Week 5: Gallstones and ERCP

Question 1

Risk factors for gallstones

Answer 1

• older age
• female 2x > male
• native amer.> hispanics >scandinavian >white> blacks> asian
• family hx: 4x more with 1st degree relative
• western diet
• obesity
• pregnancy: increase estrogen leads to lithogenic bile, cholesterol hyper secretion and supersaturation. Progesterone decreases gallbladder mobility

Question 2

Pathophysiology of Cholesterol gallstones

Answer 2

• Hepatic hyper secretion of biliary cholesterol
• supersaturated bile with cholesterol that can’t be solubilized at equilibrium by bile salts and phospholipids: hyper secretion of cholesterol and/or decrease rates of bile salt/phopholipid secretion into bile

Question 3

Pathophysiology of pigment stones

Answer 3

1. Black
   - chronic hemolysis: thalassemia, sickle cell, etc.
   - liver cirrhosis
   - due to increase in unconjugated bilirubin
2. Brown
   - bile stasis associated with infection
   - dead parasites are stone “nuclei”
   - formed in gallbladder and ducts (other stones form in gallbladder and move to duct)
   - seen in Asia from roundworm infections and Clonorchis sinensis

Question 4

Natural history of gallstones

Answer 4

1. most are asymptomatic
2. obstruction of cystic duct: cause intermittent biliary pain
3. impacted in cystic duct: acute cholecystitis
4. stone in cystic duct can compress or fistulize into bile duct: Mirizzi’s syndrome
5. stone in distal bile duct: risk of ascending cholangitis or acute biliary pancreatitis
6. stone can erode through gallbladder into duodenum
7. very rare, longstanding stones can cause gallbladder carcinoma

Question 5

Summary of presentation of gallstones and complications

Answer 5

1. biliary pain: temporary obstruction of cystic duct. No inflammation
   - RUQ pain with nausea
2. acute cholecystitis: inflammation of gallbladder. impacted stone in CD, acute inflammation, bacterial infection.
   - severe epigastric, RUQ pain, vomiting > 6 hours
   - fever, mild jaundice
3. Choledocholithiasis: stone in CBD, intermittent obstruction
   - similar symptoms to biliary pain
   - jaundice possible
4. Cholangitis: inflammation of CBD. obstruction of CBD causing bile stasis, bacteria super infection, bacteremia
   - Charcot’s Triad or Reynald’s pentad

Question 6

Acute cholecystitis

Answer 6

• lab findings: leukocystosis, bili 2-4 mg/dL, mild amylase and lipase elevation
• Rx cholecystectomy. Percutaneous drainage in advanced cirrhotic patients

Question 7

Imaging for gallstones

Answer 7

• ultrasound: good for stones in gallbladder but not in common bile duct
• cholescintigraphy (HIDA): most useful for cholecystitis
• CT: good for complications -abscess, perforation
• MRCP: MRI, non invasive, bad for CBD stones and ampulla. expensive. For pregnant patient to avoid ERCP
• EUS
• ERCP: but we only want to use the therapeutically, not for diagnostics because of high complications

Question 8

Biliary pain “colic”

Answer 8

• colic is misnomer. Pain is steady, gradual over 15min/hour, stays for an hour and resolves.
• if pain >6 hrs, suggests cholecystitis
• pain in epigastric >RUQ>LUQ
• some have radiation to shoulder
• cholecystectomy for recurring episodes
• Rx Non surgical (uncommonly used): Ursodiol -thinning of bile by reversing supersaturation with cholesterol.

Question 9

Cholecystitis

Answer 9

• inflammation of the gallbladder, 90% due to obstruction of gallbladder outlet by gallstone in cystic duct
• 3/4 patients have hx of biliary colic
• Murphy’s sign: tenderness with inspiration
• fever, mild jaundice
• pain resolves in 7-10 days
• mild AST, ALT, total Bili elevation

Question 10

Choledocholithiasis

Answer 10

• gallstones may pass from gallbladder into bile duct or can form de novo
• de novo: brown stones
• Elevated bili, alk phos
• elevated aminotranferases

Question 11

Cholangitis

Answer 11

• inflammation of the common bile duct or biliary tract+ infection
• etiology: CBD stones, malignant strictures, benign strictures, stent obstruction
• Charcot’s triad: fever/chills, jaundice, and abdominal pain
• 85% due to CBD stone and bile stasis
• E. Coli and Klebsiella most common infectious agents. Bacterial ascends from duodenum or from portal vein.
• Reynold’s pentad: charcot’s triad + altered mental status +hypotension/shock
• labs leukocytosis, bili>2, elevated alk phos, blood culture

Question 12

ERCP therapy

Answer 12

• timing: best before 24-48 hours after presentation. >72 hrs associated with poor outcomes
• risk of post ERCP pancreatitis: can be reduced in high risk patients (sphincter oddi dysfunction, prior post ERCP pancreatitis) by giving prophylactic pancreatic stents and/or rectal indomethacin