Gastric Volvulus

Michael P. Federle, MD, FACR

Key Facts

Imaging

Organoaxial volvulus: Rotation of stomach around its longitudinal axis
- Most common type
- Stomach twists either anteriorly or posteriorly
- Antrum moves from inferior to superior
Mesenteroaxial volvulus: Rotation of stomach about mesenteric axis
- Stomach rotates from right to left or left to right about long axis of gastrohepatic omentum
Entire stomach may be herniated (type 4 paraesophageal hernia) or only part (type 3 PEH)
- Either can result in volvulus, ± obstruction, ± ischemia
- Gastric wall pneumatosis = ischemia
CT chest and abdomen; performed preoperatively
- To detect associated malformation or malposition and site, size, level of diaphragmatic defect

Top Differential Diagnoses

Hiatal hernia
- Type 3 & 4 paraesophageal hernias at risk for GV
Postoperative state, stomach
- Esophagectomy with gastric pull through (conduit may twist and obstruct)

Pathology

Associated abnormalities
- Large paraesophageal hernia
- Diaphragmatic eventration or paralysis
- Hernia of colonic transverse loop ± other bowel loops

Diagnostic Checklist

Presence or absence of obstruction and ischemia are more important than remembering or reporting whether volvulus is organo- or mesenteroaxial

(Left) Chest film in an elderly woman shows stomach and other bowel within the right hemithorax. (Right) An upper GI series in the same patient confirms an organoaxial volvulus of the stomach. This is a type 4 paraesophageal hernia (intrathoracic stomach). There is minimal obstruction at the time of this study, but the patient is at risk for strangulation and obstruction.

(Left) CT in the same patient shows the stomach

within a hernia sac in the right thorax, and it is rotated on its long axis (organoaxial volvulus). (Right) Much of the transverse colon

is also within the hernia sac in the same patient. Due to the enormous size of the hiatal defect in the diaphragm, neither the stomach nor the colon was pinched as it traversed the diaphragm.

TERMINOLOGY

Abbreviations

Gastric volvulus (GV)

Definitions

Uncommon acquired twist of stomach on itself

IMAGING

General Features

Morphology
- Abnormal degree of rotation of 1 part of stomach around another part
Types of GV: Organoaxial (most common), mesenteroaxial, mixed
Organoaxial volvulus (OAV): Rotation of stomach around its longitudinal axis
- Around line extending from cardia to pylorus
- Stomach twists either anteriorly or posteriorly
- Antrum moves from inferior to superior position
Mesenteroaxial volvulus (MAV): Rotation of stomach about mesenteric axis
- Axis running transversely across stomach at right angles to lesser and greater curvatures
- Stomach rotates from right to left or left to right about long axis of gastrohepatic omentum
Mixed volvulus: Combination of OAV & MAV

Radiographic Findings

Radiography
- Abdominal plain films; patient upright
  - Double air-fluid level
  - Large, distended stomach; seen as air- and fluid-filled spheric viscus displaced upward and to left
  - Small bowel collapsed if stomach is obstructed
- Chest film: Intrathoracic; upside-down stomach
  - Retrocardiac fluid level; 2 air-fluid interfaces at different heights; suggests intrathoracic GV

Fluoroscopic Findings

Massively distended stomach in left upper quadrant extending into chest
Inversion of stomach
- Greater curvature above level of lesser curvature
- Positioning of cardia and pylorus at same level
- Downward pointing of pylorus and duodenum
OAV: 2 points of twist; luminal obstruction
Incomplete or absent entrance of contrast material into &/or out of stomach; acute obstructive GV
- OAV: Failure of contrast to enter stomach; obstruction at esophagus or proximal stomach
- If contrast material does enter stomach, it may not pass beyond obstructed pylorus
May see “beaking” at point of twist
MAV: Antrum and pylorus lie above gastric fundus