Author + information
- Received April 7, 2016
- Revision received June 2, 2016
- Accepted June 15, 2016
- Published online September 26, 2016.
- Manuel Pan, MD∗ (, )
- Soledad Ojeda, MD,
- Elena Villanueva, MD,
- Jorge Chavarria, MD,
- Miguel Romero, MD,
- Javier Suarez de Lezo, MD,
- Francisco Mazuelos, MD,
- Jose Segura, MD,
- Francisco Carrasco, MD,
- Francisco Hidalgo, MD,
- Jose Lopez Aguilera, MD,
- Sara Rodriguez, MD,
- Miguel Puente, MD and
- Jose Suarez de Lezo, MD
- ↵∗Reprint requests and correspondence:
Dr. Manuel Pan, Servicio de Cardiología, Hospital Reina Sofía, Avenida Menéndez Pidal 1, 14004 Córdoba, Spain.
Objectives The study sought to compare the safety (resistance to damage) and efficacy (ability to cross the side branch) of polymer-coated and non–polymer-coated guidewires in the jailed wire technique used during the percutaneous treatment of bifurcation lesions.
Background The jailed wire technique is a useful strategy in the treatment of bifurcation lesions by provisional stenting. However, these wires can be damaged or even be broken during their removal.
Methods We performed a randomized study in patients with bifurcation lesions treated by provisional stenting. The jailed wire technique was mandatory, and the types of guidewires, polymer-coated (n = 115) and non–polymer-coated (n = 120), were randomized. After the procedures, the wires were evaluated by stereoscopic microscopy. The induced damage in the wires was classified as follows: no damage, mild, moderate, or severe.
Results The clinical characteristics were similar between patients treated with polymer-coated or non–polymer-coated wires. Polymer-coated wires were significantly (p < 0.001) more resistant to retrieval damage (only 2 wires showed mild damage) than were non–polymer-coated wires. However, 63 (55%) of the non–polymer-coated wires were damaged; 37 (32%), 24 (21%), and 2 (2%) had mild, moderate, and severe damage, respectively. Additionally, the jailed length of the wire was a factor contributing to the degree of wire damage. The time of side branch wiring was shorter in the polymer-coated wire group (19 ± 40 s vs. 42 ± 72 s; p < 0.05).
Conclusions Jailed wires during interventional procedures of bifurcation lesions commonly showed microscopic damage. Polymer-coated wires were more resistant to retrieval damage and were more efficient in crossing the side branch ostium than non–polymer-coated wires. (Jailed Wire Technique in the Treatment of Coronary Bifurcations Lesions With Stent: Stereoscopic Microscopy Study; NCT02516891)
The jailed wire technique is a useful strategy in the treatment of bifurcation lesions by provisional stenting. However, these wires can be damaged or even broken during their removal (1–10). Clinical guidelines recommend the use of provisional stenting (11); however, the jailed wire technique is not recognized. Additionally, in the technical specifications, the manufacturing companies do not admit this indication. As such, in cases of wire rupture, the operator is held responsible. On the basis of a previous microscopy observational study (12), we postulate that jailed polymeric wires are more resistant to retrieval damage than are nonpolymeric wires during the removal of the wires. The objectives of the current study were to identify the guidewire type that is more resistant to the retrieval maneuvers after jailing, determine anatomical and technical factors influencing induced damages on the guidewires, and evaluate the ability for different guidewires to cross the side branch (SB).
Study design and population
This trial was a prospective, randomized, single-blind study conducted in our center between 2012 and 2015 (NCT02516891). The study protocol was approved by the ethics committees of our center and was conducted according to the principles of the Declaration of Helsinki, revised in Seoul 2008, regarding investigations in humans. All patients provided written, informed consent for participation in the trial. Patients flowchart and study design are presented in the Figure 1.
All included patients met the following inclusion criteria: 1) patients with stable angina, acute coronary syndrome or inducible ischemia, who had a lesion located at major bifurcation point, regardless of morphology and angulation; 2) main vessel (MV) diameter ≥2.5 mm; 3) SB diameter ≥2.25 mm by visual estimation; and 4) any type of Medina classification. The following exclusion criteria were used: 1) patients with contraindications to 1-year antiplatelet therapy; 2) cardiogenic shock; and 3) coexisting severe comorbidities.
The primary endpoint was the evaluation of induced damage in the wires by stereomicroscope. The secondary endpoints were the following: 1) to determine anatomical and technical factors influencing the induced damages in the guidewire; 2) to evaluate the ability of different guidewires to cross the SB in terms of time in SB wiring and incidence of SB wiring failure; and 3) to compare the incidence of in-hospital events in each group.
After angiographies patients were randomized by telephone calls to an external office where a random allocation sequence was generated and the participants were assigned, via sealed opaque envelopes, to polymer-coated (Pilot 50 or Whisper MS models, Abbott Vascular, Abbott Park, Illinois) or non–polymer-coated wires (Balance Middle Weight or Floppy II models; Abbot Vascular) (Figure 1). The wiring of the MV was performed according to the preference of the operator. The wiring of the SB was always attempted according to the randomization process and the time required for this maneuver was recorded. Times exceeding 5 min were considered an SB wiring failure. Subsequently, the other wire type was used to accomplish the SB wiring. After MV stenting, the jailed wire was then removed, cleaned and sent to be analyzed. The technique for stent implantation has been previously described as a stepwise strategy (13). A final kissing balloon or sequential balloon post-dilation technique was performed according to the preference of the operator (14). For SB post-dilation or kissing balloon inflation, the jailed wire was removed before these maneuvers. Stenting of the SB origin was considered when a severe acute recoil or flow-limiting dissection occurred (coronary Thrombolysis In Myocardial Infarction flow grade <3). The patients were pre-treated with dual antiplatelet medication. In the hemodynamic laboratory, patients received a bolus of 100 IU/kg of intravenous unfractionated heparin. The administration of glycoprotein IIb/IIIa inhibitors was performed at the discretion of the operator. After the procedure, all patients received 100 mg/day of aspirin indefinitely, and standard doses of clopidogrel, prasugrel, or ticagrelor for at least 12 months. The baseline bifurcation anatomy was assessed according to the Medina classification (15). Quantitative coronary angiography measurements were performed using an offline computerized quantitative coronary angiographic system (CAAS system, Pie Medical Imaging, Maastricht, the Netherlands) in our core laboratory. An intravascular ultrasound was performed at the discretion of the operator. A serial determination of the troponin I levels was performed every 6 h during the first 24 h after the procedure. Periprocedural acute myocardial infarction (AMI) was defined as elevation of cardiac troponin (cTn) values (>5 × 99th percentile upper reference limit) in patients with normal baseline values (≤99th percentile upper reference limit) or as a rise in cTn values >20% if baseline values were elevated and had been either stable or falling (16). A second definition of relevant AMI within 48 h of the PCI was also used according to Moussa et al. (17) (cTn >70 times the local laboratory upper limit of normal, or ≥35 × upper limit of normal with new pathologic Q waves). After the procedure, the patients were monitored by telephone at 6 months, and yearly thereafter. Further cardiac catheterization was recommended in the presence of symptoms.
After the guidewires were withdrawn, they were cleaned with an aqueous solution and allowed to dry before analysis. The microscopic study was performed using an SMZ-800 stereomicroscope (Nikon Instruments, Melville, New York). This microscope was mounted with a parallel double lens and interchangeable objectives with a magnification range of 1.0× to 6.3× and a standard visual field of 3.5 to 22.0 mm. Microphotographs were acquired using a DS-Fi1 color camera (two-thirds inch, high-density charged coupled devices; 5.24 million pixels; Nikon Instruments). Recorded image sizes range from 2,560 × 1,920 pixels (maximum 10 frames/s) to 1,280 × 960 pixels (maximum 21 frames/s). A 100-W P-ICI2 coaxial episcopic illuminator (Nikon Instruments) was used to improve image quality. This device controls power and light intensity via an external transformer coupled by optical fiber. Low magnification was used to evaluate the first 40 cm of the distal end of the coronary guidewire and higher magnification was used to examine areas with suspected damage in more detail. The external and internal covers were examined for changes. Images were acquired of damage, which was graded into the following 5 categories: 1) no damage: the guidewire suffered no loss of integrity over its entire length; 2) slight damage: the external cover suffered a loss of integrity ≤2 mm (Figure 2); 3) moderate damage: the external cover suffered a loss of integrity >2 mm (Figure 3); 4) severe damage: visible changes to the inner part of the guidewire (Figure 4); and 5) fracture: discontinuity at some point along the guidewire.
The sample size calculation was on the basis of a previous observational study (11). The following assumptions were considered: 1) a 2-tailed test; 2) an alpha level of 0.05; 3) power equal to 80%; 4) a randomization ratio of 1:1; 5) a moderate-severe wire damage in polymer-coated wires was assumed to be 1%, versus 22% in non–polymer-coated wires. On the basis of the previous assumptions, a sample size of 200 patients was considered sufficient to demonstrate the superiority of polymer-coated wires.
The data are expressed as the mean ± SD. A Student-Fisher pair or unpaired t test was used to compare the means from the same patient or between different groups of patients. Differences between the proportions were studied using a chi-square or Fisher exact test, as appropriate. To identify anatomical and technical factors influencing induced damage on the guidewire, variables considered relevant by clinical judgment were introduced into a multivariate model. A forward stepwise logistic regression was then performed using the wire damage (moderate or severe) as the dependent variable. The following variables were introduced into the model: SB calcification, bifurcation angle, SB diameter, SB lesion length, MV diameter, MV lesion length, MV calcification, MV stent implantation pressure, and jailed length of the wire. All the statistical analyses were performed using SPSS 20.0.0 software (SPSS Inc., Chicago, Illinois). A p value <0.05 was considered to be statistically significant.
The baseline clinical and angiographic data are shown in Table 1. Most of the patients were admitted to the hospital in an unstable clinical condition. There were no significant differences between the groups in terms of age, sex, risk factors or clinical condition (Table 1). The bifurcation site was most frequently located at the left anterior descending artery or diagonal branch. The 2 groups did not significantly differ with respect to the bifurcation location or type of bifurcation lesion, according to the Medina classification (Table 2). The angiographic data were also similar between the groups, without significant differences in terms of vessel size, lesion length, minimal lumen diameter, or severity of the stenosis (Table 3). The procedural characteristics are summarized in Table 4. The lesions in the 2 groups were treated similarly. There were no additional significant differences between the groups with regard to technical aspects (Table 4).
During the jailed wire retrieval, no complete wire rupture was encountered. Polymer-coated wires were significantly (p < 0.001) more resistant to retrieval damage (only 2 wires showed mild damage) than were non–polymer-coated wires (Table 5). However, 63 (55%) of the non–polymer-coated wires were damaged (Table 5). Two of these wires (2%) showed internal fracturing (Figure 2).
We identified the jailed length of the wire as the only determinant factor of moderate-severe wire damage in the multivariate analysis (Table 6). Other factors such as the calcification of the vessel or the MV stent implantation pressure did not show significant differences between the groups (Table 6). The ability of the wires in crossing the SB is summarized in Table 7. The time required for SB wiring was shorter in the group of polymer-coated wires (Table 7). Additionally the inability for SB wiring was lower in the same group of patients. Only 1 polymer-coated wire did not cross to the SB, and despite the alternative use of non–polymer-coated wires by the operators, the wiring of the SB could not be completed. In 6 patients assigned to non–polymer-coated wires, SB wiring failed, but the operators were able to alternatively use polymer-coated wires. The in-hospital clinical events were similar between the groups (Table 7).
In-hospital outcome and angiographic results
Angiographic success (residual stenosis <30%) was obtained in all of the parent vessels. The quantitative angiographic data are summarized in Table 3. The mean minimal luminal diameter of the treated segments and the reduction in stenosis immediately post-procedure were similar in the MV and in the SB of both groups. The final residual stenosis at the MV and SB were nearly identical in both groups.
Three patients experienced a significant periprocedural AMI (17): 1 (1%) in the polymer-coated wires group and 2 (2%) in the non–polymer-coated wires group. There were no in-hospital deaths. There were no differences in the markers of myocardial damage after the procedure between the groups or in the incidence of periprocedural AMI (Table 7).
The mean follow-up time was 29 ± 13 months. Target lesion revascularization was required in 8 patients (3.4%): 4 (3.5%) from the polymer-coated group and 4 (2.3%) from the non–polymer-coated group. Mortality during this period occurred in 6 (5.2%) patients from the polymer-coated group and 5 (4.2%) patients from the non–polymer-coated group. The clinical course was very similar between both groups of patients, without any significant differences between in terms of clinical events. Table 7 summarizes the overall incidence of major events (death, AMI, or target lesion revascularization) in both groups.
In our study, we compared the safety (resistance to damage) and efficacy (ability to cross the SB) of polymer-coated and non–polymer-coated guidewires in the jailed wire technique during the treatment of bifurcation lesions by provisional stenting.
Our findings showed that polymer-coated wires were superior to non–polymer-coated wires.
Reasons to recommend the jailing wire technique
The jailing wire technique consists of leaving a wire in the SB while implanting a stent in the MV. This maneuver has been recommended by experts from the European Bifurcation Club (18–20) due to the following potential advantages: 1) the technique helps to keep the SB open and, in case of occlusion, the guidewire is the only marker of the SB position (Figure 5); 2) it facilitates the access to the SB by favorably changing the angle of the bifurcation; 3) the jailed wire is a modality of anchoring that facilitates the intubation of the guiding catheter, providing a firmer support for the balloon to cross the origin of the SB; and 4) in extreme situations, it can be used as a rescue procedure, to pass a low-profile balloon and dilate the SB. The intervention can be concluded with an inverted crush technique (21) or with a redilation of the crushed stent in the MV once the branch occlusion has been resolved. Interestingly, in the French multicenter TULIPE (Provisional T-stenting for Coronary Bifurcation Lesion Prospective Evaluation) study, the absence of this jailed wire was associated with a greater rate of reinterventions during follow-up (22).
Complications of the jailed wire technique
This technique is not free of complications. After MV stent implantation, the wire remains trapped between the MV wall and the metallic structure of the stent. Difficulties in the removal of these wires can occur, and although extremely infrequent, the complete fracture of the wire structure can occur (1–10). This is a high-risk complication that may require urgent surgery. The incidence of this event is difficult to estimate. Louvard et al. (1) observed an incidence of 4 jailed guidewire fractures in several hundred cases. Factors determining this complication have not been systematically studied. However, the calcification of the vessel wall, the length of the trapped wire, and a high pressure used at the MV stent deployment have been suggested as predictors of jailed wire rupture. The type of wire used is another important factor that can influence decisions made by the operator. In the first descriptions of the complication (1) the fractured wires were polymer coated, and for this reason these types of wires were not recommended for the jailed technique (1,20). Since then, most of the described fractured wires were non–polymer-coated wires (2,5,6,8,10), likely due to the higher use of these wires for this indication. Because wire fracture occurs very infrequently, many patients would be necessary for a comparative study between different types of wires to demonstrate the superiority of one over the other.
No jailed wire ruptures were reported. We used a surrogate variable of wire fracture (microscopic damage observed by stereoscopic microscopy). Because these damages had no correlation with clinical events, it may constitute a limitation of the study.
In the present article, we demonstrated that 28% of jailed wires suffered some degree of microscopic damage. Most of these wires were non–polymer coated. Additionally, polymer-coated wires were more efficient in crossing the SB ostium. These induced damages were not associated with clinical events, and there were no reported fractures. On the basis of these findings, polymer-coated wires can be recommended for this indication.
WHAT IS KNOWN? Wiring of the SB before MV stenting is recommended when the SB is deemed important by the operator (jailed wire technique). However, these wires can be damaged or even be broken during their removal. On the basis of the experience from experts polymer-coated wires should be avoided in this indication.
WHAT IS NEW? In jailed wire technique, polymer-coated wires were more resistant to the retrieval damage than non–polymer-coated wires. The wiring of the SB using polymer-coated wires was faster as compared with non–polymer-coated wires.
WHAT IS NEXT? Last-generation wires from different companies should be tested in this indication. Large registries could be potentially worthy.
This project was funded under the Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2008 to 2011, ISCIII (Instituto de Salud Carlos III Spain), PI12/00440, cofunded by FEDER (Fondo Europeo de Desarrollo Regional). Drs. Pan, Ojeda, and Suarez de Lezo have received minor lecture fees from Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Abbreviations and Acronyms
- acute myocardial infarction
- cardiac troponin
- main vessel
- side branch
- Received April 7, 2016.
- Revision received June 2, 2016.
- Accepted June 15, 2016.
- American College of Cardiology Foundation
- Louvard Y.,
- Lefevre T.,
- Morice M.-C.
- Balbi M.,
- Bezante G.P.,
- Brunelli C.,
- Rollando D.
- Levine G.N.,
- Bates E.R.,
- Blankenship J.C.,
- et al.
- Villanueva E.,
- Pan M.,
- Ojeda S.,
- et al.
- Thygesen K.,
- Alpert J.S.,
- Jaffe A.S.,
- et al.
- Moussa I.D.,
- Klein L.W.,
- Shah B.,
- et al.
- Latib A.,
- Colombo A.