Extensive portal venous gas & thrombosis

Clinical History

Symptoms of vague abdominal discomfort with dizziness. Blood tests showing raised inflammatory markers/deranged liver function tests.
CT abdomen revealed portal venous gas (PVG) & thrombosis, diverticular disease/free fluid present in the pelvis. Repeat CT 9 days later showed more extensive venous thrombosis with absence of PVG.

Imaging Findings

The patient had nonspecific abdominal symptoms, systemic sepsis and deranged liver function tests. Blood cultures grew E. Coli bacteria. A CT abdomen/pelvis was performed to establish a diagnosis (Fig. 1,2).
Extensive PVG was demonstrated throughout the liver, in the lumen of the main portal vein and distal splenic vein. Both these vessels were partially thrombosed. Thrombosis and gas were present in the inferior mesenteric vein continuing into branches of the sigmoid mesentery. These merged with pockets of gas in the sigmoid mesentery and adjacent to the distal descending colon. A small amount of free fluid with sigmoid colonic diverticular changes. The inferior mesenteric artery was patent along most of its length. A small amount of gas was in the IVC.
The patient was treated with intravenous antibiotics and anticoagulants on a high dependancy ward.
A repeat CT was performed 9 days later (Fig. 3) as the patient's liver function continued to worsen. The intra-hepatic gas had resolved, however thrombus in the portal vein extended to involve the intra-hepatic portal branches. Thrombosis was also in the mesenteric vein and splenic vein. The hepatic veins were patent with significant abdominal ascites. The diverticular abscess persisted in the pelvis, with residual gas in the regional draining veins.
The worsening liver function was due to extension of portal venous thrombus. The reduction in PVG suggested an improving portal-venous sepsis.

Discussion

The presence of PVG has been associated with a poor prognosis, and its detection is best demonstrated on CT. If seen on CT, patient survival has been associated with a 71% survival rate; however, this can be higher in patients with bowel obstruction and vascular surgery [1]. The development of PVG is due to a mixture of mucosal damage, raised intra-luminal pressure, and sepsis. The presence of gas in the mesenteric veins is rare, even on CT [2].
The underlying source of the gas can be usually diagnosed with a study revealing bowel obstruction, bowel necrosis and diffuse peritonitis to be very common. Patients in this group were extremely sick having an ASA score of 4.2 and a mortality of 46.6% [3]. This high figure was due to the underlying diagnosis rather than the presence of PVG. PVG has been shown in conditions not requiring surgery, such as Crohn's disease, barium enema, colonoscopy, blunt trauma and enterovenous fistula [4].
PVG and thrombosis have been described together in a case of vague abdominal pain, sepsis, positive blood cultures and deranged liver function. This patient, however, developed worsening organ failure and subsequently died, after an initial period of improvement [5]. In our case radiological imaging corresponded with clinical improvement of sepsis, however portal venous thrombosis worsened.
Intra-abdominal sepsis is the commonest cause of acute portal venous thrombosis, and in adults this is commonly caused by diverticulitis causing a portal pyaemia. Portal venous thrombosis should be considered in cases of deranged liver function and sepsis, and may usually be picked up on ultrasound. [6]

Differential Diagnosis List

Final Diagnosis

Portal Venous Gas and Portal Venous Thrombosis

URL:	https://www.eurorad.org/case/6712
DOI:	10.1594/EURORAD/CASE.6712
ISSN:	1563-4086