Olfactory cleft adhesion in post-COVID-19 olfactory dysfunction

Abstract

Post-COVID-19 olfactory dysfunction (PCOD) typically resolves within weeks to months; however, persistent cases exist in approximately 10% of patients beyond a year. This study investigated the role of olfactory cleft adhesions in prolonged PCOD and evaluated surgical intervention as a treatment option. Four cases of PCOD unresponsive to medical therapy underwent endoscopic sinus surgery (ESS) to address bilateral olfactory cleft obstruction identified on computed tomography (CT) scan. Adhesions between the superior/middle turbinates and nasal septum were surgically divided, and silicone plates were inserted to prevent reattachment. All patients reported significant subjective improvements in olfaction within one week of silicone removal. Objective olfactory test scores continued to improve over subsequent months, and postoperative CT scan confirmed improved ventilation of the olfactory cleft. These findings suggest that adhesions formed during inflammatory healing contribute to conductive olfactory dysfunction in Long-COVID cases, distinct from sensorineural or central OD. Surgical intervention may be beneficial for carefully selected patients with PCOD persisting for at least one year, anosmia or severe olfactory loss confirmed by testing, and CT evidence of olfactory cleft obstruction. However, the risks such as mucosal damage and potential worsening or no improvement of OD should be discussed thoroughly. Individualized treatment strategies are recommended, and further studies are warranted to optimize management of persistent PCOD.