Management of post-operative pseudomonas aeruginosa infection in head and neck free flap patients: Systematic review and case series

Introduction/Aims: Pseudomonas aeruginosa (PA) is isolated in up to 12% of post-operative head and neck cancer patients, capable of surgical site tissue invasion triggering acute inflammation, thrombus formation, and localized microcirculatory collapse. This may result in flap failure and delay post-operative radiotherapy due to extended hospital stays. This report reviews literature on acetic acid washouts as adjunctive treatment for post-surgical PA infection and presents a single-centre case series. Methods: A systematic review protocol was registered with PROSPERO, and a comprehensive literature search on acetic acid use in PA infection was conducted. A retrospective single-centre review of head and neck patients undergoing ablative and reconstructive surgery with microvascular free tissue transfer (2020-2023) was performed. Patients with clinical and biochemical evidence of PA infection received 2-3 daily bedside washouts with 0.05% acetic acid for 7-14 days, alongside intravenous antibiotics. Results: Six patients with post-operative PA infection were identified. Acetic acid washouts were administered for 1-2 weeks alongside IV antibiotics based on susceptibility testing. Four patients required return to theatre (mean days post-op=20.5; range=5-44). Post-operative inpatient stays ranged from 9 to 38 days. No flap failures or metal-work removals occurred. Our literature search found no comparable studies. Conclusions: Acetic acid is an easily available, non-toxic, inexpensive topical agent, with bedside washout courses costing £28-£84 per patient. This modest expense is outweighed by the substantial health and psychological benefits of avoiding flap failure. Its low side effect profile supports its use in managing PA-infected surgical sites post-operatively in head and neck cases.