The Effect of Modified Olfactory Training on Postoperative Olfactory Dysfunction in Patients With CRS

Protocol for a Randomized Controlled Trial Evaluating the Effect of Modified Olfactory Training on Postoperative Olfactory Dysfunction in Patients With Chronic Rhinosinusitis

The goal of this clinical trial is to validate the effectiveness of the modified olfactory training device, the main questions it aims to answer are:

Is it possible that the device can treat postoperative olfactory dysfunction in patients with chronic sinusitis? Compared to the conventional device, how efficient is the modified olfactory training device for treating postoperative olfactory dysfunction in patients with chronic sinusitis?

Endoscopic sinus surgery is an effective treatment for treating olfactory dysfunction related to chronic rhinosinusitis. However, recent studies have shown that most patients experience a return of olfactory function to preoperative levels within months to a year after surgery. Clinically, olfactory training after endoscopic sinus surgery has been proven beneficial for the olfactory recovery.

The improved olfactory training device, based on a nasal bidirectional drug delivery system, can increase the deposition rate in the olfactory fissure region and improve the efficiency of olfactory training.

In this study, the investigators planned to recruit 213 patients and divided them into three groups for control group and olfactory training with conventional and modified devices, and validate the effectiveness of the modified device based on changes in cognitive function and the comparison of the outcomes of the three groups.

Inclusion Criteria:

1. A diagnosis of CRSsNP based on the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 (EPOS20).
2. The duration after endoscopic sinus surgery is 3months.
3. Olfactory dysfunction confirmed with the Sniffin's Sticks psychophysical test (TDI score≦30.5) .
4. Willingness to participate in this study and sign the informed consent form (ICF).

Exclusion Criteria:

1. Patients with olfactory impairment due to traumatic, congenital, toxic/drug-induced causes, tumors, or post-upper respiratory infections.
2. Lund-Mackay olfactory cleft score > 0.
3. Patients with severe comorbidities, such as malignant tumors.
4. Current or planned pregnancy prior to the end of study.
5. Patients who are unable to complete the study or are unable to comply with the requirements of the study (such as inability to tolerate olfactory function testing and treatment, memory or behavioral abnormalities, depression, smoking, heavy alcohol use, previous delinquent behavior)