ＨｙｐｅｒＦｏｒｍ ｏｃｃｌｕｓｉｏｎ ｂａｌｌｏｏｎ ｓｙｓｔｍを使用した脳動脈瘤の瘤内塞栓術

Abstract

After the publication of ISAT trial, intraaneurysmal coil embolization has become more widely used for treatment of aneurysm. There are, however, some disadvantages in intraaneurysmal coil embolization. One is how to treat wide neck aneurysm. Among several solutions, such as 3D coils and double catheter technique, neck plasty technique is the most effective method at present. A new balloon catheter, HyperForm balloon occlusion system (HyperForm), for neck plasty technique has recently been developed. This balloon, with a maximum diameter of 7 mm, is so soft that it is called supercompliant. We report our experiences using the balloon. The cases in this study were 13 aneurysms in 12 patients in whom intraaneurysmal coil embolization was performed using HyperForm. The site of the aneurysm was internal carotid artery (ICA) in 6, basilar bifurcation in 5, and middle cerebral artery (MCA) in 2. The procedure itself is similar to ordinary neck plasty method. Most different fashion is in the situation of basilar bifurcation aneurysm. Many basilar bifurcation aneurysms dominantly saddle one of the posterior cerebral arteries (PCAs). We usually try to navigate a neck plasty balloon through the PCA that is saddled more by aneurysm. However, during this procedure the guidewire tends to migrate inside the aneurysm. In other words, the less important it is to preserve the PCA, the easier it is to canulate. HyperForm inflates irregularly as if the balloon itself is searching for space. Thanks to this characteristic of HyperForm, the important PCA can be protected even as the HyperForm is navigated through the less important PCA. Therefore, HyperForm is very useful for intraaneurysmal embolization of basilar bifurcation aneurysm. Another possible advantage of HyperForm is its larger diameter. The largest diameter of the previously used balloon was 4.5 mm, but HyperForm has a maximum diameter of 7 mm, which is useful for ICA aneurysm. However, because of its softness, HyperForm tends to jump during treatment of ICA aneurysm. There were 2 complications in this series. Both were perforations by the guide wire, one was aneurysm and the other was perforator, in the treatment of MCA aneurysm. In conclusion, HyperForm is very useful for neck plasty technique, especially in treatment of wide neck basilar bifurcation aneurysm.