An accurate history and thorough examination are crucial for the management plan. Correlation between the clinical signs and the radiological findings will be the most important factor in the decision to proceed to laparotomy or not. Acute abdominal signs and positive radiology will mandate emergency operation in the majority of cases. On the other hand positive radiology with no acute abdominal signs may indicate a conservative treatment especially in elderly frail patients.

Is superior to other radiological modalities and it is the gold standard for diagnosis of PVG and its aetiology 4546 (see figure 2). At CT, portal vein gas appears as tubular areas of decreased attenuation in the liver, predominantly in the left lobe 47. The extent of PVG depends on the cause and severity of the underlying pathology and therefore the demonstration of a small amount of gas in the portal vein may indicate a less severe condition and suggest a less invasive approach. 48. In these cases CT scan can provide crucial information for diagnosis and whether emergency surgery is needed or not. The most important information provided by CT scan is to rule out bowel ischemia, thus a negative CT scan could help to decide the next step of management which could be a conservative one. Although modern imaging contributes to the safe and effective management plan, CT scan however, may be of limited value in certain cases where the prediction of the extent of the gastrointestinal ischemia can not be accurately assessed. Therefore partial thickness infarction and necrosis which can produce PVG and pneumatosis intestinalis may be undetectable by CT study 49.

Can be used to assess the PVG and predict the outcome50. The ultrasound features include dot-like, streak-like and fruit-pulp-like patterns 51. The real time phase of US is advantageous to detect the PVG and may be of comparable accuracy to the CT scan, however CT scan is more valuable in detecting the aetiology of PVG or excluding abdominal catastrophes 52. When US is positive, urgent clinical evaluation followed by contrast-enhanced CT is indicated to assess for associated intestinal ischemia53.

The efficacy of this modality is less than CT scan in detection of PVG 54.

This modality will delineate the portal system and is helpful in the assessment of patency of the portal vein and associated tributaries and whether there is occlusive or non occlusive ischemia.

The plain film is of no specific diagnostic criteria; nevertheless, it can show indirect signs such as oedematous bowel wall, ileus, gasless abdomen, or gas in the bowel wall and portal vein in more severe cases of bowel ischemia. Plain abdominal x-ray can detect PVG in about 12.5% of cases 55.

An increase in the white cell count in more than 50% of cases and lactic acidosis in more than 90% of patients with established bowel ischemia is usually confirmed. Polycythemia and thrombocythemia may indicate a clue to the likely cause. These non specific parameters will help in the overall assessment of patients.

Is largely applied to the underlying cause (see Additional file 1). However, there are cases where a surgeon will proceed to abdominal exploration in the presence of borderline abdominal signs. Gas in portal vein is a good predictive factor for diagnosis, management, and prognosis 56. In the past the traditional teaching is to operate once you have radiological evidence of PVG. However with the advances in diagnostic radiology, endoscopy, baseline support and intensive care setting, a less invasive approach is suggested especially for benign cases which indicate no intrabdominal catastrophe and thus reducing the rate of negative laparotomy 57. Endoscopy can be very helpful in assessment or exclusion of upper and lower gastrointestinal pathology in the presence of PVG when CT scan gave no clue to the diagnosis, therefore a more sensible decision can be made. Patients diagnosed by CT scan with obstruction, infarction or vascular problems need no further endoscopic confirmation and are candidates for emergency exploration.

Therefore, patients who present with PVG can be divided into three categories: Firstly: those who have acute abdominal features and positive diagnostic criteria will need immediate exploration by laparoscopy or laparotomy.

Secondly: Patients who have positive diagnosis of PVG but without abdominal signs, are relatively stable and have no mesenteric ischemia will be good candidates for a conservative approach 58.

Thirdly: Patients who have borderline features of acute abdomen and less dense diagnostic signs of PVG may need endoscopic examination of the upper and lower GIT as a safe approach rather than to wait for underlying bowel ischemia 59. This can be achieved using diagnostic laparoscopy which can help identify GIT pathology. In non GIT cause such as vascular disease or when the problem cannot be managed laparoscopically, laparotomy is indicated.

The history, severity of clinical signs and the density of PVG depicted by diagnostic tests will direct the management to either emergency intervention or conservative plan. With prompt surgical response a high mortality figure of 86% in bowel ischemia can be reduced to an acceptable figure 60. Although the amount of gas is correlated with the severity of the pathology, the prognosis however, was related to the pathology itself and was not influenced by the presence of the gas in the portal system 6.