Treatment strategy and clinical outcome of aneurysms of the proximal segments of the posterior-inferior cerebellar artery with endovascular technique

Objective Surgical treatment of aneurysms of the postero-inferior cerebellar artery (PICA) is difficult and complication of lower cranial nerve palsies is common.These lesions can be approached easily with endovascular technique.But,endovascular treatment for proximal aneurysms of the PICA is complicated not only by the aneurysm shape,but also by the concerns of occlusion of perforating arteries origining from the brainstem.Aim of this study is to evaluate the treatment modality and outcome of these patients.Methods Between July 2007 and December 2013,records were reviewed of 24 proximal aneurysms of the PICA treated with endovascular techniques.The aneurysms were typed according to the morphology and collateral circulation for PICA (type Ⅰ:simple type; type Ⅱ:complex type).Different endovascular interventional therapy strategies were selected according to the typing.Results Of the 24 patients,type Ⅰ was noted in 11 patients,including 10 adopted simple coil embolization and 1 adopted parent artery occlusion; type Ⅰa included 5 patients,enjoying results of 4 complete occlusion and 1 subtotal occlusion; type Ⅰb included 6 patients,enjoying results of 3 complete occlusion,1 subtotal occlusion and 2 partial occlusion; type Ⅱ was noted in 13 patients; type Ⅱa included 6 patients,and 2 adopted simple coil embolization,1 adopted dual micro-catheter embolization,1 adopted parent artery occlusion and 2 adopted stent-assisted embolization,enjoying results of 2 complete occlusion,2 subtotal occlusion and 2 partial occlusion; type Ⅱb included 7 patients,2 adopted simple coil embolization,1 adopted parent artery occlusion and 4 adopted stent-assisted embolization,enjoying results of 2 complete occlusion,3 subtotal occlusion and 2 partial occlusion; procedural rupture occurred in 1 aneurysm mainly caused by the microcatheter,leading to no death and permanent disability.One patient treated with deliberate PICA origin occlusion developed temporary dysphagia.The mean follow-up was 26 months,with modified Rankin Scale (mRS) scores of 0-2 in 22 patients and mRS scores of 3 in 2.Conclusion Proximal PICA aneurysms were challenging for endovascular treatment,and treatment can be more effective and safer when appropriate endovascular interventional therapy is selected according to the typing of aneurysm. Key words: Aneurysm;  Posterior-inferior cerebellar artery;  The proximal;  Parent vessel; Endovascular treatment;  Stent-coil embolization