Chapter 29 ■ Umbilical Artery Catheterization 161

13. Grasp cord stump, using toothed forceps, at point close

to (but not on) artery to be catheterized. If available, it

may be helpful to have an assistant scrub and assist.

a. Apply two curved mosquito hemostats to Wharton

jelly on opposite sides of the cord, away from the

vessel to be cannulated.

b. Apply traction to stabilize cord stump.

14. Introduce one of the points of the curved iris forceps

into the lumen of the artery and probe gently to a depth

of 0.5 cm.

15. Remove forceps and bring points together before introducing them once more into the lumen.

16. Probe gently to a depth of 1 cm (up to the curved

“shoulder” of the forceps), keeping the points together.

17. Allow the points to spring apart, and maintain forceps

in this position for 15 to 30 seconds to dilate vessel

(Fig. 29.10). Time spent in ensuring dilatation prior

to catheter insertion increases the likelihood of

success.

18. Release cord and set aside toothed forceps, while keeping curved forceps within artery.

19. Grasp catheter 1 cm from tip, between free thumb and

forefinger or with curved iris forceps.

Fig. 29.9. The vessels of the umbilical cord. Thin-walled

umbilical vein at 12-O’clock position is indicated by a white arrow.

One of the two umbilical arteries is to the right and directly below

the vein.

Fig. 29.10. An iris forceps is pointed into the umbilical artery

in order to dilate the lumen of the artery.

A B

Fig. 29.11. A: Inserting the catheter into the artery between the prongs of dilating forceps. Note that the

umbilical tape has been tied around the skin of the umbilicus; this should be loosened once the catheter

is secured in place. B: Close-up photo of the umbilical stump with the arterial catheter in place.