The hepatic portal circulation carries blood from GI tract (i.e. from the distil esophagus to anorectal junction) to the liver. Porto – systemic anastomosis occurs in junctional areas of venous drainage. Portal venous blood drain into liver venous sinusoids and hence in to the hepatic veins.
Portal hypertension develop when there is elevation of portal pressure is greater than 12 mmHg, while normal portal pressure is 5 – 10mmHg. As portal hypertension produce no symptoms it is usually diagnosed following presentation with decompensated chronic liver disease encephalopathy, ascites or variceal bleeding.
Pre – Hepatic: 1- Congenital portal atresia 2- Portal vein thrombosis (Neonatal sepsis) 3- Phlebitis of portal vein (abdominal infection) 4- Trauma or thrombosed porto – caval shunt. Hepatic: 1- Cirrhosis (alcoholic most frequently) 2- Chronic Active hepatitis 3- Parasitic diseases (Schiatosomiasis) Post – Hepatic: 1- Budd – Chiari syndrome (Hepatic venous thrombosis) 2- Constrictive pericarditis 3- Tricuspid valve incompetence
Decrease or reverse portal blood flow to the liver promote the development of the portosystemic anastomosis between the portal system and systemic circulation. 1- Left gastric vein into the esophageal veins at gastro- esophageal junction – esophageal and gastric varices. 2- Superior rectal vein into inferior rectal vein at lower rectum rectal varices. 3- Obliterated umbilical vein into epigastric vein – capute medusae. Esophageal and gastric varices may bleed torrentially Liver cell dysfunction/liver failure occurs in hepatic and post – hepatic causes Splenomegaly (hypersplenism may be result) The child – pug classification use to asses the severity.
Conditions Point – 1 Point – 2 Point - 3Bilirubin (µmol/L) <34 34 – 51 >51Albumin (g/L) >35 28 – 35 <28PT (sec) <3 3 – 10 >10Ascites None Moderate Moderate – severeEncephalopathy None Moderate Moderate – severe
Many investigations may be used at different time in portal hypertension such as 1- FBC, Urea & electrolytes and clotting 2- Screening tests for the causes of the cirrhosis 3- CT & ultrasound scan to assess liver morphology, diagnose Portal hypertension and assess cause. 4- Transabdominal Doppler ultrasound to assess blood flow in the portal vein and hepatic artery. Gastroscopy in acute variceal bleeding
General resuscitation Anti – coagulation for Budd – Chiari syndrome Treatment of hepatic cause Treatment Of Chronic Complication such as Esophageal gastric varices: 1- Beta – blocker (propranolol or nadolol), reduce portal venous pressure. 2- Repeated injection sclerotherapy or variceal ligation 3- Elective porto – systemic shunt (spleno – renal anastomosis) 4- Liver transplant may be considered for treatment if associated with severe liver diseases. Rectal Varices: Injection sclerotherapy Symptomatic splenomegaly: laparoscopic or open splenectomy. Ascites: Oral spironolactone, in cases of ascites, paracentesis may be required with IV albumin replacement.
Hemorrhage from the varices is acute complication of the portal hypertension. Mortality rate of first variceal bleed established portal hypertension is 30%. Causes & Features: Typical variceal bleeding is rapid in onset, copious dark blood with little mixing with food. Feature of established portal hypertension e.g. capute medusae Feature of developing hepatic encephalopathy (ingested blood provide an extremely rich meal)
Established large caliber IV access, give crystalloid fluid up to 1000 mL, if tachycardic or hypotensive. Only use O - ve blood if the patient is in extremis, otherwise wait for cross – match blood. Catheterize and place on fluid balance chart if hypotensive. Send blood for FBC, HB conc. WCC, U&E, Na, K, LFT, albumin and clotting. Always consider HDU, variceal bleeding can deteriorate extremely rapidly. Monitor pulse rate, BP and urinary output. Insertion Of sangstaken Blackmore gastro-esophageal tube may be a life saving resuscitation manure, usually only inserted without prior gastroscopy if the patient known to have varices and has life – threatening bleeding.
Blood transfusion Correct coagulopathy Esophageal balloon tamponade (sangstaken Blackmore tube) Drug therapy (vasopressin or octreotide) Endoscopic sclerotherapy or banding Assess portal vein patency (Doppler ultrasound or CT) Transjuglar intrahepatic portosystemic stent shunt Surgery: Portosystemic shunts Esophageal transection Splenectomy and gastric devescularization.