Gastric obstruction secondary to abdominal re-herniation of a giant hiatal hernia. An illustrative case to understand the pathophysiology of gastric volvulus.

Purpose: To depict the characteristics of a special type of gastric volvulus caused by acute re-herniation of a previous hiatal hernia.Materials and methods: We present the case of a male patient with known history of a giant hiatal hernia who presented to our emergency department with a chief complaint of epigastric pain, oral intolerance and incoercible vomiting in the last 24 h. On suspicion of abdominal complication, an emergent computed tomography (CT) scan was performed.Results: Gastric volvulus secondary to downward re-herniation of the fundus into the abdominal cavity was the cause of this patient's symptoms. This mechanism, which was demonstrated by comparing the CT findings of the acute episode with previous imaging studies, reveals a largely unrecognized pathogenic mechanism of gastric volvulus.Conclusions: Acute gastric volvulus should be suspected in patients with hiatal hernia. CT allows its diagnosis and likely underlying pathophysiological mechanism.

'Back-and-Forth Stomach' CT Imaging Findings of a Pathophysiologic Entity Causing Acute Gastric Volvulus.

BACKGROUND: Gastric volvulus (GV) is a life-threatening emergency condition that prompts emergent surgical management. With the advent of high-resolution computed tomography (CT), the role of radiologists in its diagnosis has become essential. Although many cases of GV have been described in the literature, its pathophysiology is still poorly understood. In addition, there is substantial terminological confusion with associated entities such as paraesophageal hernia, upside-down stomach, organo-axial or chronic GV. METHODS: We conducted a retrospective review of clinical, radiological findings and other relevant data for seven patients with previous radiological diagnoses of a large hiatus hernia who presented with acute GV to the emergency department of our institution. We report data on age, sex, medical history, clinical presentation, imaging, treatment and outcomes for each case. RESULTS: The CT findings at acute presentation showed the antrum lying above the diaphragm and dilated fundus below the diaphragm. By comparing the position of the stomach at acute presentation with previous imaging examinations, we confirmed a hypothesis put forward by a few authors decades ago that re-herniation of the gastric fundus into the abdomen is a common pathophysiologic trigger leading to acute GV. This hypothesis has not been supported by modern imaging examinations. CONCLUSIONS: We have provided imaging evidence supporting that the pathophysiology of many GVs is based on caudal re-descent of hiatal hernia into the abdominal cavity. Given the terminological disparity used in the literature in this context, we believe it appropriate to introduce and extend the term 'back-and-forth stomach' to refer to this type of GV.