Infected upper tract stones are the case where flexible ureteroscopy most often goes wrong, because raising intrarenal pressure pushes bacteria and endotoxin into the circulation. This randomised trial enrolled 185 patients with infectious upper urinary tract stones, 93 to flexible ureteroscopy with a flexible negative-suction ureteral access sheath and 92 to a traditional sheath, with matched baseline characteristics. The primary outcome was stone-free rate on the first postoperative day.
The suction group had significantly lower white cell count, C-reactive protein and procalcitonin at both six and 24 hours postoperatively (all P < .05) — the outcome that matters most in this population. Stone-free rates were higher both on day one and at 30 days (both P < .05), operating time was shorter (P < .001), hospital stay was shorter (P < .001), quality of life improved more (P < .001) and the overall complication rate was lower (P < .05). Ureteral stricture at three months occurred in three traditional and one suction patient, not a significant difference.
The biochemical result is the persuasive part: this is not a stone clearance gadget that happens to be faster, it is a device that measurably blunts the systemic inflammatory response in the population most likely to become septic. For a high-volume Indian stone practice, where infected stones are common and post-ureteroscopy sepsis is the complication that fills the intensive care unit, that is a strong argument. The trial does not report a sepsis or intensive care outcome, and single-centre randomised trials of new devices tend to flatter them, so treat the inflammatory markers as a surrogate and audit your own sepsis rate after adopting it.
- Treat infected stones as a sepsis-prevention operation first and a clearance operation second.
- Culture the urine and treat before elective ureteroscopy — a suction sheath does not replace that.
- Keep irrigation pressure low regardless of sheath type; pressure is the mechanism being addressed.
- Audit your own post-ureteroscopy sepsis rate before and after any device change.
- Inflammatory markers at 6 and 24 hours are a surrogate; no sepsis or intensive care outcome was reported.
The statistics, in plain English
Reporting only P values without effect sizes, as this trial largely does, tells you a difference exists but not how big it is — a shorter operating time significant at P < .001 could be four minutes or forty. Inflammatory markers are surrogates: lower procalcitonin at 24 hours makes sepsis less likely but is not the same as fewer patients becoming septic. With 185 patients, the stricture comparison of three against one is far too small to say anything.
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