- Design
- Multicentre randomised non-inferiority trial, terminated early
- Population
- 161 children ≤2 years with 3-month follow-up after hypospadias repair
- Primary outcome
- Urethrocutaneous fistula within 3 months
- Effect
- 8.9% vs 7.3% (RR 0.98, 95% CI 0.35 to 2.76)
A multicentre trial at 16 paediatric centres randomised children aged two or under having single-stage distal or midshaft hypospadias repair to caudal or penile block with general anaesthesia. It stopped early: 161 of 210 completed three-month follow-up.
Urethrocutaneous fistula occurred in 8.9% after caudal and 7.3% after penile block (RR 0.98, 95% CI 0.35 to 2.76). A more proximal meatus was the clearer risk factor (RR 2.8). Caudal block was associated with less intraoperative opioid (33% vs 56%), less rescue opioid (4.9% vs 15.7%) and lower recovery pain scores.
The fear that caudal block causes fistulae came from retrospective studies that did not adjust for severity. This trial does not confirm it, but its wide interval cannot exclude a difference either.
- Do not avoid caudal block for hypospadias repair on fistula concerns alone
- Consider caudal block where reducing perioperative opioid is a priority
- Record meatal position, as it predicts fistula more strongly than block type
- Discuss block choice with the urology team using this evidence
Why it matters
It weakens the case for withholding caudal analgesia from small children over an unproven fistula risk.
Don't overread it
Stopped early with 23% lost to follow-up — exploratory, not definitive.
The statistics, in plain English
An RR of 0.98 suggests no difference, but the interval from 0.35 to 2.76 is wide enough to include a risk nearly three times higher or one-third as high.
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