Design: Investigator-initiated, multicentre, open-label, randomised superiority trial (ULYSSES), stopped early
Population: 986 adults undergoing AF or left atrial tachycardia catheter ablation
Primary outcome: Venous access-site complications within 30 days
Effect: 0.6% vs 3.3%, risk ratio 0.19 (95% CI 0.05–0.63), P=0.002

ULYSSES randomised 986 patients at six centres to ultrasound-guided or palpation-guided femoral venous puncture for atrial fibrillation or left atrial tachycardia ablation. Vascular access complications are the commonest procedure-related harm of ablation, so the question is a practical one.

Access-site complications within 30 days — arteriovenous fistula, false aneurysm, or bleeding needing intervention or prolonging admission — occurred in 0.6% with ultrasound versus 3.3% with palpation (risk ratio 0.19, 95% CI 0.05–0.63). Unintended arterial punctures fell to 2% from 16%, and failed venous access needing crossover to 0.2% from 8.2%. The trial was stopped early for efficacy at its first interim analysis.

Ultrasound for femoral venous access is low-cost, already present in most electrophysiology and many cath labs, and adds little procedure time. This is a straightforward technique change rather than new equipment.

Use ultrasound rather than palpation to guide femoral venous puncture for ablation.
Access complications fell to about 0.6% from 3.3%, roughly a fifth of the rate.
Unintended arterial punctures dropped to 2% from 16%; failed access needing crossover to 0.2% from 8.2%.
The technique needs an ultrasound probe already in most labs and adds little time.

Why it matters

It turns the commonest complication of ablation into a largely avoidable one with a technique most labs already own.

The statistics, in plain English

A risk ratio of 0.19 means roughly an 80% lower complication rate; the trial stopped early for efficacy, which can overstate the size of a benefit even when its direction is secure.