⭐⭐GALL STONES ⭐⭐

                ⭐⭐GALL STONES ⭐⭐

1) DEFINITION of Gall stones :- 

     Gall stones are solid crystal deposits formed in the gall bladder, a pearly shaped sac that stores bile.

2) TYPES of Gall stones :- 

     (I) Cholesterol stones 

     (II) Mixed stones - Made of cholesterol ,

         calcium salts of carbonate, 

         phosphate, palmitate , proteins.

     (III) Pigment stones - black or greenish 

            black coloured.

⭐ NOTE ⭐- 

     # Sources of cholesterol in our body 

       are liver and food. Liver produces  

       cholesterol.

    # Cholesterol in liver helps in production

       of bile acids (cholic ,chenodeoxycholic

       acids,etc) by classic and alternate 

       pathway.

    # These bile acids further combine with

       Glycine or taurine to form bile salts.

    # Thus, bile juice contains bile salts , 

       bile acids, phospholipids, cholesterol,

       conjugated bilirubin, electrolytes ,

       water.

    # This bile juice is released into 

       intestine(duodenum) from gall bladder

       Most of the bile salts and acids are

       reabsorbed back into portal circulation

       and reach back to liver - enterohepatic

       recirculation.   

       ( portal circulation consists of vessels

        which carry blood from intestine to 

        the liver )

    # Hepatocytes take up these bile acids 

       and salts from the portal venules and

       again actively secrete them into bile

       ductules. 

    # If this enterohepatic circulation is 

       impaired by one way or the other,

       these bile acids will not be reabsorbed

       from the intestine (ileum) and hence,

       most of them will be excreted.

    

        

3) PATHOGENESIS of Gall stones:-

    (a) Admiron's hypothesis - 

       # Cholesterol, which is secreted in 

        bile , is insoluble in water. 

        It is made soluble by micelle 

        formation with bile salts and lecithin.

       # The normal bile salt : cholesterol 

         ratio is about 25 : 1.

         If it goes below 13 : 1, relative

         concentration of cholesterol 

         increases and precipitation of 

        cholesterol occurs - cholesterol 

        monohydrate crystal formation.

        ( One of the cause for decreased 

         bile salt concentration may be 

        defective enterohepatic circulation 

        as discussed above due to which bile 

        salts will not be reabsorbed and 

        concentration of bile salts will be 

        decreased leading to precipitation of 

        cholesterol crystals.

   (b) Some cholesterol is present in 

       bilayered lipid vesicles. A specific 

       glycoprotein in bile causes 

       aggregation of these vesicles - 

       nucleation. This leads to formation of

       cholesterol crystals due to nucleation.

   (c) Pigment stones may be formed due 

       to increased bilirubin.

4) ETIOLOGY of Gall stones :-

    (a) Infections - E coli, Salmonella,ascaris

                             chlonorchis sinensis ,etc.

        (These infections cause damage to 

         intestinal wall which can impair 

         the function of absorption and thus 

         impair the enterohepatic circulation)

    (b) Pancreatic juice reflux into bile duct

         (Phospholipase present in pancreatic

         juice converts lecithin to lysolecithin.

         As lecithin is important for micelle 

         formation with cholesterol,

         decreased lecithin leads to 

         precipitation of cholesterol.)

    (c) Bile stasis - (Due to stasis, 

         supersaturation of bile occurs. This 

         promotes nucleation of cholesterol

         crystals.)

         Eg - # TPN i.e total parentral nutrition.

               (Due to parentral nutrition - no

               food to digest in intestine - no

               secretion of bile in intestine - 

               stasis of bile.)

               # patient on iv fluids

               # pregnancy (progesterone impair

                 emptying of Gall bladder due to 

                 effect on sphincter of oddi)

              # vagotomy (decreased motility of

                 gall bladder - stasis

    (d) Impaired enterohepatic circulation

    (e) Factors increasing cholesterol - 

          # old age

          # obesity

          # oc pills

          # clofibrate 

    (f) Factors decreasing bile acids and 

       lecithin - 

        # ileal resection - decreased 

          absorption of bile acids 

        # cholestyramine - It binds to bile 

          acids in intestine and causes it's 

          excretion

        # estrogen - it decreases bile acid 

           transportation from hepatocytes 

           into bile canaliculi by inhibiting the

           export pumps

    (g) Pigment stones - due to increased

         bilirubin. Increased bilirubin occurs in

         case of hemolysis

         - Hemolytic anemia

         - Sickle cell anemia

         - Hereditary spherocytosis

         - Thalassemia

5) CLINICAL EFFECTS of Gall stones - 

    (A) On gall bladder :- 

          (I) May be asymptomatic

          (II) Biliary colic - severe spasmodic

               episode of pain in right 

               hypochondrium and epigastrium

               which radiates to chest, upper 

               back, shoulder.

              ( Possible causes of pain - 

               # gall stones irritate mucosa and 

                 nerve endings in the wall of 

                 biliary apparatus .

               # when the stone causes

                 obstruction ,bile stasis occurs.

                 This leads to spasm to gall 

                 bladder in attempt of emptying.

                 This muscle spasm causes pain)

              This type of pain is commonly

              seen after fatty meals ( due to 

              increased contraction of Gall 

              bladder) 

        (III) Cholecystitis - Acute or chronic

              ( Due to obstruction and stasis of 

               bile - inflammation)

        (IV) Empyema of Gall bladder - (pus 

             formed due to stasis - infection -

             inflammation)

        (V) Mucocele Gall bladder - Due to 

             outlet obstruction of Gall bladder 

             by stone. 

        (VI) Limey Gall bladder - high calcium

              carbonate content - toothpaste 

              like material.

        (VII) Carcinoma Gall bladder - due to 

               bile stasis and inflammation

        (VIII) Perforation of Gall bladder- 

                Leads to biliary peritonitis and 

                pericholecystic abscess.

    (B)On common bile duct (CBD) :-

        (I) Cholangitis

        (II) Pancreatitis

        (III) secondary stones in CBD

        (IV) Mirizzi syndrome - compression 

              of CBD by stone.

    (C) On intestine :-

        (I) Intestinal obstruction

        (II) Gall stone ileus - obstruction - 

            spasm - pain.

6) Gall stone colic - It occurs due to spasm

   of wall of Gall bladder due to impaction

  of stone in cystic duct. It commonly  

  occurs in supine position, lasts for a 

  period of time, may be associated with 

  tachycardia, restlessness. It can cause 

  vomiting , Cholecystitis , Empyema GB.

7) INVESTIGATIONS for gall stones - 

   (a) USG abdo 

   (b) Xray

   (c) CT

   (d) LFT

   (e) WBC count

8) TREATMENT of Gall stones:-

   (I) Laparoscopic cholecystectomy

      (Removal of Gall bladder)

   (II) Laparotomy - through right subcostal 

       incision ( kochers incision)

       Indications - carcinoma GB

                              CBD stones

                              patient unfit for 

                               laparoscopy.

           

           ⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐