Under-deployment of extra-large drug-eluting stent: an adapted provisional technique for selected patients with distal lesions in large left main

In provisional technique, main vessel (MV) drug-eluting stent (DES) diameter is usually selected according to distal MV to reduce carina shift. Proximal optimization technique (POT) is used to expand the DES in the proximal MV. Occasionally, the size discrepancy between left main (LM) and left anterior descending artery (LAD) may be huge and this may cause stent malapposition and poor vessel wall coverage in large-sized LM. Recently, some manufactures designed extra-large DES to treat large vessels.We developed an "adapted" provisional strategy based on under-deployment of extra-large DES in case of major size mismatch between LM and proximal LAD. Bench tests were realized in appropriately designed LM bifurcation model using an extra-large DES (Onyx XL, Medtronic, Santa Rosa, CA, USA). This technique was adopted when such "rare" anatomy was found in our clinical practice.At bench test, Onyx XL 4.5 mm stent reaches 3.8 mm at 5-6 atmospheres, with favorable stent deformation achieved after POT, kissing balloon and re-POT. This technique was performed in 10 patients undergoing unprotected LM stenting with large LM and major mismatch toward LAD. Angiographic success was achieved in all cases and optical coherence tomography assessment was performed in 5 patients revealing optimal stent result. After a follow-up of 557 days (range: 90-1369 days), clinical course was uneventful in all treated patients.Under-deployment of extra-large DES is a technical option that can be considered to optimize the provisional stenting technique in selected patients with major diameter mismatch between large-sized LM and LAD.