Endovascular treatment of very small (≤ 3 mm) intracranial aneurysms: An updated systemic review

Abstract

Aim: Previously‐published meta‐analyses have concluded that coil embolization of very small (≤ 3 mm) intracranial aneurysms carry a high risk of procedural rupture, leading to morbidity and mortality. Several case series subsequently questioned the real procedural rupture risk. We therefore carried out an updated meta‐analysis.Patients and Methods: Computerized EMBASE, MEDLINE and PubMed searches of the literature for reports on the safety and efficacy of treatment of intracranial aneurysms with a maximum dimension of ≤ 3 mm were carried out from January 1990 to January 2011. Statistical analyses were generated using SPSS for Windows Version 15.0 and Comprehensive MetaAnalysis 2.0 for Windows. Results of the meta‐analyses are presented with 95 per cent confidence intervals (CI).Results: Twelve eligible studies with 637 patients (660 aneurysms) were analysed. Procedural aneurysm rupture occurred in 39 (5.9 per cent) of 660 aneurysm treatments (random‐effect‐weighted average: 7.2 per cent; 95 per cent CI: 5.3–9.6 per cent; Q‐value: 11; I2 = 4 per cent). Immediate satisfactory occlusion was achieved in 508 (88 per cent) of 579 aneurysm treatments (random‐effect‐weighted average: 84 per cent; 95 per cent CI: 81–87 per cent; Q‐value: 48; I2 = 81 per cent). Delayed satisfactory occlusion was achieved in 379 (88 per cent) of 433 aneurysm treatments (random‐effect‐weighted average: 82 per cent; 95 per cent CI: 77–86 per cent; Q‐value: 48; I2 = 83 per cent).Conclusions: The present findings suggest that coiling of very small intracranial aneurysms is associated with 7.2 per cent procedural aneurysm rupture risk. Further prospective multicenter studies should be carried out in Hong Kong to review the procedural morbidity and mortality.