Rupture of Intradural Giant Aneurysms: The Mode of Treatment, Anatomical, and Mechanical Factors

Objective: Aneurysm rupture is often a fatal complication of giant intradural aneurysm (GIA) treatments. The purpose of this study was to review aneurysm rupture in GIA treatment. Materials and Methods: We performed a systematic review on aneurysm rupture related to GIA treatment. For each reported case, we collected the following information: aneurysm location, size and rupture status, the mode of treatment, timing of the hemorrhage, anatomical, and hemodynamic factors.Results: We identified 56 aneurysm ruptures related to treatment in 38 published studies. Of the nine intraoperative ruptures, eight occurred during endovascular procedures and one in surgical treatment. Of the 47 delayed ruptures, 72.3% occurred within 2 weeks. The prognosis of intraoperative and delayed ruptures was poor, with 83.9% experiencing death. Of these aneurysms, 75% were initially unruptured. Of the delayed ruptured aneurysms, 21.3% had prior surgical treatment, 74.4% had prior endovascular treatment, and 4.3% had prior combined surgical and endovascular treatments. Vertebrobasilar artery (VBA) location was significantly associated with aneurysm rupture after treatment, occurring at 57.2%. Flow diverter (FD) treatment seemed to elevate the delayed rupture proportion of giant paraclinoid internal carotid artery (ICA) aneurysms from 22.0% to 42.9%. FD treatment did not lower the rupture risk of giant VBA aneurysms and the corresponding death rate. Conclusion: Intraoperative and delayed aneurysm ruptures were the most challenging in endovascular treatment of GIAs. Giant VBA aneurysm had the highest rupture risk after treatment. FD seemed to elevate the delayed rupture proportion of giant paraclinoid aneurysms.