Clinical, angiographic and procedural characteristics of longitudinal stent deformation

Abstract

Recently, longitudinal stent deformation (LSD) has been reported increasingly. Even though the reported cases included almost all stent designs, most cases were seen in the Element™ stent design (Boston Scientific, Natick, MA, USA). It is considered that stent design, lesion and procedural characteristics play a role in the etiology of LSD. Yet, the effect of LSD on long-term clinical outcomes has not been studied well. Element stents implanted between January 2013 and April 2015 in our hospital were examined retrospectively. Patients were grouped into two according to the presence of LSD, and their clinical, lesion and procedural characteristics were studied. Twenty-four LSD's were detected in 1812 Element stents deployed in 1314 patients (1.83 % of PCI cases and 1.32 % of all Element stents). LMCA lesions (16.7 % vs 1.6 %, p < 0.001), complex lesions (75 % vs 35.1 %, p < 0.001), bifurcation lesions (37.5 % vs 18.3 %, p = 0.017), ostial lesions (33.3 % vs 12.8 %, p = 0.003), using of extra-support guiding catheter (54.2 % vs 22.3 %, p < 0.001) and extra-support guidewire (37.5 % vs 16.2 %, p = 0.005) were found to be more frequent in cases with LSD than in cases without it. In addition, the number of stents, stent inflation pressure and the use of post-dilatation were significantly different between the two groups. Two patients had an adverse event during the follow-up period. LSD is a rarely encountered complication, and is more common in complex lesions such as ostial, bifurcation and LMCA lesions. The use of extra-support guiding catheter, extra-support guidewires and low stent inflation pressure increases the occurrence of LSD. Nevertheless, with increased awareness of LSD and proper treatment, unwanted long-term outcomes can be successfully prevented.

Predictors and Long-Term Clinical Outcome of Longitudinal Stent Deformation

“…Therefore, a larger database to confirm the longterm clinical implication is needed. To date, the relationship 4,5,22 and these have been mostly single-center reports, did not apply any precise diagnostic criteria for LSD, and did not evaluate events beyond 1 year.…”

“…[1][2][3][4][5] The Promus Element stent has been the most frequently reported DES that is vulnerable to LSD, mainly because of its weakness against longitudinal forces which may be explained by its thin strut and offset peak-to-peak design.…”

“…[4][5][6][7] The location or complexity of lesion, mechanical effect of extra backup guiding catheter, and secondary devices such as postdilation balloons and intravascular ultrasound (IVUS) catheters were considered to be significantly related with LSD. 4,5,8,9 However, there are several short comings with these studies. First, reports have mostly been anecdotal, without a comprehensive systematic analysis including clinical, lesion, and procedural characteristics in various stent platforms.…”

“…In another study, LSD was significantly associated with the use of extra support guiding catheter or guidewire, or a passage of a second stent. 5 In addition, aggressive guide catheter manipulation, use of imaging devices including IVUS or optical coherence tomography, and multiple ballooning have been suggested as factors associated with LSD occurrence. 2,3,9,19,20 Our subgroup analysis also showed that any use of secondary devices was the single most important independent factor predicting QCA-based LSD, regardless of the lesion or stent factors.…”

Stent accordion phenomenon visualized with optical coherence tomography

“…It is possible that stents that are relatively undersized after initial deployment are subsequently 'caught' and distorted by secondary equipment that is passed into the coronary vessel with compression of the proximal edge of ostially placed stent with the guide catheter (4). It can be also induced by lesion complexity, secondary PCI equipment such as guidewires as well as the inherent mechanical properties of the stent itself (5). With regards to the stent platform, results of bench studies indicate that stent longitudinal strength, defined as the resistance to shortening or elongation, appears to be related to the number of connectors between hoops.…”