ANSWER: (A) Air embolismREF: Ear, Nose, and Throat Diseases: With Head and Neck Surgery By Walter Becker 3rd edition, http ://emedicine.medscape.com/article/862030-over vie wComplications of non-endoscopic drainage procedures can be minor or severe. The most common complication is failure to enter the sinus because of improper positioning of the trocar, incomplete penetration of the sinus mucosa, or the presence of a hypoplastic antrum. Epistaxis may occur because of laceration of the nasal mucosa or preexisting coagulopathies necessitating packing. Severe complications include orbital injury, air embolism, and death secondary to injection of air into the sinus.