Angelo Pierangelo1, David Fuks2, Abdelali Benali3, Pierre Validire3, Brice Gayet2. 1Ecole Polytechnique Paris, France, 2Department of digestive diseases, Institut Montsouris, Paris, France, 3Department of pathology, Institut Montsouris, Paris, France
INTRODUCTION: Probe-based Confocal Laser Endomicroscopy (CLE) represents an innovative technique providing real-time, in-vivo optical biopsies. It has been used in a wide range of applications, e.g. gastrointestinal endoscopy, urology and pulmonary endoscopy procedures. The aim of this study was to assess the role of intraoperative CLE for the characterization of intra-abdominal organs during laparoscopic procedures for digestive cancers.
METHODS AND PROCEDURES: Between October 2014 and July 2015, all consecutive patients with digestive cancer planned for a surgical resection were prospectively enrolled. The study was approved by an ethical committee. Real-time images of both healthy and malignant tissues were acquired by a motorized confocal ultra high definition (UHD) mini-probe with a bending distal tip providing easy access to abdominal organs. It was connected to a dual wavelength endomicroscopy system that allowed imaging in the near-infrared, at 785nm (with Indocyanine Green). A live audio-visual transmission was established during the procedure between the surgeon and the pathologist for real-time interpretation of optical biopsies. Intravenous injection or topical application of contrast agent was performed few seconds before imaging. Results of optical biopsies were compared to the definitive histopathological analysis that was considered as the reference.
RESULTS: Thirty patients (n=14 male, mean age of 66±1,7 years) were included. CLE was successfully performed with intraoperative imaging on the following organs: lymph node (n=4), peritoneum (n=15), liver (n=16), colon/rectum serosa (n= 5), pancreas/pancreatic duct (n=4), stomach (n=3), ovary (n=1), adrenal gland (n=1). Live transmission between the surgeon and the pathologist was successful in 16/30 cases, connection issues were encountered in 4 cases but which communication remained possible. Two (6%) adverse events, non related to the device tested were reported and 4 technical issues were encountered with the confocal miniprobe. According to criteria of malignancy previously described with ICG staining, the specificity and the negative predictive values of intraoperative CLE for the diagnosis of malignancy in the peritoneum were both 100%. However, the sensitivity only reached 50% (3 cancers out of 8 were detected). In the liver, it was not possible to visualize malignancy in any of the metastasis. The reasons have been identified e.g. probe optical characteristics, thickening of the liver capsule due to cancer and/or chemotherapy.
CONCLUSIONS: Intraoperative CLE with a dedicated motorized confocal miniprobe and a near infra-red illumination is feasible and safe during laparoscopic procedures. These results suggest that CLE could provide additional information intraoperatively for peritoneal characterization with live remote support of pathologists.