The new grasper-integrated single use flexible cystoscope for double J stent removal: evaluation of image quality, flow and flexibility

Background: A new single use digital flexible cystoscope (FC) Isiris α from Coloplast® with an incorporated grasper has been developed to perform double J stent removal. There is a lack of data regarding the comparison of image quality, flexibility and flow between classic cystoscopes and the new Isiris α. Materials and methods: Five different FC were used to compare the image quality, the field of view, the loss of flow and the deflection loss. Two standardized grids, three stones of different composition and a ruler’s image were filmed in four standardized different scenarios. These videos were shown to thirty subjects that had to evaluate them. Water outflow was measured in ml/sec in all devices with and without the grasper inside, instruments tip deflection was measured using a software. Results: In the subjective analysis of the image quality Isiris α was the second FC best scored. At 3 cm of distance, the field view of Isiris α was the narrowest. Comparing the water flow in the different FCs, we observed a water flow decrease in all cystoscopes when the grasper was loaded in the working channel. Isiris α deflection and flow increase when the grasper is activated. Conclusion: In terms of quality of vision and water flow, the FC Isiris α is comparable to the other digital FC tested. Field of view is narrower. The results displayed a valid alternative to the standard procedure for DJ removal.