Background

Irreversible electroporation (IRE) is a nonthermal ablation modality. A 200J application
can create deep myocardial lesions, but gas bubbles are created at the ablation electrode.
Cerebral effects of these bubbles are unknown.

Objective

To investigate gas microemboli-induced brain lesions after IRE and radiofrequency
(RF) ablation to the left side of the canine heart, using MRI and histopathology.

Methods

In 11 canines, baseline cerebral MRI scans were performed. In 9 animals, after retrograde
femoral artery access, 12±4 200J IRE applications were administered in the ascending
aorta. In 2 animals, 30 minutes of irrigated 30-Watt RF ablation using 10-30 grams
of contact force was applied in the left ventricle. At days 1 and 5 after ablation,
MRI was repeated. Afterwards, the brain tissue was histopathologically examined.

Results

All ablations and follow-up were uneventful, intracardiac echography confirmed gas
bubble formation after each IRE application. Neurological examination was normal.
MRI scans were normal in all animals at day 1, and normal in 10/11 animals at day
5. In 1 animal, a single <2 mm diameter lesion in the right temporal region could
not be excluded as a small infarct or early hemorrhagic site. Histopathologic analysis
of the same region showed no pathological changes. In all other animals, gross and
microscopic pathology was normal.

Conclusion

MRI images alone or in combination with histological follow-up did not reveal treatment-related
embolic events. Gross and microscopic pathology did not reveal evidence of treatment-related
embolic events. Irreversible electroporation seems to be a safe ablation modality
for the brain.



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