Prospective evaluation and classification of endoscopic findings for ureteral calculi

Shuzo Hamamoto,Kazumi Taguchi,Ryosuke Ando,Teruaki Sugino,Hiroyasu Miura,Takahiro Yasui,Atsushi Okada,Shinsuke Okada,Takaaki Inoue,Rei Unno,Tadashi Matsuda

doi:10.1038/s41598-020-69158-w

Shuzo Hamamoto, Kazumi Taguchi + Show 9 more

Open Access

https://doi.org/10.1038/s41598-020-69158-w

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Abstract

Difficulty in performing ureteroscopic lithotripsy (URSL) depends on endoscopic findings surrounding calculi. In this multicentre prospective cohort study of 185 patients with a single ureteral stone who underwent ureteroscopic lithotripsy registered in the SMART study between January 2014 and February 2017, we established a classification of endoscopic findings and analysed risk factors for ureteral changes. We evaluated endoscopic findings (oedema, polyps, ureteral mucosa-stone adherence, and distal ureteric tightness) based on the SMART classification. Operative time and ureteral injuries were significantly correlated with endoscopic finding grades. Multivariate analyses revealed that mucosa-stone adherence (MSA) was strongly affected by hydronephrosis grade (odds ratio, 12.4; p = 0.022) and the interval before surgery (odds ratio, 1.10; p = 0.012). The cutoff value for MSA was 98 days, with a predictive accuracy of 0.78. Risk factors for distal ureteric tightness were age (odds ratio, 0.96; p = 0.004) and early intervention (odds ratio, 0.90; p = 0.023). The cutoff value was 34 days, with a predictive accuracy of 0.72. In conclusion, appropriate intervention around 34 days (limited to 98 days) after symptom onset is necessary for treating ureteral calculi. Even if intervention passed 98 days post-symptom onset, staged URSL, alternative procedures, and detailed informed consent should be planned in advance, assuming strong MSA.

Highlights

Difficulty in performing ureteroscopic lithotripsy (URSL) depends on endoscopic findings surrounding calculi
With an area under the curve of 0.72 (95% confidence interval, 0.61–0.83) (Fig. 1b). This cutoff had a sensitivity of 76.9% and a specificity of 66.9%). In this multicentre prospective cohort study, we proposed the Skilled Endoscopic Management of Renal and Ureteral Stones (SMART) classification of ureteral changes based on endoscopic findings (EFs)
Kuroda et al reported that stone volume, HUs, operator experience, gender, preoperative stenting, and ureteral access sheath (UAS) diameter predicted operative times for fURSL8

Summary

Introduction

Difficulty in performing ureteroscopic lithotripsy (URSL) depends on endoscopic findings surrounding calculi In this multicentre prospective cohort study of 185 patients with a single ureteral stone who underwent ureteroscopic lithotripsy registered in the SMART study between January 2014 and February 2017, we established a classification of endoscopic findings and analysed risk factors for ureteral changes. The primary treatment for most ureteral calculi is fragmentation using shock wave lithotripsy (SWL) or ureteroscopic lithotripsy (URSL)[1]. Both techniques have low complication rates, advances in endoscopic technology and superior stone-free (SF) rates for URSL have led to broader therapeutic indications[2,3,4]. We prospectively evaluated EFs during URSL, established a classification of EFs at the ureteral stone site, and analysed the risk factors for ureteral changes

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