Abstract
Aims: This study aimed to assess the clinical efficacy of intravascular ultrasound (IVUS)-guided intraplaque wiring for femoropopliteal (FP) chronic total occlusion (CTO).
Methods: This single-center, retrospective, observational study was performed at the Japanese Red Cross Kyoto Daini Hospital. From March 2013 to June 2017, a total of 75 consecutive patients (mean age: 75.4±8.5 years; 59 males), who underwent endovascular treatment (EVT), having 82 de novo FP-CTO lesions, were enrolled in this study. Eleven of the lesions that met the exclusion criteria were excluded, and the remaining 71 lesions were divided into the IVUS-guided wiring group (n=34) and non-IVUS-guided wiring group (n=37). Primary patency, defined as a peak systolic velocity ratio of ＜2.4 on duplex ultrasonography, and freedom from clinically driven target lesion revascularization (CD-TLR) at 12 months were the primary outcomes.
Results: The mean lesion length was 21.6±8.9 cm. The frequencies of primary patency and freedom from CD-TLR were significantly higher in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (70.0% vs. 52.2%, p=0.045; 83.9% vs. 62.8%, p=0.036, respectively). The complete clinically true lumen angioplasty rate was also higher in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (91.1% vs. 51.3%, p＜0.001, respectively). The clinically true and false wire passage rates were respectively 97.3% and 2.7% in the IVUS-guided wiring group.
Conclusion: IVUS-guided wiring improves the clinical outcomes of EVT for FP-CTO by achieving a high clinically true lumen wire passage rate.
Introduction
Recently issued guidelines regarding peripheral arterial disease recommend an endovascular-first strategy for femoropopliteal (FP) lesions of ＜25 cm in length, including cases of chronic total occlusion (CTO)
1)
. However, there is no consensus regarding the optimal wire passage route for the recanalization of FP-CTO. Previous studies have demonstrated that the intraluminal approach did not improve the clinical outcomes of endovascular treatment (EVT) for FP-CTO lesions compared with the subintimal approach
2-
4)
. Recently, Kawasaki et al. proposed that CTO wire passage routes should be classified into the intraplaque, subintimal, and intramedial routes based on intravascular ultrasound (IVUS) examinations (
Fig.1)
5)
. They demonstrated that attempts to perform the wire loop technique with a 0.035 inch guidewire via the subintimal approach did not always result in the subintimal or intramedial route being taken. Conversely, Mori et al. reported that attempts to perform the drilling technique using a 0.014 inch guidewire via the intraluminal approach did not always result in the intraplaque route being taken
6)
. They also revealed that the intramedial CTO wire passage route is an independent risk factor for restenosis. There have not been any reports about the usefulness of IVUS-guided wiring for FP-CTO lesions with regard to the IVUS-guided approach.
Aim
In this study, we examined the clinical usefulness of an IVUS-guided wiring technique. We also investigated how often an intraplaque or subintimal wire passage route was achieved and intramedial route was avoided when this technique was performed.
Methods
Study Design and Patient Population
This single-center, retrospective, observational study was performed at the Japanese Red Cross Kyoto Daini Hospital. The study protocol was developed according to the Declaration of Helsinki and was approved by the ethics committee of our hospital. Written informed consent for the EVT was obtained from all patients who were enrolled in this study.
From March 2013 to June 2017, a total of 75 consecutive patients having 82 de novo CTO lesions were retrospectively enrolled in this study. The inclusion criteria were symptomatic patients with Rutherford class categories 2 to 5 disease, who presented with de novo CTO of the FP segment. The exclusion criteria were comorbid common femoral artery (CFA) stenosis and isolated popliteal artery occlusion. Eleven of the lesions that met the exclusion criteria were excluded. The remaining 71 lesions (64 patients) were divided into the following two subgroups according to whether or not IVUS-guided wiring was performed: the IVUS-guided wiring group (34 lesions in 31 patients) and the non-IVUS-guided wiring group (37 lesions in 33 patients) (
Fig.2)
.
Definitions
Regarding the wire passage route, intraplaque, inside the plaque; subintimal; between the plaque and media; intramedia; and between the media and adventitia were the original Kawasaki’s classification. However, the three classifications are slightly complicated for clinical use, and the clinical significance of the intraplaque and the subintimal wire passage route are difficult to differentiate. Therefore, in this study, this classification was reclassified into two subgroups: clinically true lumen, intraplaque and subintimal, and clinically false lumen, intramedia.
Procedure
All of the patients received dual antiplatelet therapy (100 mg/day aspirin and 75 mg/day clopidogrel or 200 mg/day cilostazol) before the procedure. The EVT procedures were performed by interventional cardiologists that had been certified by the Japanese Association of Cardiovascular Intervention and Therapeutics. The initial antegrade approach site was the contralateral or ipsilateral CFA, and a 6-F sheath was inserted. Five thousand units of unfractionated heparin (UH) was injected via the inserted sheath, and additional UH was administered every 60 min to maintain an activated clotting time of 250 to 300 s. To cross the target lesion, a 0.014 inch guidewire was used with the support of a 5.5- or 6-F guiding catheter for the IVUS-guided wiring and a microcatheter for the non-IVUS-guided wiring. If the antegrade approach failed, a retrograde approach was applied using a distal puncture or transcollateral angioplasty, as described previously
7-
11)
. In the retrograde approach, the wire rendezvous technique was used to achieve wire externalization
12)
. After a guidewire had been passed through the target lesion, pre-dilation was performed using a 2.0 or 3.0 mm balloon, before an IVUS evaluation was conducted. The lesions were treated using balloon angioplasty with an optimally sized balloon or provisional stenting with a bare Nitinol stent (BNS), drug-coated stent (DCS), or a stent graft. The size of the balloon or stent was determined based on the external elastic membrane (EEM) area at the distal reference site. Post-dilation was performed if residual stenosis of ＞50% was present.
Guidewire Selection
In both wiring strategies, a polymer jacketed guidewire with low penetration force (tip load: 1–3 g) was used as an initial guidewire. If this could not advance because of the hard plaque, guidewire escalation to an intermediate (tip load: 6–12 g) or high penetration (tip load: 15–45 g) force with hydro coating was performed. In the case of IVUS-guided parallel wiring, tapered intermediate or high penetration force guidewire was used to advance the guidewire forcibly in the intended direction.
IVUS-Guided Wiring
The IVUS-guided wiring strategy is shown in
Fig.3
. In the first step, a 0.014 inch guidewire with an IVUS catheter (Eagle Eye short tip; Volcano Corporation, Rancho Cordova, CA, USA) inside a 5.5- or 6-F guiding catheter was advanced using the drilling technique, and then, an IVUS examination was performed immediately. If the IVUS catheter and/or the guiding catheter could not advance, the balloon anchor technique
13)
was then performed using a 2.0 or 3.0 mm short balloon to advance the system. When the first system entered into the subintimal or intramedial space, the IVUS-guided parallel wiring technique was applied to advance a second guidewire into the intraplaque region using IVUS images obtained via the first wire. If the second step failed, retrograde wiring was performed using a 0.014 inch guidewire with a microcatheter under antegrade IVUS guidance.
IVUS Data Analysis
The IVUS data analysis was performed by two experienced cardiologists using the s5 Imaging System (Volcano Corporation, Rancho Cordova, CA, USA). Regardless of whether IVUS guide wiring was performed or not, IVUS evaluation of the following vascular parameters was performed for all lesions after passing through the guidewire as described previously
5,
6)
. Briefly, the IVUS catheter was manually pulled back at 1 cm/s under fluoroscopy with reference to a ruler. Fluoroscopy at the time of IVUS recording was stored so that the positional relationship between the IVUS catheter and the lesion could be known at the time of analysis. The measured IVUS parameters were the CTO wire passage route, which was classified into the intraplaque, subintimal, and intramedial routes; the cross-sectional EEM area at the proximal and distal reference sites; the post-procedural minimum lumen area (MLA); and post-procedural axial lumen eccentricity ratio (the ratio of the long-axis diameter to the short-axis diameter).
Outcomes
The primary outcomes of this study were the primary patency rate, which was defined as a peak systolic velocity ratio of ＜2.4 on duplex ultrasound, and the percentage of patients that were freedom from clinically driven target lesion revascularization (CD-TLR) at 12 months after the initial treatment. The other examined outcomes included the procedure time, radiation exposure time, the frequency of retrograde access, and the amount of contrast media used. These parameters were compared between the IVUS-guided and non-IVUS-guided wiring groups.
Statistical Analyses
The statistical analyses were performed on an intention-to-treat basis. Continuous variables are reported as mean±SD values. Categorical variables are shown as percentages. Continuous variables were compared using the unpaired Student’s t-test, and categorical variables were compared using the chi-square test or Fisher’s exact test. Time-dependent parameters were analyzed using the Kaplan–Meier method. For the analyses of primary and other outcomes, the groups were compared using the log-rank test. Statistical significance was defined as a p-value of ＜0.05. All statistical analyses were performed using JMP software (version 10.0.0, SAS Institute, Cary, NC, USA).
Results
The overall success rate of the procedure was 95.9%. The success rates of the IVUS-guided wiring group and non-IVUS-guided wiring group were 97.1% and 94.8%, respectively (p=0.487). Moreover, the success rate of antegrade wiring was higher in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (82.3% vs. 56.7%, p＜0.001) (
Table 1)
. Among all 22 bidirectional wiring cases, distal puncture was performed in 19 cases (distal superficial femoral artery [SFA]: 10 cases, popliteal artery [POP]: eight cases, high-tibial puncture: one case), and the transcollateral approach was applied in three cases.
Table 1.
Frequencies of the antegrade and bidirectional approaches
|
Overall (n = 71)
|
IVUS-guided cohort (n = 34)
|
Non-IVUS-guided cohort ( n = 37)
|
P-value
|
| Antegrade approach, % (n)
|
69.0 (49) |
82.3 (28) |
56.7 (21) |
＜0.001 |
| Bidirectional approach, % (n)
|
30.9 (22) |
16.7 (6) |
42.1 (16) |
|
Data are shown as absolute (percentage) values.
IVUS, intravascular ultrasound
Patients and Lesion Characteristics
The patients’ background data are shown in
Table 2
. The patients’ mean age was 75.3±8.7 years. Regarding the patients’ underlying conditions, 48% of patients had diabetes mellitus, 17% of patients had chronic kidney disease, and 32% of patients presented with chronic limb-threatening ischemia. These variables did not differ significantly between the IVUS-guided and non-IVUS-guided wiring groups. The characteristics of the lesions are presented in
Table 3
. The mean lesion length, CTO length, and reference site diameter were 21.6±8.9 cm, 16.4±9.6 cm, and 5.5±0.7 mm, respectively. The frequencies of Trans-Atlantic Inter-Society Consensus (TASC II) type C or D lesions and severe calcification, which was defined as peripheral arterial calcium scoring system
14)
grade 3 or 4 calcification, were 76% and 31%, respectively. The mean pre-procedural and post-procedural ankle–brachial index values were 0.56±0.14 and 0.90± 0.14, respectively. There were no significant differences in these variables between the two groups. Regarding the final devices used, plain old balloon angioplasty (POBA), BNS, and DCS were applied in 8%, 75%, and 14% of cases, respectively. The frequency of BNS use tended to be higher in the non-IVUS-guided group; however, the difference was not statistically significant (p=0.135).
Table 2.
Baseline patient characteristics
|
Overall (n = 71)
|
IVUS-guided cohort (n = 34)
|
Non-IVUS-guided cohort (n = 37)
|
P-value
|
| Age (years) |
75.3±8.7 |
75.1±8.3 |
75.6±9.3 |
0.822 |
| Male, % (n)
|
73.2 (52) |
79.4 (27) |
67.6 (25) |
0.113 |
| Diabetes mellitus, % (n)
|
47.8 (34) |
52.9 (18) |
43.2 (16) |
0.251 |
| Hypertension, % (n)
|
80.2 (57) |
82.4 (28) |
78.4 (29) |
0.554 |
| Dyslipidemia, % (n)
|
63.3 (45) |
70.6 (24) |
56.8 (21) |
0.089 |
| CKD (＜60 mL/min/1.73 m2), % (n)
|
16.9 (12) |
20.6 (7) |
13.5 (5) |
0.264 |
| Daily hemodialysis, % (n)
|
5.6 (4) |
8.8 (3) |
2.7 (1) |
0.116 |
| History of smoking, % (n)
|
42.2 (30) |
44.1 (15) |
40.5 (15) |
0.668 |
| History of CAD, % (n)
|
60.5 (43) |
67.6 (23) |
54.4 (20) |
0.100 |
| History of CVD, % (n)
|
28.1 (20) |
20.6 (7) |
35.1 (13) |
0.055 |
| CLTI, % (n)
|
32.3 (23) |
26.5 (9) |
37.8 (14) |
0.151 |
Continuous data are presented as the mean ± standard deviation. Categorical data are shown as absolute (percentage) values.
IVUS, intravascular ultrasound; CKD, chronic kidney disease; CAD, coronary artery disease2; CVD, cerebrovascular disease; CLTI, chronic limb-threatening ischemia
Table 3.
Lesional, procedural, and clinical characteristics
|
Overall (n = 71)
|
IVUS-guided cohort (n = 34)
|
Non-IVUS-guided cohort (n = 37)
|
P-value
|
| Lesion characteristics |
21.6±8.9 |
22.3±9.8 |
20.9±8.2 |
0.522 |
| Lesion length, cm |
|
|
|
|
| CTO length, cm |
16.4±9.6 |
16.7±11.1 |
16.0±8.2 |
0.756 |
| Reference site diameter, mm |
5.5±0.7 |
5.7±0.8 |
5.3±0.7 |
0.052 |
| TASC II C/D lesion, % (n)
|
76.0 (54) |
82.4 (28) |
70.3 (26) |
0.094 |
| Severely calcified, % (n)
|
30.9 (22) |
32.4 (11) |
29.7 (11) |
0.737 |
| BTK runoff |
1.9±0.8 |
1.8±0.8 |
2.0±0.8 |
0.460 |
| Final device |
|
|
|
0.135 |
| POBA, % (n)
|
8.4 (6) |
14.7 (5) |
2.7 (1) |
|
| BNS, % (n)
|
74.6 (53) |
52.9 (18) |
94.6 (35) |
|
| DCS, % (n)
|
14.0 (10) |
26.5 (9) |
2.7 (1) |
|
| Stent graft, % (n)
|
2.8 (2) |
5.9 (2) |
0.0 (0) |
|
| Pre-ABI |
0.56±0.14 |
0.54±0.13 |
0.57±0.14 |
0.355 |
| Post-ABI |
0.90±0.14 |
0.91±0.11 |
0.89±0.16 |
0.702 |
Data are shown as absolute (percentage) values.
IVUS, intravascular ultrasound; CTO, chronic total occlusion; TASC, trans-Atlantic Inter Society Consensus; BTK, below the knee; POBA, plain old balloon angioplasty; BNS, bare Nitinol stent; DCS, drug-coated stent; ABI, ankle-brachial pressure index
IVUS Findings
The IVUS findings are shown in
Table 4
. The cross-sectional EEM area, post-procedural MLA, and post-procedural axial lumen eccentricity ratio did not differ between the IVUS-guided and non-IVUS-guided wiring groups (proximal EEM: 35.6±13.8 vs. 34.6±15.1 mm2, p=0.773; distal EEM: 25.6±9.4 vs. 25.9±11.2 mm2, p=0.926; post-procedural MLA: 15.0±3.5 vs. 15.7±5.2 mm2, p=0.579; axial lumen eccentricity ratio: 1.4±0.6 vs. 1.5±0.4, p=0.926). Regarding the wire passage route, a clinically true lumen wire routes, including the intraplaque and subintimal routes, were achieved in 97.3% in the IVUS-guided group and 70.8% in the non-IVUS-guided group (p=0.010), whereas clinically false lumen wire route was taken in 2.7% in the IVUS-guided group and 29.2% in the non-IVUS-guided group. Complete clinically true lumen route (CTLR) was achieved in 91.1% (31 lesions) of cases in the IVUS-guided wiring group and 51.3% (19 lesions) of cases in the non-IVUS-guided group (p＜0.001).
Table 4.
IVUS findings
|
Overall (n = 71)
|
IVUS-guided cohort (n = 34)
|
Non-IVUS-guided cohort (n = 37)
|
P-value
|
| Proximal lumen EEM, mm2
|
35.2±14.4 |
35.6±13.8 |
34.6±15.1 |
0.773 |
| Distal lumen EEM, mm2
|
25.7±10.2 |
25.6±9.4 |
25.9±11.2 |
0.926 |
| Post-procedural MLA, mm2
|
15.3±4.3 |
15.0±3.5 |
15.7±5.2 |
0.579 |
| Post-procedural ALE |
1.5±0.6 |
1.4±0.6 |
1.5±0.4 |
0.926 |
| Wire-passage route |
|
|
|
0.010 |
| Clinically true lumen Intraplaque, % |
77.8 |
94.0 |
58.3 |
|
| Subintimal, % |
7.5 |
3.3 |
12.5 |
|
| Clinically false lumen Intramedia, % |
14.7 |
2.7 |
29.2 |
|
| Complete CTLR, % (n)
|
70.4 (50) |
91.1 (31) |
51.3 (19) |
＜0.001 |
Continuous data are presented as the mean ± standard deviation.
Categorical data are shown as absolute (percentage) values.
IVUS, intravascular ultrasound; EEM, external elastic membrane; MLA, minimum lumen area; ALE, axial lumen eccentricity; CTLR, clinically true lumen route
Clinical Outcomes
The clinical outcomes of the examined cases are shown in
Fig.4
. The primary patency rate at 12 months was significantly higher in the IVUS-guided group than in the non-IVUS-guided group (70.0% vs. 52.2%, (p=0.045) (
Fig.5A)
. The percentage of patients that were freedom from clinically driven TLR at 12 months was also higher in the IVUS-guided group than in the non-IVUS group (83.9% vs. 62.8%, p= 0.036) (
Fig.5B)
.
In procedural factors, although the procedure time did not differ significantly between the two groups (99.2 vs. 113.4 min, p=0.242), the amount of contrast media used was significantly lower (96.1±39.5 vs. 178.6±66.0 cm3, p＜0.001), and the fluoroscopy time was significantly shorter (48.5±23.6 vs. 58.2±29.1 min, p=0.017) in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (
Fig.6)
.
Subgroup Analysis
To investigate the efficacy of the clinically true lumen wiring, complete CTLR subgroup and incomplete CTLR subgroup in which intramedial route remained, were created and the IVUS findings of these subgroups were compared. IVUS analysis showed that the post-procedural MLA was significantly larger in the complete CTLR group than in the incomplete CTLR group (16.4±4.0 vs. 12.4±3.5 mm2, p=0.044). Moreover, the post-procedural axial lumen eccentricity ratio was significantly lower in the complete CTLR group than in the incomplete CTLR group (1.4±0.3 vs. 1.8±0.5, p=0.005) (
Table 5)
.
Table 5. IVUS findings of subgroup analysis
|
Overall (n = 71)
|
Complete CTLR cohort (n = 50)
|
Incomplete CTLR cohort (n = 21)
|
P-value
|
| Proximal lumen EEM, mm2
|
35.4±14.5 |
35.0±13.3 |
36.2±17.1 |
0.773 |
| Distal lumen EEM, mm2
|
25.9±10.2 |
26.3±10.7 |
25.1±9.5 |
0.667 |
| Post-procedural MLA, mm2
|
15.5±4.6 |
16.4±4.0 |
12.4±3.5 |
0.044 |
| Post-procedural ALE |
1.6±0.6 |
1.4±0.3 |
1.8±0.5 |
0.005 |
Continuous data are presented as the mean ± standard deviation.
CTLR, clinically true lumen route
EEM, external elastic membrane
MLA, minimum lumen area
ALE, axial lumen eccentricity
Discussion
In this study, IVUS-guided wiring improved the rates of primary patency and freedom from clinically driven TLR at 12 months after EVT for FP-CTO by achieving high rate of CTLR. Moreover, IVUS-guided wiring has several other advantages, e.g., it reduces radiation exposure, the amount of contrast media used, and the frequency of distal puncture procedures.
Previous studies have failed to prove that the intraluminal approach has a clinical benefit compared with the subintimal approach
2-
4)
. However, in these studies, intraluminal and subintimal approaches were classified based on the wiring method and/or the size of the guidewire. Furthermore, these studies did not investigate the wire passage route using IVUS. The wire passage route cannot be defined based on the wiring method, which typically involves the drilling method or knuckle loop technique, or the size of the guidewire (0.014, 0.018, or 0.035 inch), as described in previous reports
5,
6)
.
Although Ishihara et al. compared intraluminal and subintimal angioplasty on the basis of IVUS evaluations performed after guidewire insertion, they only conducted a qualitative analysis and a not-quantitative analysis of the wire passage route
4)
. Conversely, on the basis of a quantitative analysis of IVUS examinations, Mori et al. revealed that the intramedial wire passage route being used to place ＞14% stents is an independent risk factor for restenosis after EVT for FP-CTO lesions
6)
. In our study, IVUS-guided wiring reduced the frequency of intramedial wire insertion and consequently improved the clinical outcomes of interventions for FP-CTO lesions. The following can be considered as mechanisms by which IVUS-guided wiring improves clinical outcomes. Generally, balloon dilation or stent placement in the intramedial space can cause under expansion. In this study, there were no differences in the MLA in the acute phase between the IVUS-guided and non-IVUS-guided wiring groups. This might have been because IVUS optimization was performed after balloon dilation or stent placement, which might have offset any differences between the two groups. However, our subgroup analysis showed that, despite the proximal and distal reference diameters were similar between both groups, the post-procedural MLA was significantly larger and axial lumen eccentricity ratio was lower in the complete CTLR group than in the incomplete CTLR group. Post-procedural smaller MLA has been reported as a risk factor for restenosis both balloon angioplasty and stenting strategy
15-
17)
. Moreover, post-treatment asymmetry has been reported to increase the risk of restenosis after FP DCS placement
18)
, and the clinical results of our study might be affected by post-treatment MLA and asymmetry. Moreover, even if an acute gain is achieved, it has been reported that Nitinol stents can cause recoil in the chronic phase, leading to restenosis, not only in the coronary arteries but also in FP lesions, and POBA or stenting of the intramedial space might cause recoil in the chronic phase after treatment
19,
20)
. Another possible cause of restenosis is medial inflammation. Expanding the intramedial space is considered to cause medial injuries, and previous studies have shown that medial injuries induce inflammatory cell migration and endothelial cell and smooth muscle cell proliferation, leading to vessel restenosis
21-
23)
.
The main limitations of IVUS-guided wiring are that a CTLR is not always achieved and that the procedure itself requires skill and has not been standardized. Moreover, the second wire can become difficult to see because of acoustic shadows in severely calcified lesions. Regarding this issue, the development of appropriate devices, such as guiding catheters, IVUS catheters, and guidewires, is expected in the future. However, when using a debulking device, confirming the route with IVUS might improve the effectiveness of the device and the safety of the procedure. Moreover, to analyze whether there were differences in clinical outcomes between the intraplaque and subintimal routes was not possible because of the relatively small number of wires that passed via these routes in this study. This will be clarified in future well-designed prospective multicenter large-scale studies.
Limitations
1. Since this was a pilot study, it was relatively small scale, single-center, and retrospective. It has been reported that, depending on the number of cases performed each year, EVT results vary from institution to institution
24)
; hence, the results of this study cannot always be generalized. To confirm the results of this study, further investigation (RCT or well-designed prospective multicenter trial with a larger cohort) is necessary to clarify the reason for this clinical benefit.
2. The angiographic and IVUS data were not analyzed in a core laboratory.
3. It cannot be denied that the differences in the final devices used between the two groups affected the results.
4. In this study, relatively old-generation devices that did not show sufficient results in TASC II type C or D lesions
16,
25,
26)
were mainly used, and further investigation is necessary to investigate whether IVUS-guided wiring is effective for the new-generation DES and DCB.
Conclusion
The IVUS-guided wiring strategy improves the clinical outcomes of angioplasty for FP-CTO lesions by achieving a high clinically true lumen wire passage route rate. This strategy might also be useful in reducing patients’ radiation exposure, the amount of contrast media used, and the frequency of the retrograde approach.
Acknowledgements and Notice of grant support
The author(s) gratefully acknowledge the work of the past and present members of our catheterization laboratory centers. The author(s) did not receive any financial support for the research, authorship, and/or publication of this article.
COI
The author(s) declare that no potential conflicts of interest exist concerning the research, authorship, and/or publication of this article.
References
- 1) Aboyans V, Ricco JB, Bartelink MEL, Björck M, Brodmann M, Cohnert T, Collet JP, Czerny M, De Carlo M, Debus S, Espinola-Klein C, Kahan T, Kownator S, Mazzolai L, Naylor AR, Roffi M, Röther J, Sprynger M, Tendera M, Tepe G, Venermo M, Vlachopoulos C and Desormais I; ESC Scientific Document Group: 2017 ESC Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases, in collaboration with the European Society for Vascular Surgery (ESVS). Eur. Heart J, 2017; 00: 1-60
- 2) Soga Y, Iida O, Suzuki K, Hirano K, Kawasaki D, Shintani Y, Suematsu N and Yamaoka T: Initial and 3-year results after subintimal versus intraluminal approach for long femoropopliteal occlusion treated with a self-expandable nitinol stent. J Vasc Surg, 2013; 58: 1547-1555
- 3) Kim K, Ko YG, Ahn CM, Min PK, Lee JH, Yoon CH, Yu CW, Lee SW, Lee SR, Choi SH, Hoh YS, Chae IH and Choi D: Clinical Outcomes of Subintimal vs. Intraluminal Revascularization Approaches for Long Femoropopliteal Occlusions in a Korean Multicenter Retrospective Registry Cohort. Circ J, 2018; 82: 1900-1907
- 4) Ishihara T, Takahara M, Iida O, Soga Y, Hirano K, Yamauchi Y, Zen K, Kawasaki D, Nanto S, Yokoi H and Uematsu M: Comparable 2-Year Restenosis Rates Following Subintimal and Intraluminal Drug-Eluting Stent Implantation for Femoropopliteal Chronic Total Occlusion. J Endovasc Ther, 2016; 23: 889-895
- 5) Kawasaki D, Iida O, Fukunaga M, Kato M, Ohkubo N: Wire passage of 0.035-inch looped wire technique for femoropopliteal long total occlusions. J Atheroscler Thromb, 2015; 22: 1071-1079
- 6) Mori S, Hirano K, Ito Y, Yamawaki M, Araki M, Kobayashi N, Takimura H, Sakamoto Y, Tsutsumi M, Takama T, Honda Y, Tokuda T, Makino K and Shirai S: Clinical Outcomes of the Intraluminal Approach for Long Occlusive Femoropopliteal Lesions Assessed by Intravascular Ultrasound. J Atheroscler Thromb, 2017; 24: 477-486
- 7) Schmidt A, Bausback Y, Piorkowski M, Werner M, Bräunlich S, Ulrich M, Varcoe R, Friedenberger J, Schuster J, Botsios S and Scheinert D: Retrograde recanalization technique for use after failed antegrade angioplasty in chronic femoral artery occlusions. J Endovasc Ther, 2012; 19: 23-29
- 8) Kawarada O and Yokoi Y: Retrograde 3-French popliteal approach in the supine position after failed antegrade angioplasty for chronic superficial femoral artery occlusion. J Endovasc Ther, 2010; 17: 255-258
- 9) Iida T, Iida O, Okamoto S, Dohi T, Nanto K and Uematsu M: Endovascular therapy with novel high anterior tibial artery puncture for limb salvage in a case of critical lower limb ischemia. Cardiovasc Interv Ther, 2014; 29: 363-367
- 10) Tan M, Urasawa K, Koshida R, Haraguchi T, Kitani S, Igarashi Y and Sato K: Anterolateral Popliteal Puncture Technique: A Novel Retrograde Approach for Chronic Femoropopliteal Occlusions. J Endovasc Ther, 2017; 24: 525-530
- 11) Urasawa K, Sato K, Koshida R and Honma Y: Trans-collateral angioplasty for the treatment of long chronic total occlusions of superficial femoral arteries: a novel wiring technique. J Cardiovasc Surg (Torino), 2014; 55: 395-400
- 12) Kin MH, Yu LH and Mitsudo K: New Retrograde Wiring Technique for Chronic Total Occlusion. Catheter Cardiovasc Interv, 2010; 75: 117-119
- 13) Fujita S, Tamai H, Kyo E, Kosuga K, Hata T, Okada M, Nakamura T, Tsuji T, Takeda S, Bin Hu F, Masunaga N, Motohara S and Uehata H: New technique for superior guiding catheter support during advancement of a balloon in coronary angioplasty: the anchor technique. Catheter Cardiovasc Interv, 2003; 59: 482-488
- 14) Rocha-Singh KJ, Zeller T and Jaff MR: Peripheral arterial calcification: prevalence, mechanism, detection, and clinical implications. Catheter Cardiovasc Interv, 2014; 83: E212-E220
- 15) Miki K, Fujii K, Fukunaga M, Kawasaki D, Shibuya M, Imanaka T, Tamaru H, Masutani M, Ohyanagi M, Masuyama T: Impact of post-procedural intravascular ultrasound findings on long-term results following self-expanding nitinol stenting in superficial femoral artery lesions. Circ J, 2013; 77: 1543-1550
- 16) Iida O, Takahara M, Soga Y, Nakano M, Yamauchi Y, Zen K, Kawasaki D, Nanto S, Yokoi H, Uematsu M; ZEPHYR Investigators: 1-Year Results of the ZEPHYR Registry (Zilver PTX for the Femoral Artery and Proximal Popliteal Artery): Predictors of Restenosis. JACC Cardiovasc Interv, 2015; 8: 1105-1112
- 17) Fujihara M, Kozuki A, Tsubakimoto Y, Takahara M, Shintani Y, Fukunaga M, Iwasaki Y, Nakama T, Yokoi Y: Lumen Gain After Endovascular Therapy in Calcified Superficial Femoral Artery Occlusive Diseas e Assessed by Intravascular Ultrasound (CODE Study). J Endovasc Ther, 2019; 26: 322-330
- 18) Mori S, Hirano K, Nakano M, Muramatsu T, Tsukahara R, Ito Y, Ishimori H: Intravascular ultrasound measurements after drug-eluting stent placement in femoropopliteal lesions: determining predictors of restenosis. J Endovasc Ther, 2015; 22: 341-349
- 19) Roguin A, Grenadier E, Linn S, Markiewicz W and Beyar R: Continued expansion of the nitinol self-expanding coronary stent: Angiographic analysis and 1-year clinical follow-up. Am Heart J, 1999; 138: 326-333
- 20) Kumakura H, Tozuka M, Kansai H, Yoshihiro Araki, Kasama S, Ito T, Iwasaki T, Takayama Y, Ichikawa S, Fujita K, Aizaki M, Mitsui K and Minami K: Long-term Results of Endovascular Treatment in Patients with Peripheral Arterial Disease -Usefulness and Limits of Stent Treatments-. J Jpn Coll Angiol, 2005; 45: 569-575
- 21) Tarricone A, Ali Z, Rajamanickam A, Gujja K, Kapur V, Purushothaman KR, Purushothaman M, Vasquez M, Zalewski A, Parides M, Overbey J, Wiley J and Krishnan P: Histopathological Evidence of Adventitial or Medial Injury Is a Strong Predictor of Restenosis During Directional Atherectomy for Peripheral Artery Disease. J Endovasc Ther, 2015; 22: 712-715
- 22) Pels K, Labinaz M, Hoffert C and O’Brien ER: Adventitial angiogenesis early after coronary angioplasty: correlation with arterial remodeling. Atherioscler Thromb Vasc Biol, 1999; 19: 789-796
- 23) Krishnan P, Purushothaman KR, Purushothaman M, Baber U, Tarricone A, Vasquez M, Wiley J, Kini A, Sharma SK O’Connor WN and Moreno PR: Relation of Internal Elastic lamellar Layer Disruption to Neointimal Cellular Proliferation and TypeIII Collagen Deposition in Human Peripheral Artery Restenosis. Am J Cardiol, 2016; 117: 1173-1179
- 24) Iida O, Takahara M, Yamauchi Y, Shintani Y, Sugano T, Yamamoto Y, Kawasaki D, Yokoi H, Miyamoto A, Mano T, Nakamura M; OMOTENASHI investigators: Impact of Hospital Volume on Clinical Outcomes after Aortoiliac Stenting in Patients with Peripheral Artery Disease. J Atheroscler Thromb, 2020; 27: 516-523
- 25) Suzuki K, Iida O, Soga Y, Hirano K, Inoue N, Uematsu M, Yokoi H, Muramatsu T, Nanto S, Nobuyoshi M, Meguro T: Long-term results of the S.M.A.R.T. Control(TM) stent for superficial femoral artery lesions, J-SMART registry. Circ J, 2011; 75: 939-944
- 26) Tsujimura T, Takahara M, Iida O, Hiramori S, Hayakawa N, Karashima E, Miura T, Teramura M, Ichihashi K, Kojima T, Aihara H, Yamaoka T, Fujihara M, Tosaka A, Doijiri T, Mano T, Soga Y: One-Year Clinical Outcomes following Implantation of InnovaTM Self-Expanding Nitinol Stents in Patients with Peripheral Artery Diseases Presenting Femoropopliteal Artery Lesions. J Atheroscler Thromb, 2019; 26: 847-855
