage and 3 with headache. The dissecting lesions were located proximal to the posteroinferior cerebellar artery (PICA) in 1 and distal to the PICA in 4. The PICA was involved in 1 and was not visible on angiograms in 4. Angiographic findings included 8 lesions extending near the union and 5 that, were longer than 15 mm. Under general anesthesia, 2 guiding catheters were placed into both vertebral arteries, and the microcatheter was introduced into the aneurysmal dilatation, which was then embolized with GDC 10, followed by embolization of the entry and the normal lumen in the proximal vertebral artery. During occlusion of the aneurysmal dilatation, it was very important to gently place the GDC 10, which was smaller than the diameter of the aneurysmal dilatation, to loosely pack. For 2 long dissections, the microcatheter could not reach the distal part of the aneurysmal dilatation via the ipsilateral approach, because of complex structure of pseudolumen or several entries into the aneurysmal dilatation. In these cases, another microcatheter was introduced into the residual part of the dilatation through the union via the contralateral vertebral artery, resulting in complete occlusion of the lesion. In 1 case of a lesion involving the PICA as a contralateral dissection of the ruptured one, coiling with stent caused acute occlusion of the vertebral artery without neurological deficits. Another 3 embolization procedures were added to completely occlude the dissection with the patency of the PICA. Neurological deterioration due to medullary infarction postoperatively occurred in 1 patient as a possible complication. Embolization of aneurysmal dilations for vertebral artery dissections, followed by occlusion of the entry and proximal vertebral artery resulted in curative results to prevent hemorrhage and an increase of aneurysmal size. When the microcatheter could not be introduced into the distal part of the aneurysmal dilatation, the contraiateral approach should be combined to completely occlude the dilatation. In the near future, the flexible intracranial stent could be applied for the treatment of vertebral artery dissections.