Does retching matter? Reviewing the evidence-Physiology and forces.

Failure of antireflux surgery is common in children with neurodisability, with a high incidence of persistent or recurrent symptoms, including retching. Anatomical disruption of the wrap is a frequent finding, but what forces underlie this disruption? This article reviews the forces generated during potential wrap-stressing episodes, putting them into the clinical context of wrap failure. Historically, wrap failure has been attributed to pressures arising from a reduction in gastric capacity or compliance, with advocates for an additional, gastric emptying procedure, at the time of fundoplication. However, any postoperative pressure changes are small and insufficient to cause disruption, and evidence of benefit from gastric emptying procedures is lacking. Diaphragmatic stressor events are common in the presence of neurodisability, and there is now increasing recognition of an association between diaphragmatic stressors and wrap breakdown. The analysis in this review demonstrates that the greatest forces on the fundoplication wrap are those associated with retching and vomiting. The direction and magnitude of these forces are sufficient to cause wrap herniation into the thorax, and wrap separation. Clinical series confirm that retching is consistently and strongly associated with wrap breakdown. Retching needs to be addressed if we are to reduce the incidence of wrap failure. Level of Evidence V.