This is a case of a 54 year old gentleman with carcinoma of the left gingivobuccal sulcus, planned for 3-dimensional excision of the tumor with modified radical neck dissection. During neck dissection, a large vessel thought to be as the internal carotid artery was inadvertently injured, resulting in a large amount of bleeding. The vessel was controlled by ligation, but we were at a loss as to what to do next, as we had possibly ligated the left internal carotid, thereby permanently blocking the blood supply to the left brain. A careful perusal of the area, however, revealed that the vessel in question was arising from the external carotid artery, and the internal carotid artery was quite safe and untouched.

The internal carotid artery had a very long serpentine course running posterior the internal jugular vein. The hypoglossal nerve was seen to traverse anterior to the external carotid and its large branch. This confirmed that the injured vessel was not the ICA. Also, the ICA was confirmed by identifying the vagus which was lying adjacent to it. Thus this variation gave us quite a fright. We assume that the mistake was probably due to the abnormally large size of the vessel its location, which was near the area of the ICA. The vessel was later identified as a large occipital artery. As expected, the patient had no post-operative complications.