The effects of endoscopic sinus surgery on pulmonary function in chronic rhinosinusitis patients with asthma: a systematic review and meta-analysis

Purpose Evidences showed improvements in clinical asthma outcomes following endoscopic sinus surgery (ESS) in chronic rhinosinusitis (CRS) patients with asthma. However, pulmonary function benefits have remained controversial up to date. The goal of this study was to conduct a systematic review and meta-analysis to investigate the effects of ESS on pulmonary function tests in CRS patients with asthma. Methods Pubmed, Embase and Cochrane Library were searched up to March 2018 to obtain relevant studies. The researches that evaluated the effects of ESS on pulmonary function in CRS patients with asthma and had at least one parameter of pulmonary function tests before and after surgery were included in the study. Results A total of 13 studies containing 421 patients satisfied the eligibility after judgment by 2 reviewers. These included three RCTs and ten case series. The heterogeneity in parameters of spirometry and difference in data presented forms across studies along with the lack of standard deviation of some data make it difficult to synthesize results. If data were unavailable for meta-analyses, descriptive statistics were used to report study outcomes. After qualitative and quantitative analysis, the weighted mean change after ESS in forced expiratory flow between 25% and 75% of vital capacity (FEF25-75%) was 0.21L/s (95% CI 0.12-0.30); eight of ten studies supported that forced expiratory volume at 1s (FEV1) improved after ESS; five of six studies supported that peak expiratory flow (PEF) improved after ESS. However, strength of evidence is generally low to insufficient. Conclusion A generally low-quality evidence supports the association between ESS and improvements in FEF25-75%, FEV1 and PEF. A few studies met inclusion criteria for meta-analysis, which indicates the need for more high-quality studies to determine the effect of ESS.