3.04] First experiences with catheter-based intraluminal optical coherence tomography of the human upper urinary tract in vivo

Abstract

Objective Catheter-based intraluminal optical coherence tomography (OCT) with near-infrared light provides cross-sectional images of hollow organs and vessels, with a lateral resolution of 10–20 μm. We evaluated the technical success rate and demonstration of different wall layers of the human upper urinary tract (UUT) in OCT images obtained in vivo. Materials and methods The study protocol was approved by the local hospital ethics committee. The OCT probe (diameter: 0.014 in) was introduced into the UUT of 14 patients either through a cystoscope and urinary catheter, or through an uretero-renoscope to obtain single-slice cross-sectional images. OCT images were evaluated for delineation of ureteral wall layers by means of OCT software (M2, LightLab, Inc., Westford, MA). Results Catheter-based OCT of the UUT in vivo was technically successful in 14 out of 14 patients (100%). A total of 190 cross-sectional OCT images (760 quadrants) were obtained. Image quality allowed for tissue differentiation in 656/760 quadrants (86.3%). OCT distinguished urothelium and lamina propria in 552/656 quadrants (84.1%), lamina propria and muscle layer in 643/656 quadrants (98.0%), inner and outer muscle layer in 288/656 quadrants (43.9%), and different cell layers within the urothelium in 33/656 quadrants (5.0%) of cross-sectional images in healthy sections of the UUT. Urothelial cancer was presented as a thickening of the urothelium with distortion of the lamina propria. The histological sections confirmed the OCT findings. Conclusion Using OCT it appears to be possible to distinguish between different wall layers of the human upper urinary tract in vivo. Urothelial cancer involves a tumorous thickening of the urothelial layer and distortion of deeper tissue layers.