Radial-Artery Diameters in Many Children Could Support Transradial Interventions

By Will Boggs MD

August 05, 2020

NEW YORK (Reuters Health) - Many children have radial arteries large enough for transradial interventions, researchers report.

"The most interesting finding from this study, which included children from birth to 18 years, was the rapid increase in radial arterial diameter up to the age of 5 years, followed by a slower and steady increase, approaching adult dimensions by adolescence," said Dr. Adam A. Dmytriw of The Hospital for Sick Children, in Toronto, Canada.

"This has not been shown before and suggests that some teenagers could be approached as adults might for access considerations," he told Reuters Health by email.

Transradial access affords several advantages over the traditional transfemoral route, including lower risks of bleeding and vascular complications, patient preference and cost benefits. This approach has not been investigated extensively in children because of concerns regarding radial-artery size.

Dr. Dmytriw and colleagues sought to establish a reference range of radial artery diameters in children across different age groups to support clinical decision-making.

The study included 134 children ranging in age from 29 days to 18 years and ranging in weight from 1.7 kg to 149.1 kg.

The mean radial-artery diameters were 1.70 mm anteroposterior, 1.95 mm transverse, and 1.86 mm corrected, with no significant right-left difference.

Radial-artery size <2 mm has been considered a relative contraindication to transradial intervention, but newer techniques are calling that into question, the researchers note.

The diameter in males (mean, 1.90 mm) was nominally larger than in females (mean, 1.81 mm), but the difference fell short of statistical significance, the researchers report in Circulation: Cardiovascular Interventions.

Radial-artery diameters were significantly larger in children aged 12 years or older (mean, 2.19 mm) than in younger children (mean, 1.60 mm), and there was a strong correlation of radial-artery diameter with age and with weight.

The growth rate of the radial artery was rapid up to age 5 years, slower in the ages 6 to 11 years, and reasonably stable after age 12 years, where the arterial diameter approached adult size.

By early adolescence (12-14 years), the mean radial artery corrected diameter was 2.01 mm, and in later adolescence (15-18 years), the mean radial artery corrected diameter was 2.19 mm.

"While we encourage use of our age-stratified nomogram for sheath/access sizing estimates, we recommend that the artery still be sonographically sized until large-scale clinical studies prove safety," Dr. Dmytriw said. "From a procedural perspective, there are other considerations in children, like an increased tendency to forearm vasospasm, smaller curvature of the aortic arch, and room to form and manipulate a reverse-curve catheter."

"Our study is not one of interventional feasibility or safety, but rather to establish a reference range for radial access across pediatric age groups," he said. "While we have anecdotally encountered success in our early forays into transradial pediatric intervention, we are mindful both of the learning curve inherent to introducing a novel technique and the potential for conversion to femoral access."

SOURCE: https://bit.ly/2W6jwPm Circulation: Cardiovascular Interventions, online July 2, 2020.