Trifecta in flexible ureteroscopy for treatment of renal and upper ureteral calculi: A multicenter study

Purpose: To determine predictors for missing trifecta in patients who underwent flexible ureteroscopy (FURS) for treatment of renal and upper ureteric calculi. Patients and Methods: The data of adult patients with renal or upper ureteral stones who underwent FURS from June 2021 through December 2022 were retrospectively reviewed. Stone-free status (no residual stones > 3 mm) was evaluated after 3 months with non-contrast CT. Modified Clavien classification was used to grade complications. A stone-free status after a single intervention of FURS without complications was defined as trifecta. Patients were divided into two groups (trifecta and non-trifecta). Risk factors for missing trifecta were compared between both groups using univariate and multivariate analyses. Results: Three hundred twenty-three patients with mean age 48.9 +/- 13 years and mean stone length 16 +/- 5.9 mm were included. The trifecta criteria were applicable for 250 patients (71%). On multivariate analysis, risk factors for missing trifecta were stone multiplicity (OR: 3.326, 95%CI: 1.933-5.725) and non-experienced surgeons (OR: 1.819, 95%CI: 1.027-3.220). Conclusions: Multiple stones and performance of FURS by non-experienced surgeons are the independent risk factors for missing trifecta of FURS.