Confocal laser endomicroscopy for the treatment of upper urinary tract transitional cell carcinoma

OBJECTIVES: Confocal kisser endomicroscopy (CLE) is an optical technique that enables in vivo cytological characterization of a tissue. Previous studies have shown it useful in the evaluation of urinary and respiratory tracts for a better characterization of mucosal lesions, showing a high concordance between in vivo and final histopathological results. Recently, the use of CLE has been proposed for the study of transitional cell carcinoma of the upper urinary tract (UUT) during ureteroscopy, because it enables real time information about tumor grade and supplements the information of ureteroscopic biopsies, which may understimate the grade and stage of the lesion up to 43% of the cases due to its limitiations. METHODS: We performed a systematic review of the literature in the Pubmed/Medline database following the PRISMA standard. We selected 20 articles that complied with the inclusion criteria for evidence synthesis. RESULTS: Equipment miniaturization has enabled CLE as part of the diagnostic options in upper urinary tract tumors. This technique performs in vivo cytological characterization of the evaluated tissue, accomplishing differentiation between tumor and normal tissue, as well as tumor grade identification. Its communicated sensitivity and specificity reach 79%/78% respectively for low grade tumors and 67%/79% for high grade, with a substantial inter observer concordance (surgeon/pathologist; k=0.64). No complications have been communicated in the literature with the use of fluorescein or confocal laser microscopy probes in patients undergoing this technique. CONCLUSIONS: CLE represents a useful and safe tool, capable of providing cytological real time information of UUT tumors that enables tumor grade identification with substantial concordance between in vivo tumor typifying and the final histopathological analysis. For this, CLE is currently considered a tool for conservative management of UUT transitional cell carcinoma in the European Association of Urology (EAU) guidelines.