The goal of this clinical trial is to learn about the safety and effectiveness of Novabel bioabsorbable steroid-releasing stent in chronic sinusitis. The main questions it aims to answer are:

• The safety of this device for the chronic sinusitis
• The effectiveness of this device for the chronic sinusitis Participants will be implanted bioabsorbable steroid-releasing stents after FESS surgery. Participants will be asked to be back to the clinic for follow-up 14 days, 30 days, 90 days, 180 days and 360 days after procedure.

Researchers will compare test device and marketed device to see if the safety and effectiveness between these two devices are non-inferior.

Inclusion Criteria:

• Diagnose with CRS based on Chinese guidelines for diagnosis and treatment of chronic rhinosinusitis (2018), who were scheduled to undergo primary or revision bilateral ESS.
• Have evidence of bilateral sinus based on computed tomographic (CT) scan (Lund-Mackay [L-M] score of <=3 on each side).
• Can understand the purpose of this study and will to join and finish all the follow up according to the study. Sign the ICF.

Exclusion Criteria:

1. Know history of allergy or intolerance to corticosteroids or mometasone furoate.
2. The subject has a known allergic reaction or contraindication to the device material and its degradation products (L-polylactic acid, racemic polylactic acid, lactide lactate, lactic acid).
3. Clinical evidence of cystic fibrosis, severe polyposis or sinonasal tumors.
4. Clinical evidence of acute bacterial sinusitis or suspicion of invasive fungal sinusitis.
5. Glaucoma, ocular hypertension, posterior subcapsular cataracts.
6. Known history of immune deficiency or concurrent condition requiring active chemotherapy and/or immunotherapy management for the disease.
7. Clinical evidence of disease or condition expected to compromise survival or ability to complete follow-up assessments during the 360 day follow-up period.
8. Current ESS including frontal sinus surgery is aborted for any reason.
9. Pregnant or lactating female
10. Investigator determination that the potential study subject is unable to comply with study procedures and/or follow-up, or provided informed consent.
11. Currently involved in another clinical study where that participation may conflict or interfere with the treatment, follow-up or results of the clinical study.