Vacuum-assisted dedusting lithotripsy in the treatment of kidney and proximal ureteral stones less than 3 cm in size

Purpose: This study aimed to compare the outcomes of vacuum-assisted dedusting lithotripsy (VADL) using flexible vacuum-assisted ureteral access sheath (FV-UAS) versus traditional flexible ureteroscopic lithotripsy (fURL) in patients with kidney or proximal ureteral calculi less than 3 cm in size.

Methods: A total of 371 patients who successfully underwent fURL treatment were enrolled. These patients were divided into traditional fURL group and VADL group. Outcomes of both groups were compared using 1:1 propensity score-matched analysis. Stratified analyses based on stone size and location were also conducted.

Results: Finally, 103 well-matched patients in each group were identified. No septic shock or death occurred. The immediate stone-free rate (SFR) and follow-up SFR of VADL group were significantly higher (78.6% vs. 50.5%, p < 0.001; 94.2%% vs. 75.7%, p < 0.001). No difference was observed in postoperative fever rate (2.9% vs. 3.9%, p = 1.000) and duration of lithotripsy (37.7 ± 20.1 min vs. 40.3 ± 18.9 min, p = 0.235). For patients with stones ≤ 2 cm in size, the immediate SFR and follow-up SFR in VADL group were higher (86.7% vs. 60.6%, p < 0.001; 96.0% vs. 83.1%, p = 0.010). The same trend was observed in the 2-3 cm subgroup (57.1% vs. 28.1%, p = 0.023; 89.3% vs. 59.4%, p = 0.009). Although the in situ fragmentation strategy was employed more frequently in VADL group for lower pole stones, the SFR was still higher. Subgroup analyses did not reveal any significant differences in either infectious complications or duration of lithotripsy.

Conclusion: VADL technique can significantly improve the postoperative SFR for the patients with kidney or proximal ureteral stones less than 3 cm in size treated by flexible ureteroscope.