The meso-Rex shunt

The meso-Rex bypass (MRB) is an operation devised to restore mesenteric venous blood flow past an obstruction of the portal venous system proximal to the hilum of the liver. The obstructed portion of the portal vein outside of the liver usually involves the segment between the portal vein bifurcation and the confluence of the splenic and superior mesenteric veins (SMVs). Not uncommonly, the splenic and SMVs may also be involved in the thrombotic process, making the choice of veins to serve as the proximal anastomosis site more challenging. This operation was first devised to bypass obstructed portal veins following transplantation [1] but was later extended to patients with idiopathic portal venous obstruction [2-5].