title: Utilizing confocal laser endomicroscopy for evaluating the adequacy of laparoscopic liver ablation.
abstract: BACKGROUND
  Laparoscopic liver ablation therapy can be used for the treatment of primary and secondary liver malignancy. The increased incidence of cancer recurrence associated with this approach, has been attributed to the inability of monitoring the extent of ablated liver tissue.
  
  
  METHODS
  The feasibility of assessing liver ablation with probe-based confocal laser endomicroscopy (CLE) was studied in a porcine model of laparoscopic microwave liver ablation. Following the intravenous injection of the fluorophores fluorescein and indocyanine green, CLE images were recorded at 488 nm and 660 nm wavelength and compared to liver histology. Statistical analysis was performed to assess if fluorescence intensity change can predict the presence of ablated liver tissue.
  
  
  RESULTS
  CLE imaging of fluorescein at 488 nm provided good visualization of the hepatic microvasculature; whereas, CLE imaging of indocyanine green at 660 nm enabled detailed visualization of hepatic sinusoid architecture and interlobular septations. Fluorescence intensity as measured in relative fluorescence units was found to be 75-100% lower in ablated compared to healthy liver regions. General linear mixed modeling and ROC analysis found the decrease in fluorescence to be statistically significant.
  
  
  CONCLUSIONS
  Laparoscopic, dual wavelength CLE imaging using two different fluorophores enables clinically useful visualization of multiple liver tissue compartments, in greater detail than is possible at a single wavelength. CLE imaging may provide valuable intraoperative information on the extent of laparoscopic liver ablation.
authors.affiliation: Division of Surgery and Interventional Science, Royal Free Campus, University College London, Pond Street, NW3 2QG, London, UK.
authors.forename: Crispin
authors.initials: C
authors.lastname: Schneider
authors.affiliation: Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Johnson
authors.affiliation: Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Walker-Samuel
authors.affiliation: Division of Surgery and Interventional Science, Royal Free Campus, University College London, Pond Street, NW3 2QG, London, UK.
authors.forename: Kurinchi
authors.initials: K
authors.lastname: Gurusamy
authors.affiliation: Division of Tissue Engineering and Biophotonics, Kings College London Dental Institute, London, United Kingdom.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Clarkson
authors.affiliation: Division of Tissue Engineering and Biophotonics, Kings College London Dental Institute, London, United Kingdom.
authors.forename: Stephen
authors.initials: S
authors.lastname: Thompson
authors.affiliation: Division of Tissue Engineering and Biophotonics, Kings College London Dental Institute, London, United Kingdom.
authors.forename: Yi
authors.initials: Y
authors.lastname: Song
authors.affiliation: Division of Tissue Engineering and Biophotonics, Kings College London Dental Institute, London, United Kingdom.
authors.forename: Johannes
authors.initials: J
authors.lastname: Totz
authors.affiliation: Division of Tissue Engineering and Biophotonics, Kings College London Dental Institute, London, United Kingdom.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cook
authors.affiliation: Department of Medical Physics and Bioengineering, University College London, London, United Kingdom.
authors.forename: Adrien E
authors.initials: AE
authors.lastname: Desjardins
authors.affiliation: Centre for Medical Image Computing, University College London, London, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: Hawkes
authors.affiliation: Division of Surgery and Interventional Science, Royal Free Campus, University College London, Pond Street, NW3 2QG, London, UK.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Davidson
mesh_terms: D055011:Ablation Techniques / Q000379:methods*; D000818:Animals; D004724:Endoscopy; D005240:Feasibility Studies; D005260:Female; D019793:Fluorescein; D005456:Fluorescent Dyes; D006498:Hepatectomy / Q000379:methods*; D007208:Indocyanine Green; D016014:Linear Models; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D018613:Microscopy, Confocal / Q000379:methods; D008872:Microwaves / Q000627:therapeutic use*; D013552:Swine
chemical_list: D005456:Fluorescent Dyes; D007208:Indocyanine Green; D019793:Fluorescein
keywords: confocal laser endomicroscopy; liver ablation imaging; liver cancer; virtual histology