Pediatr Cardiol. 2020 Jun;41(5):1058-1066. doi: 10.1007/s00246-020-02357-4. Epub 2020 May 4.
Take Home Points:
- Avoiding femoral arterial access in vessels measuring <3mm decreased the incidence of loss of pedal pulse in infants undergoing cardiac catheterization at a single institution
- Femoral artery diameter <3mm and OD/AD ratio >40% were independent predictors of loss-of-pulse in infants following cardiac catheterization
Commentary from Dr. Arash Salavitabar (Ann Arbor MI), catheterization section editor of Pediatric Cardiology Journal Watch: The authors of this paper had previously reported on a prospective single-center study in which femoral artery (FA) diameter <3mm was an independent predictor for loss of pedal pulse (LOP). As a continuation of that initiative, this study focused on actively avoiding FA access whenever possible if the vessel diameter was <3mm and readdressing the incidence and risk factors associated with LOP in infants undergoing cardiac catheterization.
This paper reported on a 4-year period of elective cardiac catheterizations in patients ≤1 year of age and compared certain factors to the preceding periods that had been reported upon in their previous study. LOP was defined as absence of palpable or Doppler pedal pulses, as confirmed prior to the patient leaving the catheterization lab. Ultrasound evaluations were performed by a trained technician and attending cardiologist, and measurements compared to those performed by an attending radiologist. Ultrasound-guided vascular access was used universally as an institutional policy.
There were 289 patients who underwent catheterization and met criteria during this study period, as compared to 166 patients in the comparison group in the preceding period. Of note, the subject pool in this study included a greater number of patients weighing ≤3kg, with prematurity, and, thus, with smaller FA diameters when compared to prior periods previously reported on by the authors. A significantly lower number of patients had FA access during this period due to the active avoidance of accessing smaller FAs, and in return, the median diameter of FA accessed was significantly larger than in the preceding period [3.2mm (2.7-3.6) vs. 2.9mm (1.6-3.6), p=0.01]. As a result, the incidence of LOP dropped significantly both for the total cohort and for those who had a FA accessed. The ratio of the outer diameter of the catheter sheath to luminal diameter of the artery (OD/AD ratio) decreased as well, from 46.6% (range 32.4-61.3%) to 37.5% (range 30.7-66.0), p<0.01. All other procedural factors did not differ between the two periods.
When combining the subject pools from the two periods, those with LOP had a significant smaller FA diameter at baseline (median 2.4mm, range 1.6-3mm) when compared to those who did not have LOP (median 3.3mm, range 2.4-3.9). Patients with LOP were also of a younger age and smaller size. On multivariate logistic regression analysis of risk factors associated with LOP, FA diameter <3mm (OR 6.48, 95% CI 2.31-11.42, p<0.001) and OD/AD ratio >40% (OR 4.16, 95% CI 1.79-8.65, p<0.001) were independent predictors of LOP.
This policy change implemented at the authors’ institution clearly improved the rate of LOP and identified risk factors for LOP in infants undergoing a cardiac catheterization. It is difficult to determine whether information was potentially missed in the patients who had intentional avoidance of FA access, which was acknowledged as a limitation of the study. Nonetheless, knowing these associations allows for more accurate counseling prior to cardiac catheterization and procedural planning with risks in mind, as it can prevent unnecessary arterial access in patients with small FA diameters, can promote smaller sheath size to meet optimal OD/AD ratio, and can potentially guide anticoagulation thresholds.