Clinical Evaluation of Propel Nova Sinus Implant in Peripheral Sinus Ostia

Inclusion Criteria: * Patient is ≥ 18 years of age. * Patient is willing and able to comply with protocol requirements. * Patient has CS as confirmed by CT scan and defined as symptoms lasting longer than 8 consecutive weeks in duration with inflammation of the mucosa of the nose and paranasal sinuses. * Patient's condition and the planned intervention will involve at least two and a maximum of four peripheral sinuses (frontal or maxillary sinuses or combination of both). * Patient is a candidate for a planned intervention involving sinus surgery in the operating room or office setting. * Patient has nasal polyps no greater than grade 2. * Patient with nasal polyps greater than 2 are eligible after their reduction/removal during ESS without significant complications that would confound the study results and leaving the patient's anatomy amenable to sinus implant placement, as judged by the operating physician. * Female patients of child-bearing potential must not be pregnant and must agree to not become pregnant during the course of the study. * Female patients of child-bearing potential must agree to use consistent and acceptable method/s of birth control during the course of the study. * CS diagnosis confirmed and documented by CT Scan within 6 months of the procedure. * Patient has a minimum total CT stage (Lund-Mackay method) of 6. * Patient has disease in frontal and/or maxillary sinuses confirmed by CT scan. * Planned ESS includes bilateral ethmoidectomy (if judged necessary), frontal sinus surgery using Draf II (A or B) dissection and/or balloon dilation, with minimum of 5-mm diameter opening created. In the case of maxillary sinus surgery, traditional antrostomy or balloon dilation, with or without removal of uncinate process, should be performed with minimum of 5-mm diameter opening created. * Technique used for frontal or maxillary sinus surgery was the same on both sides (e.g. surgical dissection alone bilaterally, balloon dilation alone bilaterally, or both bilaterally) * Septoplasty for access to the ostio-meatal complex is permitted. Exclusion Criteria: * Patient has presence of grade 3 or 4 polyposis, unless removed during surgery and preceding implant placement. * Patient has presence of adhesions/scarring grades 3 or 4, unless removed during surgery and preceding implant placement. * Patient has known history of immune deficiency (e.g., IGG subclass deficiency or IGA deficiency, HIV). * Patient has concurrent condition requiring active chemotherapy and/or immunotherapy management for the disease (e.g., cancer, HIV, etc.). * Patient has oral-steroid dependent condition such as COPD, asthma or other condition. * Patient has known history of allergy or intolerance to corticosteroids or mometasone furoate. * Patient has clinical evidence of acute bacterial sinusitis (e.g. acute increase in purulent discharge, fever, facial pain etc.). * Patient has clinical evidence or suspicion of invasive fungal sinusitis (e.g. bone erosion on prior CT scan, necrotic sinus tissue, etc.). * Patient has evidence of disease or condition expected to compromise survival or ability to complete follow-up assessments during the 90-day period. * Patient is currently participating in another clinical trial. * Patient has history of insulin dependent diabetes mellitus. * Patient has previously undergone ESS and experienced a CSF leak or has residual compromised vision as a result of a complication in a prior ESS procedure. * Patient has known dehiscence of the lamina papyracea. * Patient has evidence of active viral illness (e.g., tuberculosis, ocular herpes simplex, chickenpox or measles). * Significant complication during the current peripheral ostia surgery/such as excessive blood loss, CSF leak or punctured lamina papyracea. * Current surgical intervention (operating room or office setting) is aborted for any reason.