Clinical diagnosis
Case 198
【Progress】
Both Case 1 and Case 2 had no specific treatment with progress observation. Follow-up CT showed spontaneous disappearance of portal venous gas.
【Discussion】
Portal venous gas was previously regarded as the sign of emergency or poor prognosis (1-4). It is true that necrosis of digestive organ causes gas production which moves to portal vein and to intrahepatic portal venous branches. However, portal venous gas on routine CT can be encountered not in the serious condition. Our both cases experienced severe or persistent vomiting and thereafter abdominal pain. Abdominal CT showed hepatic portal venous gas in the peripheral portal branches. Especially, in Case1, massive gas retention in the gastric wall was found on CT (Figs 1-3). Further, massive gas was found not only in the peripheral portal branches but also main and 1st branch portal vein (Fig. 1). The both patients suffered from brain infarction sequelae, almost lying in bed. Case 1 had percutaneous endoscopic gastrostomy and Case 2 had ventricular peritoneal shunt, indicating that they were in the poorly nutrition state with fragile gastric wall. Vomiting causes high pressure intragastric lumen in which gas penetrate the fragile gastric wall and enter the gastric vein, inducing portal venous gas.
Emphysematous gastritis indicates bacterial proliferation with necrotic gas formation (5). Our both cases were not emphysematous gastritis but gastric emphysema with no relation with bacterial infection. Then, prognosis of gastric emphysema is benign whereas that of emphysematous gastritis is poor.
There are various diseases with portal venous gas. As diseases with life-threatening portal venous gas, ischemic bowel, infectious bowel and /or necrotic carcinoma are listed and their prognosis is poor with the mortality rate of 70 to 100% (1-5). As benign diseases, pneumatosis intestinalis, intraluminal distension and iatrogenic bowel dilatation are listed. In our two cases, vomiting alone caused portal venous gas.
It is crucial to differentiate life-threatening portal gas from benign portal venous gas. Lactate dehydrogenase (LDH) and lactate on laboratory test are useful to differentiate them. The values of LDH 387U/L or greater (6) and /or lactate 3.0mg/dL or greater (7) imply the bowel necrosis. In Case 1 and Case 2, laboratory test revealed LDH 167 U/L and 244 U/L, respectively, indicative of no evidence of bowel necrosis. Practically our two cases naturally relieved under progress observation with no specific management.
【Summary】
We present two cases with portal venous gas after vomiting. The common backgrounds of two cases were in the poor nutritional state of brain stroke sequelae, indicative of fragile gastric wall. Gastric intraluminal pressure during vomiting causes intraluminal gas penetrate gastric wall causing gastric emphysema and portal venous gas. Portal venous gas was previously thought to be a life-threatening sign such as ischemic bowel, infectious bowel (emphysematous gastritis) and /or necrotic carcinoma. It is borne in mind when abdominal CT show portal venous gas, you have to not only check portal gas origin but also values of LDH or lactate itself for differentiation between bowel necrosis or benign disease. The values of LDH 387U/L or greater and /or lactate 3.0mg/dL or greater are cut-off values for the bowel necrosis.
【References】
1.Liebman PR, et al. Hepatic–portal venous gas in adults: etiology, pathophysiology and clinical significance. Ann Surg, 1978;187: 281-287
2.Peloponissios N, et al. Hepatic portal gas in adults: review of the literature and presentation of a consecutive series of 11 cases. Arch Surg, 2003; 13: 1367-1370
3.Chien-Hua L, et al. Pneumatosis intestinalis and hepatic-portal-mesenteric venous gas in intestinal ischemia. Rev Esp Enferm Dig. 2007; 99: 96-99
4.Monneuse O, et al. Portal venous gas detected on computed tomography in emergency situations: surgery is still necessary. World J Surg. 2007;31:1065-1071
5.Al-Jundi, W, et al. Emphysematous gastritis: case report and literature review. Int J Surg; 2008; 6: 63-66
6.Koami, H, et al. Risk factors for bowel necrosis in patients with hepatic portal venous gas. Surg Today. 2015; 45: 156-161
7.Wayne E, et al. Management algorithm for pneumatosis intestinalis and portal venous gas: treatment and outcome of 88 consecutive cases. J Gastrointest Surg. 2010; 14:. 437-448
2020.7.15