YTC

YTC is a 78-year-old lady, with a history of type two diabetes and hypertension. She was admitted to our hospital for inferior ST elevation myocardial infarction, for which she was given intravenous thrombolytic therapy. Percutaneous coronary intervention (PCI) was done in the next morning and the culprit lesion over left circumflex artery were treated with two drug-eluting stents. She was scheduled for staged PCI for the left coronary artery lesions two weeks later.

Echocardiogram showed normal LV systolic function and valvular function.

Coronary angiogram showed diffuse severe stenosis over middle segment of the LAD, with 90% stenosis just before and after a sizeable diagonal branch. Left main was unremarkable and the recently implanted stents in LCX were patent. The RCA was non-dominant and small in diameter.

The ostium of LM was engaged with a 7 Fr EBU 3.5 catheter. A workhorse wire could not be delivered to distal part of the LAD as it selected towards the diagonal branch. We tried to wire the LAD with the assistance of an angulated microcatheter pulled back from the diagonal branch, without success. It was decided to attempt reverse wiring of the LAD from diagonal branch in view of the extreme angulation of the LAD takeoff. The usual reverse wiring technique (RWT) facilitated by dual lumen catheter was not used, as the bulky hairpin wire and catheter complex was unlikely to negotiate through the tight proximal lesion successfully without predilation. Instead we chose the microcatheter with an 120 degree tip. It was first delivered to the diagonal branch. A pre-shaped polymer-jacket hydrophilic-coated wire with a 90 degree reverse curve was inserted into the angulated microcatheter into a small side branch of the diagonal. They were pushed forward together to prolapse the wire, forming the reverse wire at the diagonal branch. The reverse wire was carefully pulled back until it jumped into the LAD. The microcatheter was advanced into the LAD and the reverse wire was exchanged into a workhorse wire. The heavily calcified mid-LAD lesions were treated with intravascular lithotripsy with 2.5 mm balloon followed by high pressure dilatation. It was then stented with a 2.5/38 DES and post-dilated with 2.5 mm and 3.00 mm non-compliant balloon at high pressure.

This case illustrated that a single lumen angulated microcatheter would be useful for wiring a side or main branch with a very acute angle. It could assist wiring directly or indirectly by reverse wiring technique. Compared to the more commonly used dual lumen catheter-assisted RWT, the single lumen angulated microcatheter has the advantage of a better crossing profile. In cases with severe stenosis proximal to the bifurcation, this technique can circumvent the need of pre-dilation that may risk compromising the opposite branch.