Our patient is a 79-year-old female has the history of 1.Left internal carotid artery stenosis s/p stenting on 2020/06,mRS＝0, 2.Hypertension, 3.Type 2 Diabetes mellitus and 4.Dyslipidemia whopresented with unstable angina. Initially, she experienced typical anginasymptoms and was under outpatient follow-up. However, her symptoms recentlyworsened, prompting a visit to the emergency department.

Previously,during outpatient follow-up, she underwent a myocardial perfusion scan, whichrevealed RCA infarction. In the LAD and LCx territories, the findings indicatedmixed ischemia and infarction. An echocardiogram showed a borderline LVEF of49%

LAD.AVI
LCx.AVI
RCA.AVI

Highlights: "CTO intervention of the LAD with retrograde rescue of a major diagonal branch, complicated by stent dislodgement during PCI." We attempted CTO intervention for the LAD by Fielder XT-A wire, and Caravel microcatheter. Angiography showed worsening stenosis at the ostium of a major diagonal branch then A 2.0 mm balloon dilatation was performed. We switched to a retrograde approach via the diagonal branch using a Sion wire and Caravel microcatheter, successfully crossing collaterals and puncturing the distal CTO cap with a Gaia Second wire. Antegrade wiring was achieved and a 2.75 × 38 mm stent was deployed with good LAD results. However, the diagonal branch still had significant dissection, though TIMI 3 flow was preserved. We then proceeded to treat the LCx CTO. Meanwhile, the diagonal branch worsened with slower flow. With dual guiding catheters, we wired both LAD and diagonal. Retraction also failed, as the stent could not be pulled back into the guiding catheter, likely due to poor coaxial alignment damaging the proximal edge. The stent was moved to the femoral region, where balloon-assisted retrieval was unsuccessful. A Snare Technique finally allowed stent removal, but diagonal wires were lost. A retrograde approach from the LAD into the diagonal achieved externalization with TAP for  diagnoal lesion
Rescue D1 retrograde.AVI
Snare Technique.AVI

CTO intervention of the LAD with retrograde rescue of a major diagonal branch was complicated by stent dislodgement. Two key lessons were learned. First, angiography should include careful assessment of all vessels, not only the target, especially when unstable lesions are present. Diagonal ostium dissection highlighted the need for early recognition, retrograde rescue, and sometimes a two-stent strategy for significant side branches. Second, total stent loss is a critical complication with the guidewire in situ. Prompt recognition and proper retrieval—snaring for proximal loss or multiwire for proximal to mid-vessel—are essential to reduce risk and achieve procedural success.