Diseases of the Bile Ducts

Risk Factors

• 1.

  In Western countries, most cases of choledocholithiasis are secondary to the passage of gallstones from the gallbladder into the bile duct.

  • ▪

    Most of these stones are cholesterol rich and have formed in the gallbladder.

  • ▪

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

• 2.

  Certain groups of patients are at risk of forming primary duct stones, including the following:

  • ▪

    Older adults with large bile ducts and periampullary diverticula

  • ▪

    Patients with recurrent pyogenic cholangitis (RPC)

  • ▪

    Patients with chronic biliary strictures

  • ▪

    Patients at risk for biliary stasis (e.g., with cystic fibrosis)

Clinical Features

• 1.

  Symptomatic BD stones may present as follows:

  • ▪

    Pain

  • ▪

    Cholangitis

  • ▪

    Pancreatitis

  • ▪

    Jaundice

• 2.

  Asymptomatic incidentally found stones

  • ▪

    Typically, the patient is afebrile with normal complete blood count and pancreatic enzyme levels.

  • ▪

    Serum alkaline phosphatase or gamma-glutamyltranspeptidase (GGTP) levels may be mildly elevated.

  • ▪

    Stones may be found incidentally on routine imaging or intraoperative cholangiography during cholecystectomy.

  • ▪

    In older patients, anorexia may be an overlooked sign.

• 3.

  Pain from BD stones resembles pain of gallbladder origin.

  • ▪

    The pain is typically located in the epigastrium or right upper quadrant and is often prolonged but resolves within 6 hours.

  • ▪

    Abdominal tenderness is greater with cholecystitis than with BD stones.

  • ▪

    Obstructive jaundice from BD stones is usually accompanied by pain and may be accompanied by evidence of infection, including fever and chills; the latter may predominate as the presenting feature.

  • ▪

    The pain from choledocholithiasis resolves when the stone either passes spontaneously or is removed. Occasionally, some patients have intermittent pain due to transient blockage of the BD termed a “ball valve” effect.

  • ▪

    Jaundice associated with malignancy is more likely to be painless.

• 4.

  Features of cholangitis include the following:

  • ▪

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

  • ▪

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

  • ▪

    Fever may be accompanied by severe rigors.

  • ▪

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

  • ▪

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

• 5.

  The timing of clinical presentation with BD stones is variable.

  • ▪

    Before cholecystectomy

  • ▪

    During intraoperative cholangiography (IOC)

  • ▪

    Shortly after cholecystectomy

  • ▪

    Months to years or decades after cholecystectomy

• 6.

  Gallstone pancreatitis (see discussion later in chapter)

  • ▪

    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, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), GGTP, and bilirubin

  • ▪

    Marked elevations in serum ALT and AST levels may occur, even levels >1000 U/L transiently, especially with cholangitis.

  • ▪

    A high level of suspicion is required. No single blood test accurately predicts the presence of stones. In the appropriate clinical setting, an elevation in serum bilirubin has a sensitivity of 69% and a specificity of 88% for diagnosing a BD stone. For elevations in serum ALP, the values are 57% and 86%, respectively.

  • ▪

    On the other hand, the negative predictive value of normal liver biochemical test levels is high.

  • ▪

    Aminotransferase levels typically fall rapidly, even as the ALP level rises if stone impaction persists.

  • ▪

    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.

• 5.

  Distention of the liver capsule from hepatitis can cause right upper quadrant discomfort often confused with biliary pain in the setting of abnormal liver enzyme levels.

Imaging Studies

• 1.

  Ultrasonography

  • ▪

    Excellent for detecting gallbladder stones; less sensitive for BD stones

  • ▪

    May be limited by obesity and gas in the intestine

  • ▪

    Sensitive for detecting BD dilatation

  • ▪

    More sensitive for BD stones when the duct is dilated

  • ▪

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

• 2.

  Computed tomography (CT)

  • ▪

    Sensitivity <50% for BD stones

  • ▪

    Detection depends on the presence of calcifications in stones

  • ▪

    Sensitivity similar to that of ultrasonography for detecting a dilated BD

  • ▪

    Oral contrast agents should be avoided on initial images (can obscure BD stones).

• 3.

  MRCP ( Fig. 35.1 )

  • ▪

    Detection of BD stones depends on T2-weighted images

  • ▪

    Contrast provided by fluid in the ducts

  • ▪

    Sensitivity and specificity >90%

  • ▪

    Sensitivity lower for small stones

  • ▪

    Limited availability and high cost; contraindications include a pacemaker, defibrillator, or certain other metallic implants. The feasibility of an MRCP in a patient with an orthopedic implant should be discussed with the radiologist.

  

• 4.

  EUS ( Fig. 35.2 )

  • ▪

    Sensitivity and specificity rival those of ERCP.

  • ▪

    Less risk than ERCP but still requires sedation

  • ▪

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

  

• 5.

  ERCP ( Fig. 35.3 )

  • ▪

    Has been the gold standard for detecting BD stones

  • ▪

    Can miss small stones, especially in a dilated duct

  • ▪

    Sweeping the duct with a balloon catheter increases the chance of finding and removing small stones.

  • ▪

    Most often done when therapeutic intervention is anticipated

  • ▪

    Risks include pancreatitis, bleeding (usually from a sphincterotomy), retroperitoneal perforation, and anesthesia-related complications.

  

• 6.

  Percutaneous transhepatic cholangiography (THC)

  • ▪

    Seldom used for evaluation or treatment of BD stones, except in patients with acute cholangitis when ERCP is unavailable or fails or is anatomically impossible because of prior surgery

  • ▪

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

• 7.

  Overall approach

  • ▪

    Patients at high risk for a BD stone should proceed to ERCP with stone removal, followed by elective cholecystectomy.

  • ▪

    Patients at intermediate risk for a BD stone should undergo preoperative EUS or MRCP or laparoscopic cholecystectomy with intraoperative cholangiography or ultrasonography. If a stone is found preoperatively, patients should undergo ERCP with stone removal, followed by elective cholecystectomy if gallbladder stones or sludge were seen on preoperative imaging.

  • ▪

    Patients at low risk for a BD stone should undergo cholecystectomy without additional testing, provided gallstones or sludge were seen on preoperative imaging.

  • ▪

    In the setting of acute cholecystitis a dilated BD on transabdominal ultrasonography may be suggestive of, but not specific for, choledocholithiasis. In a nondilated duct (<6 mm) the risk of having a stone is <10%. At 6 mm, the risk of having a stone is up to 20%, and when the duct is >10 mm, the risk is at least 50%.

Treatment

• 1.

  ERCP with endoscopic sphincterotomy

  • ▪

    Treatment of choice at most centers

  • ▪

    Successful clearance of BD in more than 90% of patients

  • ▪

    Definitive treatment of BD stones in postcholecystectomy patients

  • ▪

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

  • ▪

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

• 2.

  Preoperative versus postoperative ERCP

  • ▪

    ERCP has no routine role before cholecystectomy.

  • ▪

    Factors that may predict the presence of BD stones are as follows:

    • –

      Elevated liver biochemical test levels

    • –

      BD dilatation on imaging

    • –

      Initial presentation with cholangitis

  • ▪

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

  • ▪

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

  • ▪

    If preoperative ERCP fails in the setting of known BD stones, alternatives include a repeat ERCP at a tertiary referral center, where a variety of methods for cannulation and stone extraction may be used, surgically assisted ERCP, or laparoscopic exploration and stone extraction when the bile duct is large.

    • –

      High success rates (80% to 90%) have been reported by expert surgeons when IOC results are positive for BD stones.

    • –

      The usual approach is the transcystic duct route.

    • –

      Laparoscopic choledochotomy is also possible.

    • –

      Surgical expertise is generally only available at expert centers.

    • –

      Many surgeons still prefer preoperative or postoperative ERCP.

• 3.

  Surgical exploration and open choledochotomy

  • ▪

    Standard of care before ERCP in the 1970s; currently seldom performed except for large retained stones not extractable by other methods

  • ▪

    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.

• 4.

  ERCP techniques for the treatment of choledocholithiasis include the following:

  • ▪

    Guidewire cannulation of BD with a sphincterotome is a common technique; the sphincterotome is advanced over a guidewire into the BD.

  • ▪

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

  • ▪

    Similarly, needle-knife fistulotomy can be performed in the setting of a large impacted stone at the level of the ampulla.

• 5.

  Large stones: May require one or more of the following advanced ERCP techniques:

  • ▪

    Mechanical lithotripsy with a large basket

  • ▪

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

  • ▪

    Electrohydraulic lithotripsy through a “baby scope”

  • ▪

    Extracorporeal shock wave lithotripsy (rarely used in the United States because of the lack of availability)

• 6.

  Complications of ERCP and sphincterotomy

  • ▪

    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.

    • –

      Symptoms of pancreatitis may not occur until 6 to 12 hours following the procedure.

    • –

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

    • –

      Rectal indomethacin may decrease the risk and severity of post-ERCP pancreatitis. It has proven efficacy in combination with a pancreatic stent and as stand-alone therapy.

    • –

      Pancreatitis is more common in patients with a difficult cannulation requiring more cannulation attempts, suspected or proven sphincter of Oddi dysfunction (SOD), and small-caliber ducts.

    • –

      Early evidence suggested that techniques such as needle-knife precut sphincterotomy or transseptal sphincterotomy have a greater risk for pancreatitis; however, when they are used early in the procedure by an expert, the risks of pancreatitis, bleeding, or perforation are equivalent to those for standard ERCP.

    • –

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

  • ▪

    Bleeding occurs in 2% to 3% and is usually self-limited.

    • –

      It may occasionally require blood transfusions and even angiographic embolization or surgery.

    • –

      Epinephrine injection, endoscopic hemostatic clip placement, deployment of a large fully covered self-expandable metal stent, balloon tamponade, or electrocautery at the time of ERCP may stop bleeding.

  • ▪

    Perforation (usually retroperitoneal) occurs in 1%.

    • –

      Post-ERCP imaging may identify benign retroperitoneal air. A small amount of retroperitoneal air can be demonstrated in up to 30% of asymptomatic patients on postprocedural CT. This must be distinguished from a true perforation or even microperforation.

    • –

      Initial symptoms after ERCP that should cause concern for perforation are chills, rigors, and back pain.

    • –

      Perforation often responds to nonsurgical management with nasogastric decompression, nasobiliary drainage (if the complication has been recognized during ERCP), and intravenous broad-spectrum antibiotics.

    • –

      Surgery may be required if signs of infection cannot be controlled with antibiotics.

    • –

      Radiologic drainage may be required if a collection forms.

  • ▪

    Infection may occur when adequate drainage is not provided following ERCP.

    • –

      An endoprosthesis can be placed to provide drainage until the BD can be cleared.

• 7.

  Long-term stent placement

  • ▪

    Reserved for patients in whom stone extraction is not accomplished or who have a stricture

  • ▪

    May be appropriate for frail or elderly patients

  • ▪

    Cholangitis occurs in 10% to 40% in ensuing years.

  • ▪

    Treatment with ursodeoxycholic acid, in combination with biliary stenting, may help facilitate subsequent stone extraction.

Clinical Features

• ▪

  Epigastric pain radiating through to the back bilaterally

• ▪

  Nausea and vomiting

• ▪

  Low-grade fever or chills

• ▪

  Tachycardia

• ▪

  Hypotension, if sequestration (“third-spacing”) of fluid is significant

Laboratory Features

• ▪

  Leukocytosis

• ▪

  Elevated liver biochemical test levels (usually to a greater degree than in alcoholic and other causes of pancreatitis)

• ▪

  Elevated serum amylase and lipase levels

• ▪

  Elevated blood urea nitrogen and creatinine levels if third-spacing is sufficient to compromise renal blood flow

• ▪

  Hypocalcemia in moderate to severe cases

• ▪

  Hyperglycemia

• ▪

  Hypoxemia, in severe cases, resulting from pulmonary capillary leak, which may result in acute respiratory distress syndrome

Ranson criteria: The most commonly used of the many classification systems to predict the severity of an episode of acute pancreatitis.

At time of admission:

• ▪

  Age >55 years

• ▪

  Blood glucose level >200 mg/dL

• ▪

  WBC count >16,000/mm ³

• ▪

  Serum lactate dehydrogenase (LDH) level >350 U/L

• ▪

  Serum AST level >250 U/L

At 48 hours, the following are noted :

• ▪

  Decrease in hematocrit value by more than 10%

• ▪

  Serum calcium level <8 mg/dL

• ▪

  Base deficit >4 mmol/L

• ▪

  Blood urea nitrogen level increase >5 mg/dL

• ▪

  Estimated fluid sequestration >6 L

• ▪

  Arterial oxygen tension <60 mm Hg

  • –

    The presence of fewer than three criteria indicates mild pancreatitis.

  • –

    Three or more criteria are associated with more severe pancreatitis and higher mortality rates.

  • –

    A simpler scoring system ( BISAP [Bedside Index of Severity of Acute Pancreatitis: blood urea nitrogen >25 mg/dL, impaired mental status, systemic inflammatory response, age >60 years, pleural effusion]) can be used.

Treatment

• ▪

  Similar to that for other forms of pancreatitis

• ▪

  Strictly nothing by mouth initially; trend in the 2010s has been toward earlier enteral feeding during recovery

• ▪

  Intravenous hydration

• ▪

  Careful recording of intake and output

• ▪

  No role for antibiotics to prevent infection in severe acute pancreatitis or sterile necrosis in the absence of cholangitis

• ▪

  Monitoring of laboratory data, including blood counts and electrolytes

• ▪

  Serial contrast-enhanced CTs to monitor patients with moderate or severe pancreatitis for the development of pancreatic necrosis, pseudocysts, or abscesses

• ▪

  Role of ERCP in gallstone pancreatitis

  • –

    ERCP has no benefit in mild gallstone pancreatitis unless clear evidence of a retained BD stone exists.

  • –

    One study demonstrated a reduced risk of local and systemic complications and shorter durations of hospitalization in severe pancreatitis.

  • –

    Meta-analyses have shown no benefit to urgent ERCP.

  • –

    The greatest benefit of ERCP is in the setting of concomitant cholangitis or pancreatic duct disruption (often presenting as severe pancreatitis).

Definition

Postcholecystectomy syndrome is a term used for the persistence of gastrointestinal symptoms, usually biliary-type pain, in a patient who has undergone a cholecystectomy .

• 1.

  Causes are numerous and are often unrelated to cholecystectomy or the biliary tract.

• 2.

  Soon after cholecystectomy, postsurgical complications such as a bile leak must be excluded.