Interrater reliability and clinical impact of the Post-Ureteroscopic Lesion Scale (PULS) grading system for ureteral lesions after ureteroscopy : Results of the German prospective multicenter BUSTER project

Abstract

The Post-ureteroscopic Lesion Scale (PULS) was designed as astandardized classification system for ureteral lesions after uretero(reno)scopy (URS). This study evaluates its routine use and apossible clinical impact based on arepresentative patient cohort. Data of 307 patients in 14German centers within the BUSTER project were used to test 3hypotheses(H): PULS score shows ahigh interrater reliability (IRR) after independent assessment by urologic surgeon and assistance personnel(H1); PULS score is correlated with the frequency of postoperative complications during hospital stay(H2); post-URS stenting of the ureter is associated with higher PULS scores(H3). Median age of patients was 54.4years (interquartile range [IQR] 44.4-65.8; 65.5% male). Median diameter of index stones was 6 mm (IQR 4-8) with 117 (38.4%) pyelo-caliceal and 188 (61.6%) ureteral stones. Overall, 70 and 82.4% of patients had pre-stenting and post-URS stenting, respectively. Stone-free status was achieved in 68.7% after one URS procedure with acomplication rate of 10.8% (mostly grade1-2 according to Clavien-Dindo). PULS scores0, 1, 2 and3 were assessed in 40%, 52.1%, 6.9% and 1% of patients, respectively, when estimated by urologic surgeons. PULS score showed ahigh IRR between the urologic surgeon and assistance personnel (κ= 0.883, p< 0.001), but was not significantly correlated with complications (ρ= 0.09, p= 0.881). In contrast, asignificant positive correlation was found between PULS score and post-URS stenting (ρ= 0.287, p< 0.001). APULS score of1 multiplied the likelihood of post-URS stenting by 3.24 (95% confidence interval 1.43-7.34; p= 0.005) as opposed to PULS score0. Removal of upper urinary tract stones using URS is safe and efficacious. Real-world data provided by this study confirm ahigh IRR of the PULS score and its clinical impact on the indication for post-URS stenting. Afuture prospective randomized trial should evaluate apossible standardization of post-URS stenting based on PULS score assessment.