Portal disorders

Cirrhosis results in elevation of portal blood pressure because of fibrotic changes within the hepatic sinusoids, changes in the levels of vasodilatory and vasoconstrictor mediators, and an increase in blood flow to the splanchnic vasculature. The pathophysiologic abnormalities that cause it result in the commonly encountered problems of ascites, portal hypertension and esophageal varices, HE, and coagulation disorders. 

Hepatic cirrhosis is an end stage process of hepatic inflammation characterised by lobular scarring, distortion of the hepatocellular architecture and disordered function, frequently with associated portal hypertension. 

Tertiary hypothyroidism, or hypothalamic hypothyroidism, results from impaired TRH stimulation of pituitary TSH. This may be due to a disorder that damages the hypothalamus or interferes with hypothalamic-pituitary portal blood flow, thereby preventing delivery of TRH to the pituitary. Tumors, trauma, radiation therapy, or infiltrative disease of the hypothalamus can cause such damage. This relatively rare form of hypothyroidism is also characterized by inappropriately low levels of serum TSH. 

Alcoholics with chronic liver disease may have disorders of fluid and electrolyte balance, including ascites, edema, and effusions. These factors may be related to decreased protein synthesis and portal hypertension. Alterations of whole body potassium induced by vomiting and diarrhea, as well as severe secondary aldosteronism, may contribute to muscle weakness and can be worsened by diuretic therapy. Some alcoholic patients develop hypoglycemia, probably as a result of impaired hepatic gluconeogenesis. Some alcoholics also develop ketosis, caused by excessive lipolytic factors, especially increased cortisol and growth hormone. 

Liver cirrhosis is among the top 10 causes of death in the Western world. The disease occurs after chronic damage to hepatic cells, mainly hepatocytes, which can be caused by viral hepatitis, chronic alcohol abuse or toxic injury, biliary disease, and metabolic liver disorders [64], Liver cirrhosis is characterized by an abnormal deposition of connective tissue in the liver, which hampers the normal functions of the liver. Other features of the disease are general tissue damage, chronic inflammation, and the conversion of normal liver architecture into structurally abnormal nodules. Secondary to these anatomical changes are disturbances in the liver function and in the hemodynamics leading to portal hypertension and intrahepatic shunting [39, 64, 103],... 

Twenty-five percent ofthrombophilic patients develop thrombosis at unusual sites resulting in cerebral venous thrombosis, mesenteric vein thrombosis, hepatic venous thrombosis, retinal vein thrombosis, purpura fulminans, splenic vein thrombosis, portal vein thrombosis, renal vein thrombosis, or axillary vein thrombosis. The thrombotic disorders may involve inflammatory factors that contribute to the vascular deficit. In addition, embolic events also play a role in the development of these thrombotic complications. 

Hepatic venous thrombosis, also known as Budd-Chiari syndrome, is caused by hypercoagulable disorders precipitated by pregnancy, infection, and birth control medication. An acute painful abdomen, sudden enlargement of the liver, and the presence of ascites make up a triad of clinical symptoms that are important in the diagnosis of this syndrome. Myeloproliferative disorders such as polycythemia vera and paroxysmal nocturnal dyspnea were previously thought to be responsible. Factor V Leiden and prothrombin 20210 mutations are also known to be responsible, Other intraabdominal thromboses include portal vein thrombosis, mesenteric vein thrombosis and renal vein thrombosis. 

Amitrano L, Brancacio V Guardascione MA, et al. Inherited coagulation disorder in cirrhotic patients with portal vein thrombosis. Hepatology 2000 3 I (2) 345-348. 

Endocrinological Disorders. The discovery that DA is a potent prolactin inhibitory factor in the portal circulation of the pituitary is the basis for the use of DA agonists to suppress unwanted normal puerperal lactation, and in treating pathological hyperprolactinaemia together with its associated anovular infertility. 

Many centres prefer to avoid using NSAIDs in any patient with liver disease because of their side-effect profile. However, if the liver disorder is purely cholestatic in origin and the disease has not progressed to cirrhosis and portal hypertension, NSAIDs may be an option. Any risk-benefit assessment should consider the potential risk of hepatotox-icity, albeit rare. There are no specific contraindications in this patient because they are not cirrhotic, do not have deranged clotting, and are unlikely to be at increased risk of deteriorating renal function. If deemed necessary an NSAID could be used cautiously. 

Contraindications include coagulation disorders, superficial hyperechoic foci (e. g. haemangioma), vascular aneurysm, portal hypertension, obstructive jaundice and hydatid cysts. Care should also be taken not to damage any unknown structures along the path of the biopsy needle. 

Enlargement of the spleen can have numerous causes. It is important to rule out any possibility that the method of investigation itself could lead to splenomegaly being simulated, such as upside-down spleen, accessory spleen(s) or wandering spleen. The involvement of the spleen in disorders of the lymphatic and reticuloendothelial system as well as of the portal and systemic circulation explains why splenomegaly is frequently found in connection with widely differing diseases. (18, 20, 23, 34-38) (s. tab. 11.2)... 

Various infectious, toxic or immunological lesions lead to a presinusoidal block in adults. From a primary endothelial lesion, endophlebitis ensues. Rich in fibres and deficient in cells, it is ultimately responsible for the obliteration and even disappearance of the portal branches. Obliterative portal venopathy (N.C. Nayak et al., 1969) with portal and periportal fibrosis and subsequent perisinusoidal sclerosis is referred to as hepatoportal sclerosis (W P. Mikkelsen et al., 1965). This is a complex disorder involving splenomegaly, hypersplenism and portal hypertension, which has also been described as non-cirrhotic portal fibrosis (XL. Boyer et al., 1967) or idiopathic portal hypertension (K. Okuda et al., 1982). (I2l, 127) Band s syndrome (7) probably fell into this group ... 

Portosystemic collaterals can divert up to 80% of the portal vein blood away from the liver. This initially results in haemodynamic disorders with subsequent (multifactorial) hyperdynamic splanchnic circulation. More and more varices develop around the bypasses in various venous areas, primarily in the form of oesophageal varices. Damage to the mucous membrane in the stomach and in the colon takes the form of hypertensive... 

Dubois, A., Dauzat, M., Pignodel, Cb., Pomier-Layrargues, G., Marty-Double, Ch., Lopez, F.-M., Janbon, C. Portal hypertension in lympho-proliferative and myeloproliferative disorders hemodynamic and histological correlations. Hepatology 1993 17 246-250... 

Valla, D., Casadevall, N., Huisse, MG., Tulliez, M., Grange, J.D., Midler, O., Binda, T., Varet, B., Rueff, B., Benhamou, J.R Etiology of portal vein thrombosis in adults. A prospective evaluation of primary myeloprohferative disorders. Gastroenterology 1988 94 1063-1069... 

It is not clearly understood why in some cases oedema without ascites and in other cases ascites without oedema as well as ascites together with oedema or even pleural effusion without ascites occur. Ascites develops most frequently during the course of liver disease (= hepatogenic ascites), in particular in chronic liver diseases with portal hypertension (= portal ascites), (s. tab. 16.7) Various mechanical, biochemical and neural disorders overlap in their effects and pathways, depending on the underlying liver disease. Only rarely is ascites found in diseases with presinusoidal localization of portal hypertension (such as portal vein thrombosis) or with minor restrictions in the synthesis of albumin (as in biliary cirrhosis). Formation of ascites occurs in about 50% of all cirrhotic patients within 10 years of... 

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