効果的な塞栓を目的としたＭＲＡによる動脈瘤内ｉｎｆｌｏｗ ｚｏｎｅの同定

Abstract

It is important to pack the inflow zone of intracerebral aneurysm to prevent coil compaction or recanalization after coil embolization of the aneurysm. In this study, we report the usefulness of magnetic resonance angiography (MRA) to identify the inflow zone of the aneurysm. Between November 2004 and March 2006, 21 patients (IC paraclinoid, 11 cases; BA tip, 3 cases; A-com, 4 cases; IC-top, 2 cases; P1, 1 case) underwent interventional coil embolization for cerebral aneurysms and MRA was used to try to depict the inflow zone of the aneurysm. We designed a 3D time-of-flight MRA technique targeted to the aneurysm with a large flip angle to emphasize the streamline into the aneurysm. We grasped the position of the inflow zone in the aneurysm by MRA before intervention. The inflow zone was packed by coils tightly with balloon neck remodeling technique and/or catheter assist technique, if necessary. The inflow zone was depicted in all 21 cases by MRA. In sidewall type aneurysms, the inflow zone existed beside the distal neck in all cases. In terminal type aneurysms, the inflow zone existed on an extension line from patent artery. Dome filling was not detected in all cases after treatment. Small neck remnant was detected in 6 cases that slightly increased in 4 cases, vanished in 1 case, remained and unchanged in 1 case 6 months after treatment. None of the cases required additional treatment. For effective coil embolization, it is important to grasp the position of the inflow zone of the aneurysm and to pack the point as tightly as possible. Identification of the inflow zone of aneurysm by MRA is useful for coil embolization.