Dificultades al aplicar la escala Post-Ureteroscopic Lesion Scale para determinar la gravedad de las lesiones de la pared ureteral

Objective: To analyze the level of agreement of the Post-Ureteroscopy Lesion Scale (PULS) and the consequences on its application in clinical practice with more reliable statistical data than the one used in the original work. Methods: 14 URS and 14 micro-URS were performed in 14 female porcine model. All the procedures were video recorded and an anatomopathological analysis was performed in each ureter. Sixteen urologists (9 endourologists and 7 general urologists) and 4 residents evaluated the ureteral lesions according to the PULS, with degrees 0, 1 and ≥2. The agreement was calculated with percentages, Kendall’s W coefficient and the indicators Fleiss’ Kappa and Krippendorff’s Alpha, while the inter-rater agreement was calculated with Spearman’s correlation and Cohen’s Kappa. Results: The percent of agreement was 11.1%. The coefficients were likewise classified as low or very low, with the greatest agreement found among the inexperienced. Also, 50% of the raters did not agree with the rest. Conclusions: The low inter-rater agreement, the specificity of the PULS and the clinical-pathological correlation suggests that this scale is not simple, and probably has a long learning curve.Objetivo: Analizar el nivel de concordancia de la Post-Ureteroscopic Lesion Scale (PULS), y examinar las consecuencias de su aplicación en la práctica clínica con datos estadísticos más fiables que los utilizados en el trabajo original. Métodos: Se realizaron 14 ureteroscopias (URS) y 14 micro-ureteroscopias (micro-URS) en 14 cerdos hembra. Todos los procedimientos se grabaron en vídeo y se realizó un análisis anatomopatológico en cada uréter. Dieciséis urólogos (9 endourólogos y 7 urólogos generales) y 4 médicos internos evaluaron las lesiones ureterales según la escala PULS, con grados 0, 1 y ≥2. La concordancia se calculó mediante porcentajes, el coeficiente W de Kendall, el índice Kappa de Fleiss y el Alfa de Krippendorff. La concordancia entre evaluadores se calculó con la correlación de Spearman y el coeficiente Kappa de Cohen. Resultados: El porcentaje de concordancia fue del 11,1%. Los coeficientes se clasificaron como bajos o muy bajos, y encontramos una mayor concordancia entre los evaluadores sin experiencia. Por otro lado, no hubo acuerdo/concordancia en/entre el 50% de los evaluadores. Conclusiones: La baja concordancia entre evaluadores, la especificidad de la PULS y la correlación clínico-patológica sugieren las dificultades del uso de esta escala y una curva de aprendizaje probablemente larga

Outcomes of ureteroscopy miniaturization on tissue damage and tissue hypoxia in a pig model

Miniaturization of ureteroscopy materials is intended to decrease tissue damage. However, tissue hypoxia and the gross and microscopic effects on tissue have not been adequately assessed. We compared the gross and microscopic effects of micro-ureteroscopy (m-URS) and conventional ureteroscopy (URS) on the urinary tract. We employed 14 pigs of the Large White race. URS was performed in one of the ureters with an 8/9.8 F ureteroscope, while a 4.85 F m-URS sheath was used in the contralateral ureter. Gross assessment of ureteral wall damage and ureteral orifice damage was performed. For microscopic assessment hematoxylin-eosin staining and immunohistochemistry for detection of tissue hypoxia were conducted. Regarding the macroscopic assessment of ureteral damage, substantial and significant differences were recorded using URS (C = 0.8), but not with m-URS. Microscopic assessment after staining with hematoxylin-eosin revealed greater epithelial desquamation in the URS group (p < 0.05). Pimonidazole staining revealed greater hypoxia in the epithelial cells than in the remainder of the ureteral layers. We conclude that m-URS causes less damage to the ureteral orifice than URS. Histopathological findings show m-URS reduces ureteral epithelial damage compared with conventional ureteroscopy. Both URS and m-URS cause cellular hypoxia.The present study is funded by the Alicante Institute for Health and Biomedical Research (ISABIAL-FISABIO Foundation) and Presurgy S.L

Post-Ureteroscopic Lesion Scale to determine ureteral wall damage, not so easy to employ

Objetivo: Analizar el nivel de concordancia de la Post-Ureteroscopic Lesion Scale (PULS), y examinar las consecuencias de su aplicación en la práctica clínica con datos estadísticos más fiables que los utilizados en el trabajo original. Métodos: Se realizaron 14 ureteroscopias (URS) y 14 micro-ureteroscopias (micro-URS) en 14 cerdos hembra. Todos los procedimientos se grabaron en vídeo y se realizó un análisis anatomopatológico en cada uréter. Dieciséis urólogos (9 endourólogos y 7 urólogos generales) y 4 médicos internos evaluaron las lesiones ureterales según la escala PULS, con grados 0, 1 y ≥ 2. La concordancia se calculó mediante porcentajes, el Coeficiente W de Kendall, el índice kappa de Fleiss y el alfa de Krippendorff. La concordancia entre evaluadores se calculó con la Correlación de Spearman y el Coeficiente kappa de Cohen. Resultados: El porcentaje de concordancia fue del 11,1%. Los coeficientes se clasificaron como bajos o muy bajos, y encontramos una mayor concordancia entre los evaluadores sin experiencia. Por otro lado, no hubo acuerdo/concordancia en/entre el 50% de los evaluadores. Conclusiones: La baja concordancia entre evaluadores, la especificidad de la PULS y la correlación clínico/patológica sugieren las dificultades del uso de esta escala y una curva de aprendizaje probablemente larga.Objective: To analyze the level of agreement of the Post-Ureteroscopic Lesion Scale (PULS) and the consequences on its application in clinical practice with more reliable statistical data than the one used in the original work. Methods: 14 URS and 14 micro-URS were performed in 14 female porcine model. All the procedures were video recorded and an anatomopathological analysis was performed in each ureter. Sixteen urologists (9 endourologists and 7 general urologists) and 4 residents evaluated the ureteral lesions according to the PULS, with degrees 0, 1 and ≥2. The agreement was calculated with percentages, Kendall's W coefficient and the indicators Fleiss’ Kappa and Krippendorff's Alpha, while the inter-rater agreement was calculated with Spearman's correlation and Cohen's Kappa. Results: The percent of agreement was 11.1%. The coefficients were likewise classified as low or very low, with the greatest agreement found among the inexperienced. Also, 50% of the raters did not agree with the rest. Conclusions: The low inter-rater agreement, the specificity of the PULS and the clinical-pathological correlation suggests that this scale is not simple, and probably has a long learning curve

Micro-ureteroscopy vs. ureteroscopy: effects of miniaturization on renal vascularization and intrapelvic pressure

Purpose Ureteroscopy (URS) is related to complications, as fever or postoperative urinary sepsis, due to high intrapelvic pressure (IPP) during the procedure. Micro-ureteroscopy (m-URS) aims to reduce morbidity by miniaturizing the instrument. The objective of this study is to compare IPP and changes in renal haemodynamics, while performing m-URS vs. conventional URS. Methods A porcine model involving 14 female pigs was used in this experimental study. Two surgeons performed 7 URS (8/9.8 Fr), for 45 min, and 7 m-URS (4.85 Fr), for 60 min, representing a total of 28 procedures in 14 animals. A catheter pressure transducer measured IPP every 5 min. Haemodynamic parameters were evaluated by Doppler ultrasound. The volume of irrigation fluid employed in each procedure was also measured. Results The range of average pressures was 5.08–14.1 mmHg in the m-URS group and 6.08–20.64 mmHg in the URS (NS). 30 mmHg of IPP were not reached in 90% of renal units examined with m-URS, as compared to 65% of renal units in the URS group. Mean peak diastolic velocity decreased from 15.93 to 15.22 cm/s (NS) in the URS group and from 19.26 to 12.87 cm/s in the m-URS group (p < 0.01). Mean resistive index increased in both groups (p < 0.01). Irrigation fluid volume used was 485 mL in the m-URS group and 1475 mL in the URS group (p < 0.001). Conclusions m-URS requires less saline irrigation volumes than the conventional ureteroscopy and increases renal IPP to a lesser extent.Authors received research funds from a public research institute (ISABIAL-FISABIO) and from Presurgy SL