What are the options for cardiac standstill during aneurysm surgery? A systematic review

To perform a systematic review of the techniques for transient circulatory arrest during intracerebral aneurysm surgery according to the PRISMA guidelines. Search of PubMed and Google Scholar using the following: ("heart arrest" OR "cardiac standstill"[All Fields]) AND ("intracranial aneurysm" OR "intracranial"[All Fields] AND "aneurysm"[All Fields]). A total of 41 original articles were retrieved, of which 17 were excluded (review articles, editorials and single-case reports). A total of 24 separate articles published between 1984 and 2018 were included in the final analysis, where the majority of patients harbored anterior circulation giant or large aneurysms. Adenosine-induced cardiac arrest gave a short, temporary asystole. The method had benefits in aneurysm with a broad neck, a thin wall, in specific localizations with narrow surgical corridors or in case of intraoperative rupture. Rapid ventricular pacing (RVP) allows a longer and more easily controlled hypotension. Its use is largely limited to elective cases. Deep hypothermic circulatory arrest required a complex infrastructure, and fatal procedure complications lead to a 11.5-30% 30-day mortality rate, limiting its application to giant or complex aneurysm of the basilar artery or to residual posterior circulation aneurysm after endovascular treatment. Adenosine and RVP are both effective options to facilitate clipping of complex aneurysms. However, their use in patient with ischemic heart disease and cardiac arrhythmias should be avoided, and their safety in the context of subarachnoid hemorrhage is yet to be determined. Today, deep hypothermic circulatory arrest is almost obsolete due to endovascular alternatives.