The accordion phenomenon
A 65 year old man, with a history of non-insulin dependent diabetes, arterial hypertension, hyperlipidaemia, and coronary artery bypass graft surgery, presented with crescendo angina. Salient features on angiography include a normal left ventricular function (ejection fraction 82%), occlusion of the mid left anterior descending (LAD) artery, a 70% proximal stenosis in the first marginal, and occlusion of the second marginal branch of the left circumflex artery (panel A), occlusion of the left internal mammary graft to the first marginal, and a patent right internal mammary graft to the LAD. Percutaneous coronary intervention (PCI) to the first marginal branch was performed. Because of the tortuosity of the vessel, a 6 French Left Amplatz 2 guiding catheter and a heavyweight guide wire (ACS Hi-Torque) were chosen to successfully cross the stenosis. The stenosis was predilated up to 18 atm (Mercury 2.5 × 20 mm balloon, Jomed) and a drug eluting stent (Taxus 3.5 × 24 mm) was deployed at 18 atm. Angiography revealed a good result at the stented segment (10% stenosis); however, a new long 70% stenotic lesion just distal to the stent was observed (panel B). Administration of intracoronary glyceryl trinitrate had no effect. This “virtual stenosis”, however, disappeared when the guide wire was withdrawn (panel C), with the final angiography showing a good result with a normal distal vessel.
This case demonstrates the “accordion” or “concertina” phenomenon, caused usually by mechanical alteration of the geometry and curvature of a tortuous vessel by a stiff PCI wire, resulting in invagination and shortening of the vessel wall. The importance of recognising this cannot be overstated, as it stops unnecessary further PCI to an otherwise normal coronary segment.