Diagnostic ultrasound ( PDFDrive )

CHAPTER 17 Ultrasound-Guided Biopsy of Chest, Abdomen, and Pelvis 615
A
GB
GB
A
A
B
A
GB
C
FIG. 17.19 Ultrasound-Guided Drainage of Pyogenic
Liver Abscess Secondary to Cholecystitis. (A) Longitudinal
ultrasound image shows cholelithiasis, complex thickening of
the gallbladder (GB) wall, and adjacent debris-containing luid
collection representing abscess (A) in the liver. (B) Drainage
catheter within the abscess. (C) Subsequent sinogram through
drainage catheter (arrow) shows communication (dashed arrow)
between the gallbladder (GB) and abscess (A).
of the biliary system only by “chance,” whereas ultrasound allows
guided, direct puncture of the appropriate bile duct.
Pancreas
Percutaneous aspiration or drainage of pancreatic luid collections
typically arises in the setting of pancreatitis. In the absence of
infection or obstruction of an adjacent hollow viscus, acute
pancreatis-related peripancreatic luid collections require no
therapy. 152 Similarly, sterile pancreatic necrosis does not usually
require treatment.
Infected pancreatic necrosis and some pseudocysts eventually
require percutaneous intervention. Although CT is superior to
ultrasound in evaluation of pancreatitis, ultrasound provides easy
guidance for percutaneous interventional procedures (e.g., luid
aspiration) in these patients. Standard management of infected
pancreatic necrosis is surgical debridement. 153 However, percutaneous
drainage may provide short-term control of sepsis in
almost 75% and cure in 50% of patients. Such a procedure typically
involves very-large-bore catheters with frequent, vigorous irrigation,
essentially resulting in a “percutaneous necrosectomy.” 154
Pancreatic pseudocysts arise in about 6% of patients following
an episode of acute pancreatitis. 155 About half of pseudocysts
will resolve spontaneously (but only a third of those >6 cm). 156,157
Simple aspiration of pancreatic pseudocysts is associated with
a high rate of recurrence; therefore catheter drainage is preferred
in select cases 156-159 (Fig. 17.22). Depending on location, endoscopic
cystogastrostomy is another commonly used technique.
Indications for pancreatic pseudocyst drainage include the
following 160 :
• Symptoms related to pseudocyst
• Complication of infection or bleeding
• Increase in size during the observation period
• A diameter of 6 cm or more
• No decrease in size during last 6 weeks of observation