Portal venous gas

Portal venous gas is merely the accumulation of gas in the portal vein and its branches. It needs to be distinguished from pneumobilia, although this is usually not too problematic, when associated findings are taken into account along with the pattern of gas (i.e. peripheral in portal venous gas, central in pneumobilia).

Although traditionally considered a harbinger of death, portal venous gas is increasingly recognised in a variety of conditions, many of which do not carry as high mortality or morbidity risks.

Causes of portal venous gas are best divided according to the age of the patient:

• child
  • umbilical vein catheterisation
  • necrotising enterocolitis (NEC)
  • neonatal gastroenteritis
  • erythroblastosis fetalis
  • postoperative finding in corrective bowel surgery.
• adult
  • alterations of bowel wall
    • ischaemic bowel (usually mural gas as well as mesenteric gas : mortality of 75 - 90% : but gas is not an independent predictor)
    • necrotic / ulcerated colorectal carcinoma (CRC)
    • inflammatory bowel disease (IBD)
    • perforated peptic ulcer
  • bowel luminal distention
    • iatrogenic gastric and bowel dilatation (e.g upper and lower endoscopic procedures, enemas)
    • paralytic ileus / mechanical obstruction
    • acute gastric dilatation
    • barotrauma.
  • Intra-abdominal sepsis
    • diverticulitis
    • pelvic abscess
    • cholecystitis and cholangitis
    • appendicitis
  • unknown mechanism
    • pneumatosis intestinalis
    • chronic obstructive pulmonary disease (COPD)
    • corticosteroid usage

See also

• abnormal intra abdominal gas