Login to Access Video or Poster Abstract: MP78-20
Sources of Funding: none

Introduction

Real-time confocal laser endomicroscopy (CLE) provides in vivo microscopic images of tissues using a low-energy laser light source. This has been described to be particularly useful in distinguishing between low-grade (LG) and high-grade (HG) bladder transitional cell carcinoma. However, little is known on its potential utility in upper tract urothelial carcinoma (UTUC). The aim of this study is to describe our initial experience with CLE for the evaluation of UTUC.

Methods

Between January and September 2016, 15 flexible ureteroscopies (f-URS) were performed at our center with CLE for UTUC. A semirigid and/or a flexible digital ureteroscope [Karl Storz, Tuttlingen, Germany] were used in all the patients. An initial inspection of the ureter and renal collecting system was performed in white light with a “no touch technique” (no wire) to macroscopically identify all potential suspicious lesions. CLE was then performed using the Cellvizio® system (Mauna Kea Technologies, Paris, France) according to the following protocol: 10 mL of fluorescein was injected into the renal cavities and left indwelling for 5 minutes. A 3Fr- diameter probe (UroFlex™ B) was inserted through the working channel of the ureteroscope and then placed in contact with the lesions. The reading of the surgeon (low grade vs high grade) was documented in the operation report. Biopsies using a 3 Fr biopsy forceps or a 1.8 Nitinol Basket (COOK) were then performed. The same dedicated genitourinary pathologist blind to the surgeon reading, examined all specimens. A third person compared the informations obtained with CLE with the corresponding histopathological reports.

Results

Data on 15 patients (13 males and 2 females) are reported. The mean age was 70 (range 61-81). Mean diameter of tumors at CT scan was 22 mm (range 8-50 mm). Tumor locations were: two in the renal calyxes, three in the renal pelvis, 4 in the proximal ureter and 6 in the distal ureter. A total of 22 biopsies were taken. In 9 patients CLE allowed to obtain images with characteristic features compatible with low-grade (LG) UTUC; in 5 patients with high grade (HG) UTUC and in one case CIS. We found correspondence between the CLE images and the final histopathological results in 7/9 cases of LG UTUC (78%), in 4/5 cases of HG UTUC (80%) and in 1/1 case of CIS (100%). In the LG UTUC group two cases (22%) were up-staged to HG at the final histopathology. In the HG UTUC one case (20%) was down-staged to LG.

Conclusions

CLE might improve the accuracy of the available current tools to characterize the grade of UTUC, therefore providing a better selection of patients for a conservative endourological treatment.

Funding

none