Portal Vein Thrombosis:
Portal Vein Thrombosis can be seen in a variety of clinical context, and an acute portal venous thrombosis can be a life-threatening condition. Noncirrhotic presinusoidal portal hypertension is the major cause of portal vein thrombosis.Portal venous hypertension can be bland or malignant(e,g tumor thrombus), and it is a critical finding in liver transplant candidates.
Clinical Presentation Of Portal Vein Thrombosis.
- often vague and non-specific.
- If acute thrombosis is present especially if superior mesenteric venous system is involved then presentation is likely to be with acute ischemic bowel,mimicking superior mesenteric artery occlusion.
In acute condition thrombus may be main evident,with findings related to ischemic bowel(especially if significant superior mesenteric venous involvement is also present).
In chronic cases, cavernous transformation of portal vein is seen.
Portal Vein Thrombosis
- Acute thrombosis is sometimes difficult to detect with grey scale imaging alone as the thrombus may be hypoechoic. With time, it becomes more echogenic and easier to identify.
- Colour Doppler is able to demonstrate absent flow in the portal vein and even to evaluate partial thrombosis, but attention to the Doppler filters and gain and is necessary to avoid colour overwrite of partial thrombosis.
- Intrahepatic branches of portal vein ,SMV(superior mesenteric vein) and hepatic vein should be examined in order to estimate the assess of thrombus because in 20%of the patient with Budd-Chiari syndrome will also have likely to have a portal vein thrombosis.
- Colour doppler is also very useful for evaluating any thrombus tumor, which will likely to show internal colour vascularity.
- In comparison Bland thrombus is bland on colour doppler.