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    ABSTRACT: Objective: Our aim was to evaluate a fluorescence-based enhanced-reality system to assess intestinal viability in a laparoscopic mesenteric ischemia model. Materials and 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.
    Annals of surgery 03/2013; DOI:10.1097/SLA.0b013e31828d4ab3 · 8.33 Impact Factor
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    ABSTRACT: Background: The aim of this study was to assess the accuracy of a novel imaging modality, three-dimensional (3D) metabolic and radiologic gathered evaluation (MeRGE), for localizing parathyroid adenomas (PAs). Methods: Consecutive patients presenting with primary hyperparathyroidism who underwent both thin-slice cervical computed tomography (CT) and (99m)Tc-sestamibi (MIBI) scanning were included. 3D-CT reconstruction was obtained using VR-RENDER, which was used to perform 3D virtual neck exploration (3D-VNE). The MIBI scan was then fused with the 3D reconstruction to obtain 3D-MeRGE. Sensitivity, specificity, and accuracy were assessed. Parathyroid gland volume and preoperative parathormone (PTH) levels were analyzed as predictive factors of correct localization (i.e., correct quadrant). Results: A total of 108 cervical quadrants (27 patients) were analyzed. Sensitivities were 79.31, 75.86, 65.51, and 58.61 % with 3D-MeRGE, 3D-VNE, MIBI, and CT, respectively. Specificity was highest with CT (94.93 %) followed by 3D-VNE (92.4 %). MIBI and 3D-MeRGE had the same specificity (88.6 %). 3D-MeRGE and 3D-VNE achieved higher accuracy than MIBI or CT alone. Mean PTH values were significantly higher in patients with lesions that were correctly identified (true positive, TP) than in those whose lesions were missed (false negative, FN) with 3D-VNE (219.60 ± 212.77 vs. 98.75 ± 12.76 pg/ml; p = 0.01) and 3D-MeRGE (217.69 ± 213.76 vs. 09.75 ± 20.48 pg/ml; p = 0.02). The mean parathyroid gland volume difference between TP and FN was statistically significant with all modalities except CT. Conclusions: 3D-MeRGE and 3D-VNE showed high accuracy for localization of PAs. 3D-MeRGE performed better than MIBI or CT alone for detecting small adenomas and those with a low PTH level.
    World Journal of Surgery 04/2013; DOI:10.1007/s00268-013-2021-x · 2.64 Impact Factor
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    ABSTRACT: Augmented Reality (AR) in surgery consists in the fusion of synthetic computer-generated images (3D virtual model) obtained from medical imaging preoperative work-up and real-time patient images with the aim to visualize unapparent anatomical details. The potential of AR navigation as a tool to improve safety of the surgical dissection is presented in a case of pancreatico-duodenectomy (PD). A 77-year-old male patient underwent an AR-assisted PD. The 3D virtual anatomical model was obtained from thoraco-abdominal CT scan using customary software (VR-RENDER®, IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM®, Karl Storz, Tüttlingen, Germany) as well as different visible landmarks (inferior vena cava, left renal vein, aorta, superior mesenteric vein, inferior margin of the pancreas). A computer scientist manually registered virtual and real images using a video mixer (MX 70; Panasonic, Secaucus, NJ) in real time. Dissection of the superior mesenteric artery and the hanging maneuver were performed under AR guidance along the hanging plane. AR allowed for precise and safe recognition of all the important vascular structures. Operative time was 360 min. AR display and fine registration was performed within 6 min. The postoperative course was uneventful. The pathology was positive for ampullary adenocarcinoma; the final stage was pT1N0 (0/43 retrieved lymph nodes) with clear surgical margins. AR is a valuable navigation tool that can enhance the ability to achieve a safe surgical resection during PD.
    Journal of Gastrointestinal Surgery 08/2013; 17(11). DOI:10.1007/s11605-013-2307-1 · 2.80 Impact Factor
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