Path Notes: Cholelithiasis***** (gall stones in gallbladder) Flashcards
What is Cholelithiasis? Describe the epidemiology:
Cholelithiasis = gall stones in gallbladder
Common - affecting 10-20% of adult population in Western Countries
Most (80%) are silent
What are the types of stones?
- Cholesterol stones - account for 80% in the Western world. Contain >50% crystalline cholesterol monohydrate
- Pigment stones - composed predominantly of bilirubin calcium salts
What are the key risk factors for cholesterol stones?
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- Fair skin - more common amongst ‘fair-skinned’ ethnic groups, in western countries
- Forty (increasing age)
- Female (2:1)
- Fertile (Oestrogens-OCP and pregnancy increase expression of lipoprotein receptors and increase cholesterol uptake; also stimulate HNG-CoA reductase which increases biosynthesis of cholesterol)
- Fat (associated with obesity and rapid weight loss)
What is associated with acquired cholelithiasis?
gall bladder stasis
What is associated with hereditary cholelithiasis?
leads to less absorbed cholesterol, and increased production of cholesterol
Describe Cholesterol Stones?
Also describe pathogenesis
Cholesterol monohydrate crystals that aggregate to form stones
10-20% of cholesterol stones are radio-opaique (because they have sufficient calcium carbonate)
Cholesterol is rendered soluble by:
- Bile
- Water-soluble bile salts
- Water-insoluble lecithins
(the former two acts as detergents)
- Stones occur when cholesterol concentrations exceed the solubilising capacity - supersaturation
- Cholesterol can no longer remain dispersed by the detergents, and forms solid cholesterol monohydrate crystals
- Free cholesterol is toxic to the gallbladder, and penetrates the wall, leading to gall bladder hypomobility
- There then subequent hypersecretion of mucous within the gallbladder, which traps the crystals, permitting their aggregation into stones
Describe Pigment Stones
Composed of bilorubin calcium salts
Choleserol hypersecretion by hepatocytes within the liver promotes excessive cholesterol ester accumulation within the lamina propria of the gallbladder
This causes the gallbladder’s mucosal surface to be studded with multiply minute yellow flecks - strawberry gallblader
Describe the Clinical Presentation of Gallstones
May be asymptomatic - these are called ‘silent stones’ and don’t need to be treated
Colicky / constant pain due to the obstructive nature of the stones in RUQ
Pain may radiate between the shoulder blades or below R shoulder
Typically worse after fatty meals and alcohol
Thus often occurs at night
Thus patient may present with a bit of weight loss if they have been avoiding fatty meals or meals altogether
Murphy’s sign is positive*
What are some key complications of gall stones?
Biliary Colic
Acute Cholecystitis
Chronic Cholecystitis
Choledocholithliasis
(In association with the above / complications of the above - Empyema, perforation, fistula, cholangitis, obstructive jaundice, gallstone ileus, increased risk of cancer in the gallbladder)
What is Cholecystitis?
Inflammation of the gallbladder, which may be acute, chronic, or acute on chronic
Almost always associated with gall stones
Describe Acute Cholecystitis, and the two types
Acute inflammation of the gall bladder
- Acute Calculous Cholecystitis:
- Accounts for 90% of Acute Cholecystitis
- Usually precipitated (90% of the time) by obstruction of the neck of the gallbladder or cystic duct - Acute Acalculous cholescystitic
- Accounts for 10%
- Occurs in severely ill patients
Describe the Pathogenesis of Acute Calculous Cholecystitis:
- Irritation and inflammation of the obstructed gallbladder
- Accumulation of bile and other products within the gallbladder leads to:
- Disruption of mucosal layer
- Release of prostaglandins that contribute to mucosal and mural inflammation - Results in gall-bladder dysmobility, increased luminal pressure, and compromised blood flow
More complicated version - probs don’t need to know???
(((2. Actions of mucosal phospholipases hydrolyze the luminal lecithins to toxic lysolecthins that disrupt the protective mucosal layer
- Detergent action of bile salts
- Prostaglandins released within will contribute to mucosal and mural inflammation )))
Describe the Pathogenesis of Acute Acalculous Cholecystitis:
Occurs in severely ill, thus risk factors include:
- Sepsis with hypotension
- Multi-system organ failure
- Immunosuppression
- Major trauma and burns
- Diabetes
- Infections
Pathogenesis likely involves ischaemia, as the cystic artery is an end artery
Describe the macroscopic features of Cholecystitis:
- Enlarged, tense GB
- Bright red and blotchy
- Violety/green/black discoloration is imparted by subserosal haemorrgahes
- Fibrin, and in severe cases, suppurative exudate
- Cloudy or turbid bile that may contain large amounts of fibrin, pus and haemorrhage (if purely pus, then is Empyema)
In mild cases:
- Gall bladder wall thickening with hyperaemia
- Due to oedema
In severe cases:
- Gangrenous cholecystitis
- With small-large perforations
Describe the Microscopic appearance of Cholecystitis
- Oedema
- Leukocyte infiltration
- Vascular congestion
- In severe cases:
- Flank abscess formation
- Gangrenous necrosis
Describe the clinical presentation of an individual with Cholecystitis:
- RUQ / epigastric pain
- Mild fever
- Tachycardia
- Anorexia
- Sweating
- Nausea and Vomiting
- May be sudden onset
- May require urgent surgery, or may resolve
Resolution occurs within 7-10 days, and frequently within 24 hours
*25% of cases develop more serious symptoms, requiring immediate surgery
**Higher incidence of gangrene occurs in Acalculous cholecystitis (because is typically associated with cholecystitis due to ischaemia secondary to other serious condition)
What is chronic cholecystitis?
May be a secondary or repeated bout of mild-severe acute cholecystitis
Associated with cholelithiasis in over 90% of cases
Describe the pathogenesis of chronic cholecystitis:
Unsure of exact pathogenesis
Likely to occur due to the supersaturated bile predisposing to both chronic inflammation and stone formation
Complete obstruction to outflow of bile is not a requisite*
Microbial organisms can be cultured in ~1/3 of cases - E.coli or enterocoli
Describe the macroscopic features of chronic cholecystitis:
Serosal membrane changes vary:
- Dull and fibrotic
- Smooth and glistening
Fibrous adhesions can occur
GB wall is variably thickened
Wall has opaque/grey appearance
Reduced wall flexibility
Describe the microscopic features of chronic cholecystitis:
- variable degrees of inflammation may be present
- Lymphocytes, plasma cells and macrophages are found in the mucosa and sub-serosal fibrous tissue
- Reactive proliferation of the GB mucosa may give rise to buried pits of epithelium in the wall
- Outpouching of the epithelium into the muscular layer and sub-serosal tissue = entrapped epithelial crypts
Rarely, dystrophic calcific-porcelain gallbladder develops - associated with increased risk of cancer
What is Xanthogranulomatous Cholecystitis?
Rare condition
- Shrunken, nodular and chronically inflamed galbladder
- Foci of haemorrhage and necrosis
- Gallstones are usually present
- Rarely, ‘porcelain gallbladder’ develops - condition where gallbladder calcifies. This is associated with increased risk of cacer
Describe the clinical presentation of an individual with chronic cholecystitis:
- Recurrent attacks of colicky or steady RUQ pain
- +/- nausea and vomiting
- Intolerance (due to episodes) for fatty foods and alcohol (potentially)
Describe some of the main complications of acute and chronic cholecystitis:
- Cholangitis or sepsis - bacterial infection
- Perforation causing local abscess formation
- Rupture with peritonitis
- Biliary-enteric fistula, with entry of air and bacteria into the biliary tree, and gallstone ileus
- Aggravation of pre-existing illness
- Porcelain gallbladder
What is choledocholithiasis?
Presence of gall stones within the bile ducts of the biliary tree
What is cholangitis? Most common cause?
Cholangitis is the term used to describe bacterial infection of the bile ducts, most commonly secondarily to obstruction by gallstones and strictures, leading to stasis
What is ascending cholangitis?
Ascending cholangitis is bacterial infection of the intra-hepatic biliary ducts
Common pathogens involved in ascending cholangitis?
E. coli Klebsiella Clostridium Bacteriodes Enterobacter Group D Streptococci
Describe the clinical presentation of ascending cholangitis
- Fever
- RUQ pain
- Jaundice
Tend to look (because they are) very unwell
Life threatening condition
