Complex intracranial aneurysms: a DELPHI study to define associated characteristics

Area of Science:

• Neurosurgery
• Interventional Neurology
• Vascular Surgery

Background:

• Intracranial aneurysms pose significant risks, with rupture leading to subarachnoid hemorrhage and high mortality.
• Defining complex intracranial aneurysms (CIAs) is challenging due to differing criteria for surgical and endovascular treatments.
• A lack of consensus on CIA definition impacts treatment planning and patient outcomes.

Purpose of the Study:

• To achieve consensus on the variables that define complex intracranial aneurysms (CIAs).
• To establish standardized criteria for identifying complex aneurysms across different treatment modalities.

Main Methods:

• An international Delphi process involving 50 specialists across multiple disciplines.
• Three rounds of surveys utilizing Likert scales and open-ended questions to gather expert opinions.
• Statistical analysis to determine consensus and stability of defined CIA variables.

Main Results:

• Open surgery CIAs criteria: fusiform/blister shape, dissecting etiology, giant size (≥25mm), broad/extensive neck, calcification, thrombus, collateral branches, specific locations, vasospasm, and need for bypass.
• Endovascular CIAs criteria: giant size, very wide neck (dome/neck ratio ≤1:1), and collateral branches from the sac.
• Significant differences identified in complexity definitions based on intended treatment modality.

Conclusions:

• The definition of aneurysm complexity is treatment-dependent.
• Divergent complexity factors for open surgery versus endovascular treatment necessitate distinct criteria.
• Consensus criteria for CIAs can inform and guide the selection of the optimal treatment strategy.