Differential Diagnosis for Portal Venous Gas (PVG)
The presence of gas in the portal venous system, as indicated by a CT abdomen showing gas throughout the periphery of the liver, is a critical finding that warrants a thorough differential diagnosis. The patient's symptoms of vomiting and diarrhea for one week further guide the diagnostic considerations.
Single most likely diagnosis
- Mesenteric Ischemia: This condition is a leading cause of PVG and is characterized by insufficient blood flow to the intestines, which can lead to bowel infarction. The patient's symptoms of vomiting and diarrhea, combined with the CT findings, make this a highly plausible diagnosis.
Other Likely diagnoses
- Necrotizing Enterocolitis: Although more common in neonates, this condition can occur in adults, especially those with compromised immune systems or severe intestinal infections. It involves the death of intestinal tissue, which can lead to gas in the portal venous system.
- Inflammatory Bowel Disease (IBD): Severe cases of IBD, such as Crohn's disease or ulcerative colitis, can lead to complications including toxic megacolon, which may result in PVG.
- Diverticulitis: Complicated diverticulitis, particularly if it involves perforation, can lead to PVG.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Bowel Perforation: Any condition leading to perforation of the bowel can result in PVG. Early diagnosis is crucial as it often requires immediate surgical intervention.
- Septic Shock: While not a direct cause of PVG, septic shock can result from conditions that also lead to PVG (e.g., severe infections). Recognizing and treating the underlying cause promptly is vital.
Rare diagnoses
- Gastrointestinal Cancer: Rarely, cancers of the gastrointestinal tract can lead to PVG, either through direct invasion of the portal venous system or through complications like bowel obstruction and subsequent ischemia.
- Intra-abdominal Infections: Certain infections, such as abscesses or infected pancreatic pseudocysts, can very rarely lead to PVG if they involve gas-producing organisms and communicate with the portal venous system.