Author + information
Patient initials or identifier number
Relevant clinical history and physical exam
A 77 year-old man admitted to our emergency department due to persisting chest oppression and diagnosed with acute anterior myocardial infarction.
Coronary risk factors were hypertention and dyslipidemia.
Relevant test results prior to catheterization
ECG：ST elevation in V1-4
Echo cardiogram：LVEF：40%, Anterior area mid～apex akinesis
Relevant catheterization findings
CAG revealed total occlusion in middle segment of LAD.
Others did not admit stenosis.
The continuously primary PCI was performed for LAD. After thrombus aspiration and pre-dilation of the lesion with Hiryu balloon 2.75 x 15 mm, we obtained TIMI3. When we observed in IVUS, there a was large difference between proximal and distal reference diameter. We implanted SYNERGY stent 2.5 x 28 mm in accordance with distal reference diameter and post-dilated with the Hiryu balloon 3.5 x 10 mm against the malapposition of the middle to the proximal portion of the stent(dis 6→mid 14→prox 18 atm). When we observed in IVUS, high intensity echo protruding into the lumen was observed at the middle portion of the stent, and at the same part, partial disappearance of the strut was confirmed. With this, it became no reflow. We suspected this phenomenon as a stent fracture. When we dilated the lesion with Hiryu balloon 2.5 x 15 mm, the high intensity echo protruding was disappeared and coronary flow was improved.
In this case, there was large difference between proximal and distal reference diameter, and by the post balloon dilation for stent partial malapposition, the stent fracture was occurred. Because there is a risk that TLR increases in the fracture site, It is necessary to be conscious of over-dilation of the stent.