Impact of Intraoperative 3-Dimensional Volume-Rendering Rotational Angiography on Clip Repositioning Rates in Aneurysmal Surgery

Objective: Three-dimensional (3D) rotational angiography (RA), a gold standard imaging tool for the evaluation of cerebral aneurysms after clipping, can currently be performed intraoperatively in a hybrid operating room (OR). However, its role in intraoperative aneurysmal surgery is unclear. We aimed to study the value of intraoperative 2-dimensional digital subtraction angiography (2D-DSA) and 3D-RA for the evaluation of aneurysms after clipping, in terms of clip repositioning. Methods: We included patients with cerebral aneurysms who were treated with microsurgical clipping in a hybrid OR. After aneurysmal clipping and indocyanine green video angiography assessment, intraoperative 2D-DSA and 3D-RA with volume-rendering (VR) images of the clipped aneurysm were obtained. The incidence rate of clip repositioning was determined, and aneurysm-related factors associated with suboptimal clipping that required clip revision after intraoperative angiography evaluation were analyzed. Results: Between September 2016 and August 2017, 24 consecutive patients with 35 aneurysms were treated with microsurgical clipping. A clip repositioning rate of 17.1% was revealed after intraoperative 3D-VR imaging and initial indocyanine green-video angiography. 3D-VR was able to demonstrate all aneurysmal remnants, whereas 2D-DSA helped confirm flow stagnation in compromised vessels. Challenging aneurysms of size >7 mm (P = 0.043) and neck width >4 mm (P = 0.012) were significantly associated with a higher incidence of suboptimal aneurysmal clipping. Conclusions: A hybrid OR, with angiography facilities for high-resolution 2D-DSA and 3D-VR images, allows neurosurgeons to perform high-quality surgery. The routine use of intraoperative 3D-RA may not be necessary; however, it is invaluable for treating challenging aneurysms.