Diagnostic ultrasound ( PDFDrive )

CHAPTER 17 Ultrasound-Guided Biopsy of Chest, Abdomen, and Pelvis 613
A
B
C
D
FIG. 17.17 Ultrasound-Guided Transvaginal Drainage of Pelvic Abscess. (A) Contrast-enhanced CT scan shows an abscess (A) deep in the
pelvis, posterior to the uterus (U). (B) TVS shows needle tip (arrow) in abscess cavity (A). (C) With the catheter exchange technique, a locking-loop
catheter (arrows) was inserted into the abscess cavity for drainage. (D) In a different patient, TVS shows needle within adnexal cyst at time of
aspiration centered within needle guide markers.
As with abscesses elsewhere in the body, the sonographic appearance
of hepatic abscess is usually a complex luid collection.
Both ultrasound and CT provide excellent guidance for percutaneous
aspiration or drainage of hepatic abscesses, with a 67% to
94% cure rate. 133,136-138
Some suggest treating pyogenic liver abscesses with antibiotics
and percutaneous needle aspiration alone, without catheter
drainage, although multiple aspiration procedures may be
required. 139 Such an approach is particularly reasonable in smaller
abscesses, less than 5 cm. 140,141 Multiple small (<1 cm) microabscesses
are typically treated with antibiotics alone ater
diagnostic aspiration. 142 Final cure oten depends on identiication
and appropriate treatment of the infectious source.
Amebic liver abscesses are caused by Entamoeba histolytica.
Most amebic liver abscesses are efectively treated with metronidazole
alone with 85% to 95% success. 143,144 However, percutaneous
abscess drainage of amebic abscesses is indicated if the
diagnosis is uncertain, the cavity is large (>5 cm) or enlarging,
pyogenic superinfection is a concern, or there are signs of abscess
cavity rupture. 144,145 Catheter drainage in these situations is safe
and generally provides a rapid cure.
Historically, liver hydatid abscesses caused by Echinococcus
granulosus were considered a contraindication to percutaneous
abscess drainage because of the concern of anaphylactic reaction
to cyst contents. More recently, these abscesses have been successfully
treated with percutaneous aspiration combined with
appropriate anthelmintic therapy. 146
Complications of percutaneous hepatic abscess drainage
include sepsis, hemorrhage, and catheter transgression of the
pleura. Sepsis may occur in up to 25% of patients, even with
antibiotic therapy. 141 Intercostal placement of a drain should be
avoided; such a path could introduce bacteria into the pleural
space.
Biliary Tract
Gallbladder. Percutaneous cholecystostomy has evolved
into a favorable alternative to surgery in critically ill patients
with acute calculous and acalculous cholecystitis. In contrast to