INTRODUCTION: To reduce the risk of complications, immediate surgical treatment of frontal sinus outflow tract (FSOT) fractures has been a standard practice. With surgical and technologic advances, conservative management (i.e. observation) of FSOT fractures has become more common. Unfortunately, complication rates with observation are unknown. This study evaluates these risks.

METHODS: All FSOT injuries, between January 1, 2005, and May 1, 2019, were identified. Patient demographics, fracture patterns, surgical intervention, complications (major - CSF leak & mucocele; minor – sinusitis), and long-term sequelae were recorded. FSOT fractures were classified as either “disrupted” (bony violation of the FSOT with residual patent tract) or “obstructed” (bony obstruction of the FSOT). Patients with follow up imaging >90 days were included. Patients undergoing immediate surgical intervention were excluded.

RESULTS: One hundred thirty-six patients were identified and 31 met criteria. Eight patients were found to have complications (26%) at 14.2 months median follow up. There were 3 major complications (2 delayed CSF leaks and 1 mucocele) (10%) and 5 minor complications (sinusitis) (16%). Delayed surgical intervention was required in 4 patients (13%) and there were no long-term sequelae. When analyzed by type of injury, FSOT obstruction accounted for all major (11%) and 3 minor complications (11%); while FSOT disruption accounted for only 2 minor complications (7%).

CONCLUSION: No FSOT disruption and 13% of FSOT obstruction patients ultimately required surgical intervention. There were no long-term sequelae. Observation is a viable treatment option in this patient population given reasonable assurance of long-term follow up.