Needle-based confocal endomicroscopy for in vivo histology of intra-abdominal organs: first results in a porcine model (with videos)

Background: Probe-based confocal laser scanning endomicroscopy enables in vivo real time histopathology of the mucosa layer. Recently, a prototype of a new confocal miniprobe has been developed that is small enough to be introduced through a 22-gauge puncture needle. Objective: The aim of this study was to evaluate the feasibility of such needle-based confocal laser scanning endomicroscopy (nCLE) for in vivo histology of various organs in a porcine model. Design: Feasibility study. Setting: Nonsurvival animal experiments with the animals under general anesthesia at three academic centers. Interventions: Ten pigs were examined while they were under general anesthesia. Either EUS-guided organ puncture or natural-orifice transluminal endoscopic surgery (NOTES) procedure was used. The confocal miniprobe was inserted through the 22-gauge needle, and puncture of various intra-abdominal structures and organs was performed (lymph nodes, diaphragm, ovaries, liver, spleen, and pancreas) after intravenous injection of fluorescein (5-10 mL 1% or 2 mL 10% solution). Real-time sequences were recorded. Biopsy specimens were taken for standard histopathology. Main Outcome Measurements and Results: It was technically feasible to introduce the needle-based confocal miniprobe into various organs at the time of EUS or NOTES procedures. The device enabled real-time in vivo collection of images at histologic resolutions and of acceptable image quality from several intra-abdominal organs interrogated. Limitations: Data were assessed in an experimental animal setting and on healthy organs only. Conclusions: Needle-based confocal laser endomicroscopy (CLE) of intra-abdominal organs is feasible in a porcine model. This innovative, minimally invasive technique has the potential to facilitate in vivo histology during EUS punctures or NOTES peritoneoscopy.