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PATHOLOGY OF THE GALLBLADDER AND BILIARY TREE 57
A
B
Figure 3.24 Normal gallbladder wall vascularity. (A) In a normal gallbladder, colour Doppler can demonstrate the
cystic artery (arrowhead) but does not demonstrate flow near the fundus. (B) Power Doppler is more sensitive and can
demonstrate flow throughout the wall (arrows) in a normal gallbladder; this must not be mistaken for hyperaemia.
pericholecystic abscess may develop in the later
stages. A positive Murphy’s sign may help to focus
on the diagnosis, but in unconscious patients the
diagnosis is a particularly difficult one.
Because patients may already be critically ill with
their presenting disease, or following surgery, there
is a role for ultrasound in guiding percutaneous
cholecystostomy at the bed-side to relieve the
symptoms. 18
Chronic acalculous cholecystitis implies a recurrent
presentation with typical symptoms of biliary
colic, but no evidence of stones on ultrasound.
Patients may also demonstrate a low ejection fraction
during a cholecystokinin-stimulated hepatic
iminodiacetic acid (HIDA) scan. The symptoms
are relieved by elective laparoscopic cholecystectomy
in most patients, with similar results to those
for gallstone disease 19 (although some are found to
have biliary pathology at surgery, which might
explain the symptoms, such as polyps, cholesterolosis
or biliary crystals/tiny stones in addition
to chronic inflamation).
Complications of cholecystitis
Acute-on-chronic cholecystitis
Patients with a long-standing history of chronic
cholecystitis may suffer (sometimes repeated) attacks
of acute inflammation. The gallbladder wall is thickened,
as for chronic inflammation, and may become
focally thickened with both hypo- and hyperechoic
regions. Stones are usually present (Fig. 3.27).
Gangrenous cholecystitis
In a small percentage of patients, acute gallbladder
inflammation progresses to gangrenous cholecystitis.
Areas of necrosis develop within the gallbladder
wall, the wall itself may bleed and small abscesses
form (Fig. 3.28). This severe complication of the
inflammatory process requires immediate cholecystectomy.
The gallbladder wall is friable and may rupture,
causing a pericholecystic collection and possibly
peritonitis. Inflammatory spread may be seen in
the adjacent liver tissue as a hypoechoic, ill-defined
area. Loops of adjacent bowel may become adherent
to the necrotic wall, forming a cholecystoenteric
fistula.
The wall is asymmetrically thickened and areas
of abscess formation may be demonstrated. The
damaged inner mucosa sloughs off, forming the
appearance of membranes in the gallbladder lumen.
The gallbladder frequently contains infected debris
The presence of a bile leak may also be demonstrated
with hepatobiliary scintigraphy, using technetium
99 , which is useful in identifying a bile