Hiatal hernias associated with acid reflux: size larger than 2 cm matters.

Hiatal hernia (HH) is associated with gastroesophageal reflux disease (GERD); the effect of HH size on GERD is not well defined. To evaluate the relationship between HH size as measured by high-resolution esophageal manometry (HREM) and reflux parameters on esophageal pH-impedance testing (multichannel intraluminal impedance-pH [MII-pH]) to define HH sizes associated with GERD. HREM and MII-pH studies were reviewed. The relationship of HH size to other parameters was analyzed with multivariable logistic regression. Correlation coefficients were determined using Spearman and Pearson's tests. A total of 897 patients underwent both HREM and MII-pH. There were 529 (58.9%) patients with HH size <1 cm, 203 (22.6%) with HH 1.0-1.9 cm, and 165 (18.4%) with HH ≥2 cm. Larger HH size was associated with lower esophageal sphincter (LES) basal and residual pressures (r = -0.43 and r = -0.48, p < 0.01), higher acid exposure time (AET) (r = 0.17, p < 0.01), number of acidic refluxes (r = 0.16, p < 0.05), and number of reflux episodes detected by impedance (total r = 0.22, p < 0.01). HH ≥ 2 cm compared with smaller size HH was associated with higher proximal AET%, acidic refluxes, and reflux episodes detected by impedance (p < 0.05). Increasing HH size was associated with older age, higher AET, and number of reflux episodes. HH ≥2 cm was associated with multiple worsened GERD parameters. Low LES pressure was weakly associated with an increase in the number of reflux episodes. Larger HHs, particularly >2 cm, are associated with more severe GERD parameters.