Utility and Feasibility of a Low-Cost System to Simulate Clipping Strategy for Cerebral Aneurysms Using Three-Dimensional Computed Tomography Angiography with Virtual Craniotomy

Abstract

Objective: To assess utility and feasibility of a low-cost system to simulate clipping strategy for cerebral aneurysms using patient-specific surgically oriented three-dimensional (3D) computed tomography angiography with virtual craniotomy.

Methods: From 2017 to 2021, 53 consecutive patients scheduled for aneurysm clipping underwent preoperative planning using 3D computed tomography angiography with virtual craniotomy. The model was oriented in the surgical position to observe the anatomy through surgical corridors. Clipping was planned considering 3 parameters: shape of the clip, clip type (standard vs. fenestrated), and clipping strategy (simple vs. multiple). We used a scoring system (0-3) to assess the concordance of virtual planning with real surgery by assigning 1 point for each correctly predicted parameter. Qualitative assessment of 3D models was a secondary end point.

Results: In 51 patients, 3D images perfectly matched the real anatomy shown in surgical videos. Concordance scores of 0, 1, 2, and 3 occurred with a frequency of 5%, 14%, 38%, and 43%, respectively. Concerning the shape of the clip, clip type, and clipping strategy, the concordance occurred in 73%, 80%, and 59%, respectively. Compared with simple clipping, strategies with multiple clippings were more difficult to predict correctly. Concordance scores of 0, 1, 2, and 3 occurred with a frequency of 5.7%, 5.7%, 31.4%, and 57.1%, respectively, in simple clipping and 4.8%, 28.6%, 47.6%, and 19%, respectively, in multiple clipping.

Conclusions: In our experience, use of 3D computed tomography angiography with virtual craniotomy is an easy and useful solution to plan clipping strategy. The surgeon's awareness of the surgical anatomy is improved. Although this method has some technical limitations, it represents a low-cost alternative if complex and expensive simulation systems are not available.

Keywords: Cerebral aneurysms; Microsurgical clipping; Surgical planning; Surgical simulation; Virtual craniotomy.