This is a randomised, unblinded interventional device proof of concept pilot trial in which patients undergoing nasal surgery will be selected for either photodisinfection therapy (PDT) with the Steriwave™ ND System, or control with nares swabbed with 'photosensitizer formulation' preoperatively.

This trial will primarily assess the safety and efficacy of nasal photodisinfection treatment in decreasing post-operative events in patients undergoing nasal surgery. After signing informed consent, and before surgery, participants will receive a baseline culture of the anterior nares to determine nasal bacterial colonization and will have a flexible nasendoscopy to determine their Lund-Kennedy (LK) endoscopic score. Subjects will then be randomised to nasal PDT (which includes two applications of 'photosensitizer formulation' [0.01% methylene blue with 0.25% chlorhexidine solution], two minutes apart), along with light therapy, or control with nares swabbed twice with 'photosensitizer formulation' with two minutes in between (no light therapy). Following treatment, participants will be re-cultured (2 weeks after the surgery ± 7 days) and reviewed for antibiotic use and surgical site infection (SSI) using LK endoscopic scoring. At 30 days, all participants will be followed up by telephone to review if they received antibiotics for presumed postoperative infection. Standard post-operative care will be provided according to the type of surgery performed. Any required interventions post-operatively will be documented.

Preoperative nasal decolonisation has been shown to achieve significant reductions in surgical site infections at sites remote from the nasal cavity. It would therefore seem to have great potential in reducing the risk of post-operative infections after sinonasal surgery, and therefore reduce antibiotic usage. If surgeons have confidence in the treatment, those that routinely prescribe prophylactic antibiotics may also be pursued to change their practice.

The aim of this study is to assess the efficacy and safety of photodisinfection therapy versus control with nares swabbed with 'photosensitizer formulation' (0.01% methylene blue with 0.25% chlorhexidine solution) to reduce the antibiotics usage for presumed SSI inpatients undergoing nasal surgery. The investigators hypothesise that preoperative photodisinfection will demonstrate greater efficacy compared to control with nares swabbed with 'photosensitizer formulation' (0.01% methylene blue with 0.25% chlorhexidine solution) in reducing the usage of antibiotics for presumed surgical site infection (SSI) among patients undergoing nasal surgery.

The investigators will also further evaluate the effectiveness of nasal decolonisation in eliminating colonization of the anterior nares with S. aureus and other potentially pathogenic microbes. The anterior nares are often considered the primary reservoir of S. aureus and other pathogens on the body (36). Therefore, this product could play an important role in helping to eliminate the anterior nares as a pathogen reservoir in surgical patients.

This study is meant to provide further safety, efficacy, and methodological data, but is not intended to establish definitive statistical significance. If required, this study will support a subsequent larger study that would establish statistical significance for the reduction of surgical site infections, but which is currently not the subject of this protocol.

Inclusion Criteria:

• Patients ≥ 16 years

• Patients scheduled to undergo elective:

  • Endoscopic Sinus Surgery (ESS) with or without adjunctive Septoplasty and/or Turbinoplasty
  • Septoplasty with or without adjunctive Turbinoplasty
  • Closed Septoplasty with or without adjunctive Turbinoplasty

• Judged by the Investigator as suitable for participation in the study without safety concerns based on medical history and physical examination

• Willing and able to provide written informed consent prior to participation in the clinical investigation

• Willing and able to comply with all study related procedures

Exclusion Criteria:

-• Patients undergoing open septorhinoplasty, anterior or septal biopsies, or post cautery

• Congenital or acquired immunodeficiency, bone marrow disease, diabetes, autoimmune conditions requiring immunosuppressive treatment, any immunosuppressive medication at the time of consent or within the last 4 weeks before randomisation
• Primary or secondary ciliary dyskinesia, cystic fibrosis
• Patients who have received antibiotics within a week before randomisation
• Patients who receive prophylactic antibiotics or antibiotics prior to discharge
• Systemic steroid treatment less than 4 weeks before randomisation
• History of frequent nose bleeds, or a condition that increases the risk of excessive bleeding
• Undergoing active cancer treatment at time of consent/ or planning to start cancer treatment within trial period or completed cancer treatment within the last 4 weeks
• Any disease, condition (medical or surgical), or drug or alcohol abuse, which, in the opinion of the investigator, might compromise the study results, or would place the patient at increased risk of infection
• Previously treated with radiation on the face, head, or neck regions
• Female patients who are pregnant or breastfeeding at the time of consent
• Received a study drug in a clinical trial for an investigational drug within the previous 30 days from consent, or 5 half-lives, whichever is longer
• Used antimicrobial wash or wipes within 7 days of randomisation or during the study period
• Patients with allergies / hypersensitivity to methylene blue, polymethyl methacrylate (PMMA), or to chlorhexidine gluconate (CHG)

The trial will be conducted in accordance with the Data Protection Act 2018. The chief investigator will ensure that participant's anonymity is maintained throughout the study and following completion of the study.

Pseudonymised data will be shared with the study Statistician who is an employee of the Trust and member of the study team. It will be extracted from REDCap and sent via encrypted email in a locked Excel document. After the analysis the data will be archived in Iron Mountain.

No data will be shared outside of GSTT during the course of the study.

Data will not be shared with the device manufacturer.