Neurology India, Vol. 58, No. 2, March-April, 2010, pp. 177-178
Intracranial aneurysms previously treated with endovascular therapy: What next?
Department of Neurosurgery, Endovascular Neurosurgery and Interventional Neuroradiology, Hadassah University Hospital, Jerusalem, Israel
Correspondence Address:J E Cohen, Department of Neurosurgery, Endovascular Neurosurgery and Interventional Neuroradiology, Hadassah University Hospital, Jerusalem, Israel, email@example.com
Code Number: ni10051
Surgical clipping has been the preferred therapeutic option for cerebral aneurysms for decades. The endovascular option (coiling) was developed in the early 1990s and was refined only by the end of that decade with the meteoric development of new endovascular devices, the incorporation of sophisticated and more advanced angiography technology, and increasing technical skills and experience of interventionalists. The clipping versus coiling rivalry had begun.
The first indications of coiling were the most complex and difficult surgical cases: patients with high-grade hemorrhages, elderly patients with significant comorbidities, posterior circulation aneurysms and post-clipping aneurysm remnants. Partial clipping of cerebral aneurysms occurs in about 4% of surgical procedures and the risk of hemorrhage persists if the aneurysm is not completely excluded. Reoperations are often difficult, technically demanding and may carry an increased risk of complications. Certain partial clipping types assist and favor a stable coiling procedure allowing more compact coils casts. , The endovascular treatment of partially clipped aneurysms proved to be safe and constituted a valuable option to microsurgery. The interactions between surgeons and interventionalists proved to be rewarding for both.
The controversy of surgical clipping versus endovascular coiling of cerebral aneurysms was partially solved after the International Subarachnoid Aneurysm Trial (ISAT).  ISAT was the first multicenter, prospective randomized trial comparing the safety and efficacy of endovascular coil treatment and surgical clipping for the treatment of ruptured brain aneurysms. ISAT study concluded that in patients with a ruptured intracranial aneurysm, for which endovascular coiling and neurosurgical clipping are therapeutic options, the outcome, in terms of survival free of disability at 1 year, is significantly better with endovascular coiling. After these findings, there are an increasing number of physicians and patients opting for endovascular therapy. With the growing volume of aneurysms treated with endovascular methods and the unavoidable risks of incomplete coiling, coil compaction and aneurysm recanalization, the volume of partially treated aneurysms requiring a second endovascular procedure or surgical management is also growing. A second endovascular procedure is usually more complex and requires the addition of coils with or without assisting devices such as balloons or stents or the implantation of the recently introduced flow-diverters. The surgical therapy of partially coiled aneurysms requires special consider ations from the surgeon′s point of view. In this issue, Kumar et al.  report their experience of surgically treating five such patients, with good results. Surgeons have to act within new surgical scenarios dealing with endovascularly implanted materials, protruding coils and extruded coils. These implanted materials may ease or, on the contrary, complicate the surgical clipping procedure. Direct clipping is the preferred microsurgical treatment for coiled aneurysms and may be predicted by the relationship between coil width and compaction height.  Bypass strategy has been recommended for unclippable coiled aneurysms because it can be executed methodically, has predictable ischemia times, and is associated with more favorable results than thrombectomy, coil extraction, and clip reconstruction.
The optimal management of cerebral aneurysms is only possible with for any department of neurosurgery with a balanced interaction between surgeons and intervetionalists.
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