Exposure Of The Supraclinoid Segment Of Internal Carotid Artery Before And After Removal Of The Anterior Clinoid Process In The Computed Tomographic Images Simulating The Exposure Of Supraorbital Keyhole Surgery

Objective To study the exposure of the supraclinoid segment of internal carotid artery before and after removal of the anterior clinoid process in the computed tomographic images simulating the exposure of supraorbital keyhole surgery, provide anatomical data for treating aneurysms at this segment and explore the feasibility of clipping aneurysms covered by anterior clinoid process.Methods 30 patients who received CTA examination of their heads in the Affiliated Hospital of Hainan Medical College during June 2008 and March 2010 were studied. Volume rendering and image fusion techniques were applied to reconstruct the images of arties and skull. After arties and skull exposed during the supraorbital keyhole surgery were simulated, the length of the supraclinoid segment of internal carotid artery exposed before removal of the anterior clinoid process was measured. Then the length of the supraclinoid segment of the internal carotid artery exposed after manual subtraction of the anterior clinoid process in the images was measured. At last, the measurements before and after removal of the anterior clinoid process were compared.Results①The length of the supraclinoid segment of the internal carotid artery exposed before removal of the anterior clinoid process was 14.7±3.7 mm.②The length of the supraclinoid segment of the internal carotid artery exposed after removal of the anterior clinoid process was 30.6±4.1 mm.③The differences between the measurements before and after removal of the anterior clinoid process were statistically significant (P<0.05). The increased length of the supraclinoid segment of the internal carotid artery was 15.8±3.5 mm.Conclusion①Computed tomographic images reconstructed can simulate the exposure of skull and internal carotid artery revealed by supraorbital keyhole surgery.②The exposed length of the supraclinoid segment of internal carotid artery can be increased after removal of the anterior clinoid process during supraorbital keyhole surgery. The proximal parent artery can be controlled by removing the anterior clinoid process. Aneurysms at supraclinoid segment of the internal carotid artery covered by the anterior clinoid process can be safely revealed and clipped by removing it.