RECENT STUDIES INMANAGEMENT OF PORTAL VEIN

Abstract

The portal vein is the vein of the gut that drains blood from the abdominal part of the gastrointestinal tract from the lower third of esophagus to halfway down the anal canal including spleen, pancreas and gall bladder( Dean, et al. 2000) The term portal vein thrombosis (PVT) refers to the complete or partial obstruction of blood flow in the trunk of portal vein , due to the presence of a thrombus in the vassel lumen (Bayraktar and Harmanci ,2006).This includes its right and left intrahepatic branches. It may even extend to the splenic or superior mesenteric veins or towards the liver involving intra hepatic portal branches (Chawla,2009). From a pathophysiological point of view, PVT is a consequence of the so-called ‘Virchow’s triad’, which comprises venous stasis, endothelial injury, and hyper coagulopathy. For this reason, the underlying cause of PVT includes malignancy, chronic liver diseases, local inflammatory processes, systemic disorders including myeloproliferative disorders, and thrombophilia. In a high percentage of patients two or more risk factors are present (Pieri, et al. 2013). According to time of development, localization, pathophysiology and evaluation PVT can be classified as follow: • Acute or chronic. • Extra or intrahepatic. • Occlusive or non-occlusive. • Progressive or self-resolving. PVT onset can be acute or chronic. This is an particular distinction, which is sometimes difficult to apply in clinical practice; patients who develop symptoms, such as abdominal pain, nausea, and fever, within sixty days prior to hospital admission, might have an acute PVT development (Ponziani,et al. 2010) PVT can be classified into four categories, depending on the extension (Groeschl,et al 2016)confined to the portal vein beyond the confluence of the splenic vein; extended to the superior mesenteric vein, but with patent mesenteric vessels; extended to the whole splanchnic venous system, but with large collaterals; or with only fine collaterals (Basit, et al 2015).This classification is useful to evaluate patient’s operability and clinical outcome. In fact, when thrombosis is extended to both portal and mesenteric veins, the risk of bowel ischemia is considerable and mortality high, despite a lower risk of variceal bleeding( Rajesh, et al .2015). Approximately 43% of patients with portal vein thrombosis are asymptomatic ,clinical presentation of PVT depends on the site, extent (partial or complete), chronicity(acute or chronic), and course (progressive or self-resolving) of thrombosis determine their clinical presentation as well as their complications in affected patients .While partial PVT is usually discovered incidentally by routine diagnostics and remains clinically silent, the complete occlusion of the vein (90–100% of the lumen) is associated with abdominal and/or lumbar pain characterized by sudden onset or progressive development over the course of a few days( Pieri, et al.2013).Acute and complete thrombosis is usually associated with intestinal congestion and occasionally with non-sanguineous diarrhea. In this case, a diffuse and homogeneous thickening of the intestinal wall may be present in imaging Studies.