A 4.7Fr stent was better tolerated than 6Fr after ureteroscopy, at the cost of more dislodgement

Design

Single-centre randomised trial, patient- and assessor-blinded

Population

124 patients having elective ureterorenoscopy with lithotripsy in India

Primary outcome

Stent tolerability by IPSS and USSQ at 3 weeks

Effect

USSQ 73 vs 80 (difference -7, -13 to -1.5); grade 3 complications 8.8% vs 3.2%

This single-centre trial in India, blinded for patients and assessors, randomised 124 patients having elective ureterorenoscopy and intracorporeal lithotripsy to a 4.7Fr or 6Fr PTFE double-J stent for three weeks; 119 were analysed.

At three weeks, IPSS did not differ (mean difference -0.7, 95% CI -2 to 1), but overall Ureteral Stent Symptom Questionnaire scores were better with the thinner stent (73 vs 80; difference -7, -13 to -1.5). Stone-free rates were similar. Grade 3 complications, mainly dislodgement, were more frequent with 4.7Fr (8.8% vs 3.2%; RR 2.6, 0.5-13).

Stent symptoms are the commonest complaint after ureteroscopy and drive unplanned visits. A thinner stent is a simple change that patients noticed.

The dislodgement signal is imprecise but real enough to matter, so a thinner stent suits patients where displacement would be least harmful.

• Consider a 4.7Fr stent when a short post-ureteroscopy stent is needed.
• Prefer 6Fr where dislodgement would be dangerous, such as a solitary kidney or significant oedema.
• Warn patients about stent symptoms and give a clear removal date.
• Ask whether a stent is needed at all after uncomplicated ureteroscopy.

Why it matters

Stent discomfort is the part of stone surgery patients remember, and stent calibre is an easy lever on it.

Don't overread it

This single-centre trial was not powered for complications, so the dislodgement difference is uncertain in both directions.

The statistics, in plain English

A 7-point USSQ difference is statistically significant, with a confidence interval from 1.5 to 13 points. The dislodgement relative risk of 2.6 has an interval from 0.5 to 13, so the trial cannot tell whether thinner stents truly dislodge more often.

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