Retrograde-Antegrade Left Main Coronary Artery Stenting

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Recurrent ischemic symptoms are the most frequent reason for repeat revascularization in post coronary artery bypass artery (CABG) patients. Of the reported 8% per year of patients who suffer from recurrent ischemia, 5% annually are attributable to the progression of atherosclerosis in the native coronary arteries.^1–3
Repeat surgical intervention in this group of patients has been associated with a higher mortality rate than the initial CABG and a documented higher complication rate, lower angina relief^4–7 and the risk of compromising a functioning left internal mammary artery (LIMA) graft. Percutaneous intervention plays a very important role in this increasingly common clinical scenario. It has been proven safe and successful when applied to native vessels after CABG.⁸
Retrograde revascularization of a protected left main (LM) and other native coronary arteries has been previously documented,^9,10 but there is limited experience in a combined approach to achieve patency of a totally occluded LM artery. We described here a case that required such a method of intervention.

Case Report. The patient is a 55-year-old Caucasian male with a long history of hypertension and hyperlipidemia who underwent emergent surgical revascularization 4 months prior for critical LM disease. At that time, he had a LIMA grafted to the LAD, a saphenous vein graft (SVG) to the posterior descending artery and an additional SVG graft to the first diagonal. During his cardiac rehabilitation visits he developed worsening angina despite maximization of medical therapy. It was decided to bring the patient back to the cardiac catheterization laboratory with the intention of opening the LM artery to improve circulation to the circumflex artery which was not grafted. The diagnostic angiogram showed patent surgical grafts, with total occlusion of the LM artery which could not be cannulated despite the deployment of various diagnostic catheters (Figure 1). Cusp injections were also performed, but no further information about the LM ostium was obtained. The LAD showed a 90% stenosis proximal to the LIMA graft insertion which impaired the retrograde filling of the proximal LAD and the left circumflex artery territory, and the SVG to the diagonal did not fill retrogradely to the circumflex artery (LCx). The decision was made to intervene on the proximal LAD via the LIMA in order to provide retrograde filling of the circumflex artery. A LIMA catheter was used for engaging the LIMA graft, and with a Choice PT wire and a Voyager OTW 2.5 x 8 mm balloon, we were able to advance the wire retrogradely into the LAD. The wire was crossed over the total occlusion of the LM ostium and entered the ascending aorta (Figures 2 and 3). With the wire across the LM at the ostium of the vessel, we elected to attempt an antegrade intervention of the artery to avoid the foreseeable difficulties of retrogradely passing a stent into the proximal LAD. A 6 Fr arterial sheath was placed in the left femoral artery, and a Voda 3 guiding catheter was positioned coaxially and aligned with the LM artery. A second wire, Pilot 150, was then advanced antegradely into the LM (Figure 4). Once we had confirmed the position of this second wire in the LM and LAD, the balloon catheter and the Choice PT wire were removed from the LIMA. Through the Voda guiding catheter, we initially performed PTCA of the LM using a Voyager 3 x 12 mm balloon. Next, we deployed a 3.5 x 13 mm Cypher™ stent in the LM with its distal edge just before the trifurcation of this vessel into LAD, ramus and LCx . The angiographic results obtainedwere excellent, with restoration of flow in the LCx territory (Figure 5). The patient tolerated the procedure well, and was discharged from the hospital 24 hours after this intervention without complications. At the next follow-up visit, the patient was angina-free.

Discussion. This is a case that reflects a frequent problem in current interventional practice: percutaneous intervention in post-bypass patients. It required an innovative method in order to recanalize a recent total occlusion of the LM artery with an origin that could not be determined in an antegrade fashion, but was successfully reached retrogradely. There were no major problems crossing the lesion once the origin was confirmed, although the literature reports this as the first-line problem associated with chronic total occlusion (CTO),^11,12 with success rates that range from 40–81%. It proved to be a safe intervention on a protected LM occlusion. The patient received a sirolimus-eluting stent which, based on the current literature,¹³ may be an alternative therapy to surgical revascularization of patients with LM disease. Valgimigli¹⁴ reports an HR of 0.52 for major cardiovascular events in the drug-eluting stent (DES) group compared with bare-metal stent (BMS) patients who underwent intervention of the LM coronary artery (median follow up of 503 days). This finding is consistent with that of Chieffo15 who documented a 20% incidence of MACE at 6 months in LM DES patients compared with 35.9% in LM BMS patients. Both studies showed the efficacy of DES compared with BMS in this group of patients. The case described here demonstrates an unusual retrograde-antegrade approach to achieve a successful result in recanalizing a recent “flush occlusion” of the LM which could not be identified in the usual antegrade-only approach.