Frontal Sinusitis and Nasocutaneous Fistula as Complication of Frontal Sinus Posterior Table Fracture

Objective: To discuss the uncommon complication of nasocutaneous fistula from sinusitis secondary to frontal sinus fracture.

Study Design: Retrospective case report, literature review.

Background: Frontal sinus fractures are a well-known sequela of high-velocity craniofacial trauma. Goals of the initial evaluation of frontal sinus injury include determination of involvement and/or displacement of the anterior and posterior tables, obstruction of the nasofrontal duct, and intracranial injury. Management to avoid complications includes reconstruction of anterior table fractures, and cranialization with dural repair and/or frontal sinus obliteration when the posterior table is injured. Early complications encompass infectious processes such as meningitis, cerebral abscess, and osteomyelitis; as well as CSF leak. Late complications include mucoceles, mucopyoceles, cerebral abscess, encephalocele, and cosmetic defects. Combined anterior and posterior table fractures are almost always associated with injury to the nasofrontal orifices (ostia, ducts) which can lead to early and late complications, however, nasocutaneous fistula has never been described in the literature as a result of posterior table fractures.

Case Description: 21 year-old otherwise healthy male with a history of assault 4 months prior presented with recurrent left periorbital abscess and spontaneous drainage of purulent secretions through a hyperemic lesion in the frontal process of the maxilla. One month prior, he had a similar infection and was treated at the emergency department with I&D and antibiotics. Imaging revealed significantly displaced frontal sinus posterior table fracture with obstruction the left frontal sinus outflow. It also showed opacification of the left frontal sinus and bony erosion in the left frontal process of the maxilla with contiguous soft tissue density from frontal sinus and nasal cavity to subcutaneous tissue. Patient had no clear rhinorrhea.

Methods: The procedure was performed by an endoscopic endonasal approach. Intraoperatively it was confirmed the obstruction of the nasofrontal duct by the displaced bony fragment, with purulent drainage within the frontal sinus and communication with a cutaneous fistula tract to the left nasal wall. A wide Draf III frontal sinusotomy was performed, which allowed careful dissection of the fractured posterior table from the dura-mater. The bony fragment was removed and the sinus carefully inspected. Pulsation was noticed at the dehiscent area of the posterior table, but no evidence of CSF leak. Finally the area of the nasocutaneous fistula was debrided and covered with a free mucosal graft from the nasal cavity floor. At 2-month-follow-up. Frontal sinus was widely patent with resolution o of the infection. The nasocutaneous fistula was closed with no further drainage.

Discussion: Cutaneous fistula formation is an uncommon complication of frontal sinus fracture. The patient had a protracted course until imaging was obtained and this diagnosis was suspected. Here we were able to perform an endoscopic endonasal approach to address this rare late complication and perform a reconstruction with a free mucosal graft.

Conclusion: Successful treatment of frontal sinusitis complicated with nasocutaneous fistula from a posterior table fracture. The posterior table fragment was successfully removed trough purely endoscopic endonasal approach and the nasal defect of the cutaneous fistula was covered with a free mucosal graft.