A negative-suction access sheath blunted the inflammatory response after surgery on infected stones

Design

prospective randomised controlled trial

Population

185 patients with infected upper urinary tract stones, 93 suction sheath and 92 traditional sheath

Primary outcome

stone-free rate on the first postoperative day

Effect

higher stone-free rate at day 1 and 30 days (both P<0.05); lower white cell count, CRP and procalcitonin at 6 and 24 hours

Infected upper urinary tract stones are the setting where ureteroscopy most often goes wrong, because raised intrarenal pressure during irrigation pushes bacteria and endotoxin into the circulation. A flexible negative-suction ureteral access sheath is designed to keep that pressure down while clearing fragments. This prospective randomised trial assigned 185 patients with infected upper tract stones to flexible ureteroscopy with the suction sheath (93) or a traditional access sheath (92), with baseline characteristics comparable between groups.

The suction group had lower white cell counts, C-reactive protein and procalcitonin at both 6 and 24 hours after surgery, all statistically significant. Stone-free rates were higher on day one and at 30 days, operative time and hospital stay were both shorter, and the overall complication rate was lower. Ureteral stricture at three months occurred in three patients with the traditional sheath and one with suction — a difference too small to interpret.

The trial reports significance without publishing the effect sizes for most outcomes, which limits how firmly any single number can be quoted. What it supports is a procedural choice rather than a prescribing one: where the indication is an infected stone, the sheath that controls intrarenal pressure is the one to reach for, and the post-operative inflammatory markers give you an early read on whether that worked.

• Reserve the strongest version of this conclusion for infected stones — that is the population studied
• Check procalcitonin and C-reactive protein at 6 and 24 hours if you want an early signal of a systemic response
• Treat the urine before elective surgery on an infected stone regardless of which sheath you use
• Note that stricture rates were similar, so the suction sheath is not shown to be safer for the ureter
• Ask what your unit stocks — this is an equipment decision made long before the case

Why it matters

It makes post-ureteroscopy sepsis a question of how the case is plumbed, not only of how it is covered with antibiotics.

Don't overread it

Most outcomes are reported as significant without effect sizes, so the size of the benefit cannot be stated from this report.

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