Confocal Laser Endomicroscopy (CLE) based on ultraminiature miniprobes (Cellvizio®, Mauna Kea Technologies,
Paris, France) is able to image the inner microstructure of retroperitoneal full organs punctured during EUS-FNA
procedures, such as pancreas, liver or lymph nodes. Therefore, pCLE can provide an easy-to-use and precise adjunct tool
to ultrasonographic interventions in order to target suspicious areas for biopsies in EUS-FNA.
Material and Methods:
Probe-based CLE (pCLE) was performed on ex-vivo surgically resected specimens after topical application of
fluorophores in standard 19G and 22G needles. Two prototype miniprobes ("S-probe" 300 microns diameter, field of
view 400*280 microns, and "S-probe" 650 microns diameter, field of view 500*600 microns) were then inserted into the
needles and enabled visualization of the inner microstructures of uterus, lung, kidney, stomach and esophagus, in both
healthy and cancerous conditions.
Then, pCLE was performed in-vivo on four pigs during three NOTES and one EUS-FNA procedures after intravenous
injection of 2-7mL fluorescein 1-10% using the prototype "S-probe" 350 microns diameter inserted in 19G FNA needles.
Liver, pancreas and spleen were imaged.
During the ex-vivo experiments, pCLE made it possible to distinguish microstructures, such as alveoli and macrophages
in the lungs. During the in-vivo experiments, Cellvizio® video sequences showed hepatic lobules and the portal vein in
the liver, and red and white pulp in the spleen.
pCLE provides in vivo cellular information about full organs. It has the potential to help target biopsies during EUSFNA,
which suffers from a high rate of false negatives, thus increasing its sensitivity.