Microsurgical Clipping of Unruptured Anterior Circulation Aneurysms—A Global Multicenter Investigation of Perioperative Outcomes
Authors: Sauvigny Jennifer , Drexler Richard , Pantel Tobias F. , Ricklefs Franz L. , Catapano Joshua S. , Wanebo John E. , Lawton Michael T. , Sanchin Aminaa , Hecht Nils , Vajkoczy Peter , Raygor Kunal , Tonetti Daniel , Abla Adib , El Naamani Kareem , Tjoumakaris Stavropoula I. , Jabbour Pascal , Jankowitz Brian T. , Salem Mohamed M. , Burkhardt Jan-Karl , Wagner Arthur , Wostrack Maria , Gempt Jens , Meyer Bernhard , Gaub Michael , Mascitelli Justin R. , Dodier Philippe , Bavinzski Gerhard , Roessler Karl , Stroh Nico , Gmeiner Matthias , Gruber Andreas , Figueiredo Eberval G. , Coelho Antonio Carlos Samaia da Silva , Bervitskiy Anatoliy V. , Anisimov Egor D. , Rzaev Jamil A. , Krenzlin Harald , Keric Naureen , Ringel Florian , Park Dougho , Kim Mun-Chul , Marcati Eleonora , Cenzato Marco , Krause Linda , Westphal Manfred , Dührsen Lasse , Sauvigny Thomas 
Published: January 2024

BACKGROUND AND OBJECTIVES:
Microsurgical aneurysm repair by clipping continues to be highly important despite increasing endovascular treatment options, especially because of inferior occlusion rates. This study aimed to present current global microsurgical treatment practices and to identify risk factors for complications and neurological deterioration after clipping of unruptured anterior circulation aneurysms.

METHODS:
Fifteen centers from 4 continents participated in this retrospective cohort study. Consecutive patients who underwent elective microsurgical clipping of untreated unruptured intracranial aneurysm between January 2016 and December 2020 were included. Posterior circulation aneurysms were excluded. Outcome parameters were postsurgical complications and neurological deterioration (defined as decline on the modified Rankin Scale) at discharge and during follow-up. Multivariate regression analyses were performed adjusting for all described patient characteristics.

RESULTS:
Among a total of 2192 patients with anterior circulation aneurysm, complete occlusion of the treated aneurysm was achieved in 2089 (95.3%) patients at discharge. The occlusion rate remained stable (94.7%) during follow-up. Regression analysis identified hypertension (P < .02), aneurysm diameter (P < .001), neck diameter (P < .05), calcification (P < .01), and morphology (P = .002) as preexisting risk factors for postsurgical complications and neurological deterioration at discharge. Furthermore, intraoperative aneurysm rupture (odds ratio 2.863 [CI 1.606-5.104]; P < .01) and simultaneous clipping of more than 1 aneurysm (odds ratio 1.738 [CI 1.186-2.545]; P < .01) were shown to be associated with an increased risk of postsurgical complications. Yet, none of the surgical-related parameters had an impact on neurological deterioration. Analyzing volume-outcome relationship revealed comparable complication rates (P = .61) among all 15 participating centers.

CONCLUSION:
Our international, multicenter analysis presents current microsurgical treatment practices in patients with anterior circulation aneurysms and identifies preexisting and surgery-related risk factors for postoperative complications and neurological deterioration. These findings may assist in decision-making for the optimal therapeutic regimen of unruptured anterior circulation aneurysms.