Advanced hepatic ablation technique for creating complete cell death: irreversible electroporation.
OBJECTIVE
To evaluate the effectiveness of irreversible electroporation (IRE) in hepatic tissue ablation and the radiologic-pathologic correlation of IRE-induced cell death.


METHODS
On approval of the animal research committee, 16 Yorkshire pigs underwent ultrasonography (US)-guided IRE of normal liver. A total of 55 ablation zones were created, which were imaged with US, magnetic resonance (MR) imaging, and computed tomography (CT) and evaluated with immunohistochemical analysis, including hematoxylin-eosin (H-E), Von Kossa, and von Willibrand factor (vWF) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.


RESULTS
At gross section examination, the mean diameter of the ablation zones was 33.5 mm + or - 3.0 (standard deviation) and was achieved in 6.9 minutes (mean total procedure time per ablation), with a mean difference of 2.5 mm + or - 3.6 between US and gross section measurements (r = 0.804). No complications were seen in any of the 16 animals. IRE ablation zones were well characterized with US, CT, and MR imaging, and real-time monitoring was feasible with US. H-E, Von Kossa, and vWF staining showed complete cell death, with a sharply demarcated treatment area. Bile ducts and vessels were completely preserved. Areas of complete cell death were stained positive for apoptotic markers (TUNEL, BCL-2 oncoprotein), suggesting involvement of the apoptotic process in the pathophysiology of cell death caused by IRE.


CONCLUSIONS
In an animal model, IRE proved to be a fast, safe, and potent ablative method, causing complete tissue death by means of apoptosis. Cell death is seen with full preservation of periablative zone structures, including blood vessels, bile ducts, and neighboring nonablated tissues.
Lee
Edward W
EW
Division of Interventional Radiology, Department of Radiology, Ronald Reagan Medical Center at UCLA, David Geffen School of Medicine at UCLA, 757 Westwood Plaza, Suite 2125, Los Angeles, CA 90095, USA. EdwardLee@mednet.ucla.edu
Chen
Christine
C
Prieto
Veronica E
VE
Dry
Sarah M
SM
Loh
Christopher T
CT
Kee
Stephen T
ST
D000818:Animals; D016923:Cell Death; D003287:Contrast Media / Q000008:administration & dosage; D018274:Electroporation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage; D020287:In Situ Nick-End Labeling; D007472:Iohexol / Q000008:administration & dosage; D008099:Liver / Q000000981:diagnostic imaging / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D023421:Models, Animal; D034421:Sus scrofa; D014057:Tomography, X-Ray Computed; D018084:Ultrasonography, Interventional
D003287:Contrast Media; D007472:Iohexol; C064925:gadodiamide; D019786:Gadolinium DTPA