**Author details**

376 Aneurysm

anatomical features and originating perforators, though its ability to demonstrate calcification or thrombosis is limited (Hoit, 2006). CTA accomplishes above limitations and moreover shows surrounding bony structures. In posterior fossa or ICA GIAs MRA can visualise adhering neural structures, although is performed occasionally in our institution. Conservative approach is preferred in individuals in fourth or fifth Hunt-Hess grade, excepting those with intracerebral haemorrhage. Conscious and informed patient's attitude to proposed GIA's treatment method is an important factor in making a decision. Endovascular therapy is approached to older individuals with high cardiopulmonary risk and when surgery is contraindicated. For ruptured GIAs an increased radiographic cerebral oedema may prevent direct clipping. Wide-necked GIAs not feasible for clipping should be secured by endovascular methods. GIAs originating at BA trunk or BA bifurcation with the neck located lower than normal are also offered endovascular treatment. A preferable group of patients for direct neck clipping are those younger than 65 years old. All GIAs amenable for clipping in neurosurgeon's opinion should be secured in this manner. In our institution distal PCA or ACA GIAs are excluded from a circulation by clipping technique. However, the most controversy refers to GIAs that are not suitable for both endovascular therapy and microsurgical clipping. In this case an endovascular therapy transforms these lesions into a chronic disease with a relapsing clinical course by further retreatments and repeated risk exposure (Sughrue, 2010). Flow-diverting stents potentially offer a meaningful benefit over surgery, although the outcome has not been sufficiently confirmed. Nonetheless, if endovascular therapy or direct clipping are not amenable bypass or parent artery sacrifice (trapping) is recommended, though bypass is not allowed in acute phase of SAH. Proper qualification to one of above surgical method is validated in balloon occlusion test (BTO). However this test is not meticulous enough, therefore the decision of treatment method can be supplemented by Xenon computer tomography or single-photon emission computed tomography (SPECT). Patients younger than 70 years old with equal or lower than grade II in American Society of Anaesthesiologists scale are qualifying for high-flow bypass without

BTO, which is in accordance with contemporary literature (Cantore, 2008).

surgery, definitive and durable therapy.

GIA by considering expected remaining lifetime.

**6. Conclusions/perspectives** 

The contemporary experience with GIAs is limited to retrospective analysis of selected group of ICA GIAs (Szmuda & Sloniewski, 2011). Nonetheless, it demonstrates that experienced neurosurgeon (senior author - PS) can achieve excellent results using a single

General unsatisfactory outcomes of GIAs do not warrant risky microsurgical or endovascular interventions. The more accustomed the neurovascular surgeon is the more difficult is the selection of the appropriate method for securing GIAs. However, in experienced hands the outcomes after treatment of giant and smaller aneurysms do not differ. In elderly populations, the efficacy must be weighed against the natural history of the Tomasz Szmuda and Pawel Sloniewski *Neurosurgery Department, Medical University of Gdansk, Poland* 
