Surgical Nuances of Clipping After Coiling: Looking Beyond the International Subarachnoid Aneurysm Trial

After the introduction of Guglielmi Detachable Coils (GDC), endovascular management of ruptured and unruptured aneurysms became a viable alternative to surgical clipping as a "minimally invasive" option. Endovascular management of aneurysms became even more common after the International Subarachnoid Aneurysm Trial, which was one of the first prospective, randomized trials comparing clipping and coiling, showed reduced dependency and death in patients undergoing coiling after two months and one year. As the numbers of patients treated by endovascular therapy grow neurosurgeons are facing increasing challenges of clipping difficult aneurysms not suitable for coiling, including those that are wide-necked, thrombosed or involving many perforators. In addition, treatment failures (recurrent and residual aneurysms after coiling) pose difficult treatment scenarios fraught with complications due to surrounding adhesions, coil migration and involvement of adjacent neurovascular structures. Thus, we analyzed the recent literature dealing with the nuances of clipping after coiling and reviewed the current management principles involved in treating these difficult aneurysms.