Abstract
Purpose: Pneumatosis intestinalis in association with gas in the superior mesenteric and hepatic portal vein (portomesenteric venous gas) is typically due to bowel infarction, and carries an ominous outcome. Much less commonly, it may be the result of nonischemic etiologies. We present a rare case of acute perforated appendicitis associated with pneumatosis intestinalis of the small bowel loop, and portomesenteric venous gas
Materials and methods: A 79-year-old male patient suffered from diffuse abdominal pain and cold sweating in the morning of the admission. Mild fever, tachycardia, diffuse abdominal distension and tenderness were noted. The blood analyses showed leukocytosis. Plain abdominal radiograph revealed distension of the bowel loop. CT of the abdomen showed swollen appendix with periappendiceal fluid, distension of small bowel loop, bowel wall gas in a segment of small bowel loop, and portomesenteric venous gas. Therefore, a CT diagnosis of acute perforated appendicitis, and probably bowel infarction was made.
Results: Emergency exploratory laparotomy was performed. Fecal material was seen surrounding the cecum, and the appendix showed gangrenous change and perforation. Appendectomy was done. A 30 cm segment of ileum disclosed hyperemic change and markedly distended, and decompression was performed. Two days later, second-look laparotomy showed no bowel ischemia. Due to persistent post-operative fever and turbid discharge from the surgical site, the patient’s family asked for transfer to the other hospital on the 15th postoperative day. The patient was finally discharged after infection control at the other hospital for a 43-day period of the second hospitalization. No bowel ischemia was noted during the second course of the hospitalization.
Conclusion: The mechanism of pneumatosis intestinalis and portomesenteric gas may be due to increased intraluminal pressure and associated mucosal disruption of the small bowel, leading to gas entering the bowel wall, through the superior mesenteric vein and subsequently to the hepatic portal vein. The clinical outcome is determined by the underlying disease, and not just the presence of superior mesenteric and portal venous gas.

Key words: acute appendicitis; pneumatosis intestinalis, portomesenteric venous gas