Summary
The nasal conchal bullae (NCB) were historically considered relatively innocuous structures, but recent publications have highlighted their potential as sources of both primary or secondary infection in horses presenting with persistent unilateral nasal discharge. While the radiographic morphology and landmarks of the NCB have been extensively described, computed tomography (CT) remains the most sensitive modality for diagnosing NCB empyema. Standard sinoscopic treatments for sinusitis potentially bypass these structures, possibly leading to treatment failure. Surgical treatment of the conchal bullae aims to establish drainage and to remove any inspissated exudate or devitalised tissue. This is most commonly achieved via a trans-nasal endoscopic approach. Transcutaneous extra-nasal techniques based on pre-established anatomical landmarks have also been described in equine cadavers. This report describes diagnosis and surgical planning assisted by CT, followed by a minimally invasive, extra-nasal osteotomy in a case where anatomy precluded a trans-nasal approach. The procedure allowed fenestration of the dorsal conchal bulla (DCB), transendoscopic removal of inspissated material, and placement of an indwelling Foley catheter to facilitate postoperative lavage. The horse recovered uneventfully, and long-term follow-up indicated sustained resolution of clinical signs.