Overview
Distinguish common sliding hiatus hernia from paraoesophageal complications, manage associated reflux and escalate obstruction, volvulus or ischaemia without delay.
The diaphragmatic crura, phreno-oesophageal attachments and lower oesophageal sphincter normally align to form the antireflux barrier. In a sliding hernia the gastro-oesophageal junction and proximal stomach move cranially, weakening this alignment and increasing reflux propensity. Sliding hernias are common with age, central adiposity and raised intra-abdominal pressure, but an image alone does not prove the cause of every chest or upper abdominal symptom. Treat the clinical reflux phenotype and investigate alarm features rather than chasing small changes in measured hernia size.
Paraoesophageal hernias preserve or displace the junction in differing ways while part of the stomach lies alongside the oesophagus; type IV can contain colon, small bowel, spleen or other viscera. A large intrathoracic stomach may reduce meal capacity, compress lung or heart, kink the outlet, bleed at the diaphragmatic impression or rotate around its axes. Chronic intermittent symptoms can abruptly become an emergency. Pain, retching and obstruction may precede ischaemia, and lactate can remain normal early, so the clinical and imaging pattern drives urgent surgical discussion.