Preoperative cerebral aneurysm assessment by three-dimensional magnetic resonance angiography: feasibility of surgery without conventional catheter angiography

In this study, we aimed to assess whether surgery could be performed in patients with cerebral aneurysms by using three-dimensional (3-D) magnetic resonance (MR) angiography alone, without conventional catheter angiography. A total of 108 patients who had undergone MR angiography and aneurysm surgery between January 1998 and January 2004 were enrolled in this study. The study subjects included 49 patients without subarachnoid hemorrhage (SAH) and 59 patients with SAH. In our preliminary study, 13 patients without SAH were diagnosed using 3-D MR angiography compared with catheter angiography and 3-D computed tomographic angiography before surgery. The 3-D MR angiography demonstrated all 18 unruptured aneurysms that were detected by catheter angiography. Thirty-six patients without SAH and 59 patients with SAH were examined using 3-D MR angiography. In 33 patients (91.6%) without SAH and 56 patients (94.9%) with SAH, we were able to reach a diagnosis on the basis of 3-D MR angiography alone. A majority of aneurysms were regular-sized and located in the anterior part of the circle of Willis. A total of 89 patients (93.7%) who underwent surgery with the aid of 3-D MR angiography alone were treated successfully and had no complications related to the lack of information that might have been gathered by catheter angiography. The 3-D MR angiography provided the authors with the aneurysm locations as well as with surgically important information regarding the configuration of the aneurysmal sac and neck and its relationship with the surrounding vessels. In the remaining 6 patients, 3-D MR angiography was followed by catheter angiography to acquire additional diagnostic confirmation. The results of this study support the notion that 3-D MR angiography can replace conventional catheter angiography for preoperative assessment in the majority of regular-sized anterior circulation aneurysms.