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.

Machine perfusion: initial results in an expanded criteria donor kidney transplant program.

BACKGROUND: Delayed graft function (DGF) negatively impacts graft survival. Expanded criteria donors (ECD) show a higher rate of DGF. Hypothermic machine perfusion (HMP) has shown a DGF decrease and an increase of survival at 1 year. Several authors found that renal resistance (RR) at the end of machine perfusion was an independent risk factor for the development of DGF and poorer graft survival. The objective of this study was to analyze HMP results in the context of an ECD program and assess the impact of donor parameters and resistance index (RI) during perfusion in graft survival after kidney transplantation. METHODS: Donor age, terminal creatinine, machine perfusion time, percentage of glomerulosclerosis, and RI at the end of the perfusion were considered as risk predictors. Univariate and multivariate Cox regression analysis was constructed to find independent risk factors of DGF. Finally, diagnostic validity for RR was determined by sensitivity, specificity, and positive and negative predictive values. RESULTS: Twenty-three percent of patients developed DGF. We found no difference in the ability of flow or RI to predict the development of DGF. The predictive accuracy of RI for DGF by receiver operator characteristic curve was poor, with a c-statistic of 0.66 (95% CI, 0.50-0.81; P = .046). Our analysis did not identify risk factors that predicted graft survival at 1 year. Patient and graft survival were 98.8% and 89.7%, respectively. CONCLUSIONS: HMP has reduced the rate of DGF in our cohort of recipients of ECD grafts compared with historical data (23.3% vs 38.0%). Analysis did not identify risk pretransplant factors for graft survival at 1 year.

Resistance index determination in the pre and post kidney transplantation time points in graft dysfunction diagnosis.

BACKGROUND: Donor shortage necessitates the development of tools capable of objectively assessing kidney graft quality from expanded criteria donors and kidneys donated after cardiac death. The deteriorating donor profile is leading to a shift from cold storage toward machine perfusion preservation. Several authors found that renal resistance (RR) at the end of machine perfusion was an independent risk factor for the development of delayed graft function (DGF). In contrast, Doppler ultrasonography in the posttransplant period reveals renal hemodynamics and is useful in diagnosing renal allograft dysfunction. We sought to determine concordance between RR and the resistance index (RI) and their diagnostic value in the assessment of graft viability. METHODS: RR was determined at the end of perfusion during hypothermic machine preservation and RI was measured by Doppler ultrasonography in the early posttransplant period. Agreement between these 2 measures was established by means of the intraclass correlation coefficient (ICC). Diagnostic validity for RR and RI was determined by sensitivity, specificity and positive and negative predictive values. RESULTS: The ICC was 0.135, which indicates a slight agreement. RR and RI had limited value in the prediction of DGF for a specific kidney as reflected by a c-statistic of 0.58 and 0.66, respectively. CONCLUSIONS: There is no agreement between the RR and RI, which may be owing to the different conditions under which measurements are made. The poor predictive power of RR for DGF indicates that kidneys should not be discarded based on RR criteria alone.