Improvement in Olfaction following Modified Endoscopic Lothrop Procedure

Abstract

Objectives: The Modified Endoscopic Lothrop Procedure (MELP) is performed for severe cases of chronic rhinosinusitis (CRS) refractory to standard medical and surgical treatments. It involves creating a wide neo-ostium connecting both frontal ostia and the removal of bone between the frontal beak and the olfactory fossa. The posterior margins of dissection are the fibers of the first olfactory neurons; therefore, this procedure may influence sense of smell. The aim of this study was to assess the objective sense of smell pre- and post-MELP. Methods: A prospective study of 20 patients with severe recalcitrant CRS undergoing MELP. Preoperative and postoperative sense of smell was assessed with the University of Pennsylvania Smell Inventory Test (UPSIT). Results: Mean UPSIT scores improved from 19.8 to 25.5 following MELP (p=0.0277, t-test). The greatest improvement was seen in patients with a poor sense of smell preoperatively; mean UPSIT 11.6 to 22.4 (p=0.0026, t-test). In patients with a good sense of smell preoperatively, this was not affected negatively by MELP; mean UPSIT 29.25 to 29 (p=0.9351, t-test). Conclusions: Modified Endoscopic Lothrop Procedure can have a beneficial effect on postoperative sense of smell, and importantly, the operation does not cause any disturbance in sense of smell following surgery in this cohort of patients.