Ch. 54 – Biliary System

1574 Section X Abdomen
Figure 54-25 Endoscopic retrograde cholangiopancreatography
of patient with recurrent pyogenic cholangitis. Note the presence
of intrahepatic stone and stricturing of the bile ducts.
Noncalculous Biliary Disease
Acute Acalculous Cholecystitis
Acute infl ammation of the gallbladder can occur without
gallstones. Acute acalculous cholecystitis accounts for 5%
to 10% of all patients with acute cholecystitis and is the
diagnosis in about 1% to 2% of patients undergoing cholecystectomy.
It has a more fulminant course than acute
calculous cholecystitis and more commonly progresses
to gangrene, empyema, or perforation. Acute acalculous
cholecystitis occurs most frequently in elderly and critically
ill patients after trauma, burns, long-term parenteral
nutrition, and major operations such as abdominal aneurysm
repair and cardiopulmonary bypass. Although the
exact etiology is unclear, gallbladder stasis and ischemia
have been implicated as causative factors. Stasis is
common in critically ill patients not being fed enterally
and may lead to colonization of the gallbladder with
bacteria. Visceral ischemia is also common in patients
with acute acalculous cholecystitis and may explain the
high incidence of gallbladder gangrene.
The signs and symptoms of acute acalculous cholecystitis
parallel acute calculous cholecystitis. Patients may
also present with only unexplained fever, leukocytosis,
and hyperamylasemia without right upper quadrant tenderness.
If untreated, rapid progression to gangrene and
perforation may occur. 37 Radiologic fi ndings are also
similar except for the absence of gallstones. Ultrasonography
is the diagnostic test of choice, especially because
it can be done at the bedside. Cholescintigraphy demonstrates
absent gallbladder fi lling, but the false-positive
rate may be as high as 40%.
Emergency cholecystectomy is the appropriate treatment
for acute acalculous cholecystitis for patients who
are stable enough to tolerate the anesthetic and procedure.
Because of the high incidence of gangrene, perforation,
and empyema, open cholecystectomy is often the
preferred approach. Because most patients are critically
ill, the morbidity rate of acute acalculous cholecystitis in
recent series is 40%. If patients are unfi t for surgery,
percutaneous, ultrasound-guided, or CT-guided cholecystostomy
is the treatment of choice. If the diagnosis is
uncertain, percutaneous cholecystostomy can be both
diagnostic and therapeutic. About 90% of patients will
improve with percutaneous cholecystostomy.
Acute Cholangitis
Cholangitis is an ascending bacterial infection of the
biliary ductal system with obstruction most commonly
due to choledochal stones. Although cultures of the gallbladder
and bile ducts are usually sterile, in the presence
of common bile duct stones or other obstructing pathology,
the incidence of positive bile cultures increases. The
most common organisms present in the bile in patients
with cholangitis include E. coli, Klebsiella pneumoniae,
Streptococcus faecalis, and Bacteroides fragilis. Even in
the presence of high bacteria counts, clinical cholangitis
and bacteremia do not develop unless obstruction causes
elevated intraductal pressures. Although stones are the
most common cause of obstruction in cholangitis, other
etiologies include benign and malignant strictures, anastomotic
strictures, cholangiocarcinoma, and periampullary
cancer.
Diagnosis
Cholangitis may be either self-limited or toxic with severe
illness, including jaundice, fever, abdominal pain, mental
status changes, and hypotension (Reynold’s pentad).
Fever and chills are the most common presentation and
are due to cholangiovenous and cholangiolymphatic
refl ux. Normal biliary pressures range from 7 to 14 cm
H 2O; in the presence of bactibilia and normal biliary
pressures, hepatic vein blood and perihepatic lymph are
sterile. However, with partial or complete biliary obstruction,
intrabiliary pressures rise to 18 to 20 cm H 2O, and
organisms rapidly appear in both the blood and lymph.
The most common causes of biliary obstruction are
choledocholithiasis, benign strictures, biliary-enteric anastomotic
strictures, and cholangiocarcinoma and periampullary
cancer. Before 1980, choledocholithiasis was the
cause of about 80% of the reported cases of cholangitis,
but in recent years, malignant strictures have become a
more frequent cause in tertiary referral centers. Leukocytosis,
hyperbilirubinemia, and elevations of alkaline phosphatase
and transaminases all are common in patients with
cholangitis. Although ultrasound, CT, and MRI may be
helpful in identifying the cause of obstruction, cholangiography
is mandatory as a diagnostic and potentially therapeutic
intervention. If ERCP is not available, PTC should
be performed. Cholangiography will identify the level of
and reason for obstruction, allow for culture and possible
biopsy if a mass is present, and provide drainage of the
bile ducts with stents, catheters, or dilation.