- Design
- Multicentre randomised non-inferiority trial, stopped early
- Population
- 161 children aged 2 or under with single-stage distal or midshaft hypospadias repair
- Primary outcome
- Urethrocutaneous fistula within 3 months
- Effect
- 8.9% caudal vs 7.3% penile; RR 0.98 (95% CI 0.35–2.76)
Retrospective studies have linked caudal blocks to more urethrocutaneous fistula after hypospadias repair, without always accounting for severity. A trial across 16 paediatric regional anaesthesia network centres randomised children up to two years old having single-stage distal or midshaft repair to caudal or penile block under general anaesthesia.
Of 210 enrolled, 161 completed three months. Fistula occurred in 8.9% after caudal and 7.3% after penile block (RR 0.98, 95% CI 0.35–2.76). A proximal meatus nearly tripled fistula risk. Caudal blocks needed less intraoperative opioid (33% vs 56%) and less rescue opioid, with lower recovery-room pain scores.
The trial stopped early with losses to follow-up, so its interval is wide. It gives no support to avoiding caudal block on fistula grounds, and the analgesic advantage is clear.
- Do not avoid caudal block for hypospadias repair solely over fistula concern.
- Expect less opioid use with caudal than penile block.
- Recognise that meatal position, not block type, was the main fistula risk factor.
- Discuss block choice with the surgical team in advance.
Why it matters
It weakens a retrospective concern that has steered some teams away from caudal blocks.
Don't overread it
The trial stopped early, and its interval cannot exclude a clinically important difference.
The statistics, in plain English
A relative risk interval from 0.35 to 2.76 is very wide: the data fit a large reduction or a near-tripling of fistula. 'No significant difference' here reflects uncertainty, not proven equivalence.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for anaesthesiology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free