Investigation of the safety of irreversible electroporation in humans

A single-center prospective nonrandomized cohort study was performed to investigate the safety of irreversible electroporation (IRE) for tumor ablation in humans.

Thirty-eight volunteers with advanced malignancy of the liver, kidney, or lung (69 separate tumors) unresponsive to alternative treatment were subjected to IRE under general anesthesia. Clinical examination, biochemistry, and computed tomography (CT) scans of the treated organ were performed before, immediately after, and at 1 month and 3 months after the procedure.

No mortalities occurred at 30 days. Transient ventricular arrhythmia occurred in four patients, and electrocardiographically (ECG) synchronized delivery was used subsequently in the remaining 30 patients, with two further arrhythmias (supraventricular tachycardia and atrial fibrillation). One patient developed obstruction of the upper ureter after IRE. One adrenal gland was unintentionally directly electroporated, which produced transient severe hypertension. There was no other evidence of adjacent organ damage related to the electroporation. Other adverse events were not directly related to IRE, but two patients developed temporary neurapraxia as a result of arm extension during a prolonged period of anesthesia. Although not a primary aim of this preliminary study, complete target tumor ablation verified by CT was achieved in 46 of the 69 tumors treated with IRE (66%). Most treatment failures occurred in renal and lung tumors. Biopsy in three patients showed coagulative necrosis in the regions treated by IRE.

IRE appears to be safe for human clinical use provided ECG-synchronized delivery is used. Comparative evaluation with alternative ablative technologies is warranted.