CT-monitored percutaneous cryoablation in a pig liver model: pilot
Lee FT Jr, Chosy SG, Littrup PJ, Warner TF, Kuhlman
JE, Mahvi DM.
IDepartment of Radiology, University of Wisconsin,
Madison 53792, USA. firstname.lastname@example.org
PURPOSE: To determine the safety and feasibility
of percutaneous cryoablation with computed tomographic (CT) guidance
in a pig liver model. MATERIALS AND METHODS: Nine angiographic balloons
(mean diameter, 9 mm) were placed in the livers of seven domestic
pigs (mean weight, 30.0 kg +/- 14.0 [SD]) as tumor-mimicking lesions.
By using ultrasonographic and CT guidance, two 2.4- or 3.0-mm cryoprobes
were placed flanking the balloon, and a 15-20-minute freezing process
was performed. Hemostasis was achieved by placing absorbable cellulose
fabric down the probe tract. After 24-96 hours, animals were sacrificed,
and their livers were removed and were sectioned axially at 5-mm
intervals for comparison with CT images. RESULTS: All animals survived
the procedure without complication. No serious hemorrhage was found
in any case. Ice balls were readily visualized at CT because they
appeared as areas of decreased attenuation (1.0 HU +/- 20.7) when
compared with areas of normal liver (48.2 HU +/- 6.3, P < .05).
The mean ablative margin was 1.7 cm, and only one of nine cases,
the one with probe failure, had a positive margin. Beam-hardening
artifact from the metal probes was present but did not interfere
with the procedure. Ice-ball size and shape corresponded closely
to the area of necrosis determined at histopathologic analysis.
CONCLUSION: CT-monitored percutaneous cryoablation is feasible and
safe in this pig liver model.
PMID: 10352592 [PubMed - indexed for MEDLINE]