Spontaneous meso-portal shunt following orthotopic liver transplantation in a child. 
Post-transplant children are regularly followed by colour Doppler US exam.  Liver parenchyma, biliary tract and portal, subhepatic and arterial vascularisation are checked.  We observed a post-transplant child with spontaneous meso-portal bypass after portal vein thrombosis (PVT).  After orthotopic liver transplantation (OLT), PVT is frequently observed.  When it occurs early (before 3 weeks), it has been identified as a cause of graft failure.  On the other hand, late PVT (after 3 weeks) can be extremely well-tolerated, with cavernous transformation of the portal vein and formation of hepatopetal collaterals that deliver blood to the liver.  However, extrahepatic portal hypertension (EHPH) and its related complications can develop.  Cavernoma transformation is usually seen, but spontaneous shunt is not yet described in transplant patients.  Distinction from the classic cavernoma can be achieved by the depiction of a single transcapsular vessel.  This bypass partially corrects the EHPH.  However it was decided to completely prevent shunt development by performing a surgical mesenterico-left portal vein bypass.