title: Enhanced-reality video fluorescence: a real-time assessment of intestinal viability.
abstract: OBJECTIVE
  Our aim was to evaluate a fluorescence-based enhanced-reality system to assess intestinal viability in a laparoscopic mesenteric ischemia model.
  
  
  METHODS
  A small bowel loop was exposed, and 3 to 4 mesenteric vessels were clipped in 6 pigs. Indocyanine green (ICG) was administered intravenously 15 minutes later. The bowel was illuminated with an incoherent light source laparoscope (D-light-P, KarlStorz). The ICG fluorescence signal was analyzed with Ad Hoc imaging software (VR-RENDER), which provides a digital perfusion cartography that was superimposed to the intraoperative laparoscopic image [augmented reality (AR) synthesis]. Five regions of interest (ROIs) were marked under AR guidance (1, 2a-2b, 3a-3b corresponding to the ischemic, marginal, and vascularized zones, respectively). One hour later, capillary blood samples were obtained by puncturing the bowel serosa at the identified ROIs and lactates were measured using the EDGE analyzer. A surgical biopsy of each intestinal ROI was sent for mitochondrial respiratory rate assessment and for metabolites quantification.
  
  
  RESULTS
  Mean capillary lactate levels were 3.98 (SD = 1.91) versus 1.05 (SD = 0.46) versus 0.74 (SD = 0.34) mmol/L at ROI 1 versus 2a-2b (P = 0.0001) versus 3a-3b (P = 0.0001), respectively. Mean maximal mitochondrial respiratory rate was 104.4 (±21.58) pmolO2/second/mg at the ROI 1 versus 191.1 ± 14.48 (2b, P = 0.03) versus 180.4 ± 16.71 (3a, P = 0.02) versus 199.2 ± 25.21 (3b, P = 0.02). Alanine, choline, ethanolamine, glucose, lactate, myoinositol, phosphocholine, sylloinositol, and valine showed statistically significant different concentrations between ischemic and nonischemic segments.
  
  
  CONCLUSIONS
  Fluorescence-based AR may effectively detect the boundary between the ischemic and the vascularized zones in this experimental model.
authors.affiliation: *IRCAD-IHU †Department of Anesthesiology ‡Membrane Biophysics Laboratory and Nuclear Medicine Chemistry Institute §Physiology Laboratory, Oxidative Stress, University of Strasbourg, France ¶CHUV, University Hospital of Lausanne, Switzerland.
authors.forename: Michele
authors.initials: M
authors.lastname: Diana
authors.forename: Eric
authors.initials: E
authors.lastname: Noll
authors.forename: Pierre
authors.initials: P
authors.lastname: Diemunsch
authors.forename: Bernard
authors.initials: B
authors.lastname: Dallemagne
authors.forename: Malika A
authors.initials: MA
authors.lastname: Benahmed
authors.forename: Vincent
authors.initials: V
authors.lastname: Agnus
authors.forename: Luc
authors.initials: L
authors.lastname: Soler
authors.forename: Brian
authors.initials: B
authors.lastname: Barry
authors.forename: Izzie Jacques
authors.initials: IJ
authors.lastname: Namer
authors.forename: Nicolas
authors.initials: N
authors.lastname: Demartines
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Charles
authors.forename: Bernard
authors.initials: B
authors.lastname: Geny
authors.forename: Jacques
authors.initials: J
authors.lastname: Marescaux
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes; D007090:Image Interpretation, Computer-Assisted; D007208:Indocyanine Green; D007421:Intestine, Small / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D007511:Ischemia / Q000378:metabolism / Q000473:pathology*; D019344:Lactic Acid / Q000378:metabolism; D010535:Laparoscopy; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008638:Mesenteric Arteries / Q000601:surgery; D008643:Mesentery; D055442:Metabolome; D008928:Mitochondria / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013552:Swine; D014741:Video Recording
chemical_list: D015415:Biomarkers; D005456:Fluorescent Dyes; D019344:Lactic Acid; D007208:Indocyanine Green