Intracranial aneurysms of the posterior circulation associated with a fenestration: a systematic review.

INTRODUCTION A fenestration is an anatomical variation that most commonly involves vessels of the posterior circulation, which can predispose the formation of aneurysms and represents a further technical challenge for treatment. There are no large series and the incidence of complications is unknown. This paper is a systematic review on this topic. EVIDENCE ACQUISITION The relevant English literature was reviewed and the data was extracted for each patient and collected in a pool. Demographics, localization of fenestration, morphology and aneurysm topography, admission and follow-up clinical status, treatments, complications and occlusion rate were recorded. EVIDENCE SYNTHESIS We analyzed 62 articles published between 1992 and 2016 including 120/133 patients/aneurysms. The most commonly involved segment was the vertebro-basilar junction (82.5%), followed by the basilar trunk (10%). About 96.6% of reported aneurysms were saccular and 80.3% were ruptured. The preferred treatment was endovascular (86.67%) and a surgical clipping was reported in just over 13% of patients. A complete/almost complete occlusion was obtained in about 80% of cases, with a global rate of complications of 12.5%. A serious clinical condition at onset has been independently associated with poor outcome at multivariate analysis (P<.001). CONCLUSIONS This systematic review has shown that endovascular occlusion is the treatment of choice for posterior circulation aneurysms associated with fenestrations, being highly effective, with an occlusion rate of about 80%, unchanged at follow-up. Although he presence of a fenestration can make more complex the aneurysm occlusion, and the occurrence of complications is not negligible, it is not considered a limiting condition for treatment.