Endovascular Methods for the Treatment of Intracranial Cerebral Aneurysms Joseph J. Gemmete, MD a, *, Augusto Elias, DDS, MD b , Neeraj Chaudhary, MD, MRCS, FRCR c , Aditya S. Pandey, MD c INTRODUCTION Microsurgical clipping of intracranial aneurysms has been the historical definitive standard for the treatment of intracranial aneurysms. 1 Today’s sur- gical techniques routinely achieve complete exclu- sion of the aneurysm from the circulation without compromise of the parent vessel or arterial perfo- rators in a large number of patients. However, there are several risk factors that may put the patient at increased risk of morbidity and mortality, including aneurysm size and location, patient’s age, and the medical condition of the patient. 2 In addition, according to the International Subarach- noid Trial (ISAT), patients with subarachnoid hem- orrhage (SAH) fared better with endovascular coiling than those with surgical clipping. 3 To over- come some of the limitations of surgical clipping, a Division of Interventional Neuroradiology and Cranial Base Surgery, Departments of Radiology, Neurosur- gery, and Otolaryngology, University of Michigan Health System, UH B1D 328, 1500 East Medical Center Drive, Ann Arbor, MI 48109-5030, USA; b Division of Interventional Neuroradiology, Department of Radiology, University of Michigan Health System, 1500 East Medical Center Drive, Ann Arbor, MI 48109-5030, USA; c Division of Interventional Neuroradiology, Departments of Neurosurgery and Radiology, University of Mich- igan Health System, 1500 East Medical Center Drive, Ann Arbor, MI 48109-5030, USA * Corresponding author. E-mail address: gemmete@med.umich.edu KEYWORDS  Intracranial cerebral aneurysm  Balloon remodeling  Flow diverters  Coiling of cerebral aneurysm  Stent-assisted coiling of cerebral aneurysm  Onyx HD 500  Complications from coiling of intracranial aneurysms KEY POINTS  The annual risk of aneurysm rupture, based on the International Study of Unruptured Intracranial Aneurysms, is 0.7% per year.  The 30-day case fatality after subarachnoid hemorrhage (SAH) is 38%, and 10% to 20% of SAH survivors remain dependent.  Cerebral aneurysms can be treated with simple coiling, balloon remodeling, stent-assisted coiling, Onyx HD 500, and flow diversion.  The International Subarachnoid Trial showed an absolute risk reduction in death of 7.4% in patients presenting with SAH treated with endovascular coiling in comparison with surgical clip placement.  A Barrow Institute study prospectively randomized 500 SAH patients to clipping versus coiling. At 1 year a modified Rankin Score of greater than 2 was observed in 33.7% of clipped patients, compared with 23% of patients with coils.  The Pipeline Embolization Device in the Intracranial Treatment of Aneurysms trial treated 31 intra- cranial aneurysms with a mean aneurysm size of 11.5 mm and mean neck size of 5.8 mm. Follow-up angiography at 6 months demonstrated complete occlusion of the aneurysm in 93.3% of patients. Neuroimag Clin N Am - (2013) -–- http://dx.doi.org/10.1016/j.nic.2013.03.007 1052-5149/13/$ – see front matter Ó 2013 Elsevier Inc. All rights reserved. neuroimaging.theclinics.com