A Rare Complication of Functional Endoscopic Sinus Surgery: Maxillary Atelectasis-Induced Spontaneous Enophthalmos

Background The first case report of spontaneous enophthalmos due to maxillary atelectasis as a late complication of FESS is presented. Methods Chart review of a 24-year-old male who developed a left progressive enophthalmos within three months post bilateral functional endoscopic sinus surgery. Results The preoperative computed tomography showed a normal left maxillary sinus. The postoperative computed tomography revealed a left maxillary atelectasis with a descending orbital floor. The subject received revised endoscopic sinus surgery and his enophthalmos was stable without further progression after the operation. Conclusions This may have been caused by an ostium occlusion with retention of secretions inducing sinus inflammation, osteolytic activity, and osseous remodeling of the sinus walls. A negative pressure may develop. When the pressure gradient exceeds the sinus wall tension, maxillary atelectasis and enophthalmos occur. Prevention of this complication of FESS should include making a patent naso-antral window, minimizing mucosal trauma, and careful postoperative sinoscopic treatment. A “functional” sinus is the goal.