Effects of vascular morphological features and ultrasound-guided vascular cannulation techniques on the success of femoral artery catheterisation in newborns.

Ultrasound-guided vascular access is a technique that can increase safety as well as technical and procedural success when performing invasive cardiovascular procedures. The aim of this study was to evaluate the effects of two cannulation techniques and vascular morphological properties on the success of femoral artery catheterisation in neonatal patients. We recruited 65 consecutive patients requiring femoral artery catheterisation and randomly divided them into two groups: Group 1, in-plane technique (n = 31) and Group 2, out-of-plane technique (n = 34). We compared the preparation duration, puncture duration, number of punctures, number of arterial punctures, number of unsuccessful interventions, hematoma incidence and vascular morphological characteristics between the groups. The mean age of Group 1 was 17.16 ± 7.04 days, and the mean age of Group 2 was 17.20 ± 7.40 days, with no difference observed between the groups (p > 0.05). Four patients in Group 1 and nine patients in Group 2 developed hematoma (p = 0.172). Hematoma was strongly correlated with the number of venous punctures (r = 0.632; p = 0.001) and the number of needle advancements (r = 0.415; p = 0.001). In terms of artery-vein position, patients whose artery overlapped the vein by > 50% required clearly longer artery cannulation durations than the other patients (p < 0.001). Although the in-plane technique has a steep learning curve, it was found superior in terms of procedure-related factors such as the number of trials, the incidence of hematoma and arterial puncture counts, as it offers advantages such as the ability to evaluate the lumen and a better control of the needle advancement direction.