2026 Proffered Presentations
S058: RETAINED FRONTAL ETHMOID CELLS CAUSING DELAYED INFECTIOUS COMPLICATIONS FOLLOWING COMPLEX FRONTAL SINUS SURGERY: A CASE SERIES HIGHLIGHTING MULTIDISCIPLINARY MANAGEMENT AND ANATOMIC PITFALLS
Russel T Wagner, BS1; Amin B Kassam, MD2; Hannah L Walsh, BS2; Melanie B Fukui, MD2; Usman A Khan, MD, PhD2; Neil S Mundi, MD2; Stephen J Winkler, MD2; Emily Sitkowski, BS2; Cenorina Martinez, BS2; Sammy Khalili, MD2; 1Edward Via College of Osteopathic Medicine; 2Intent Medical Group
Objective: To describe delayed infectious complications arising from retained ethmoid air cells following complex open frontal sinus surgeries and emphasize the importance of comprehensive anatomic management and multidisciplinary collaboration in preventing these outcomes.
Methods: We present a case series of four patients with extensive surgical histories, including open frontal sinus cranialization, obliteration, and multiple cranioplasties, who developed delayed postoperative infections. Detailed review of imaging, operative findings, and intraoperative cultures identified residual ethmoid air cells as persistent sources of infection. Surgical management included removal of infected hardware, debridement of osteomyelitic bone, eradication of retained air cells, and reconstruction with vascularized flaps and titanium mesh.
Results: All four patients experienced delayed postoperative infections several months to years following their initial open frontal sinus surgeries performed at outside institutions. Each case demonstrated the presence of retained ethmoid air cells within the lateral frontal sinus region, which served as reservoirs for chronic infection despite prior interventions. Effective management necessitated multiple complex revision surgeries facilitated by a multidisciplinary team including neurosurgery, endoscopic skull base surgery, head and neck reconstructive surgery, neuroradiology, and oculoplastics. All patients achieved resolution of acute infection following definitive surgical management and prolonged antibiotic therapy.
Conclusion: Retained ethmoid air cells are an underrecognized source of persistent infection following complex open frontal sinus and skull base surgeries. These cells can remain viable even after extensive sinus exenteration and reconstruction, contributing to osteomyelitis, hardware infection, and wound breakdown. A comprehensive understanding of sinus drainage pathways is essential to preventing these complications. Thorough preoperative imaging review, meticulous intraoperative dissection, and multidisciplinary surgical management are essential to identifying and addressing these anatomic contributors to prevent delayed infectious complications.
Figure 1. A) Coronal CT demonstrating a large right fronto-orbital mucocele with adjacent erosion of the superior orbital rim. B) Axial CT showing the fronto-orbital mucocele and a possible frontal septal cell. The retained pneumatized cells contributing to infection were suspected to originate from either a frontal septal cell or a supra agger frontal cell.
Figure 2. A) Coronal CT showing a right frontal bone defect with surrounding soft tissue infection over prior reconstruction. B) Axial CT showing a persistent right supraorbital ethmoid air cell, suspected source of abscess. A retained supra agger frontal cell may also have contributed.
Figure 3. A) Axial CT demonstrating an anterior table defect of the frontal sinus due to chronic osteomyelitis and prior surgeries, contributing to recurrent infectious complications. B) Axial CT highlighting the anterior table defect and associated subgaleal air and fluid, consistent with recurrent osteomyelitis. C) Axial CT revealing a possible intersinus frontal cell, which likely was a contributor to persistent sinus disease and infection. D) Coronal CT identifying both a right supraorbital ethmoid cell and a left supra agger frontal cell, both of which were suspected contributors to the patient’s ongoing infectious process despite previous sinus surgeries.
Figure 4. A) Coronal CT showing a retained supra bulla cell near the right orbital roof. B) Axial CT highlighting the same cell, the suspected infection source.