Summary:
Prepared by
Andrew Del Gaizo, MD,
Department of Radiology, Emory University School of Medicine,
Atlanta, GA, and Bharat Raval, MD, Department of Radiology, The
University of Texas at Houston, Houston, TX.
CASE SUMMARY
A 65-year-old obese woman presented with severe right-side
Prepared by
Andrew Del Gaizo, MD,
Department of Radiology, Emory University School of Medicine,
Atlanta, GA, and Bharat Raval, MD, Department of Radiology, The
University of Texas at Houston, Houston, TX.
CASE SUMMARY
A 65-year-old obese woman presented with severe right-sided
abdominal pain, nausea, vomiting, and fever. Her medical history
included end-stage renal disease secondary to type 2 diabetes
mellitus. The physical examination revealed right-upper-quadrant
tenderness but was otherwise unremarkable. On admission, laboratory
workup showed a moderately elevated white blood cell count and an
elevated alkaline phosphatase. Ultrasound (Figure 1) and computed
tomography (CT) (Figure 2) of the abdomen were performed.
IMAGING FINDINGS
The ultrasound of the gallbladder revealed a large intraluminal
gallstone or multiple small gallstones within a contracted
gallbladder, evident from the parallel curved echogenic lines with
distal acoustic shadowing. This is known as the wall-echo shadow
triad, or the double-arch shadow sign.
1
The CT scans confirm the presence of a large calcified
intraluminal gallstone, measuring 2.5 cm in diameter (Figure 2).
The thin rim of soft tissue surrounding the calcification
represents the collapsed gallbladder. In addition, a tortuous,
tubular structure containing air and contrast is seen anterior to
the gallbladder. The tract extends anterior and inferior, from the
gallbladder fossa to the hepatic flexure of the colon, representing
a cholecystocolonic fistula.
DIAGNOSIS
Cholecystocolonic fistula secondary to erosion that was caused
by a large gallstone and chronic cholecystitis
DISCUSSION
Cholecystocolonic fistulas are a rare condition, comprising
<0.2% of all biliary tract disease.
2,3
The typical patient is a woman in the sixth or seventh decade of
life with multiple comorbidities.
4-6
The patient often presents with symptoms characteristic of
cholecystitis, including right-upper-quadrant pain, nausea,
vomiting, and fatty-food intolerance.
4
Therefore, a diagnosis cannot be made on clinical symptoms and
laboratory values alone.
Biliary-enteric communications result from erosion of a
gallstone in 90% of cases.
4,7
This is often the consequence of cholecystitis. The inflammation
can lead to adhesions between the biliary tract and the bowel.
Pressure necrosis by the gallstone against the inflamed wall can
then lead to erosion and fistula formation.
8,9
Most biliary enteric fistulas involve the duodenum; however, 10% to
20% of the communications involve the colon.
10
Of these, most involve the hepatic flexure because of its relative
proximity to the gallbladder fossa.
10
In patients with biliary-enteric communication to the duodenum,
the potential for gallstone ileus exists. This occurs when a large
gallstone (usually >2.5 cm in diameter) becomes lodged at the
ileocecal junction.
8
The classic presentation, although seen only in approximately one
third of patients, includes small bowel obstruction, visualization
of the obstructing stone, and pneumobilia.
6
In patients with biliary-enteric communication to the colon, the
potential for impaction at the sigmoid colon, the narrowest portion
of the large intestines, exists.
8
Symptoms in these patients include abdominal pain and distention
and tend to develop slowly. No obstructing stone was discovered in
the patient described in this case. Therefore, either the stone
responsible for the fistula is still present in the gallbladder, or
the stone responsible was too small to cause obstruction and was
passed without notice.
The treatment for a symptomatic cholecystocolonic fistula is
surgery. The operatio inflammation can lead to adhesions between
the biliary tract and the bowel. Pressure necrosis by the gallstone
against the inflamed wall can then lead to erosion and fistula
formation.
8,9
Most biliary enteric fistulas involve the duodenum; however, 10% to
20% of the communications involve the colon.
10
Of these, most involve the hepatic flexure because of its relative
proximity to the gallbladder fossa.
10
In patients with biliary-ent inflammation can lead to adhesions
between the biliary tract and the bowel. Pressure necrosis by the
gallstone against the inflamed wall can then lead to erosion and
fistula formation.
8,9
Most biliary enteric fistulas involve the duodenum; however, 10% to
20% of the communications involve the colon.
10
Of these, most involve the hepatic flexure because of its relative
proximity to the gallbladder fossa.
10
In patients with biliary-ent inflammation can lead to adhesions
between the biliary tract and the bowel. Pressure necrosis by the
gallstone against the inflamed wall can then lead to erosion and
fistula formation.
8,9
Most biliary enteric fistulas involve the duodenum; however, 10% to
20% of the communications involve the colon.
10
Of these, most involve the hepatic flexure because of its relative
proximity to the gallbladder fossa.
10
In patients with biliary-ent inflammation can lead to adhesions
between the biliary tract and the bowel. Pressure necrosis by the
gallstone against the inflamed wall can then lead to erosion and
fistula formation.
8,9
Most biliary enteric fistulas involve the duodenum; however, 10% to
20% of the communications involve the colon.
10
Of these, most involve the hepatic @