Intravascular ultrasonic assessment of post-operative remodelling of aortic coarctation repaired by use of a subclavian flap.

BACKGROUND

We have used intravascular ultrasound in an attempt to clarify the extent of vascular remodelling of the aortic arch after the repair of aortic coarctation by use of a subclavian flap.

METHODS

We investigated 13 patients with coarctation of the aorta, ranging in age from 1.4 to 43.0 months, with a mean of 20.8 months, who underwent aortoplasty by incorporation of a subclavian flap. The mean postoperative period was 19.6 months, with a range from 0.03 to 41.2 months. The luminal morphology of the aortic arch was evaluated by intravascular ultrasound at the time of post-operative catheterization.

RESULTS

We observed 3 cases longitudinally. Over the period of observation, we found three types o f morphology of the aorta at the site of incorporation of the subclavian flap, namely a snowman shape with two inflection points, a pisiform shape with one inflection point, and a round shape without any points of inflection. There was a correlation between the cross-sectional shapes at the site of the subclavian flap in the postoperative period (p < 0.01). In each case, we measured the cross-sectional area at the site of subclavian flap, at the descending aorta, and at the distal aortic arch. The cross-sectional area, and the increment of the cross-sectional area at the site of subclavian flap, was larger.

CONCLUSION

The shape of the lumen subsequent to repair of aortic coarctation changes progressively from a snowman, to a pisiform, and finally to a round shape. Greater growth of the subclavian flap compared to the native wall of the aorta was observed for at least the first 4 years after repair. This finding may improve our understanding of the remodelling process of the arterial trunks after surgical repair.