Chronic Stent Recoil of Different Design of Stents: An Intravascular Ultrasound Study

Lee, Nae Hee; Hong, Myeong Ki; Park, Seong Wook; Lee, Cheol Whan; Kim, Young Hak; Cho, Goo Young; Nah, Deuk Young; Kang, Duk Hyun; Song, Jae Kwan; Kim, Jae Joong; Park, Seung Jung

Abstract

BACKGROUND: The chronic stent recoil of Palmaz-Schatz stent was minimal. However, the chronic stent recoil of other types of stents has not been determined. We evaluated the chronic stent recoil of different design of stents.
METHODS
Serial (after stent implantation and follow-up) intravascular ultrasound images using automatic transducer pullback devices were obtained in 70 native coronary artery lesions: slotted-tube design of Palmaz-Schatz stent 30 and NIR 10, sinusoidal ring design of GFX 20, and coil design of CrossFlex 10. Measurements of stent cross-sectional area (CSA) (4 image slices in Palmaz-Schatz stent and 7 image slices in GFX, NIR and CrossFlex) using computerized planimetry were performed. Stent CSA post-stenting and follow-up was compared to evaluate the chronic stent recoil of different designs of stent. The chronic stent recoil (%) was defined as (post-intervention-follow-up) stent CSAx100/post-intervention stent CSA.
RESULTS
The changes of stent CSA between post-intervention and follow-up period were minimal in NIR stent, Palmaz-Schatz and GFX. However, there was significant reduction of stent CSA in CrossFlex stent. Compared with other types of stents, the changes of stent CSA were significantly larger in CrossFlex stent (p=0.001). The chronic stent recoil was significantly larger in CrossFlex stent than in other types of stents (4.0+/-6.0% vs 0.7+/-5.8% in GFX stent, 0.4+/-5.0% in Palmaz-Schatz and 0.3+/-3.0% in NIR, p=0.001, respectively). There were no significant differences of chronic stent recoil among GFX, NIR and Palmaz-Schatz stent.
CONCLUSIONS
The chronic stent recoil was minimal in slotted-tube and sinusoidal ring designs of stent. However, there was significant chronic stent recoil in coil design of stent.