Eligibility Criteria
All published studies including case reports and interventional studies reporting original patient data were included. The inclusion criteria were: studies published in English, studies where PNN was performed either with or without additional procedures, and where measures of objective/subjective outcomes and/or complications were reported. Studies were excluded if they were unavailable in English, undertaken on animals, included patients with chronic rhinosinusitis with nasal polyps, or if other neurectomy procedures (eg vidian neurectomy) were performed instead of PNN.