Page 68 of 73 PORTAL HYPERTENSIA AND VARICOSITY OF THE GULLET
Etiology. Extrahepatic narrowing of a portal vein is the reason of 50 — 70% of cases of portal hypertensia at children; approximately in 2/3 of these cases the etiological factor does not manage to be established. At many patients portal hypertensia arises soon after the birth, and at every third patient it is preceded by catheterization of an umbilical vein for the purpose of infusion.
Distribution of an infection on lymphatic ways from a navel to the venous canal can cause thrombosis of a portal vein. Other possible mechanism — delay of a venous blood-groove in the period of a normal obliteration of an umbilical vein and a venous channel. At children of advanced age in development of portal hypertensia the abdominal injury, pancreatitis, tumors or inflammatory infiltrates in the field of portal fissures play a role. The arteriovenous fistulas which are formed in a spleen at an illness to Gosha also promote increase of pressure in a portal vein. Among the rare reasons of increase of pressure in a portal vein at children it is necessary to call thrombosis of hepatic veins, or Badd's syndrome — Kiari.
One of basic reasons of portal hypertensia — cirrhosis; development of cicatricial fabric breaks an intra hepatic blood stream owing to what pressure increases in veins (section 12.101). At most of the patients who survived after operation for an atresia of bilious ways, and at all not operated patients portal hypertensia develops. Many diseases causing cirrhosis in children progress slowly and lead to portal hypertensia rather late. Insufficiency of ai-antitrypsin, Wilson's illness — Konovalova, a mucoviscidosis, a tripsinemiya and chronic active hepatitis belong to such states. Inborn fibrosis of a liver can be also complicated by portal hypertensia. Pressure increases in a portal vein also after removal of the right hepatic lobe as all venous blood stream tests big resistance in the rest of a vascular bed.
Patomorfologiya. At extrahepatic narrowing of a portal vein the structure of a liver is not changed. A blood quantity from portal system comes to a liver through collateral vessels in the supporting sheaves, phrenic, hepatonephric and hepatoenteric veins. At vnutripechenochn of obstruction of branches of a portal vein collateral circulation of a role does not play. At some children kavernopodobny transformation of a portal vein when it is substituted with a set of gyrose thin-walled veins is observed. Remains to unknown, portal hypertensia is in this case the reason or a consequence, but it should be noted that pressure in a portal vein exceeds pressure in the lower vena cava upon 150 mm of the Art. of normal saline solution. At the same time a system porto-caval anastomosis opens that conducts to a varicosity of the second order. Such anastomosis is in area of the cardia of transition, in retroperitoneal veins, in an internal hemorrhoidal texture of a rectum, around a round sheaf. Venous "nodes" of the lower third of a gullet and cardial department of a stomach are especially subject to an erosion from which massive bleeding can result. Any patient with portal hypertensia can have complications connected with a gipersplenichesky syndrome.
Clinical manifestations. The first symptom of portal hypertensia at children usually is plentiful vomiting blood or a tar-like chair. The age at which there is portal hypertensia depends on a basic disease. At children of early age ascites, but not bleeding is more often observed. At disturbance of an intra hepatic blood-groove the patient has a jaundice. It is sometimes observed the gyrose expanded saphenas ("the head of the Jellyfish") dispersing from a navel, Internal hemorrhoidal "nodes" at children arise seldom.
Diagnosis. X-ray inspection allows to find expansion of zones of a gullet. In rare instances portal hypertensia coexists with a round ulcer of a stomach. Varicose veins are unmistakably distinguished during an ezofagogastroskopiya. The phlebectasia can also be seen at retrograde catheterization of an umbilical vein, a splenoportografiya or a selective angiography. Splenoportografiya allows to measure pressure and a blood stream in splenic and portal venous systems. The selective angiography reveals a portal vein less accurately, than the splenoportografiya, but gives the chance to determine the size of an upper mesenteric vein. With its help it is possible to define the place of the bleeding which is not connected with portal hypertensia, for example at a traumatic hemobilia. At last, by means of an angiography it is possible to administer the angiotonic drugs directly in portal system.
Treatment. At children the hematemesis at a gullet varicosity usually stops spontaneously even if the only medical measure consists in hemotransfusion. The patient should enter a gastric tube through a nose to have an opportunity quantitatively to define intensity of bleeding and volume of the streamed blood. This procedure is not contraindicated even at risk of strengthening or resuming of bleeding. At many patients varicose veins of cardial department of a stomach, but not a gullet bleed. It is desirable to control the central venous pressure to define what volume of blood needs to be compensated. It is necessary to register such important indicators as blood pH, saturation of an arterial blood oxygen, the content of electrolytes. At children the liver failure as a result of the cirrhosis complicated by bleeding seldom develops. Locally or intravenously enter extract of a back share of a hypophysis with the purpose to cause reduction of veins of internals and by that to reduce inflow of blood to bleeding venous "nodes". Cooling of a stomach, apparently, does not promote the termination of bleeding. If bleeding does not manage to be stopped, it is possible to resort to a tamponade by means of a triple probe of Sengshtagen — Blekmera. In many cases bleeding stops when inflating only distal, gastric, a cylinder. Unfortunately, bleeding often renews when pressure in a cylinder is reduced.
In pediatric practice seldom it is necessary to operate patients with bleedings according to vital indications. Now 2 ways of surgical intervention are accepted: direct excision or bandaging of varicose veins or creation of the shunt between portal system and the general circulation (section 12.100).
There are many methods of unloading of portal system. Good results are yielded by the splenorenalny shunt. Siguira reported about a positive effect of thoracoabdominal operation at they within which chest cavity tie up up to 80 varicose veins or their branches. The gullet is crossed, and then anastomosed with the purpose to interrupt an intramural venous anastomosis. In an abdominal cavity alloy all veins of an upper half of a stomach. After this operation performed at several children, bleeding did not renew, and we believe that the operation Siguira is more preferable than shunting.