The Biliary System - Gallstone Disease and Obstruction (DMUT 2000) PDF

The Biliary System Gallstone Disease and Biliary Obstruction QE II/Dalhousie School of Health Sciences DMUT 2000 – Topic 13 Gallstone Disease Cholelithiasis W-E-S Sign Biliary Sludge Milk of Calcium Bile ...

The Biliary System Gallstone Disease and Biliary Obstruction QE II/Dalhousie School of Health Sciences DMUT 2000 – Topic 13 Gallstone Disease Cholelithiasis W-E-S Sign Biliary Sludge Milk of Calcium Bile Cholelithiasis  AKA – Gallstones in the gallbladder  Incidence  Common  Found worldwide  Highest incidence  Europe & N. America ~10-20% of population  1 in 5 develop complications Cholelithiasis Risk Factors  “5 F’s”  Alcoholic cirrhosis  Female  Diabetes   estrogen and progesterone  Pregnancy  Forty  Related to  estrogen and  Fat progesterone  Fertile (Fecundity)  Genetics  Fair  Any condition causing bile stasis  Increasing age  ICU care, TPN, paralysis  Obesity  Gastric bypass surgery Cholelithiasis Pathophysiology  Depends on the type of stone formed  Most important factors affecting gallstone formation:  Abnormal bile composition  Bile stasis  Infection  Formation occurs in 3 stages:  Saturation of bile with cholesterol  Initiation of stone formation (crystallization)  Growth of stone to a detectable size Pathophysiology Gallstone Composition  Cholesterol stones  Calcium bilirubinate stones  “Pigment” stones  Calcium carbonate stones  Rare  Majority of stones are a mixture of the three compositions Cholelithiasis Clinical Manifestations  Variable depending on whether complications occur  Uncomplicated  Complicated  Asymptomatic (80%)  Biliary colic  Mild symptoms  Jaundice  Indigestion  Fever  Fat intolerance  Diaphoresis  Nausea & vomiting  +ve Murphy’s sign  Lab Tests  Leukocytosis   Bilirubin   SAP Biliary Colic  Acute, intermittent epigastric or RUQ pain  May radiate to right shoulder or back  Post-prandial  Often occurs 1-5 hour after a meal  May wake a patient up at night  Occurs with:  Contraction of gallbladder around a stone  Obstruction of cystic duct or biliary duct  Pain is relieved if the obstructing component is freed  Ex: Stone rolls back into GB or passes into duodenum Cholelithiasis Sonographic Appearance  Variable in number and size  Echogenic with posterior acoustic shadow  High reflectivity and high absorption by the stone  Due to large acoustic impedance difference between the stone and adjacent bile  Stones < 5mm may not demonstrate shadowing  FOCUS is important for this  Best shadow occurs when stone is in focal zone  Mobile  Mobility must be demonstrated  Scan patient in multiple positions (LLD, or upright) Cholelithiasis Sonographic Appearance Multiple, non-shadowing echogenic foci Rumack Fig 6-33A Multiple, shadowing echogenic foci Single, shadowing stone Cholelithiasis Sonographic Appearance Supine position, stone appears impacted in LLD position, stone rolls to dependent GB neck position (fundus) Cholelithiasis Sonographic Pitfalls  Stones may fill GB lumen (W-E-S sign)  Tiny stones may layer along posterior wall  Change patient position  Stones may be hidden in the neck of the GB  May be mistaken for normal dense fibromuscular tissue  Change patient position  Impacted stones will not move Cholelithiasis Sonographic Pitfalls Stone in neck, moves with change in patient position Multiple layered stones move with change in patient position W-E-S Sign  Occurs when the GB lumen is filled with stones (or 1 large stone)  Important to demonstrate the GB wall  W – Wall  Anterior wall of GB  E – Echo  Echo of anterior aspect of stone  S – Shadow  Shadow from stone W-E-S Sign W = Wall (anterior) of GB E = Echo of anterior aspect of stones S = Shadow from stones Rumack Fig 6-33B Cholelithiasis Sonographic Appearance  W-E-S Sign Differential Diagnoses  Air in GB wall  Emphysematous cholecystitis  Calcification of GB wall  Porcelain GB  Air in the biliary tract  Pneumobilia  Cholecystectomy  GB removed Biliary Sludge  AKA – Biliary sand, microlithiasis A mixture of particulate matter, crystals and bile  Most likely caused by bile stasis  May be a pre-cursor to stone formation  Usually asymptomatic Biliary Sludge Risk Factors  Risk factors  Pregnancy  Rapid weight loss  Prolonged fasting  Critical illness  Long-term TPN  BMT Biliary Sludge Sonographic Appearance  Amorphous, low-level echoes  Non-shadowing  Mobile (slow)  Settles in dependent position  Fluid-fluid levels  “Tumefactive sludge”  Focal collections of sludge  Mimic tumors  “Hepatization” of the gallbladder  Sludge may completely fill GB and appear isoechoic to liver Biliary Sludge Sonographic Appearance Tumefactive sludge – should be mobile Fluid-fluid levels Rumack Fig 6-38 Hepatization – look for the GB wall Biliary Sludge DDX  Hematobilia  Blood in the bile  Pseudosludge  Polypoid masses  No vascularity in sludge  Sludge is mobile Carcinoma Hematobilia Pseudosludge  Not real  Slice thickness artifact  Averaging of echoes from the liver adjacent to the GB  Change patient position or scan plane to resolve Biliary Sludge Complications  Spontaneous resolution (50%)  Persist but asymptomatic (20%)  Persist but become symptomatic (10-15%)  Biliary colic  Acalculous cholecystitis  Pancreatitis  Gallstone development (5-15%) Milk of Calcium Bile  AKA – Limey bile  Rare  Thickbile with an  calcium content  Associated with GB stasis  May migrate into bile ducts  Appears as highly echogenic material with shadowing  Mobile Rumack Fig 6-37 Milk of Calcium Bile Echogenic bile Layers out with a change in position Cholelithiasis/Sludge Complications and Treatment  Complications  Treatment  Choledocholithiasis  Elective surgery  Cholecystitis  If symptomatic  Gallstone pancreatitis  Dietary management  GB hydrops  Low-fat diet  Courvoisier’s GB  Alternative therapies  Cholangitis  “Flushes”  Unproven Biliary Obstruction Overview of Causes Clinical Symptoms Sonographic Appearance Determining the Level of Obstruction Choledocholithiasis Biliary Obstruction  Obstruction of the bile ducts  Partial or complete  Any bile duct at any level  Tiny intrahepatic ducts  RHD, LHD, Cystic duct, CHD, CBD  Intrinsic to duct  Stones, sludge, bile duct neoplasms, inflammation or infection, congenital diseases  Extrinsic compression  Mirrizzi’s syndrome, neoplasms (hepatic, pancreatic) Causes of Bile Duct Obstruction  Choledocholithiasis  Intrinsic neoplasms  Stones in the ducts  Cholangiocarcinoma  Most common cause  GB carcinoma  Invasive neoplasms  From another site  Congenital diseases  Metastases to the ducts  Caroli’s disease  Choledochal cysts  Extrinsic compression  Biliary atresia  Mirizzi’s syndrome  Pancreatitis  Infection  External neoplasms  Cholangitis  Pancreatic carcinoma  Parasites  Liver neoplasms Biliary Obstruction Clinical Symptoms  Pain  May be painless (usually due to external compression)  Jaundice  bilirubin (direct)   serum alkaline phosphatase (SAP)  Symptoms of causative agent Bile Duct Obstruction Sonographic Appearance  Obstruction of ducts will only occur proximal to obstructing entity  Proximal ducts will:  Be anechoic  Be increased diameter  Remember normal measurements  Demonstrate posterior acoustic enhancement  NOT demonstrate flow on color Doppler Bile Duct Obstruction Sonographic Appearance Dilated CBD Dilated intrahepatic ducts Bile Duct Obstruction Sonographic “Signs”  Peripheral lucencies  Ducts seen in the periphery of the liver  Not usually demonstrated in these areas  “Flashlight” sign  Acoustic enhancement posterior to dilated bile ducts  Bile ducts demonstrate > enhancement than blood vessels  “Too many tubes” sign  Stellate branching appearance around porta hepatis  “Parallel channel” and “Double barrel shot gun” sign  Dilated duct adjacent to PV branch Bile Duct Obstruction Sonographic “Signs” Parallel channel “Too many tubes” Biliary Obstruction Questions To Ask Yourself  Is the gallbladder dilated?  Are there stones within the GB?  Is there biliary duct dilation?  Which ducts are dilated?  Determine which level obstruction is at  What is causing the obstruction?  Is it within ducts or external to ducts? Determining Level of Bile Duct Obstruction  Dilated RT (or LT) intrahepatic ducts with normal CHD and CBD  Obstruction is localized to RHD (or LHD) branches  Dilated intrahepatic ducts with normal CHD and CBD  Obstruction is proximal to CHD  Dilated intrahepatic ducts and CHD with normal CBD and small GB  Obstruction is at level of CHD  Dilated intrahepatic ducts, CHD, CBD and GB  Obstruction is distal to CBD  Pancreatic head, ampulla of duodenum Determining Level of Bile Duct Obstruction Choledocholithiasis  Stones in the bile ducts  Chole = biliary, docho = ducts, lithiasis = stones  Primary or secondary forms Primary Secondary Formation of stones occurs in Formation of stones occurs in the GB the ducts  Stones migrate into ducts Causes: Most common cause Sclerosing cholangitis  Up to 20% of patients with Caroli’s disease gallstones will have stones in the Parasites ducts Previous biliary surgery Sickle cell anemia Choledocholithiasis Sonographic Appearance  Depends of size and composition of stones  Highly echogenic  With posterior acoustic shadowing  Small (