title: Irreversible electroporation adjacent to the rectum: evaluation of pathological effects in a pig model.
abstract: OBJECTIVE
  To evaluate the effects of irreversible electroporation (IRE) on the rectum wall after IRE applied adjacent to the rectum.
  
  
  METHODS
  CT-guided IRE adjacent to the rectum wall was performed in 11 pigs; a total of 44 lesions were created. In five pigs, ablations were performed without a water-filled endorectal coil (group A); in six pigs, ablation was performed with the coil to avoid displacement of the rectum wall (group B). The pigs were killed after 7-15 days and the rectums were harvested for pathological evaluation.
  
  
  RESULTS
  There was no evidence of perforation on gross postmortem examination. Perirectal muscle lesions were observed in 18 of 20 ablations in group A and in 21 of 24 ablations in group B. Inflammation and fibrosis of the muscularis propria was observed in ten of 18 lesions in group A and in ten of 21 lesions in group B. In group A, findings were limited to the external layer of the muscularis propria except for one lesion; in group B, findings were transmural in all cases. Transmural necrosis with marked suppurative mucosal inflammation was observed in seven of 21 lesions in group B and in no lesion in group A.
  
  
  CONCLUSIONS
  IRE-ablation adjacent to the rectum may be uneventful if the rectum wall is mobile and able to contract. IRE-ablation of the rectum may be harmful if the rectum wall is fixed adjacent to the IRE-probe.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
authors.forename: Helmut
authors.initials: H
authors.lastname: Schoellnast
authors.forename: Sebastien
authors.initials: S
authors.lastname: Monette
authors.forename: Paula C
authors.initials: PC
authors.lastname: Ezell
authors.forename: Gordon
authors.initials: G
authors.lastname: Single
authors.forename: Majid
authors.initials: M
authors.lastname: Maybody
authors.forename: Martin R
authors.initials: MR
authors.lastname: Weiser
authors.forename: Yuman
authors.initials: Y
authors.lastname: Fong
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Solomon
mesh_terms: D000818:Animals; D001707:Biopsy, Needle; D003287:Contrast Media; D004195:Disease Models, Animal; D018274:Electroporation / Q000379:methods*; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D011897:Random Allocation; D012007:Rectum / Q000473:pathology* / Q000601:surgery*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013552:Swine; D036542:Tomography, Spiral Computed / Q000379:methods
chemical_list: D003287:Contrast Media