Gap between UAS and ureteroscope predicts renal stone-free rate after flexible ureteroscopy with the fragmentation technique

Autor: Masahiro Yao, Hirokazu Kiuchi, Takehiko Ogawa, Hisakazu Odaka, Takahiko Watanabe, Mitsuru Komeya, Junichi Matsuzaki
Rok vydání: 2020
Předmět:
Zdroj: World Journal of Urology. 39:2733-2739
ISSN: 1433-8726
0724-4983
DOI: 10.1007/s00345-020-03459-7
Popis: To assess the effect of our new classification on surgical outcomes after flexible ureteroscopy (fURS) for kidney stones.We retrospectively examined 128 patients after single renal fURS procedures performed using ureteral access sheaths (UASs) with the fragmentation technique. Based on the gap (calculated by subtracting the ureteroscope diameter from the UAS diameter), enrolled patients were divided into three groups: small ( 0.6 mm), medium (0.6 to 1.2 mm), and large space groups (≥ 1.2 mm). Stone-free (SF) status was defined as either complete absence of stones (SF) or the presence of stones 4 mm in diameter on non-contrast computed tomography (NCCT).The SF rate was significantly lower in the small space group (50% in small, 97.9% in medium, 89.2% in large; p = 0.001). Perioperative complications over Clavien-Dindo Grade I were observed in 16.7%, 4.2%, and 8.1% of patients, respectively (p = 0.452). The ratio of stone volume and operative time (efficiency of stone removal) was significantly higher in the large space group compared to the small and medium space groups (0.009 ± 0.003 ml/min, 0.013 ± 0.005 ml/min, 0.027 ± 0.012 ml/min, respectively; p 0.001).Our findings that gaps 0.6 mm (1.8 Fr), including the combination of a 9.5-Fr UAS and a small caliber ureteroscope, improve SF rates, and larger gaps facilitate stone removal efficiency providing the basis for future development of clinical protocols aimed at improving outcomes.
Databáze: OpenAIRE
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