⭐ PORTAL HYPERTENSION ⭐

          ⭐ PORTAL HYPERTENSION ⭐

1) PORTAL VENOUS SYSTEM:- 

    (A) Portal venous system is a venous

        system which starts from capillaries

        and also ends in capillaries. It starts 

        from capillaries of abdominal part of          gastrointestinal tract, pancreas,                   spleen, gall bladder and ends in

       capillaries of liver i.e sinusoids .

    (B) Function of Portal venous system:-

         (I) It carries partially deoxygenated 

         blood from git organs to the liver.

         This blood contains nutrients, toxins

         and other substances from intestine.

         (II) In the liver, there is detoxification,

          metabolization, storage of nutrients.

        (III) Then this blood from liver goes to 

           the heart.

    (C) Course of portal venous system:- 

         (I) Capillaries of git organs merge to 

           form portal vein.

         (II) Portal vein enters liver and divides

           into portal venules.

         (III) Portal venule, hepatic arteriole,

           and bile duct form portal triad which

           is present near hepatic lobule.

           ( Hepatic lobule is systemic 

           arrangement of hepatocytes. It has

           portal triad at periphery, 

           hepatocytes and blood sinusoids 

           in the middle portion and central 

           vein in the centre of lobule.)

       (IV) Portal venule and hepatic 

           arteriole join and merge with the 

           sinusoids which supply blood to 

           the hepatocytes.

       (V) The sinusoids end in central vein.

           Central veins of each hepatic lobule

           join to form hepatic vein. Hepatic

           vein drains into IVC i.e inferior

           vena cava and then to heart.

                    ⭐⭐⭐⭐⭐

2)WHAT IS PORTAL HYPERTENSION?

    (A) Portal hypertension is increased

        pressure in portal vein >10 mm Hg.

    (B) Normal portal venous pressure is 

        5 -10 mm Hg/ 10 - 15 cm saline.

    (C) It can also be defined by HVPG i.e 

        Hepatic venous pressure gradient.

        HVPG = WHVP - FHVP 

        ( # WHVP = Wedged hepatic venous

         pressure i.e pressure in hepatic 

         sinusoids. The sinusoidal pressure 

         is similar to portal pressure with only

         slight difference. The WHVP is only

         slightly lower than portal venous

        pressure due to pressure equilibration

         through interconnected sinusoids but

         this difference is clinically 

         insignificant.

         It is measured by inflating a balloon 

         at the tip of catheter and thus 

         occluding a tributary of hepatic vein.

         Thus , blood flow in the tributary 

         stops due to occlusion and the static

         column of blood transmits pressure

         from the sinusoids to the tip of 

         catheter. 

         # FHVP = Free hepatic venous

          pressure i.e pressure in hepatic vein.

          During its measurement, balloon is 

          not distended. 

          This pressure is same as pressure in

          IVC.)

    (D) HVPG thus denotes difference 

         between pressures in hepatic 

         sinusoids and hepatic vein.

         Normally, it is between 1 to 5 mm Hg.

    (E) If HVPG >5 mm Hg, it denotes portal

        hypertension. This indicates that 

        pressure in sinusoids (WHVP) is very          high when the balloon is inflated and 

        tributary is blocked.

        This occurs in cases like liver 

        cirrhosis because the static column

        of blood created by balloon cannot be

       decompressed at sinusoidal level due

       to disruption of normal inter sinusoidal

        communications in cirrhosis.

       Thus in cases like cirrhosis, damaged

        architecture of liver impairs the flow 

        of blood from sinusoids to hepatic 

       vein, thus increasing the backpressure

        in portal vein.

   (F) HVPG >10 mm Hg denotes 

        portosystemic shunting and collateral

        formation with risk of variceal     

        bleeding.

                   ⭐⭐⭐⭐⭐

3) PATHOPHYSIOLOGY of Portal Hypertension :- 

    (A) Due to some cause, there is 

         resistance to the flow of portal 

         venous blood.

    (B) Increased resistance causes 

         formation of collaterals (small blood

         vessels bypassing the site of 

         obstruction) in oesophagus, stomach

         rectum, anterior abdominal wall ,

         vasculature of kidney, ovary, testis, 

         etc.

    (C) The blood eventually bypasses the 

        liver due to these collaterals and 

        directly enters systemic circulation.

                      ⭐⭐⭐⭐⭐

4) CAUSES OF PORTAL HYPERTENSION:-

    (A) Prehepatic causes - 

         ( WHVP and FHVP are normal.

          HVPG is normal)

        (I) Portal venous thrombosis or 

           splenic venous thrombosis :- 

           thrombus causes obstruction to 

           blood flow and thus causes 

           increased portal pressure.

        (II) Pressure on portal vein due to 

           stomach or pancreas - obstruction

           to blood flow.

        (III) Hypercoagulable states - 

            thrombosis.

        (IV) Periportal inflammation- 

            Inflammation leads to fibrosis and

            narrowing of lumen of vein.

        (V) Trauma - injury can induce blood

            clot formation

    (B) Hepatic causes:- 

        ( WHVP is increased, FHVP is normal,

          HVPG is increased)

        (I) Presinusoidal - obstruction of 

           portal venules.

           # Schistosomiasis (worm infection)

           # Congenital hepatic fibrosis

             ( Congenital malformation of 

              portal venules)

           # TB - inflammation and fibrosis

           # Sarcoidosis - inflammation and 

              granuloma formation.

           # Wilson's disease- copper builds 

             up - damage.

           # Non cirrhotic portal fibrosis 

       (II) Sinusoidal - obstruction and 

            damage to sinusoids.

           # Liver cirrhosis

           # Alcoholic or viral hepatitis

           # Fatty liver of pregnancy

           # Non-alcoholic steatohepatitis

           # Wilson's disease- excess copper

             build up causes damage to liver.

           # Polycystic liver disease.

           # Hemochromatosis - Excessive 

             iron is stored in liver causing 

             damage.

      (III) Post sinusoidal - 

           # Veno occlusive disease of central

            vein

           # sinusoidal obstruction syndrome

    (C) Post hepatic causes- 

        ( WHVP is increased, FHVP is 

         increased, HVPG is normal) 

       # Budd Chiari syndrome - Hepatic vein

          thrombosis.

       # Inferior Vena Cava thrombosis

       # Right heart failure - backpressure in

         IVC.

       # Tricuspid insufficiency -regurgitation

         of blood into right atrium and then 

         into IVC.

       # Congestive heart failure

       # Pulmonary hypertension - 

          backpressure into right heart and 

          then IVC.

                      ⭐⭐⭐⭐⭐

5) SITES OF COLLATERALS AND VARICES:

    (A) Oesophagus - between left gastric

        and short gastric veins and azygous

        vein.

    (B) Umbilicus- caput medusae - between

        paraumbilical vein and anterior

        abdominal vein.

    (C) Lower end of rectum - between

        superior, middle and inferior

        haemorrhoidal vein.

    (D) Retroperitoneum

    (E) Bare area of liver.

                       ⭐⭐⭐⭐⭐

6) CLINICAL FEATURES OF PORTAL

    HYPERTENSION :-

( Some of these may be present while 

  some may not be present)

    (A) Hematemesis and Melena 

         ( Hematemesis- presence of blood in

          vomit.

          Melena - presence of blood in stool )

        It occurs due to bleeding from 

        fragile varices in oesophagus, rectum.

        It can lead to anemia and shock.

    (B) Caput medusae- collaterals around

        umbilicus. 

.   (C) Ascites, anasarca, hepatic                           hydrothorax - due to portal                            hypertension, hydrostatic pressure in

        veins is increased causing leakage

        of fluid outside.

    (D) Splenomegaly - Congestive 

        splenomegaly due to backpressure

        in splenic vein which is a tributary of

        portal vein.

    (E) Venous hum - sound produced due 

        to turbulent blood flow in veins due to

        increased pressure - heard more 

        during inspiration in epigastric region.

    (F) Hemorrhoids ( piles) - due to rectal 

        varices.

    (G) Foetor hepaticus - musty odour of 

        breath - this is due to the mercaptans

        reaching the lungs directly as liver is

        bypassed due to collaterals.

    (H) General features - 

        # Jaundice - in case of hepatic

                               damage

        # Pruritus - In case of hepatic cause

           ( Liver disease), cholestasis causes 

           rupture of bile ductules and entry

           of bile salts in blood which further

            accumulate under skin causing

            itching.

         # Abdominal pain - causes- nerve                   irritation due to  ascites or                             intraabdominal bleeding from                       varices or swollen liver ,etc.

         # Anorexia , weight loss - due to 

           decreased food intake or improper

           digestion of food when bile is 

           decreased.

         # fatigue

         # Hypotension -

           ( Splanchnic circulation- arterial 

            branches which supply git, liver,

            spleen, pancreas . These arterial

            branches further form capillaries

            and terminate in portal venules. )

            Portal hypertension causes 

            splanchnic vasodilation due to 

            release of vasodilators like Nitric

            oxide. Splanchnic vasodilation 

            causes hypotension.

        # Cyanosis - due to portopulmonary

          anastomosis with flow of blood in

          direction of pulmonary veins.

        # Muscle cramps - common in 

           cirrhosis

        # Bleeding, bruises - inadequate 

           clotting factor production in case 

           of liver damage.

    (I) Signs of liver failure - 

       Gynaecomastia , Testicular atrophy,

       Palmar erythema , spider nevi, parotid 

       enlargement, hepatorenal syndrome, 

        hepatopulmonary syndrome, 

       cardiomyopathy, osteodystrophy,

       hepatic encephalopathy , etc 

      ( EXPLAINED AT THE LAST) 

    (J) Liver consistency - if firm - cirrhosis

    (K) Spontaneous bacterial peritonitis- 

        Due to ascitic fluid infection.

    (L) Previous history of risk factors like

        Alcohol, OC pills ,etc

                     ⭐⭐⭐⭐⭐

7) INVESTIGATIONS OF PORTAL HYPERTENSION :-

    (A) Barium swallow - varices in 

          Oesophagus - bag of worm 

          appearance

    (B) Upper g.i scopy - to see varices

    (C) Barium enema - rectal varices

    (D) Rectoscopy -  rectal varices

    (E) LFT i.e liver function test

    (F) USG - ascites, liver or spleen

        enlargement, varices.

    (G) HVPG i.e hepatic venous pressure

        gradient.

    (H) Portal venography

    (I) Blood - anemia, thrombocytopenia,

       leucopenia ( due to hypersplenism)

    (J) CT,MRI ,CT angiography

    (K) Liver biopsy

    (L) Ascitic fluid study - for cells, proteins

        SAAG ( serum Ascitic albumin

        gradient) if >1.1 = portal hypertension

                    ⭐⭐⭐⭐⭐

8) TREATMENT OF PORTAL HYPERTENSION :- 

    (A) General :-

        (I) Nutrition

        (II) Treat anemia, if present 

        (III) Vit K 10 mg im - required for 

              synthesis of coagulation factors

              which are decreased in liver 

              disease.

        (IV) Blood transfusion - variceal 

             blood loss

    (B) Treat the cause

    (C) Beta blockers - propranolol ,nadolol

         - they cause vasodilation and 

           decrease blood pressure . It 

          decreases chances of variceal 

          rupture.

    (D) Nitrates - GTN - release of NO - 

         vasodilation.

    (E) Surgeries to reduce portal pressure-

          # TIPSS - Transjugular intrahepatic

             Portosystemic shunt - a tunnel is

             created through liver to connect

             portal vein to one of the hepatic

             veins thereby shunting the blood.

         # Portosystemic shunt

    (F) Liver transplantation

    (G) Treat ascites - bed rest , monitoring

         of body weight, abdominal girth, 

         fluid intake and urine output , urine 

         and serum electrolyte estimation , 

         RFT, salt and fluid restriction , 

         diuretics, 

        If refractory, 

        # salt free albumin , paracentesis,

          Shunt surgeries.

    (H) Treat variceal bleeding.

                  ⭐⭐⭐⭐⭐⭐⭐⭐              

            

    ⭐  SIGNS OF LIVER CELL FAILURE ⭐

1) Jaundice - decreased ability of liver to conjugate bilirubin , unconjugated bilirubin increases and builds up in blood.

2) Gynaecomastia - due to hyperestrogenism. ( Estrogen has 

anti inflammatory properties. In liver disease, some inflammatory mediators       induce the genes involved in synthesis of estrogen in an attempt to decrease inflammation.)

3) Testicular failure - Hyperestrogenism suppresses GnRH and hence testosterone production leading to testicular failure.

4) Loss of body hair - due to hyperestrogenism and decreased testosterone.

5) Palmar erythema - Increased estrogen causes increased production of nitric oxide (vasodilator) and thus causes vessels to dilate - erythema ( redness)

6) Spider naevi - central arteriole surrounded by many small arterioles like spider legs - this occurs due to increased estrogen. Estrogen causes vasodilation and enlargement of vessels.

7) Ascites- due to increased hydrostatic pressure in portal vein and its branches.

8) Foetor hepaticus - musty odour of 

        breath - this is due to the mercaptans

        reaching the lungs directly as liver is

        bypassed due to collaterals.

9) Hepatomegaly - in early stages of cirrhosis

10) Anemia - due to variceal bleeding

                                   hypersplenism.

11) Osteodystrophy - Vit D3 is hydroxylated to 25 hydroxy Vit. D3 in liver. Due to liver disease, 25 Hydroxy Vit D3 is not formed. So bone mineralisation and calcium absorption is affected.

Other cause is decreased absorption of fat soluble Vit D from intestine due to decreased conjugated bilirubin production.

12) White nails - Terry's nails - Nails that are entirely white except for a small band of pink or brown at the tip are called Terry's nails. They occur due to decreased vascularity & increased connective tissue.  (Damage to the liver from inflammation leads to the activation of the stellate cells. This stellate cells cause formation of myofibroblasts and also secrete TGF-beta1 which leads to fibrotic response & proliferation of connective tissue.)

13) Dupuytren's contracture - Contraction of palmar aponeurosis & flexion of fingers due to fibrosis- Abnormal proliferation of fibroblasts are involved in development of Dupuytren's contracture.

14) Parotid gland enlargement - Malnutrition in cirrhosis leads to neuropathy of autonomic innervation of parotid gland. 

15) Breast atrophy & menstrual irregularities in women-  SHBG is produced in liver. It has high affinity for testosterone than estrogen. It transports testosterone in blood in inactive form. Liver disease leads to decreased SHBG. Thus, amount of active testosterone increases.

16) Cirrhotic cardiomyopathy- Portal hypertension leads to peripheral vasodilation due to release of vasodilators like NO, CO, etc.This leads to splanchnic vasodilation with increased splanchnic blood flow & relatively decreased Central circulation. In response to this, sympathetic nervous activities increase which causes increase in heart rate & cardiac output(hyperdynamic circulation).

17) Hepatic encephalopathy- Due to liver disease, toxins are not metabolised by liver & they reach brain.

18) Hepatorenal syndrome-  It occurs due to severe renal vasoconstriction resulting from complex changes in splanchnic & general circulations as well as systemic & renal vasoconstrictors & vasodilators.

19) Flapping tremor- encephalopathy

20) Hepatopulmonary syndrome- Due to increased production of vasodilators like NO, the blood vessels in the lung dilate which affects the amount of oxygen that moves from the lungs into the bloodstream(overperfusion relative to ventilation i.e. V/P mismatch.)

21) Pleural effusion- Causes- entry of Ascitic fliud through diaphragmatic defects. Other cause - due to Hypoalbuminemia, plasma oncotic pressure decreases leading to transudation of fluid.

22) Clubbing-  Due to increase in peripheral blood flow with dilatation of AV anastomosis in the fingers. 

23) Skin pigmentation

                  ⭐⭐⭐⭐⭐⭐⭐⭐