Portal circulation and portal hypertension BY AMNA BUTOOL

it includes overview of portal circulation and complete information of portal hypertension

1. PORTAL CIRCULATION AND PORTAL HYPERTENSION BY : AMNA BUTOOL👩‍⚕️ PHARM D

2. PORTAL CIRCULATION LOCATION OF LIVER : Liver is located in right upper quadrant,from 5 th intercoastal space in midclavicular line down to right coastal margin Wt of liver:1800g in men, 1400g in women Liver has two lobes ,each lobe has an independent vascular and duct supply.

3. liver is supplied with blood majorly by 2 blood vessels 1)hepatic artery 2)portal vein 1)HEPATIC ARTERY: the branch of aorta that supplies oxygenated blood to liver is called hepatic artery. The liver receives oxygenated blood through hepatic artery and is involved in metabolic processes,the blood after processed by liver is then drained into hepatic vein,and finally to right atrium through inferior vena cava . So , liver receives oxygenated blood from HEPATIC ARTERY and drains deoxygenated blood into hepatic vein.

4. 2)PORTAL VEIN:70% of blood flow to liver is only through portal vein , and remaining of bloodflow is however through hepatic artery. Hepatic portal vein or portal vein is a blood vessel that carries blood from GIT,gallbladder,pancreas,spleen to the liver. This blood contains the nutrients and toxins which are absorbed from gastrointestinal tract. Within the liver,blood runs through tiny channels where I exchanges contents within the liver cells.The nutrients are processed,toxins and pathogens are removedfrom the blood before it exits liver via hepatic veins.

5. PORTAL VEIN HEPATIC ARTERY HEPATIC VEIN

6. PORTAL HYPERTENSION: Portal hypertension is used to describe elevated pressures in portal venous system. Portal hypertension is a pressure in portal venous system that is atleast 5mmHg higher than the pressure in the inferior vena cava. Normally,portal vein pressure ranges between 1-4 mmHg higher than hepatic vein pressure ,pressure that exceeds this limit defines portal hypertension.

7. CAUSES OF PORTAL HYPERTENSION: 1)PRE- HEPATIC CAUSES 2)HEPATIC CAUSES 3)POST-HEPATIC CAUSES

8. PRE HEPATIC CAUSES: a)Alterations of portal venous blood flow can lead to portal hypertension. b)Arteriovenous malformation of splenic vasculature(blood vessel that drains blood from spleen into portal vein), c)Splenomegaly, d)Portal vein thrombosis

9. HEPATIC CAUSES: a)Cirrhosis is the most common cause of portal hypertension,where irreversible change in normal liver tissue results in degeneration of functioning liver cells and their replacement with fibrous connective tissue also called scarring of liver. Cirrhosis is mostly caused by chronic viral hepatitis c ,alcohol induced liver disease,hepatitis B,DILD,etc . Portal hypertension is considered as advanced complication of cirrhosis. b)schistosomiasis is another hepatic cause where flat worms invade the liver c)sarcoidosis leads to portal hypertension where inflammatory form granulomas in liver

10. POST-HEPATIC CAUSES: a)right sided heart failure. b)constrictive pericarditis. Both right sided hear failure and constrictive pericarditis, Restrict blood flow from heart to the lungs and to rest of the body Blood accumulates downwards including into portal circulation. c)Budd- chiari syndrome :a thrombus or a tumor inside hepatic veins obstructs hepatic venous flow towards inferior vena cava.

11. PATHOPHYSIOLOGY: Pre hepatic ,hepatic ,post hepatic causes obstruction prevention of blood flow towards inferior vena cava Accumulation of venous blood in hepatic portal system Decreased blood supply to liver Diminshed liver function and decreased blood detoxification , Buildup of toxic metabolites like ammonia in blood Ammonia and other toxins pass through BBB(Blood brain barrier) HEPATIC ENCEPHALOPATHY.

12. accumulation of venous blood I hepatic portal system Increased blood pressure in hepatic portal system PORTAL HYPERTENSION

13. COMPLICATIONS OF PORTAL HYPERTENSION: PORTAL HYPERTENSION blood is backed up into spleen Congestive splenomegaly(enlarged spleen) HYPERSPLENISM(spleen traps blood elements like RBCs,WBCs , platelets. Anemia,leukopenia,thrombocytopenia . Endothelial cells lining the blood vessels release more nitric oxide(compensatory mech’sm ) Peripheral arteries dilates Plasma volume expands Fluid in blood vessels is more likely to grt pushed into tissues and across tisseues into large pen spaces like peritoneal cavity called ASCITES Bacteria invades the peritoneal cavity BACTERIAL PERITONITIS

14. PORTAL HYPERTENSION FORMATION OF PORTOSYSTEMIC SHUNTS BLOOD IS DIVERTED AWAY FROM PORTAL VENOUS SYSTEM AND BACKS UP INTO SYSTEMIC VEINS

15. PORTOSYSYSTEMIC SHUNTS OCCURS WHERE SYSTEIC VENOUS SYSTEM AND PORTAL VENOUS SYSTEM ARE CONNECTED The hepatic portal system could be connected with the systemic venous system that collects blood from rest of the body. 1)Inferior portion of oesophagus 2)Superior portion of anal canal 3)Round ligament of liver(which used to b the umbilical vein during fetal life).

16. The hepatic portal system could be connected with the systemic venous system that collects blood from rest of the body. 1)Inferior portion of oesophagus 2)Superior portion of anal canal 3)Round ligament of liver(which used to b the umbilical vein during fetal life).

17. At birth,the umbilical cord is cut and umbilical vein collapses to form round ligament. The round ligament stays shut ,because pressures in portal venous system and systemic venous system are same i.e.,12mmHg.

18. PORTOSYSTEMIC SHUNTS OESOPHAGUS Esophageal varices or enlarged oesophageal veins These oesophageal varices are very fragile,easily rupture Massive upper GI bleeding RECTUM /ANAL CANAL HEMMORHOIDS or Enlarged veins ANAL BLEEDING ROUND LIGAMENT Portal HTN cause round ligament to re-channel Allows Blood from portal system to pass into sysremic veins of abdomen Systemic veins dilate called CAPUT MEDUSAE

19. CLINICAL FEATURES: A-ascites B-bleeding( oesophageal&rectal ) C-caput medusae D-diminished liver function E-enlarged spleen

20. ASCITES OESOPHAGEAL BLEEDING CAPUT MEDUSAE IMPAIRED LIVER FUNCTION ENLARGED SPLEEN

21. CAPUT MEDUSAE ANAL BLEEDING

22. CLINICAL MANIFESTATIONS: Portal hypertension is asymptomatic until complications occur VISIBLE SIGNS: a) distended abdomen (ascites), b)caput medusae, c) GI bleeding:hematemesis (vomiting blood),melena or hematochezia d)liver impairment:jaundice e)hepatic encephalopathy:asterixix,altered consciousness,lethargy,seizure,coma

23. DIAGNOSIS: 1)HEPATIC VENOUS PRESSURE GRADIENT MEASUREMENT-gold standard technique -catheter is inserted inside IVC and PORTAL VEIN to measure difference between both pressures 2)LIVER ULTRASOUND -detects nodules in cirrhosis 3)CT SCAN OR MRI- ascites,cirrhosis,splenomegaly 4)LAB TESTS:CBP, LIVER ENZYMES,SEROLOGY. 5)UPPER GI ENDOSCOPY-detects esophageal varices.

24. TREATMENT: MEDICAL THERAPY : BETA-BLOCKERS:propranolol-for portal hypertension DIURETICS +SODIUM RESTRICTION –for ascites OCTREOTIDE-oesophageal varices ENDOSCOPIC THERAPY, BANDING: variceal ligation with elastic rings, SCLEROTHERAPY, BALLON TAMPONADE, SURGICAL SHUNTS.