For the proposed internal pilot study 20 patients who consent to participate and meet all inclusion criteria and none of the inclusion criteria will be enrolled. The internal pilot study will be carried out at sites located in Ottawa , Winchester, Toronto, Barrie, Sault Saint Marie and London Ontario. A total of 7 investigator-surgeons will participate. Since this is an internal pilot study a sample size was not calculated, rather, the 20 patients enrolled in the internal pilot study will be included as part of the total sample of the definite non-inferiority trial, which has been calculated to be 140 patients. The pilot will recruit 15% of the total sample which is sufficient to achieve the main goal of this pilot i.e. establish the feasibility of the main trial. Eligible participants will be randomly assigned in a 1:1 fashion to either the experimental (endoscopic polypectomy performed in clinic, EPIC) or the control group (functional endoscopic sinus surgery, FESS) . Patients will be allocated to treatment group using web-based central randomization to protect against bias , these data will be used to confirm the design the non-inferiority randomized control trial.
Duration of treatment period For both experimental (endoscopic polypectomy performed in clinic, EPIC) and control (functional endoscopic sinus surgery, FESS) groups, the day the treatment is completed will be considered to be time "0". There is no change to either procedure related to the participant having enrolled into the study. After the treatment day, participants will enter a follow-up period where the final study related evaluation is 90(± 5) days following their procedure.
Frequency and duration of follow up Enrolled participants will be re-evaluated by the investigators after their procedure twice, which is the normal frequency of visits for postoperative care for patients who have undergone surgical treatment for chronic rhinosinusitis with polyps. The first follow-up evaluation at 15 days (± 5 days) following the procedure and the last will occur 90 days (± 5 days) following the treatment. The last follow-up is chosen to be at 90 days given the primary outcome measure of interest is the sinonasal outcome test-22 (SNOT-22) score. Three months after treatment the SNOT-22 does not appear to change substantially with further follow-up. A landmark study completed by Hopkins et al. (2006) with a cohort of over 3000 patients who had undergone endoscopic sinus surgery for chronic sinusitis and who were followed for 36 months demonstrated that the sinonasal outcome test SNOT-22 scores at 3 months following surgery were not different from those measured at 12 or 36 months. Therefore, the 3-month (90 days) follow-up has been specifically chosen for this study given the primary outcome measure being used is also the SNOT-22 score.
Long Term Follow up:
After the second follow up visit, patients will enter a long term follow-up period which will last 5 years. During this period, patients will receive the following questionnaires via mail: SNOT-22, EuroQol (EQ-5D-5L) questionnaire, work productivity and impairment questionnaire (WPAI), Satisfaction Survey and the Individual Health Resource Consumption. These questionnaires will be mailed at 6 months, 1,2,3,4 and 5 years after the procedure. At this time patients will also be asked if they have had additional surgeries for their chronic rhinosinusitis with nasal polyps
