Sonographically Detected Hepatic Portal Venous Gas - Prevalence, Causes, and Clinical Implications

Hepatic portal venous gas (HPVG) is a rare clinical finding, often caused by a severe underlying disease. In the literature as well as in clinical practice, HPVG is considered "signum malum" with a poor prognosis and bowel ischemia as the most common cause. Most studies are based on the results of computed tomography (CT) examinations. The aim of this retrospective study is to report on the prevalence, causes, and clinical course of HPVG in a monocentric cohort of abdominal ultrasound (US) investigations.

The US database of an academic teaching hospital was searched with specific keywords (timespan 01/2000 to 12/2020). Reports, pictures, and clinical data of all cases with HPVG were re-evaluated.

Out of 134 804 US examinations, 8 HPVG cases were identified. There was a wide variety of underlying diseases, with mesenteric ischemia being seen in only 2 cases. 5 patients were discharged in stable condition, with 4 of them having undergone surgical treatment. 2 patients who had rejected further measures died, and one was lost to follow-up.

HPVG is a rare phenomenon in clinical US. However, ultrasonographic prevalence is comparable to the prevalence in CT studies. Underlying diseases are mostly severe, and in nearly all cases an underlying cause can be found by thorough investigation. In some cases, US may even be superior to CT scans for the detection of HPVG. Despite its rarity, every sonographer should know the typical sonographic presentation of HPVG, and appropriate images should be included in US teaching modules.