An Adolescent Patient with Coarctation of Aorta Treated with Self-Expandable Nitinol Stent
An 18-year-old female, height of 165 cm and body weight of 55 kg, was diagnosed with a native aortic coarctation. She has no significant difficulty in her usual activities and exercises. She has complained only of intermittent headache. Her blood pressure (BP) measurements were 123/64 mm Hg and 123/62 mm Hg at her right and left arm, while 86/47 mm Hg and 83/49 mm Hg at her right and left ankle, showing 50 mm Hg higher BP in the upper extremities (). On echocardiographic study, discrete aortic coarctation was diagnosed with the peak pressure gradient across the stenotic lesion of 50 mm Hg by Doppler study (). On chest CT angiogram a discrete narrowing at the isthmic portion of the aortic arch due to a posterior shelf lesion was seen (). The narrowest dimension of the stenotic lesion was 4-5 mm, and the dimensions of the pre- and post-coarctation descending aorta were 16 mm and 19 mm, respectively (). The distance from the origin of left subclavian artery to the coarctation site was 24 mm.\nA 20 mm self-expandable nitinol stent (Hercules vascular stent 20×60 mm, S&G Biotech, Seongnam, Korea) was deployed across the coarctation site, without previous balloon dilatation procedure (). No further balloon dilatation was done immediately after the stent deployment to avoid unnecessary tissue injury. Immediately after the procedure, the peak pressure gradient across the coarctation site decreased from 50 mm Hg to 20 mm Hg (), and the dimension of the stenotic lesion shown by the stent waist somewhat increased from 4-5 mm to 8 mm on angiography and plain chest X-ray images (). We decided to wait and see for further self-expansion of the stent.\nThree months after the procedure, the dimension of the stent waist had enlarged gradually up to 13 mm on plain X-ray and 11.5 mm on CT images (). Further interventional procedure, such as instent low-pressure balloon dilatation, was suggested to trim the remnant waist of the stent. But the patient and her parents were happy with the present status and refused any further procedures.\nOne year after the stent deployment, the dimension of the stent waist further increased slightly up to 14 mm (). The BP measurements in the upper extremities somewhat decreased, while the BP measurements in the lower extremities increased significantly up to higher than those of the upper extremities (). On echocardiographic study, the exact Doppler pressure gradient across the pervious stenotic site was not available because the images of the previous stenotic lesion were poor and definite flow turbulence was not found, suggesting the remnant stenosis not significant. Subjectively, as she felt no significant difficulty in her physical activity before the stent insertion, she felt not so much difference in her physical activity after the stent insertion. However, she said she felt more warmness in her lower extremities after the stent insertion than before, having more tolerance for cold weather when she was wearing skirts.