Confocal Laser Endomicroscopy in the Management of Endoscopically Treated Upper Urinary Tract Transitional Cell Carcinoma: Preliminary Data

To describe our initial experience with confocal laser endomicroscopy (CLE) for the evaluation and treatment of patients with upper urinary tract transitional cell carcinoma (UUT-TCC).Preliminary data were analyzed from 11 patients with suspicion of UUT-TCC scheduled for flexible ureteroscopy (f-URS) and consensual holmium-YAG laser tumor ablation. CLE was performed before endoscopic biopsy and laser photoablation of the suspected lesion using a 3F-diameter flexible probe UroFlex™ B (Cellvizio® system; Mauna Kea Technologies, Paris, France), which allows to obtain microscopic resolution imaging (3.5 μm), with a field of view of 325 μm and a depth of tissue imaging of 40 to 70 μm. Video sequences were analyzed offline and thereafter compared with histopathologic findings.CLE technique was feasible and showed good quality imaging in all patients. Overall, the Cellvizio system provided reliable images of healthy urothelium when the probe was pointed toward normal tissue, showing umbrella cells on the surface and vessels in the lamina propria. Moreover, CLE displayed the characteristic features of high-density cellular aggregates and fibrovascular stalks in four patients with pathologically confirmed low-grade UUT-TCC. In the patient with pathologically confirmed high-grade UUT-TCC, more distorted microarchitecture and tortuous vessels were clearly recognized with CLE.These preliminary data showed the feasibility of CLE technique when applied to the diagnosis of UUT-TCC. Further clinical studies are required to confirm CLE accuracy in distinguishing healthy urothelial tissue from malignant lesions, thus helping clinicians in targeting ureteroscopic biopsy and improving the conservative management of UUT-TCC patients.