Longitudinal Stent Elongation Research Articles

Longitudinal Stent Elongation: A Rare Complication of Third-Generation Drug-eluting Stent Platform

Abstract Longitudinal stent deformation (LSD) is an infrequent complication of percutaneous coronary intervention. While the occurrence of gross LSD is a rare phenomenon, minor changes in length are common and have been recognized as accepted behavior of stents during implantation. Due to the proximity of the guide catheter, ostial or ostio-proximal lesions are prone to stent deformation either by the guide or other devices during navigation. Moreover, to satisfy the fractal geometry of coronary bifurcation, the proximal optimization technique is commonly performed during different bifurcation procedures, which can subject the stent to extreme overexpansion resulting in structural deformation. We describe two cases of longitudinal stent elongation during ostial deployment and try to analyze the factors behind this rare, yet complicated behavior of the latest-generation drug-eluting stent.

Longitudinal Stent Elongation Due to Inappropriate Post-Dilatation - Insight From a Bench Test.

Longitudinal Stent Elongation Due to Inappropriate Post-Dilatation - Insight From a Bench Test.

TCT-271 Incidence and Predictors of Longitudinal Stent Elongation: Insights From Pooled Analysis of Indian Single Centre Drug-Eluting Stent Cohort

TCT-271 Incidence and Predictors of Longitudinal Stent Elongation: Insights From Pooled Analysis of Indian Single Centre Drug-Eluting Stent Cohort

Longitudinal stent elongation or shortening after deployment in the coronary arteries: which is dominant?

BackgroundStent manufacturers always record stent shortening data while they do not record stent elongation data. The aim of this study is to identify both stent shortening and elongation occurring after deployment in the coronary arteries and know their percentage.ResultsThe length of coronary stents was measured by intravascular ultrasound (IVUS) by (1) edge-to-edge (E-E) length, measured from the appearance of the first distal strut to the last proximal strut, and (2) area-to-area (A-A) length, measured from the first distal struts seen at more than one IVUS quadrant to the last proximal struts seen at more than one IVUS quadrant. Stent shortening was defined as both E-E and A-A lengths were shorter than the manufacturer box-stated length (shortened group). Stent elongation was defined as both E-E and A-A lengths were longer than the manufacturer box-stated length (elongated group), otherwise unchanged group. Consecutive 102 stents deployed in ischemic patients were included. Stent elongation was detected in 67.6% (69 stents), and shortening was detected in 15.7% (16 stents), while unchanged stents were detected in 16.7% (17 stents). Although the 3 groups had similar box-stated length and predicted foreshortened length, they had significantly different measurements by IVUS, p<0.001 for each comparison. Differences from box-stated length were 1.9±1.4mm, −1.4±0.4mm, and 0.4±0.3mm, respectively, p<0.001. The elongated group had significantly longer differences from the corresponding box-stated and predicted foreshortened lengths, while the shortened group had significantly shorter differences from the corresponding box-stated length and similar foreshortened length. By multinomial regression analysis, the plaque-media area and stent deployment pressure were the independent predictors of the stent length groups, p=0.015 and p=0.026, respectively.ConclusionsChange in stent length is not only shortening—as mentioned in the manufacturer documents—but also stent elongation. Stent elongation is dominant, and the most important predictors of longitudinal stent changes are plaque-media area and stent deployment pressure.

Effectiveness of the proximal optimization technique for longitudinal stent elongation caused by post-balloon dilatation.

To evaluate the effectiveness of the proximal optimization technique (POT) to prevent longitudinal stent elongation. The mechanism of stent elongation, which occurs after post-balloon dilation, is still unclear. A total of 103 lesions treated with optical coherence tomography guided coronary intervention between May 2013 and November 2017 were retrospectively analyzed. Lesions were divided according to the circumferential degree of malapposition at the stent edge immediately after deployment into well-apposed group (<180°) and malapposed group (≥180°). Post-dilation was performed from distal to proximal within the stent until August 2016 (non-POT cohort), and POT was applied thereafter (POT cohort). In the POT cohort, post-dilation was done at the proximal portion of the stent with sufficiently large balloon to minimize malapposition followed by distal dilatations. Stent elongation length was defined as the change in stent length from stent deployment to after post-dilatation. In the non-POT cohort, 72 lesions, including 54 lesions in the well-apposed group and 18 in the malapposed group were analyzed. Stent elongation length was significantly longer in the malapposed group than in the well-apposed group (1.51 ± 1.34 mm vs 0.13 ± 0.84 mm, P < 0.01). In the POT cohort, 31 lesions including 21 in the well-apposed group and 10 in the malapposed group were analyzed. Stent elongation length was not significantly different between the groups (-0.09 ± 0.91 mm vs 0.30 ± 0.99 mm, P = 0.29). Malapposition of the stent edge is responsible for longitudinal stent elongation caused by post-dilatation. POT appeared to effectively prevent longitudinal stent elongation.

Impact of post-dilatation on longitudinal stent elongation: An in vitro study

ObjectivesTo evaluate whether balloon inflation for post-dilatation causes longitudinal stent deformation (LSD). Methods and resultsTwo stents, sized 2.5mm×28mm and 3.5mm×28mm (Nobori®, biodegradable polymer biolimus-eluting stent; Ultimaster®, biodegradable polymer sirolimus-eluting stent; Terumo Co., Tokyo, Japan), were deployed at nominal pressure in straight and tapered silicon vessel models. Then, post-dilatation was performed in two ways: dilatation from the distal (D-P group) or proximal (P-D group) side of the stent. Microscopic findings showed that the stents were elongated during every step of the procedure regardless of the post-dilatation method and type of vessel model. The D-P group showed linear elongation during each step of post-dilatation (straight model: 28.7±0.3mm vs. 29.9±0.3mm, p=0.002; tapered model: 28.0±0.1mm vs. 29.9±0.1mm, p<0.001). In contrast, in the P-D group, the most significant change was observed in the first step of post-dilatation and only slight changes were observed thereafter (straight model: 28.6±0.1mm vs. 29.5±0.1mm, p<0.001; tapered model: 28.2±0.1mm vs. 29.5±0.1mm, p<0.001). Optical frequency domain imaging analysis showed that the frequency of stent strut malapposition was positively correlated with the percentage change in stent length (r=0.74, p<0.0001). ConclusionLSD was observed during every step of post-dilatation in both the straight and tapered vessel models. However, some differences were observed between the D-P and P-D groups. Minimizing stent strut malapposition may reduce the risk of LSD.

TCTAP C-262 Acute Coronary Syndrome Resulted in Longitudinal Stent Elongation During Post-dilatation with Semi-compliant Balloon and Subsequent Thrombus-shift Derived from Culprit Lesion

TCTAP C-262 Acute Coronary Syndrome Resulted in Longitudinal Stent Elongation During Post-dilatation with Semi-compliant Balloon and Subsequent Thrombus-shift Derived from Culprit Lesion

TCTAP C-116 Longitudinal Stent Elongation from ‘LAD' to ‘LMCA' During Retraction of Entrapped Jailed Guidewire from Diagonal Side Branch

### Patient initials or identifier number PS ### Relevant clinical history and physical exam Mr. PS 37 years non-diabetic, non-hypertensive male presented with exertional chest pain (CCS-Class-II) for 3 months. He is smoker, dyslipidaemic and hyperuricaemic. His mother died suddenly at the age of

TCTAP A-142 Longitudinal Stent Elongation: Is Stent Elongation Occurs in Our Daily Practice?

We experienced two cases of longitudinal stent elongation (LSE) during stent deployment and disclose that LSE occurs when stents were expanded in air pressure and in malapposition vessel models. Following tests were performed to disclose the occurrence LSE. Test1: Five kinds of drug eluting stents

Longitudinal stent deformation elongating to left main trunk

A 67-year-old woman was admitted with an acute coronary syndrome. Angiographic examination revealed diffuse severe stenosis of the left circumflex artery. A Pressure Wire Certus (St. Jude Medical, St. Paul, MN, USA) was passed to the second post-lateral (PL) branch. To prevent side-branch occlusion, a SION wire (Asahi Intecc Co., Aichi, Japan) was left in the first PL branch, and a SION blue wire (Asahi Intecc) was placed in the second obtuse marginal branch. We implanted an everolimus-eluting stent (PROMUS Element 2.5×24mm, Boston Scientific, Natick, MA, USA) in the culprit lesion. After retrieving the protection wire in first PL branch with resistance, we performed post-dilatation. However, the intravascular ultrasound images showed that the proximal portion of the implanted stent had elongated approximately 2mm to the left main trunk (LMT), although the position of the distal edge of the stent was unchanged. We decided to additionally place a stent from the ostium of the LMT to the proximal left anterior descending coronary artery, and a biolimus-eluting stent (NOBORI 3.0×18mm, Terumo Co., Tokyo, Japan) was implanted successfully. Longitudinal stent elongation might be caused by the small number of links between the hoops of a stent, originally intended to improve deliverability.

Impact of longitudinal stent elongation during percutaneous coronary intervention

Background: Longitudinal stent deformation is one of the hottest topics. We experienced a case of stent elongation during stent deployment. Considering this, the following tests were performed. Methods: Four kinds of drug eluting stents (DES: Xience Prime (XP), Plomus Element (PE), Nobori (N) and Cypher select plus (CY)) with three 3x28mm stents of each were used for each test. In test 1, all stents were dilated five times at rated burst pressure (RBP) in air pressure. In test 2 and 3, all stents (except CY in test 3) were implanted in a tapered phantom model with the proximal and distal diameter being 3.5mm and 3mm respectively, at nominal pressure and single post-dilation to proximal portion of the stents was performed with RBP using 3.5x15mm semi-compliant balloon (SC) (Test 2) and 3.5x15mm high-pressure balloon (HP) (Test 3). Stent length before and after each tests were measured. To disclose the relationship between stent elongation and the types of balloon catheters (BC) used, four SC (A to D) and three HP (E to G) were also tested. Three 3mm BC with two types of the length were tested (short: 15mm in SC and 8-10mm in HP, long: 20mm in SC and 15mm in HP). All BC were inflated at nominal pressure and RBP in air pressure and the change of length (%) were checked. Results: Lengths of stent elongation was significantly different between all DESs in Test 1. However, no significant difference was observed in test 2 and 3 except for CY (Table 1). All BC elongated with RBP inflation in significantly different rates, however, similar results between short BC and long BC were observed (Table 2). View this table: Table 1. Elongation of DESs View this table: Table 2. Elongation of BC Conclusion: Longitudinal stent elongation was observed in all kinds of DESs tested, especially in new generation stents. We must considerer this phenomenon when deploying stents, especially long ones.

Insights into longitudinal stent elongation phenomenon after high pressure additional post stent dilatation from bench testing

Objective: To evaluate how post stent dilatation with large balloons has impact on stent elongation. Methods: Four kind of stents (Fig1-b) were deployed into a silicon tube model; 10mm of one side of the stent was attached to the model wall and 10mm on the opposite side of the stent was free from the vessel wall (Fig1-a). Then, in each model, post stent dilatation (PD) (Fig1-b) was performed with four different kind of 3.5mm balloons at nominal (NP) and rated balloon pressure (RP). A total of 16 stents were tested, and difference of degree of stent elongation in the stent portion which was free from the wall (delta stent length) was measured and compared among different kind of stents and different kind of balloons. Furthermore, four kind of deployed stents were also dilated three times at RP to evaluate the impact of repeated dilataton on stent elongation. Result: Stent elongation was observed in all models. Delta stent length before and after PD at NP and RP were 0.41±0.15mm and 1.15±0.37mm, respectively. Compared with different four kind of stents, there was no significant difference in delta stent length before and after PD at both NP and RP (p=0.58, 0.96, respectively), however compared with different four kind of post dilatation balloons, significant difference in delta stent length before and after PD was observed at both NP and RP (p=0.016, <0.001, respectively). Moreover, repeated post dilatation led to delta stent length was getting longer in all stents, and the degree may also depends on difference kind of stents. ![Figure][1] Conclusion: Stent elongation after post stent dilatation was observed in this ex vivo model which may be mainly influenced by the type of post dilatation balloons and dilatation pressure. Repeated post dilatation may have an effect on aggravation of stent elongation. [1]: pending:yes

Impact of Longitudinal Stent Elongation During Percutaneous Coronary Intervention

Longitudinal stent deformation is one of the hottest topics these days. We met stent elongation during percutaneous coronary intervention (PCI). The bench test was done to clarify the stent elongation during PCI.