Portal hypertension is defined as an increase of blood pressure in the portal venous bed beyond the physiological values. In childhood it is usually caused by an increase of resistance to the blood flow from the mesenteric venous circulation through or to the liver. The increase of resistance is the consequence of an obstruction in the portal system. Depending on the site of this obstruction, we can divide all causes of portal hypertension into three main categories: Prehepatic portal hypertension (the most frequent type of portal hypertension in children, 60–75 %) Intrahepatic portal hypertension, secondary to hepatocellular injury leading to cirrhosis (for instance, biliary atresia) Post-hepatic portal hypertension (Budd-Chiari syndrome, rare in children) Prehepatic portal hypertension can be caused by thrombosis of the portal vein, portal vein congenital stenosis/atresia or postnatal fibrotic stenosis. Occlusion of the main trunk of the portal vein may lead to the formation of a venous cavernoma. The significant manifestation of portal hypertension in childhood is massive upper gastrointestinal bleeding from oesophagogastric varices’ rupture. The second most common finding is splenomegaly and hypersplenism. Ultrasonography with Doppler interrogation, noninvasive angiography, and upper endoscopy are essential in the evaluation of portal hypertension in childhood. Prevention of variceal bleeding, both in children and adults, is obtained by medical therapy and endoscopic treatment of varices which is also an emergency treatment. The treatment of choice for symptomatic portal hypertension from extrahepatic portal obstruction is a surgical shunt. Surgical shunts are of two kinds portosystemic shunts and the mesentericoportal shunt. The first one is inspired on the principle of artificially improving the portosystemic derivation that the organism puts into action spontaneously, but often in an insufficient degree, through the collateral circles both superficial and deep. The second one, unlike portosystemic shunting, restores portal flow to the liver, thus acting as a physiologic bypass. Portal hypertension accompanied by advanced liver dysfunction from either venous outflow obstruction or intrinsic liver disease is ultimately treated by transplantation. Prognosis depends on shunt patency and on the severity of liver disease. Those with cirrhosis eventually require liver transplantation before the development of end stage disease. With complimentary medical therapy, endoscopic intervention, and shunt surgery, the ultimate prognosis is excellent.
Di Salvo, N., Maffi, M., Lima, M. (2017). Portal Hypertension in Children. Cham : Springer [10.1007/978-3-319-40525-4_27].
Portal Hypertension in Children
Lima, Mario
2017
Abstract
Portal hypertension is defined as an increase of blood pressure in the portal venous bed beyond the physiological values. In childhood it is usually caused by an increase of resistance to the blood flow from the mesenteric venous circulation through or to the liver. The increase of resistance is the consequence of an obstruction in the portal system. Depending on the site of this obstruction, we can divide all causes of portal hypertension into three main categories: Prehepatic portal hypertension (the most frequent type of portal hypertension in children, 60–75 %) Intrahepatic portal hypertension, secondary to hepatocellular injury leading to cirrhosis (for instance, biliary atresia) Post-hepatic portal hypertension (Budd-Chiari syndrome, rare in children) Prehepatic portal hypertension can be caused by thrombosis of the portal vein, portal vein congenital stenosis/atresia or postnatal fibrotic stenosis. Occlusion of the main trunk of the portal vein may lead to the formation of a venous cavernoma. The significant manifestation of portal hypertension in childhood is massive upper gastrointestinal bleeding from oesophagogastric varices’ rupture. The second most common finding is splenomegaly and hypersplenism. Ultrasonography with Doppler interrogation, noninvasive angiography, and upper endoscopy are essential in the evaluation of portal hypertension in childhood. Prevention of variceal bleeding, both in children and adults, is obtained by medical therapy and endoscopic treatment of varices which is also an emergency treatment. The treatment of choice for symptomatic portal hypertension from extrahepatic portal obstruction is a surgical shunt. Surgical shunts are of two kinds portosystemic shunts and the mesentericoportal shunt. The first one is inspired on the principle of artificially improving the portosystemic derivation that the organism puts into action spontaneously, but often in an insufficient degree, through the collateral circles both superficial and deep. The second one, unlike portosystemic shunting, restores portal flow to the liver, thus acting as a physiologic bypass. Portal hypertension accompanied by advanced liver dysfunction from either venous outflow obstruction or intrinsic liver disease is ultimately treated by transplantation. Prognosis depends on shunt patency and on the severity of liver disease. Those with cirrhosis eventually require liver transplantation before the development of end stage disease. With complimentary medical therapy, endoscopic intervention, and shunt surgery, the ultimate prognosis is excellent.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
