The effect of surgical repair of hiatal hernia (HH) on pulmonary function: a systematic review and meta-analysis.

PURPOSE: Hiatal hernia is renowned for the symptom of reflux, and few physicians associate a hiatal hernia with pulmonary issues. It is widely acknowledged that a hiatal hernia can be treated with surgery. However, less is known about how the surgical procedure would benefit pulmonary function. Thus, the aim of this study was to determine whether surgical repair can improve pulmonary function in patients with hiatal hernias.

METHODS: We registered the protocol on the PROSPERO (International Prospective Register of Systematic Reviews) platform (no. CRD42022369949). We searched the PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases for cohort studies that reported on the pulmonary function of patients with hiatal hernias. The quality of each cohort study was evaluated using the Newcastle-Ottawa scale (NOS). We then calculated mean differences (MDs) with 95% confidence intervals for these continuous outcomes. Each study's consistency was appraised using the I2 statistic. The sensitivity analysis was performed using the trim-and-fill method. Publication bias was confirmed using the funnel plot visually and Egger regression test statistically.

RESULTS: A total of 262 patients from 5 cohorts were included in the meta-analysis. The quality evaluation revealed that, of these 5 papers, 3 received 8 NOS stars out of 9 stars, 1 received 9, and the other received 7, meaning all included cohort studies were of high quality. The results showed that surgical repair for a hiatal hernia significantly improved forced expiratory volume in 1 s (FEV1; weighted mean difference [WMD]:0.200; 95% CI 0.047-0.353; I2  = 71.6%; P = 0.010), forced vital capacity (FVC; WMD: 0.242; 95% CI 0.161-0.323; I2  = 7.1%; P = 0.000), and total lung capacity (TLC; WMD: 0.223; 95% CI 0.098-0.348; I2  = 0.0%; P = 0.000) but had little effect on residual volume (RV; WMD: -0.028; 95% CI -0.096 to 0.039; I2  = 8.7%; P = 0.411) and the diffusing capacity carbon monoxide (DLCO; WMD: 0.234; 95% CI -0.486 to 0.953; I2  = 0.0%; P = 0.524).

CONCLUSION: For individuals with hiatal hernias, surgical repair is an efficient technique to improve respiratory function as measured by FEV1, FVC, and TLC.