Emory University School of Medicine

1. Biliary Stones
    a. Gallstones (cholelithiasis)
    b. Ductal stones (choledocholithiasis)
        We will be talking about secondary, not primary ductal stones

2. Complications
    a. Inflammation
    b. Obstruction/stasis
    c. Malignancy

3.  Epidemiology (more common with age, in patients over 60)
    a. 10-15% of men
    b. 20-40% of women
    c. Risk factors include childbearing, estrogen supplementation, birth control pills, hypertriglyceridemia, 
        inflammatory bowel disease, and hyperalimentation.

4. Etiology
     Composed largely of cholesterol, bilirubin/bile pigments, and calcium salts - cholesterol stones most 
     common in the West, pigment stones seen in cirrhosis, hemolytic anemias, and infection.  Supersaturation 
     and stone formation are the result of cholesterol overproduction, bile pigment underproduction, bacterial
     deconjugation and stasis.

5. Imaging
    a. KUB - only 15-20% have sufficient calcium to be visible.
    b. Ultrasound - 98+% sensitive
    c. CT - approximately 75% sensitivity, again dependent on composition
    d. MRI - similar or more sensitive than ultrasound, see stones as small as 2mm.

6. Acute cholecystitis
     a. Risk in up to 1/3 of patients harboring stones
     b. First line of detection usually ultrasound, accuracy in excess of 88% - fast and portable.  Findings include
         stones, wall thickening, lumen distention, pericholecystic fluid, pain/Murphy sign (98% positive predictive 
         value in setting of stones and gallbladder-specific pain).
     c. HIDA helpful in indeterminant ultrasound
     d. CT also helpful in complicated cases
         1. perforation
         2. abscess formation
         3. emphysematous complications
         4. porcelain wall
     e.  Gangrenous cholecystitis
         1. 2-30% of cases
         2. Characterized by ischemia and wall necrosis
         3. Imaging findings include wall thickening, striations, intraluminal membranes, segmental absence of 
             wall enhancement
     f. Emphysematous cholecystitis
         1. Higher mortality, up to 15%
         2. More common in males (71%) and diabetics (50%).
     g. Perforated cholecystitis
         1. 8-12% of cases of acute cholecystitis
         2. Three patterns of spillage/complication
               i. Diffuse peritoneal spread
               ii. Focal abscess
               iii. Fistula

7. Chronic complications of gallstones
    a. Chronic cholecystitis
        1.  95% contain stones
        2.  Fibrotic, thickened wall
        3. Compromised distensability and compliance
        4. May not have surrounding inflammatory changes/fluid
    b. Mirizzi syndrome
        1.  Up to 2% of patients with symptomatic gallstone disease
        2. Obstruction of CHD or CBD secondary to stone or inflammation involving the cystic duct or
            gallbladder neck
    c. Choledochoenteric fistula (Gallbladder ileus)
        1.  Obstruction of bowel, usually ileum secondary to stone passed via fistula between gallbladder 
             and duodenum
        2. 1-5% of non-malignant causes of small bowel obstruction, in some series up to 25% in patients over 60.
        3. Rigler's triad (seen in only 30%)
             i. Bowel obstruction
             ii. Pneumobilia
             iii. Distal stone 

    d. Spilled gallstone
        1.  Occurs in up to 6-8% of cases
        2.  Complication uncommon - 1%, present with infection/abscess
        3. Most common location is subhepatic, but can occur anywhere
        4. Time of presentation variable, anywhere from 1 month to 10 years, most common around 4 months.
        5. Requires stone removal.
    e. Porcelain gallbladder
        1.  Consequence of chronic inflammation
        2.  Focal/diffuse calcification within wall
        3. 20-50% risk of ultimate malignant degeneration
        4. Indicator for elective cholecystectomy
    f. Malignancy
       Chronic irritation secondary to presence of stones felt to be a major contributor to occurrence, 65-90% of 
       cancers occur in setting of stones.

8. Ductal stones (choledocholithiasis)
Primary vs secondary
     a. 2-3%/year have migration of stones
     b. 1-2% symptomatic (colic, biliary obstruction, pancreatitis)
     c. Imaging
          1.  22-70% ultrasound sensitivity
          2. 65-88% sensitivity with MDCT, up to 95% with positive biliary contrast
          3. Sensitivity of 85-100% sensitivity with MRI/MRCP, detect stones down to 2 mm in size.
     d. Complications
          1.  Acute
               i. Ascending cholangitis
               ii. Biliary pancreatitis
          2. Chronic
               i.  Jaundice/cirrhosis