12 - VERY LONG-TERM OUTCOME OF TRANSCATHETER POLYTETRAFLUOROETHYLENE-COVERED STENT IMPLANTATION IN A GIANT CORONARY ANEURYSM IN A CHILD WITH KAWASAKI DISEASE

Background: We previously reported the first case of a giant right coronary artery (RCA) aneurysm with stenoses in an eight-year-old boy with Kawasaki disease that was successfully treated by transcatheter implantation of a polytetrafluoroethylene-covered stent. More than 18 years have passed since the stent was implanted. Here we report on his very long-term outcome.

Case report: The patient is now 26 years old. The onset of KD was at the age of six, and he developed coronary artery aneurysms in the left anterior descending coronary artery (LAD, 6.5mm in diameter) and the RCA (10.5mm in diameter). Two years later, at the age of eight, he presented symptoms of myocardial ischemia. Coronary angiography showed regression of LAD aneurysm, while the giant RCA aneurysm had 90% localized stenosis at the proximal and 50% localized stenosis at the distal site. The giant RCA aneurysm was successfully treated by transcatheter implantation of a polytetrafluoroethylene-covered stent. Since then, warfarin has been discontinued and antiplatelet agents have been administered. Eleven years later, at the age of 19, coronary angiography showed good RCA flow with mild localized stenosis(41.1% at the proximal site and 47.5% at the distal site). Optical coherence tomography showed that the inner surface of the stent was almost completely covered by endothelium. The neoatherosclerotic change was noted at the proximal site of the stent. More than 18 years have passed since the stent was implanted, the patient is still living a healthy life with no symptoms on antiplatelet medication.

Discussion: Polytetrafluoroethylene-covered stent implantation in a giant coronary aneurysm with stenoses resulted in a significant improvement in coronary artery flow, not only by dilating the stenoses but also by changing the flow in the aneurysm from the stagnant to laminar. One possible explanation for the favorable long-term outcome is that the culprit lesion was not in the left coronary artery but in the RCA.

Conclusion: The very long-term outcome of transcatheter implantation of a polytetrafluoroethylene-covered stent in a giant coronary aneurysm with stenoses in an eight-year-old boy with Kawawsaki disease was satisfactory. Although further follow-up is needed, polytetrafluoroethylene-covered stent implantation is considered a promising treatment option.