Unexpected bleeding caused by arterial variation inferolateral to levator palpebrae.

When incisional or nonincisional double-eyelid operations are in process, unexpected bleeding adjacent to the lateral canthal area is often encountered. The unexpected bleeding may result in intraoperative hematoma and swelling. It may also cause temporary intraoperative ptosis. The intraoperative swelling along the designed double-eyelid line or temporary ptosis may prevent surgeons from taking an accurate measurement of the height of fold. Therefore, surgeons might have difficulties making symmetrical double-eyelid lines. Among the detailed dissections of 230 eyelids along the orbital septum and levator palpebrae during incisional double-eyelid operations, 25 cases of noticeable arterial variation were found adjacent to the inferolateral end of levator palpebrae. The artery is located 4-5 mm medial from the lateral canthus, at the inferior margin of levator palpebrae. During the dissections, the artery was found to be superficial to the orbital septum and it could be traced down into a deeper layer along the inferior end of levator palpebrae. It connects to the lateral canthal artery behind the levator palpebrae. During double-eyelid operations, accidental tearing of this artery, even at the superficial layer of orbital septum, might cause the retraction of the cleaved arterial end down into the levator palpebrae. The bleeding from the retracted arterial end rapidly makes a large hematoma posterior to the levator palpebrae, causing temporary intraoperative ptosis and an asymmetric double fold, and possibly retrobulbar hematoma and blindness. We should bear in mind the possibility of presence of this artery. Once bleeding of this artery begins, clamping this artery and the inferolateral portion of levator palpebrae with a hemostat is effective in preventing massive hematoma posterior to levator palpebrae and ptosis, but electocoagulation is not effective. A cadaver dissection study, with red colored latex injection into the ophthalmic artery, is in progress.