Diseases of the bile ducts

Chapter 33 Diseases of the bile ducts



Ira M. Jacobson, MD, Douglas M. Weine, MD



Key Points



1 Diseases of the bile ducts (BDs) usually manifest with symptoms and signs related to BD obstruction, including pain, jaundice, pruritus, fever, and elevated serum levels of liver biochemical tests

2 Choledocholithiasis, the most common benign disorder of the biliary tree, may manifest in patients with an intact gallbladder, who usually harbor gallbladder stones, or in patients who have had a cholecystectomy. Predictors of BD stones in patients with a compatible history include elevated liver biochemical test levels, duct dilatation, stones visualized in the duct on imaging studies, and an initial presentation with cholangitis.

3 In the diagnosis and management of BD stones before laparoscopic cholecystectomy, endoscopic retrograde cholangiopancreatography (ERCP) should be restricted to patients in whom BD stones are strongly suspected and in whom therapeutic intervention is likely. Magnetic resonance cholangiopancreatography (MRCP) is used commonly for noninvasive diagnosis. Endoscopic ultrasonography is also highly sensitive and specific.

4 Endoscopic sphincterotomy is the most common technique used for removal of BD stones, either before or after cholecystectomy. Laparoscopic extraction of BD stones during cholecystectomy is an alternative approach when intraoperative cholangiography results are positive and surgical expertise is available.

5 Endoscopic intervention plays an important role in the diagnosis and treatment of complications of cholecystectomy, such as biliary leaks and strictures.

6 Anatomic and congenital anomalies, such as choledochal cysts, can lead to jaundice, pancreatitis, and biliary carcinoma if these anomalies are not recognized and treated.


Bile Duct Stones



Composition



1. Most BD stones are cholesterol stones that have formed in the gallbladder.

2. Black pigment stones are formed in the gallbladder and are associated with hemolytic disorders such as sickle cell disease. They are also common in persons with cirrhosis.

3. Brown pigment stones make up the majority of BD pigment stones, form within the BD, and are associated with chronic biliary stasis, biliary strictures, and recurrent pyogenic cholangitis.


Clinical features



1. Presenting features of BD stones are as follows:
image Pain

image Cholangitis

image Pancreatitis

image Jaundice

2. Pain from BD stones resembles pain of gallbladder origin.
image Epigastric or right upper quadrant pain is present.

image Abdominal tenderness is greater with cholecystitis than with BD stones.

image Obstructive jaundice from BD stones is usually accompanied by pain.

image Jaundice associated with malignancy is more likely to be painless.

3. Features of cholangitis include the following:
image Charcot’s triad, consisting of abdominal pain, fever, and jaundice: Each feature may not be present in all patients with cholangitis.

image Reynolds’ pentad consists of Charcot’s triad plus hypotension and altered mental status.

image Fever may be accompanied by severe rigors.

image Cholangitis is more frequent with BD stones than with malignant BD obstruction.

image Severe cholangitis must be considered life-threatening and requires urgent intervention.

4. The timing of presentation with BD stones is variable:
image Before cholecystectomy

image During intraoperative cholangiography (IOC)

image Shortly after cholecystectomy

image Months to years or decades after cholecystectomy

5. Gallstone pancreatitis (see later)
image Small gallstones pose a greater risk of pancreatitis than do large stones (they migrate more easily through the cystic duct).


Laboratory features



1. Elevations in serum liver biochemical test levels include alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, gamma glutamyltranspeptidase (GGTP), and bilirubin.
image Marked elevations in serum ALT and AST levels may occur, even levels higher than 1000 U/L transiently, especially with cholangitis.

image Levels fall rapidly, even as the alkaline phosphatase level rises if stone impaction persists.

image This condition can be confused with hepatitis.

2. Elevations in serum amylase and lipase levels suggest concomitant acute pancreatitis.

3. Elevations in the white blood cell (WBC) count occur with cholangitis or pancreatitis.

4. Positive blood cultures can be found with cholangitis.


Imaging studies



1. Ultrasonography
image Excellent for detecting gallbladder stones; less sensitive for BD stones

image May be limited by obesity, gas in the intestine

image Sensitive for detecting BD dilatation

image More sensitive for BD stones when the duct is dilated

image Absence of BD dilatation or detectable stones does not exclude BD stones

2. Computed tomography (CT)
image Sensitivity lower than 50% for BD stones

image Detection depends on the presence of calcifications in stones

image Sensitivity similar to that of ultrasonography for detecting a dilated BD

image Need to avoid oral contrast agents on initial images (can obscure BD stones)

3. Magnetic resonance cholangiopancreatography (MRCP) (Fig. 33.1)
a. Detection of BD stones depends on T2-weighted images

b. Contrast provided by fluid in the ducts

c. Sensitivity and specificity greater than 90%

d. Sensitivity lower for small stones

e. Limited availability and high cost; contraindications include pacemakers, defibrillators, or certain other metallic implants
image Feasibility should be checked with the radiologist regarding compatibility with orthopedic implants.

4. Endoscopic ultrasonography (EUS) (Fig. 33.2)
image Sensitivity and specificity rival those of endoscopic retrograde cholangiopancreatography (ERCP)

image Less risk than ERCP but still an endoscopic procedure requiring sedation

image Most suitable for choledocholithiasis when EUS and ERCP can be performed at the same session

5. ERCP (Fig. 33.3)
image Has been the “gold standard”

image Can miss small stones, especially in dilated ducts

image Most often done when therapeutic intervention is anticipated

image Risks of ERCP include pancreatitis, bleeding (usually from sphincterotomy), retroperitoneal perforation, and anesthesiology-related complications.

6. Percutaneous transhepatic cholangiography (THC)
image Seldom used for evaluation or treatment of BD stones, except with acute cholangitis when ERCP is unavailable or fails or is anatomically impossible because of prior surgery

image Occasionally used to facilitate a “rendezvous procedure” (combined THC and ERCP) when ERCP alone fails

image

Fig. 33.1 Magnetic resonance cholangiographic image showing a large stone in the distal bile duct.


image

Fig. 33.2 Endoscopic ultrasonographic image of a bile duct stone.


image

Fig. 33.3 A, Endoscopic retrograde cholangiogram (ERC) showing a distal bile duct stone (arrow) before stone extraction. B, Stone adjacent to the sphincterotomy site after balloon extraction.



Treatment



1. ERCP and endoscopic sphincterotomy: treatment of choice at most centers
image Successful clearance of BD in more than 90% of patients

image Definitive treatment of BD stones in postcholecystectomy patients

image Most common treatment of BD stones when laparoscopic cholecystectomy is planned and BD stones are documented or strongly suspected

image Permits leaving gallbladder intact after ERCP in patients at high risk for surgery; need for subsequent cholecystectomy is 10% to 20% within 5 to 10 years

2. Role of preoperative versus postoperative ERCP
a. ERCP has no routine preoperative role.

b. Risk factors for BD stones are as follows:
image Elevated liver biochemical test levels

image BD dilatation on imaging

image BD stones seen on imaging

image Initial presentation with cholangitis

c. Preoperative ERCP is appropriate when the suspicion for BD stones is high.

d. Postoperative ERCP is effective therapy if BD stones are confirmed on IOC.

e. Unsuccessful postoperative ERCP may result in a second operation (should seldom occur in experienced centers).

3. Laparoscopic cholecystectomy plus extraction of BD stones
image High success rates (80% to 90%) are reported by expert surgeons when IOC results are positive for BD stones.

image The usual approach is the transcystic duct route.

image Laparoscopic choledochotomy is also possible.

image Surgical expertise is still not widely available.

image Many surgeons prefer preoperative or postoperative ERCP.

4. Open choledochotomy
image This was standard care before ERCP in the 1970s; it is seldom performed currently except for large retained stones not extractable by other methods.

image It is performed either at the time of cholecystectomy or after a patient presents with symptomatic choledocholithiasis.

image If the gallbladder contains stones, laparoscopic cholecystectomy after ERCP extraction of BD stones is usually performed, but leaving the gallbladder intact is an option in high-risk patients.

5. ERCP techniques for the treatment of choledocholithiasis
image Guidewire cannulation of BD using a sphincterotome is a common technique; the sphincterotome is advanced over a guidewire into the BD.

image Needle-knife precut sphincterotomy is performed when cannulation of the BD is difficult.

6. Large stones: may require more advanced ERCP techniques
image Mechanical lithotripsy with a large basket

image Extracorporeal shock wave lithotripsy (rarely used in the United States)

image Laser lithotripsy through choledochoscopy: “baby scope” inserted into the BD through the channel of a side-viewing endoscope

image Electrohydraulic lithotripsy through a “baby scope”

7. Complications of ERCP and sphincterotomy
a. Pancreatitis occurs in 5% of patients. It may result either from the diagnostic portion of the procedure or from cautery-induced injury to the pancreatic duct orifice.
image Symptoms of pancreatitis may not occur until 6 to 12 hours following the procedure.

image Management of post-ERCP pancreatitis is similar to that of other forms of pancreatitis.

image No pharmacologic means of proven efficacy exist to prevent ERCP-related pancreatitis.

image Pancreatitis is more common in patients with a difficult cannulation, suspected or proven sphincter of Oddi dysfunction (SOD), or a needle-knife precut sphincterotomy.

image Temporary placement of a stent in the pancreatic duct appears to reduce the risk, as well as the severity, of post-ERCP pancreatitis.


b. Bleeding occurs in 2% to 3% and is usually self-limited.
image It may occasionally require blood transfusions and even angiographic embolization or surgery.

image Epinephrine injection, balloon tamponade, or electrocautery at the time of ERCP may stop bleeding.

c. Perforation

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Jun 4, 2016 | Posted by in GASTROENTEROLOGY | Comments Off on Diseases of the bile ducts

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