Anterior Temporal Approach for Clipping Posterior-Projecting Supraclinoid Carotid Artery Aneurysms: A More Lateral Corridor to Better Visualize the Aneurysm Neck and Related Branches.

Background: Direct visualization of the aneurysm neck and its related branches during microsurgical clipping of supraclinoid internal carotid artery (SICA) aneurysms using a standard pterional approach may be difficult, especially when aneurysms are posteriorly projected. We evaluated the efficacy and safety of an anterior temporal approach for clipping posterior-projecting SICA aneurysms.

Methods: Between December 2017 and March 2020, 26 patients with posterior-projecting SICA aneurysms who received microsurgical clipping via an anterior temporal approach were retrospectively reviewed. The percentage of complete aneurysm obliteration, intraoperative visualization, and preservation of related branches were evaluated.

Results: Aneurysm locations were the posterior communicating artery (PCoA) (internal carotid artery [ICA]-PCoA) in 22 patients (84.6%), the anterior choroidal artery (AChA) (ICA-AChA) in 3 patients (11.5%), and both locations in 1 patient (3.9%). Complete aneurysm obliteration was achieved in all patients. For ICA-PCoA aneurysms in which the PCoA was preoperatively identified, the artery was intraoperatively identified in all cases and preserved 100% after surgery. For ICA-AChA aneurysms, AChAs were intraoperatively identified and preserved in all cases after surgery. Procedural-related infarction was 8.7% for ICA-PCoA aneurysms and 7.7% for all SICA aneurysms. Transient oculomotor nerve palsy was found in 2 patients (7.7%). No postoperative temporal contusion was detected. A good outcome at 3 months after surgery was achieved in 90% of patients for good clinical-grade subarachnoid hemorrhage and unruptured cases.

Conclusions: The anterior temporal approach is safe and effective for clipping SICA aneurysms with posterior projection, with a high preservation rate of the related branches.