Fig. 2

Longitudinal stent deformation (LSD) rates of different types of 4.0-mm-diameter stents following post-dilatation with a 5.0-mm noncompliant balloon. Six types of stents including the XIENCE Xpedition 4.0 mm × 28 mm, the Helios 4.0 mm × 28 mm, the Firehawk 4.0 mm × 29 mm, the BuMA 4.0 mm × 30 mm, the Nano Plus 4.0 mm × 29 mm, and the Excrossal 4.0 mm × 29 mm were subjected to an initial OCT examination after being deployed. Stent length 1 (SL1) of each stent was measured. Subsequently, each stent was subjected to a second OCT examination after post-dilatation by a 5.0-mm noncompliant balloon that measured stent length 2 (SL2). The LSD rate post-dilatation was calculated with the following formula: LSD rate = (SL2-SL1)/SL1 × 100%. The XIENCE Xpedition, Helios, Firehawk, and Nano Plus stents were slightly elongated in the longitudinal axis after high-pressure dilatation, and their average elongation rates were 2.82%, 3.09%, 5.88%, and 8.41%, respectively. The BuMA and Excrossal stents were slightly shortened in the longitudinal axis after high-pressure dilatation, and their average shortening rates were − 1.67% and − 2.58%, respectively (P < 0.05, n = 3)