Technical feasibility of transnasal endoscopic anterior ethmoid artery ligation: Assessment with intraoperative CT imaging

Background: The objective of this study was to evaluate the technical feasibility of endoscopic anterior ethmoid artery (AEA) ligation for acute control of epistaxis. Methods: A prospective study was conducted using eight cadaver heads. Pre- and intraoperative CT scans were performed using the xCAT (Xoran Technologies, Inc., Ann Arbor, MI). Skull base anatomy relative to the AEA was reviewed preoperatively. Endoscopic AEA ligation was attempted in all sides with a mesentery. Ligation was not deemed feasible in AEAs without a mesentery. It was attempted on two sides without a mesentery to assess risk of skull base and orbital disruption. Intraoperative CT scans were performed to assess the position of the clips and the integrity of the skull base and lamina papyracea. Results: The mean lateral lamella height was 4.75 and 4.83 mm on the right and left, respectively. Of the 16 arteries, 6 (37.5%) of the AEAs were within a bony mesentery. No AEA canals were dehiscent. Four of the six AEAs (66%) within a mesentery were successfully clipped and two (33%) were partially clipped by endoscopic evaluation. Both arteries without mesentery where clipping was attempted were partially clipped by endoscopic examination. Review of intraoperative CT scans showed that the AEA with a mesentery was clipped successfully on three sides, partially on one side, and unsuccessfully on two sides. AEA clipping was unsuccessful on both sides without a mesentery. One AEA without a mesentery showed skull base disruption after ligation by endoscopy and CT. None of the specimens showed orbital injury. Conclusion: Intraoperative CT scanning revealed that AEA ligation was less successful than was apparent endoscopically. Effective AEA clipping was performed in 50% of cases with a mesentery. Endoscopic clipping was not technically feasible in cases with AEA without a mesentery. Overall, AEA clipping was only technically feasible in 3 of 16 sides (18.8%).