Pathogenic mechanisms of intestinal pneumatosis and portal venous gas: should patients with these conditions be operated immediately?

Surgical Case Reports

Table 1 Our hypothesis about classification of IP

① Infection	Mechanism
	Gas-producing bacteria infect and colonize the intestinal wall. Mucosal rupture is not always involved.
	Clinical cases
	Sepsis caused by acute mesenteric ischemia and others.
	Prognosis
	Highly likely to have severe infection or to have already developed sepsis, and a fatal outcome is likely.
	Therapeutic strategies
	Emergency surgery should first be considered.
② Mucosal rupture + increased intraluminal pressure	Mechanism
	Intestinal gas seeps into the damaged mucosa and gradually migrates to the deep layer; infection does not always occur concomitantly.
	Clinical cases
	Inflammatory bowel disease, gastric cancer or ulcer, ileus, severe constipation, blunt abdominal trauma, and so on.
	Prognosis
	The risk of perforation is low when the extent of mucosal rupture is limited. If the rupture persists for a long time, it will be complicated by bacterial infection and progress to the above “infection.”
	Therapeutic strategies
	Emergency surgery is not always required.
③ Mixed type	① + ②

IP can be classified into three types according to pathogenesis: (1) infection, (2) rupture (damage) of the intestinal mucosa + increased intestinal intraluminal pressure, and (3) mixed type