Successful percutaneous coronary intervention to the left anterior descending artery in-stent chronic total occlusion via the left internal mammary artery graft: a case report

Background: Percutaneous coronary intervention (PCI) via left internal mammary artery (LIMA) graft is technically challenging, requires special consideration due to association with potential complications and therefore, infrequently performed. Data on in-stent chronic total occlusion (CTO) PCI via the LIMA graft is even rarer.

Case summary: A 59-year-old male with a background history of coronary artery bypass graft surgery and previous PCI, presented with progressive chest pain on mild exertion, in the setting of a chronic coronary syndrome. Transradial coronary angiography revealed significant native three-vessel disease with CTO of right coronary, left anterior descending (LAD) and left circumflex arteries. Left internal mammary artery-LAD was widely patent. The previous LIMA-LAD stent at the anastomosis had a CTO with severe in-stent restenosis (ISR) at the distal end of the stent in the native LAD. The distal LAD was filled from bridging collaterals. Following discussion at the heart team meeting, he underwent successful complex PCI of LAD CTO via the LIMA graft at the site of ISR of previous LIMA-LAD anastomosis stent, which was finally treated with drug-coated balloon (DCB) angioplasty.

Discussion: Recurrent angina post-coronary revascularization can be very challenging to manage by medical therapy alone. Percutaneous intervention of complex coronary lesions in these patients requires experience and skill, especially when approaching lesions using the LIMA as a conduit. The use of DCB for ISR management is a well-known strategy; however, adequate lesion preparation is the key to satisfactory outcome.