Shu-Hsun Chu², Yun Chen¹, Shiue-Cheng Tang³

¹Department of Surgery, Far Eastern Memorial Hospital, Taipei, Taiwan; ²Cardiovascular Center, Far Eastern Memorial Hospital, Taipei, Taiwan; ³Department of Chemical Engineering, National Tsing Hua University, Shin-Chu, Taiwan

Background & Aims: The intrinsic opacity of intestinal tissue impedes its evaluation by high-resolution, in-depth optical microscopy. Through microtome sectioning can cause distortions and artifacts that hazard an accurate view of the intestinal biopsy specimen after small intestine transplantation. We therefore attempted to develop a microtome-free 3-dimensional (3D) confocal imaging method for characterization of the biopsy specimen.

Methods: We applied an optical-clearing solution, FocusClear, to permeate and reduce the opacity of intestine tissues from biopsy. Tissues were obtained from patients through elective interval biopsy after small intestine transplantation at our hospital and were labeled with fluorescent probes and examined by confocal microscopy in the FocusClear solution. The voxel-based confocal micrographs were processed with Amira software for 3D visualization and analysis.

Results: Treatment of tissues with the optical-clearing solution improved photon penetration, resulting in the acquisition of images with subcellular-level resolution across the mucosa, submucosa, and muscle layers (if presence). Collectively, the acquired image stacks were processed by projection algorithms for 3D analysis of the spatial relations in villi, crypts, and connective tissues. These imaging technologies allowed for viewing the morphology of the whole intestinal villi after transplantation.

Conclusions: This new optical method for penetrative imaging of intestine tissues does not require tissue sectioning and provides a useful tool for 3D presentation and analysis of the intestine after transplantation in the future.