Diagnosis of Abdominal Hernia

Initial Diagnostic Approach

The American College of Surgeons recommends that for most abdominal hernias, clinical examination combined with CT scan with intravenous contrast is the diagnostic approach of choice, as CT provides superior sensitivity and specificity compared to physical examination alone and can identify hernia location, contents, and complications 1, 2
Internal hernia is suspected and should be imaged with CT, as these cannot be diagnosed clinically 1

The World Journal of Emergency Surgery suggests that CT with intravenous contrast is the imaging modality of choice for abdominal hernias, with 14-82% sensitivity and 87% specificity for diaphragmatic hernias 1, 2, 3
CT accurately identifies the hernia location, size of the defect, hernial contents, and complications such as obstruction, ischemia, or perforation 1, 2, 3
Key CT findings to identify include discontinuity of the abdominal wall or diaphragm, "collar sign", and signs of complications: bowel wall thickening, pneumatosis, lack of contrast enhancement indicating ischemia 2, 3, 4

The World Journal of Emergency Surgery states that internal hernias require CT for diagnosis, as they cannot be diagnosed clinically due to nonspecific presentation 1
CT is the only reliable method to identify internal hernias before they progress to strangulation 1
In post-bariatric surgery patients, CT with both oral and IV contrast is mandatory, as altered anatomy makes clinical and radiological diagnosis challenging 4
Negative CT does not rule out internal hernia in post-bariatric patients, and a low threshold for diagnostic laparoscopy should be maintained if symptoms persist 4
For diaphragmatic hernias, chest X-ray is recommended as initial study, followed by CT if positive or if suspicion remains high, with CT identifying diaphragmatic discontinuity, herniated organs, and signs of visceral ischemia 2, 3