The dilemma of 12/14F ureteral access sheath (UAS) usage: a case control study.

BACKGROUND: The insertion of a ureteral access sheath (UAS) is a frequent procedure during flexible ureteroscopy (fURS) to facilitate kidney stone treatment. The aim of this study was to investigate the influence of 12/14 French (F) UAS on fURS outcomes. METHODS: We performed a retrospective monocentric analysis of fURS procedures conducted at the Department of Urology (University Hospital Schleswig-Holstein, Lübeck, Germany) for kidney stone treatment via lithotripsy or basket stone retrieval between September 2013 and June 2017. Uni- and multivariate analyses were done with the help of RStudio (Version 1.0.136) software. RESULTS: In total, 283 consecutive fURS were analyzed. UAS was applied in 98 cases (34.63%). The insertion of UAS was preferred in cases with multiple kidney stones and larger median maximal stone diameter (p < 0.05). UAS usage correlated with elevated radiation exposure in seconds (94 vs. 61; p < 0.0001), prolonged operation time in minutes (99 vs. 66, p < 0.0001), length of hospital stay over 48 h (LOS, 22.49% vs. 10.81%; p = 0.015), more frequent postoperative systemic inflammatory response syndrome (SIRS, 13.27% vs. 4.32%; p = 0.013) and lower postoperative stone-free rates (60.20% vs. 78.92%; p = 0.0013). Moreover, we conducted uni- and multivariate subgroup analysis for cases with multiple kidney stones (≥ 2) and comparable stone burden; UAS was inserted in 48.3% of these cases (71/147). On multivariate logistic regression, UAS insertion was statistically associated with prolonged operation time in minutes (101 vs. 77; p = 0.004). No statistical differences regarding radiation exposure, stone-free rates, postoperative SIRS rates or LOS were noted between UAS and non-UAS patients with multiple kidney stones of similar size (p > 0.05). CONCLUSIONS: 12/14F UAS does not seem to improve overall outcomes in fURS for kidney stones. In patients with multiple kidney stones it may be associated with elevated operation time without a clear benefit in terms of improved stone-free status or reduced perioperative complication rate. Further prospective randomized studies to specify the indications for UAS usage are urgently needed.

New computed tomographic predictors of complicated perioperative course of 17.5F mini-percutaneous nephrolithotomy (mini-PNL).

PURPOSE: Radiological parameters predicting a postoperative stone-free status (SFS) or a complicated perioperative course of mini-PNL, are scarce. Our aim was to identify such factors for prone 17.5F mini-PNL. METHODS: A monocentric cohort of 103 cases was retrospectively analysed for factors predicting SFS and relevant complications, i.e. Clavien-Dindo (CD) ≥ 2. Parameters measured on preoperative supine CT included maximal stone diameter, skin-to-stone distance (SSD), ideal tract length (ITL), access angle, minimal T12-Lower Kidney Pole distance (T12LP) and minimal Iliac Crest-Lower Kidney Pole distance (ICLP). Infundibulopelvic angle (IPA) was measured on intraoperative pyelography. RESULTS: The median maximal stone diameter was lower in cases with postoperative SFS [16 mm (Min. 10; Max. 35) vs. 20 mm (Min. 6; Max. 85), p = 0.0052]. CD ≥ 2 was more frequent in cases with a bigger stone burden [19 mm (Min. 13; Max. 85) vs. 16 mm (Min. 6; Max. 49), p = 0.0056] and with the ribs in the access angle [7/23 (30.43%) vs. 8/76 (10.53%); p = 0.0454]. T12LP significantly differed in cases with and without CD ≥ 2 [80.48 mm (± 21.31) vs. 90.43 mm (± 19.42), p = 0.0397]; however, it had no influence on SFS (p > 0.05). SSD, ITL, IPA and ICLP were significant regarding neither SFS nor CD ≥ 2 prevalence (p > 0.05). Using multivariate logistic regression, T12LP was confirmed as an independent predictor on CD ≥ 2 prevalence. CONCLUSIONS: Preoperative computed tomographic factors indicating elevated kidney position influence perioperative course of mini-PNL. T12LP and the presence of ribs in the access angle are, apart from stone diameter, the most useful indicators for cases at risk of CD ≥ 2.

The Impact of Endourological Experience on Flexible Ureteroscopy Outcomes and Performance at Different Levels of Expertise: Retrospective Multifactorial Analysis.

INTRODUCTION: The aim of this study was to analyze the influence of residents' participation in flexible ureteroscopy (fURS) on intra- and postoperative outcomes. MATERIALS AND METHODS: Intra- and postoperative parameters were compared in a retrospective monocentric setting between 3 groups: "resident group" (47 cases) for surgeries performed by experienced residents alone, "consultant group" (245 cases) for surgeries performed by consultants alone, "resident plus consultant group" (124 cases) for training surgeries between September 2013 and June 2017. RESULTS: Patients operated by residents alone had a significantly smaller median kidney stone diameter (5.0 vs. 7.0 mm for "consultant group" and 6.0 mm for "resident plus consultant group," p = 0.011), shorter operating time (median 47.0 vs. 63.0 and 77.0 min, p < 0.001) and fluoroscopy time (median 39.0 vs. 69.5 and 89.0 s, p < 0.001), as well as shorter postoperative hospital stay (p = 0.013). The laser application rate was the smallest in the "resident group" (10.64 vs. 31.43 and 29.84%, p = 0.009). Univariate analysis revealed no relevant differences regarding flexible ureteroscope defect rate, postoperative stone-free rate, or ≥2 Clavien-Dindo classification complications between the groups (p > 0.05). CONCLUSION: A proper case selection of less complicated cases, especially without laser application, could balance the experience deficit of the residents. fURS can be incorporated as a part of residents' training without an impact on fURS device defect rate or clinical outcomes.