Cholelithiasis

Cholelithiasis = Gallstones disease

Choledocholithiasis = stone in bile ducts

History of Presenting illness:

1. asymptomatic gallstones: no symptoms or complications
2. Biliary colic:
• gallstones impact in cystic duct during gallbladder contraction, increasing gallbladder tension
• pain relieve over 30-90 minutes
• sporadic and unpredictable pain
• pain localise at epigastrium/ right hypochondrium
• may radiate to right scapular tip
• pain not relieve by emesis, antacids, defecation, flatus or positional changes
• may be accompanied by diaphoresis, nause, vomiting, dyspepsia, bloating, fat intolerance

Physical Examination:

• uncomplicated biliary colic: no fever, pain poorly localized, no guarding or rebound tenderness
• acute cholecystitis: localized pain, with rebound or guarding. positive Murphy sign. Fever may be present
• severe cases: absent/ hypoactive bowel sounds
• Charcot triad: severe right upper quadrant tenderness + jaundice + fever = suggestive of ascending cholangitis

Pathophysiology:
- occurs because certain substances in bile are present in high concentrations that approach the limits of their solubility
- supersaturated bile will precipitate and forming microscopic crystals
- crystals trapped in gallbladder mucus, producing gallbladder sludge
- over time, the crystals grow, aggregate, and fuse to form macroscopic stones
- occlusions of the ducts by stones produces complications of gallstone diseases

Common gallstones:

Cholesterol gallstones

• 80% of the cases
• factors affecting cholesterol gallstones formation: 
• amount of cholesterol secreted by liver cells relative to lecithin and bile salts
• degree of concentration and extent of stasis of bile in gallbladder

Calcium, bilirubin, and pigment gallstones

• unconjugated bilirubin tends to form insoluble precipitates with calcium
• calcium enters bile passively along with other electrolytes
• calcium bilirubinate may then crystallize and form stones
• various oxidations cause bilirubin precipitates to take on jet-black colour
• bacteria hydrolyze conjugated bilirubin and resulting increase in unconjugated bilirubin which can precipitate formation of stones
• bacteria also hydrolyze lecithin to release fatty acids, which also may bind calcium and precipitate
• these stones have claylike consistency and termed brown pigment stones.

Mixed gallstones

• cholesterol gallstones may become colonized with bacteria and can elicit gallbladder mucosal inflammation
• enzymes from bacteria hydrolyze bilirubin conjugate and fatty acids
• cholesterol stones may accumulate substantial proportion of calcium bilirubinate and other calcium salts, producing mixed gallstones

Aetiology:

1. Cholesterol gallstones: associated with female sex, increasing age, obesity, pregnancy, gallbladder stasis, drugs, hereditary
2. Black and brown pigment gallstones
   • occur in person with high heme turnover i.e disorder of haemolysis
   • intraductal statis and chronic colonization of bacteria: predispose to brown pigment gallstones
3. Other comorbidities:

• Crohn disease, ileal resection, other diseases of ileum that decreases bile salt reabsorption
• predisposing condition to gallstones formation: burns, total parenteral nutrition, paralysis, ICU care, major trauma

Complications of gallbladder stones:

- acute cholecystitis due to persistent stone impaction

- gallbladder empyema due to colonization of bacteria and pus formation

- fibrosis of gallbladder wall: chronic cholecystitis

- gallbladder adenocarcinoma

- cholecystoenteric fistula

Complications of stones in common bile duct (choledocholithiasis):

- increased liver enzymes and jaundice

- ascending cholangitis

- acute pancreatitis: due to stone impaction in ampulla of Vater that obstruct pancreatic duct

- Other complications: Mirizzi syndrome (fusion of gallbladder to extrahepatic biliary tree), gallstone ileus


Differential diagnoses:

1. appendicitis
2. bile duct strictures
3. bile duct tumours
4. cholangiocarcinoma
5. cholecystitis
6. gallbladder cancer

Treatment:

Asymptomatic

• surgical treatment not recommended. higher risks of developing complications with interventions
• cholecystectomy indicated if: large gallstones (>2cm), non-functional or calcified gallbladder, spinal cord injuries/ sensory neuropathies, sickle cell anaemia
• elective cholecystectomy: cirrhosis, portal hypertension, children, transplant candidates, diabetes with minor symptoms 
• Medical Dissolution
• Ursodeoxycholic acid (ursodiol) - 
• gallstone dissolution agent
• reduces cholesterol saturation of bile
• reduce liver cholesterol secretion

Symptomatic

• Cholecystectomy
• removal of gallbladder
• indicated for patient with symptoms and complications
• Cholecystostomy
• placing of drainage tube in gallbladder
• results in clinical improvements
• Endoscopic sphincterotomy
• incision through sphincter of Oddi and intraduodenal portion of common bile duct, creating opening for stones to pass through

Prevention

• Ursodeoxycholic acid treatment can prevent gallstone formation