Ischemic Event and Risk Factors of Embolic Stroke in Atherosclerotic Cerebral Aneurysm Patients Treated with a New Clipping Technique

Intra-Aneurysmal Rupture of an Atheroma during the Clipping of Large Atherosclerotic Aneurysm of the Middle Cerebral Artery: A Case Report with Video Demonstration

“…Since the publication of the International Subarachnoid Aneurysm Trial (ISAT), 5 the number of endovascular procedures performed for the treatment of intracranial aneurysms has increased significantly, and a high rate of silent ischemia (defined as hyperintense lesions on diffusion-weighted MRI) or symptomatic ischemia has been reported (42-61% and 5.6-30%, respectively). 1,2,[6][7][8][9][10][11] This can occur as a result of several factors, such as repeated catheter manipulation, the detachment of intra-aneurysmal thrombi, and migration of newly formed thrombi by embolic materials. Few studies to date, however, have reported on the rate of ischemic events during microsurgery, although a lower occurrence rate of 9.8% for silent ischemia and 2% for symptomatic stroke were described during microsurgical clipping of aneurysms.…”

“…2 Another study noted that the presence of an atherosclerotic aneurysm enhances the risk of generating a shower of thrombi to the distal artery and a resulting cerebral infarction. 1 In the case of atherosclerotic or calcified aneurysms, placement of the clip while minimizing these complications is extremely challenging 3 and therefore requires special attention during surgery.…”

“…1 Using this technique, they reported a postoperative cerebral infarction rate of only 2.9% and commented that low wall shear stress in the remnant atherosclerotic neck will slow the growth of the aneurysm. 1,12 Because an unstable plaque is very weak, it can easily migrate with the force of clip compression or repeated surgical manip-ulation. 1,2 Lawton et al proposed a classification scheme 13 in which direct clipping produces the best surgical results for "clippable" thrombotic aneurysms, and trapping and bypass surgery produce more favorable outcomes than a thrombectomy or clip reconstruction in patients with concentric-type thrombotic aneurysms ("unclippable") 13 Thrombectomy-clip reconstruction may be an alternative surgical approach for atherosclerotic aneurysms, although the challenges of this approach include incomplete proximal control and difficulty in reconstructing a neck in the presence of severe atherosclerotic thickening.…”

“…1,12 Because an unstable plaque is very weak, it can easily migrate with the force of clip compression or repeated surgical manip-ulation. 1,2 Lawton et al proposed a classification scheme 13 in which direct clipping produces the best surgical results for "clippable" thrombotic aneurysms, and trapping and bypass surgery produce more favorable outcomes than a thrombectomy or clip reconstruction in patients with concentric-type thrombotic aneurysms ("unclippable") 13 Thrombectomy-clip reconstruction may be an alternative surgical approach for atherosclerotic aneurysms, although the challenges of this approach include incomplete proximal control and difficulty in reconstructing a neck in the presence of severe atherosclerotic thickening. We therefore suggest the following protocol for the treatment of atherosclerotic aneurysms: (1) determine whether the aneurysm is clippable or unclippable (eccentric or concentric atherosclerosis); (2) if the aneurysm is clippable, surgical manipulation should be minimized, and techniques to avoid clipping any atherosclerotic areas may be required; and (3) if the aneurysm is unclippable, alternative trapping and bypass techniques should be carefully considered.…”

“…1,2 In cases of atherosclerotic or thrombosed aneurysms, an embolic shower to the distal artery is a well-recognized cause of silent or symptomatic postoperative cerebral infarction. 1,3 We describe a unique case of an intra-aneurysmal atheroma rupture after permanent clipping of a large atherosclerotic aneurysm of the middle cerebral artery (MCA). Possible treatment strategies and special surgical techniques to minimize ischemic complications in cases of atherosclerotic aneurysms are discussed.…”