title: Gallbladder Cryoablation: Proof of Concept in a Swine Model for a Percutaneous Alternative to Cholecystectomy.
abstract: OBJECTIVE
  To investigate the feasibility of percutaneous gallbladder cryoablation (GBC) under CT guidance in a swine model with histopathologic correlation.
  
  
  METHODS
  Institutional Animal Care and Use Committee approval was obtained for this study protocol. Five pigs underwent GBC. Under CT guidance, 3-4 cryoprobes were positioned percutaneously at the gallbladder margins. Thermocouple probes were placed percutaneously at the gallbladder fundus, neck, free wall, and gallbladder fossa. Two freeze-thaw cycles ranging from 10 to 26 min were performed. The subjects were sacrificed 5 h after cryoablation. The gallbladder and bile ducts were resected, stained, and examined microscopically.
  
  
  RESULTS
  GBC was completed in all subjects. A 10-mm ablation margin was achieved beyond all gallbladder walls. Thermocouple probes reached at least -20 °C. Intra-procedural body temperature decreased to a minimum of 35 °C but recovered after the procedure. Intra- and post-procedural vital signs otherwise remained within physiologic parameters. Non-target ablation occurred in the stomach and colon of the first two subjects. Histology demonstrated complete denudation of the gallbladder epithelium, hemorrhage, and edema within the muscularis layer, and preservation of the microscopic architecture of the common bile duct in all cases.
  
  
  CONCLUSIONS
  Percutaneous gallbladder cryoablation is feasible, with adequate ablation margins obtained and histologic changes demonstrating transmural necrosis. Adjacent structures included in the ablation may require conservative ablation zones, hydrodissection, or continuous saline lavage.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Campus Box 0946, San Francisco, CA, 94107-5705, USA. hugh.mcgregor@ucsf.edu.
authors.forename: Hugh C J
authors.initials: HC
authors.lastname: McGregor
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Campus Box 0946, San Francisco, CA, 94107-5705, USA.
authors.forename: Maythem
authors.initials: M
authors.lastname: Saeed
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Campus Box 0946, San Francisco, CA, 94107-5705, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Surman
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Campus Box 0946, San Francisco, CA, 94107-5705, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Ehman
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Campus Box 0946, San Francisco, CA, 94107-5705, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Hetts
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Campus Box 0946, San Francisco, CA, 94107-5705, USA.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Wilson
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, Campus Box 0946, San Francisco, CA, 94107-5705, USA.
authors.forename: Miles B
authors.initials: MB
authors.lastname: Conrad
mesh_terms: D000818:Animals; D002763:Cholecystectomy; D003452:Cryosurgery / Q000379:methods*; D005240:Feasibility Studies; D005704:Gallbladder / Q000601:surgery*; D023421:Models, Animal; D015641:Radiography, Interventional; D013552:Swine; D014057:Tomography, X-Ray Computed
keywords: Cholecystitis; Cryoablation; Gallbladder