CASE REPORT
A 40-year-old male smoker and tobacco chewer presented to the emergency department eight hours after onset of resting angina. The patient’s history was unremarkable without any record of similar symptoms experienced earlier. He also did not have a family history of ischemic heart disease. His physical examination revealed a heart rate of 116 beats/min, blood pressure of 90/66 mmHg, respiratory rate of 20 breaths/min, and oxygen saturation (SPO2) of 88%. Electrocardiography showed ST elevation in V2-V6, I, and aVL, suggestive of anterior wall myocardial infarction (AWMI). During hospitalization, the patient developed hemodynamically unstable ventricular tachycardia (VT) which was treated with DC cardioversion. The patient was immediately rushed to the cath-lab for primary PCI.
After engaging the LMCA with a 6F EBU 3.5 Launcher guiding catheter (Medtronic Inc, Minneapolis, USA) an occlusion within the LMCA was encountered. Initial considerations included the possibility of a dissection induced by the guide catheter or a complete thrombotic occlusion of the LMCA, given the absence of observable branches or distal vasculature beyond this occlusion point (Fig 1. & Video 1) . Due to complaints of persistent chest pain by the patient, cautious advancement of the workhorse guide wire was performed, leading to an extension of staining. Finally, the lesion was crossed using a Fielder FC guidewire (polymer jacket and hydrophilic wire, Asahi Intecc, Aichi, Japan) originally intended for wiring the left anterior descending artery (LAD) and achieving some flow (Fig. 2) , but ultimately went into a diagonal branch (Video 2) . As the thrombosuction catheter was unable to cross, the LMCA lesion was pre-dilated with a 2 x 10 mm semi-compliant balloon.
After establishment of partial blood flow within the LMCA (Fig. 2) , a 6 x10 mm aneurysm was discovered in the LMCA (Fig. 3 & Video 3) . The case was discussed with among the cardiothoracic surgical team. The decision was made to pursue revascularization using PCI. Two other Fielder FC wires were introduced into both the LAD and the ramus intermedius (RI). Dilation of the RI was also performed with a 2 x 10 mm semi-compliant balloon( Fig. 4 & Video 4) While both LAD and RI achieved thrombolysis in myocardial infarction (TIMI) grade I flow, efforts to wire the left circumflex artery (LCx) were unsuccessful (Video 5) . Consequently, a decision was made to employ a 5F TIG diagnostic catheter (Terumo Corporation, Shibuya -Ku, Tokyo) to perform an angiogram of the right coronary artery (RCA)s via the radial route. This imaging revealed the RCA was normal, however, a grade 3 retrograde collateral circulation was evident from the RCA to the LCx, suggestive of LCx chronic total occlusion (CTO) (Fig. 5 & Video 6) .
Our intended approach involved the placement of a covered stent in the LM-LAD. However, due to the delayed availability of the designated stent and the patient’s compromised hemodynamic state, a 3.5 x 20 mm Promus Elite stent (Everolimus Eluting Platinum Chromium Coronary Stent System, Boston Scientific Corporation, Marlborough, USA) was deployed from LMCA to LAD (Fig. 6 & Video 7) . Subsequent to stent implantation a 4 x 10 non-compliant balloon was employed for post-dilatation. This yielded improved blood flow in the LAD and diagonal. Notably, on intravascular ultrasound (IVUS) imaging, the LM aneurysm was visualized as a radiolucent shadow with layers and scintillating blood shadow surrounding the stent struts and the stent appeared to dangle, creating a potential nidus for thrombus formation (Fig. 7 & Video 8) .  In an endeavor to exclude the aneurysm, a 3.8 x 26 mm Graftmaster covered stent (Coronary Stent Graft System, Abbott Vascular, Santaclara, USA) was subsequently deployed from ostial LMCA, encompassing the LCx and small sized RI extending up to the LAD/diagonal bifurcation,(Video 9) and post-dilated with a 5 x 8 mm non-compliant balloon.
Finally, TIMI II flow in both LAD and diagonal was achieved(Fig. 8 & Video 10). Post procedure IVUS revealed bright echo reflection due to the covered stent and echo drop out was observed behind the multiple layers of stents (Fig. 9 & Video 11) . The patient was discharged on aspirin, clopidrogrel, rivoraxaban and high dose statin. At 3-month follow-up, angiography revealed TIMI III flow into the LAD and its branches (Fig. 10 & Video 12) and complete obliteration of the aneurysm. The patient’s symptoms improved, and he was symptomatically better.