Coil-protected embolization technique for a branch-incorporated aneurysm

A small branch-incorporated aneurysm is an aneurysm with a small branch incorporated into the sac or the neck. It is one of the most difficult aneurysms to treat with coil embolization. The aim of this study was to evaluate the safety and effectiveness of the coil-protected embolization technique for small-branch incorporated aneurysm. Fourteen aneurysms (2 ruptured and 12 unruptured) in 12 patients (mean age, 56 years, range, 40-73 years; 6 men and 6 women) were treated with the coil-protected embolization technique during the period between February 2007 and October 2011. Clinical and angiographic outcomes were retrospectively evaluated. All aneurysms were successfully treated without any complications during the procedure. Immediate post-treatment angiographies demonstrated complete or near complete occlusion in 12 and incomplete occlusion in 2 patients. Two patients had a delayed small embolic infarction in the relevant posterior circulation territory and middle cerebral artery territory 10 days and 14 days later, respectively, but both recovered completely or almost completely (modified Rankin scale score [mRS score], 0 and 1, respectively). During the clinical follow-up period (mean, 21 months; range: 2-58 months), all patients reported an mRS score of 0 (n = 10) or 1 (n = 2). Vascular imaging follow-up (catheter angiography: n = 3 and MR angiography: n = 8) was available in 11 aneurysms at 6-12 months. All 11 aneurysms showed complete occlusion except for 1 minor neck recurrence that did not require further treatment. In this series of cases, the coil-protected embolization technique seems to be feasible and effective in the treatment of small-branch incorporated aneurysms.