- Design
- Multicentre randomised non-inferiority trial, terminated early
- Population
- 161 children aged ≤2 years with distal or midshaft hypospadias repair (of 210 randomised)
- Primary outcome
- Urethrocutaneous fistula within 3 months
- Effect
- 8.9% caudal vs 7.3% penile; RR 0.98 (95% CI 0.35 to 2.76)
Some retrospective studies linked caudal block to urethrocutaneous fistula after hypospadias repair, prompting some surgeons to ask for penile blocks instead. This multicentre trial at 16 paediatric centres randomised 210 children aged two or under having single-stage distal or midshaft repair; 161 completed three-month follow-up.
Fistula occurred in 8.9% after caudal and 7.3% after penile block (RR 0.98, 95% CI 0.35 to 2.76). A proximal meatus was the clear risk factor (RR 2.8). Children given a caudal block needed less intraoperative opioid (33% vs 56%) and less rescue opioid (4.9% vs 15.7%) and had lower recovery pain scores.
The trial stopped early and lost about a quarter of children to follow-up, so its estimate is wide and cannot rule out a meaningful difference. The authors call it exploratory.
It does, however, weaken the case for abandoning caudal block on fistula grounds alone, and it shows the analgesic advantage that would be lost.
- Caudal block gave better analgesia and less opioid use than penile block in this trial
- Fistula rates were similar, but the estimate is imprecise
- Proximal hypospadias carried a higher fistula risk whatever the block
- Agree the block choice with the surgeon, using this trial to inform the discussion
Why it matters
It is the first randomised test of a fear that has changed paediatric block practice.
Don't overread it
The trial stopped early and is underpowered; it cannot exclude a clinically important difference.
The statistics, in plain English
The risk ratio of 0.98 has a confidence interval from 0.35 to 2.76, which means the true effect could be anything from a large reduction to nearly three times the risk. The trial was too small to settle the question.
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