title: Irreversible electroporation: evaluation of nonthermal and thermal ablative capabilities in the porcine kidney.
abstract: OBJECTIVE
  To compare the renal ablative capabilities of nonthermal irreversible electroporation (NT-IRE) with those of thermal irreversible electroporation (T-IRE) in a porcine model.
  
  
  METHODS
  A total of 24 laparoscopic renal ablations were performed in 12 pigs using a novel generator capable of alternately delivering NT-IRE and T-IRE. Each pig underwent unilateral interpolar ablation straddling the renal pelvis and lower pole ablation, using a single modality. The pigs were killed at 24 hours and 7 and 21 days. Basic serum laboratory tests, cardiac enzyme levels, and retrograde pyelograms were obtained before and immediately after ablation and at death. Ablation adequacy and lesion size were assessed by histologic examination.
  
  
  RESULTS
  All procedures were successfully completed without complications. For NT-IRE vs T-IRE, the median lesion size (long axis) at 24 hours, 7 days and 21 days was 3.0 vs 3.3 cm (P = 1.0), 2.5 vs 3.9 cm (P = .04), and 1.2 vs 2.8 cm (P = .03), respectively. Prolonged urinary extravasation and collecting system scarring were observed only for T-IRE. Both NT-IRE and T-IRE ablated the renal tissue adequately. NT-IRE was characterized by acute hemorrhagic necrosis, sparing the large blood vessels and extracellular matrix, and T-IRE by coagulation necrosis with associated moderate inflammation.
  
  
  CONCLUSIONS
  NT-IRE and T-IRE both safe and effectively ablate normal porcine kidneys. NT-IRE created smaller lesions with unique histologic characteristics. Significant collecting system injury occurred with T-IRE. Additional preclinical evaluation aimed at optimizing the ablation protocols is needed.
authors.affiliation: Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9110, USA.
authors.forename: Ephrem O
authors.initials: EO
authors.lastname: Olweny
authors.forename: Payal
authors.initials: P
authors.lastname: Kapur
authors.forename: Yung K
authors.initials: YK
authors.lastname: Tan
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Park
authors.forename: Mehrad
authors.initials: M
authors.lastname: Adibi
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Cadeddu
mesh_terms: D055011:Ablation Techniques; D000818:Animals; D018274:Electroporation / Q000379:methods*; D007668:Kidney / Q000601:surgery*; D010535:Laparoscopy; D013552:Swine