Crural closure, not fundoplication, results in a significant decrease in lower esophageal sphincter distensibility

The esophagogastric junction (EGJ) is a complex anti-reflux barrier whose integrity relies on both the intrinsic lower esophageal sphincter (LES) and extrinsic crural diaphragm. During hiatal hernia repair, it is unclear whether the crural closure or the fundoplication is more important to restore the anti-reflux barrier. The objective of this study is to analyze changes in LES minimum diameter (D_min) and distensibility index (DI) using the endoluminal functional lumen imaging probe (FLIP) during hiatal hernia repair.

Following implementation of a standardized operative FLIP protocol, all data were collected prospectively and entered into a quality database. This data were reviewed retrospectively for all patients undergoing hiatal hernia repair. FLIP measurements were collected prior to hernia dissection, after hernia reduction, after cruroplasty, and after fundoplication. Additionally, subjective assessment of the tightness of crural closure was rated by the primary surgeon on a scale of 1 to 5, 1 being the loosest and 5 being the tightest.

Between August 2018 and February 2020, 97 hiatal hernia repairs were performed by a single surgeon. FLIP measurements collected using a 40-mL volume fill without pneumoperitoneum demonstrated a significant decrease in LES D_min (13.84 ± 2.59 to 10.27 ± 2.09) and DI (6.81 ± 3.03 to 2.85 ± 1.23 mm²/mmHg) after crural closure (both p < 0.0001). Following fundoplication, there was a small, but also statistically significant, increase in both D_min and DI (both p < 0.0001). Additionally, subjective assessment of crural tightness after cruroplasty correlated well with DI (r = - 0.466, p < 0.001) and all patients with a crural tightness rating ≥ 4.5 (N = 13) had a DI < 2.0 mm²/mmHg.

Cruroplasty results in a significant decrease in LES distensibility and may be more important than fundoplication in restoring EGJ competency. Additionally, subjective estimation of crural tightness correlates well with objective FLIP evaluation, suggesting surgeon assessment of cruroplasty is reliable.