Original Article 1071 Wire Passages of 0.035-inch Looped Wire Technique for Femoropopliteal Long Total Occlusions Daizo Kawasaki 1, Osamu Iida 3, Masashi Fukunaga 4, Masaaki Kato 2 and Nobukazu Ohkubo 2 1 Cardiovascular Division, Department of Internal Medicine, Morinomiya Hospital, Osaka, Japan 2 Department of Cardiovascular Surgery, Morinomiya Hospital, Osaka, Japan 3 Kansai Rosai Hospital, Cardiovascular Center, Hyogo, Japan 4 Cardiovascular Division, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan Aim: Although it is understood that a looped wire technique using a 0.035-inch wire for femoropopliteal (FP) long chronic total occlusions (CTOs) goes to the subintima, there has been no systematic assessment of wire passages. The purpose of this study is to examine these passages by intravascular ultrasound (IVUS) after looped wire technique for FP long CTOs. Methods: Between March 2012 and October 2014, 57 consecutive FP long CTO lesions (mean lesion length, 246 42 mm), involving the superficial femoral artery ostium and treated with IVUSguided endovascular therapy, were enrolled. After IVUS confirmed that the initial wire passage was intraplaque, the looped wire technique was routinely conducted through the CTO body. Based on IVUS findings, the wire passage was classified into 3 types: intraplaque, subintimal, and intramedia. Results: At the FP lesion in the proximal, middle, and distal segments, the wire proceeded intraplaque in 98%, 25%, and 20% cases; subintimal in 2%, 61%, and 52%; and intramedia in 0%, 14%, and 28%, respectively. The success rate of antegrade wiring was 74%, with the remaining 26% cases requiring an additional retrograde approach. Conclusions: The looped wire technique variably proceeds to intraplaque, subintimal, or intramedia, even starting from intraplaque in FP long CTOs. J Atheroscler Thromb, 2015; 22: 1071-1079. Key words: Looped wire technique, Wire passage, Intravascular ultrasound Introduction Indication for endovascular therapy (EVT) has extended from only TransAtlantic Inter-Society Consensus (TASC) A or B to C or D femoropopliteal (FP) lesions 1, 2). EVT for FP long chronic total occlusions (CTOs) is challenging because of the failure of the guidewire re-entry at the distal true lumen after subintimal crossing in the occluded segment. The subintimal approach, introduced in 1989 by Bolia et al. 3) and usually conducted using a 0.035-inch wire accompanying the supporting catheter through the occlusion Address for correspondence: Daizo Kawasaki, Morinomiya Hospital, Cardiovascular Division, 2-1-88, Morinomiya, Joutouku, Osaka-city, Osaka, 5360025, Japan E-mail: daizou0524909@hotmail.com Received: January 7, 2015 Accepted for publication: March 10, 2015 site, is preferred because of its relative simplicity, lower cost, and higher procedural success rate 4). However, success of this approach depends on plaque distribution and wire position at the distal end of CTOs; an inappropriate subintimal to true distal lumen crossing could lead to lesion enlargement and pivotal collateral vessel loss 5). Aim Although it is understood that a looped wire technique using a 0.035-inch wire for FP long CTOs goes to the subintima, there has been no systematic assessment of wire passages. The purpose of this study is to examine wire passages by intravascular ultrasound (IVUS) after looped wire technique for FP long CTOs.
1072 A B C D E F Fig.1. Definition of wire passage according to IVUS findings. (A) Intraplaque is defined as an inside plaque. (B) Subintimal is between the plaque and media. (C) Intramedia is between the media and adventitia. Angioscopic findings of each passage. (D) Intraplaque has some dissection, unstable plaque, and thrombus. (E) Subintimal is plaque free without an apparent dissection or thrombus albeit oval shape. (F) Intramedia is rough and small. Methods Patients and Lesions This study was performed as a prospective, multicenter analysis. Between March 2012 and October 2014, 57 consecutive FP long ( 15 cm) CTO lesions involving the superficial femoral artery (SFA) ostium were treated with IVUS-guided EVT and a looped wire technique. All patients suffered from symptoms because of FP lesions (Fontaine classification grade, 2 4), which affected the quality of life despite exercise and optimal medication. Physical and noninvasive examinations, including ankle brachial index (ABI), duplex ultrasound, and imaging studies (computed tomography, magnetic resonance imaging, or angiography), were performed prior to EVT. Patients with acute or subacute limb ischemia, a history of lower extremity bypass surgery, residual aortoiliac artery disease, and severe calcified lesions were excluded. All patients provided written informed consent. Definitions Wire passage in occlusive lesions was classified according to IVUS findings: intraplaque, inside the plaque; subintimal, between the plaque and media; and intramedia, between the media and adventitia (Figs. 1A-C). Angioscopic findings after balloon predilatation were as follows: intraplaque, with some dissection and/or unstable plaque/thrombus; subintimal, plaque-free space without apparent dissection or thrombus albeit oval shape; and intramedia, rough and small (Figs. 1D-F). FP segments were classified into 3 segments: proximal and middle, the upper and lower halves, respectively, between femoral bifurcation and Hunter canal, and distal, below the Hunter canal.
1073 A B C D E F Fig.2. Procedural steps for a combination of IVUS-guided wiring and looped wire technique. A 6-F straight guiding catheter is placed immediately before the CTO entrance stump. (A) IVUS-guided wiring is performed with a 0.014-inch wire to cross intraplaque the few first centimetres at the CTO entrance. (B) The 6-F guiding catheter is advanced until the point confirmed as intraplaque by IVUS. (C and D) The 0.014- inch wire and IVUS are then removed from the sheath, and a looped wire technique is performed with a 0.035-inch small J-type hydrophilic guidewire (Radifocus; Terumo, Tokyo, Japan) and a supporting 4-F catheter (Grideach; Terumo), which are advanced until immediately before the CTO exit. (E) The 6-F guiding catheter is then advanced until immediately before the CTO exit; the 0.035-inch small J-type hydrophilic guidewire and a supporting 4-F catheter are removed from the sheath, and the 0.014-inch wire and IVUS are repositioned at the CTO exit. (F) When the wire is subintimal immediately before the distal true lumen without plaque, it is directly crossed to the distal true lumen with an IVUS-guided parallel wire technique. Procedure Either ipsilateral or contralateral femoral puncture was selected depending on the condition of the iliac artery and/or femoral bifurcation position. A 6-F sheath (Medikit, Parent plus, Japan) was commonly used for both approaches. Systemic heparin (5000 U) was administered to achieve an activated clotting time of 200 s. A 6-F straight guiding catheter was placed immediately before the CTO entrance of the SFA stump. The first few centimeters at CTO beginning into intraplaque was crossed using IVUS-guided wiring with a 0.014-inch wire (Fig. 2A), and a 6-F guiding catheter was advanced until the point confirmed as intraplaque by IVUS (Fig. 2B). Both the 0.014-inch wire and IVUS, but not the 6-F guiding catheter, were removed from the sheath. A looped wire technique was performed by advancing a 0.035-inch small J-type hydrophilic guidewire (Radifocus; Terumo, Tokyo, Japan) accompanied with a 4-F catheter (Gridecath; Terumo) up to immediately before the CTO exit
1074 Table 1. Patient and lesion characteristics Patient Characteristics Age, years Male Risk factors Hypertension Hyperlipidemia Diabetes mellitus Renal insufficiency ( 30 ml/min/1.73 m 2 ) Regular hemodialysis Current smoking Fontaine grade (1/2/3/4) Lesion Characteristics TASC classification (A/B/C/D) Lesion length, mm CTO length, mm Proximal stump (CTO entrance) Above Hunter canal (CTO exit) Distal true lumen without plaque Distal run off Calcification (none/mild/moderate) Procedural Characteristics Approach (Crossover/Ipsilateral) Procedural success Parallel wire technique at CTO entrance Antegrade success Parallel wire technique at CTO exit Bidirectional success Wire passage time, min Number of wires used Stent number Stent length, mm Contrast volume, ml Ankle brachial index Before After Data are presented as mean SD or as numbers (percentages). egfr, estimated glomerular filtration rate CTO, Chronic total occlusion 73 7 (54) 42 (78) 45 (83) 31 (57) 21 (39) 9 (17) 2 (4) 16 (30) 0/44/0/10 (0/81/0/19) 0/0/5/52 (0/0/9/91) 246 42 (57) 228 44 (57) 44 (77) 41 (72) 39 (68) 2.0 0.6 (57) 15/28/14 (26/49/25) 30/27 (53/47) 57 (100) 31 (54) 42 (74) 21 (50) 15 (26) 28 17 (57) 2.8 1.0 (57) 2.3 0.5 (57) 249 48 (57) 30 21 (57) 0.66 0.13 (57) 0.97 0.09 (57) (Figs. 2C, D). The 6-F guiding catheter also was advanced until immediately before the CTO exit, and the 0.035-inch small J-type hydrophilic guidewire and supporting 4-F catheter were removed from the sheath. Furthermore, the 0.014-inch wire and IVUS were positioned at the CTO exit (Fig. 2E). The wire passage of each FP segment was assessed with IVUS. When the wire was intraplaque immediately before the distal true lumen, it was directly crossed to obtain the lumen. When the wire was subintimal immediately before the distal true lumen without plaque, it was directly crossed to the lumen with an IVUS-guided parallel wire technique (Fig. 2F). When the wire was subintimal with the diseased distal true lumen or intramedia immediately before the distal true lumen, it was crossed with bidirectional wiring. After the wire was crossed through the totally occluded lesions, lesions were dilated with a proper size balloon according to the IVUS measurement. A self-expanding nitinol stent was deployed at the site if there was 30% residual stenosis or a flow-limiting dissection. Balloon postdilatation after stent implantation was performed with
1075 Table 2. Difference between antegrade success and failure (retrograde success) egfr, ml/min/1.73 m 2 TASC classification (A/B/C/D) Lesion length, mm CTO length, mm Lesion CTO length, mm Proximal stump Plaque of distal true lumen Above Hunter canal (CTO exit) Calcification (none/mild/moderate) Wire passage time, min Number of wires used Stent length, mm Stent number, mm Contrast media volume, ml Antegrade success (n 42) 50 21 0/0/4/38 (0/0/10/90) 245 43 231 46 13 23 31 (74) 9 (21) 28 (67) 12/23/7 (28/55/17) 20 11 2.5 1.0 245 51 2.2 0.5 31 18 Antegrade failure (n 15) 50 27 0/0/1/14 (0/0/7/93) 259 32 218 34 41 27 13 (87) 9 (60) 13 (87) 3/5/7 (20/33/47) 49 15 3.6 0.7 260 37 2.4 0.5 29 28 Data are presented as mean SD or as numbers (percentages). p 0.05, p 0.01 egfr, estimated glomerular filtration rate CTO, Chronic total occlusion a 5-mm balloon at rated pressure. After a successful recanalization, all patients received a combination of aspirin (100 mg/day) and cilostazol (200 mg/day) or clopidogrel (75 mg/day) for at least 1 year. IVUS Analysis IVUS was performed in all cases with a commercially available IVUS console (s5tm Imaging System; Volcano, Rancho Cordova, CA, USA) and a phasedarray 20-MHz IVUS catheter (Eagle Eye Gold; Volcano). The wire was changed from 0.035-inch to 0.014-inch to evaluate the looped wire passage. Moreover, a manual pullback at a constant speed of 10 mm/ s was performed and recorded from the CTO exit to the common femoral artery through the entire FP segment. The wire passage was classified into intraplaque, subintimal, and intramedia for each FP segment (i.e., proximal, middle, and distal). Angioscopic Analysis Angioscopy was conducted using Vecmova NEO (FiberTech, Tokyo, Japan). Detailed angioscopy product specifications and procedures have been previously elsewhere 6). In brief, after predilatation with a 4-mm balloon for the CTO segment, the optical fiber was placed at the distal segment of the SFA and was manually pulled back from the distal to the proximal segments. Angioscopic images comprised 3,000 full-color pixels and were stored on digital videotapes for offline analysis. Statistical Analysis Statistical analysis was performed using StatView 5.0 (STATVIEW, Abacus Concepatients, Berkeley, California). Results are expressed as mean SD. Unpaired Student s t test was used to compare parameters between antegrade and retrograde success groups. A p value of 0.05 was considered statistically significant. Results Baseline Characteristics Patient and lesion characteristics are summarized in Table 1; 81% patients had intermittent claudication, and 19% had critical limb ischemia. Diabetes and renal insufficiency were present as notable comorbidities in 39% and 17%, respectively. All lesions were classified as TASC class C or D. All CTO lesions were occluded from the entrance. The mean lesion and CTO length was 246 42 mm and 228 44 mm, respectively. The proximal stump was present at the CTO entrance in 77% cases; the distal end of CTO was located above the Hunter canal in 72% cases. Furthermore, 68% of the distal true lumen did not have any plaque, and 74% lesions had calcification. Procedural Results Procedural results are shown in Table 1. Technical success was obtained in all cases with 54% cases requiring IVUS-guided parallel wire technique for
1076 Table 3. IVUS findings of wire passage after looped wire technique Intraplaque Subintimal Intramedia Proximal segment (n 57) Middle segment (n 57) Distal segment (n 25) 98 25 20 2 61 52 0 14 28 Data are presented as percentages. acquiring the intraplaque position at the CTO entrance. The wire was successfully crossed using an antegrade approach in 74% of all cases with 50% requiring IVUS-guided parallel wire technique to reenter the distal true lumen at the CTO exit (Fig. 2F); 26% cases without a successful antegrade crossing required distal access for bidirectional wire crossing. The mean wire passage time was 28 17 min, and the average stent number and length was 2.3 0.5 and 249 48 mm, respectively. ABI improved from 0.66 0.13 to 0.97 0.09 after treatment. In antegrade failure (retrograde success) vs. success (Table 2), the lesion length minus the CTO length was significantly greater (41 27 vs. 13 23 mm, p 0.01). The distal true lumen had some plaque more frequently (60% vs. 21%, p 0.01), and this result indicates that the diseased distal true lumen is more likely associated with antegrade failure. The calcification extent was more pronounced (none/mild/moderate: 20/33/47% vs. 28/55/17%, p 0.05); the wire passage time was significantly longer (49 15 vs. 20 11 min, p 0.01). IVUS Findings At the FP lesions in the proximal, middle and distal segments, the wire went intraplaque in 98%, 25%, and 20%; subintimal in 2%, 61%, and 52%; and intramedia in 0%, 14%, and 28%, respectively (Table 3). Discussion Definition of Wire Passage in CTOs To our knowledge, this is the first report on IVUS and the angioscopic definition of wire passage in the treatment of peripheral artery occlusive disease considered as a subintimal approach and shown to have a more variable course. Subintimal Angioplasty vs. Intraplaque Angioplasty Intraluminal (i.e., intraplaque and subintimal) balloon angioplasty and/or stenting are preferred over extraluminal (i.e., intramedia) to maintain chronic patency. Stenting currently is considered a mainstream treatment for TASC class C and D lesions because of an improved long-term outcome of EVT for FP lesions compared with balloon angioplasty 7, 8). It is believed that the expansion of the subintimal stent is less than that of intraplaque stent; stent expansion is associated with prognosis at chronic phases. In our experience with IVUS guidance, the subintimal stent expansion achieves as full as intraplaque stent expansion at chronic phases except in severely calcified lesions (Fig. 3), supporting our previous report 9). As previously discussed, although IVUS-guided wiring is feasible and safe with 0.014- or 0.018-inch wires, the costs and procedural time are greater 10). If there is no difference of chronic patency between subintimal and intraplaque approaches, the looped wire technique, which is user friendly and more reasonable, would be a better choice for long FP occlusive lesions. Saving the Collateral Primary patency after stenting is lower for TASC class C/D than for A/B FP lesions 11). If restenosis and/or stent occlusion occur after treatment, the patient s clinical status will be dependent on the quality and quantity of collateral vessels. Subintimal angioplasty may possibly lead to major collateral vessels loss, which can occur in 26% and 47% of proximal and distal segments, respectively, according to Lipsitz et al. 5, 12). Saving the collateral vessels is very important for maintaining the clinical status if restenosis and/or stent occlusion occur. In this study, we crossed the wire intraplaque with IVUS guidance at the CTO entrance to save the deep femoral artery, which is the major supplying artery to the distal segment. IVUSguided parallel wire technique was required in 54% cases for crossing intraplaque, indicating a low probability of intraplaque wire penetration with only a 0.035-inch wire. We also controlled the wire with IVUS guidance at the CTO exit to save the collateral artery supplying the distal true lumen. When the wire was located in the subintimal space, the wire was crossed as proximal as possible with IVUS guidance to save the collateral.
1077 A B C Fig.3. Representative subintimal stenting. (A) This diagnostic angiogram before treatment reveals CTOs from the ostium to the middle segment of the right superficial femoral artery (occlusion length, 210 mm). The wire is crossed into subintimal through the CTO lesion. (B) The final angiogram and IVUS after stent implantation. The stent is not fully expanded because of subintimal. (C) The angiogram 12 months later and IVUS after stent implantation. The stent is completely expanded, and there is no in-stent restenosis. Antegrade vs. Bidirectional Wiring According to IVUS Findings at the CTO Exit For a successful antegrade wiring, the wire needs to be intraplaque at the CTO exit, regardless of plaques in the distal true lumen, or subintimal at the CTO exit without plaques in the distal true lumen. When the wire is subintimal and there are some plaques in the distal true lumen, the wire can be crossed to the distal true lumen at the point with the thinnest plaque; however, the lesion may become longer, which may cause a loss of pivotal collateral vessels. Bidirectional wiring is required to save the collateral vessels when the wire is intramedia. As described in Table 2, FP long CTO, which have enough stump at the beginning of CTO and less plaque at the distal true lumen, are suitable for looped wire technique and the most likely to complete the treatment without using parallel wire technique in the highest chance. Required Distal Puncture In this study, the distal true lumen in 15 patients could not be recanalized using an antegrade approach; thus, bidirectional wiring was used. In Europe and the United States, true lumen re-entry catheters are clinically effective at gaining the wire passage back to the distal true lumen and facilitating a successful EVT of
1078 CTO 13) ; however, true lumen re-entry catheters have not yet been approved in Japan. Retrograde access can be performed with only a microcatheter and 0.014-inch wire. Distal SFA and tibial, but not popliteal arteries, were used for retrograde access. The distal access was punctured under fluoroscopic guidance in the supine position with a microcatheter and 0.014-inch wire. The mechanism using which retrograde wiring more readily goes intraplaque through the CTO lesion remains unknown; therefore, the wire can be crossed intraluminal with a combination of antegrade and retrograde wiring, even if the antegrade looped wire went intramedia. Hemostasis for the distal access was provided with inside ballooning and outside manual compression. The bidirectional wire passage time is markedly longer than the antegrade wiring time. IVUS findings at the CTO exit may shorten the wire passage time, omitting the need for retrograde access. Retrograde access is a safe and feasible option in cases of failed antegrade wiring 14, 15). Study Limitations This study has several limitations, including the small sample size, possibility that the results obtained with looped wire technique starting from intraplaque may not reflect those achieved with looped wire technique, lack of a comparative study because angioscopic analysis was not conducted for all cases, owing to the medical reimbursement system, and lack of inclusion of chronic data after angioplasty for each passage because of the limited number of intramedia angioplasty. In most cases, when the wire was going intramedia, it finally crossed intraplaque or subintimal by bidirectional wiring. Conclusion A looped wire technique starting intraplaque may variably follow intraplaque, subintimal, or intramedia routes. None. Sources of Funding Conflicts of Interest The authors declare no conflict of interest. Acknowledgments We acknowledge the expertise of Mrs. Mana Fon- teneau and CE. Aya Nakata of Morinomiya Hospital. References 1) Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG: Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC ). J Vasc Surg, 2007; 45 (Suppl. S): S5-67 2) White JV, Ryjewski C: Progress in the endovascular treatment of intermittent claudication: rationale for changes in the TASC classification. Semin Vasc Surg, 2007; 20: 54-61 3) Bolia A, Brennan J, Bell PR: Recanalisation of femoropopliteal occlusions: improving success rate by subintimal recanalisation. Clin Radiol, 1989; 40: 325 4) Laxdal E, Jenssen GL, Pedersen G, Aune S: Subintimal angioplasty as a treatment of femoropopliteal artery occlusions. Eur J Vasc Endovasc Surg, 2003; 25: 578-582 5) Lipsitz EC, Ohki T, Veith FJ, Rhee SJ, Kurvers H, Timaran C, Gargiulo NJ, Suggs WD, Wain RA: Fate of collateral vessels following subintimal angioplasty. J Endovasc Ther, 2004; 11: 269-273 6) Sakai S, Mizuno K, Yokoyama S, Tanabe J, Shinada T, Seimiya K, Takano M, Ohba T, Tomimura M, Uemura R, Imaizumi T: Morphologic changes in infarct-related plaque after coronary stent placement: a serial angioscopy study. J Am Coll Cardiol, 2003; 42: 1558-1565 7) Laird JR, Katzen BT, Scheinert D, Lammer J, Carpenter J, Buchbinder M, Dave R, Ansel G, Lansky A, Cristea E, Collins TJ, Goldstein J, Jaff MR; RESILIENT Investigators: Nitinol stent implantation versus balloon angioplasty for lesions in the superficial femoral artery and proximal popliteal artery: twelve-month results from the RESIL- IENT randomized trial. Circ Cardiovasc Interv, 2010; 3: 267-276 8) Soga Y, Iida O, Suzuki K, Hirano K, Kawasaki D, Shintani Y, Suematsu N, Yamaoka T, Tsuchiya T, Miyashita Y, Okazaki S, Shinozaki N, Takahashi H: Clinical impact of bisoprolol versus carvedilol in patients undergoing femoropopliteal stenting. J Atheroscler Thromb, 2014; 21: 691-702 9) Soga Y, Iida O, Suzuki K, Hirano K, Kawasaki D, Shintani Y, Suematsu N, 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 10) Kawasaki D, Tsujino T, Fujii K, Masutani M, Ohyanagi M, Masuyama T: Novel use of ultrasound guidance for recanalization of iliac, femoral, and popliteal arteries. Catheter Cardiovasc Interv, 2008; 71: 727-733 11) Soga Y, Iida O, Hirano K, Yokoi H, Nanto S, Nobuyoshi M: Mid-term clinical outcome and predictors of vessel patency after femoropopliteal stenting with self-expandable nitinol stent. J Vasc Surg, 2010; 52: 608-615 12) Green JS, Newland C, Fishwick G: Positive outcome following unsuccessful subintimal angioplasty. Eur J Vasc Endovasc Surg, 1998; 16: 266-270 13) Hausegger KA, Georgieva B, Portugaller H, Tauss J, Stark G: The outback catheter: a new device for true lumen re-
1079 entry after dissection during recanalization of arterial occlusions. Cardiovasc Intervent Radiol, 2004; 27: 26-30 14) Schmidt A, Bausback Y, Piorkowski M, Werner M, Bräunlich S, Ulrich M, Varcoe R, Friedenberger J, Schuster J, Botsios S, Scheinert D: Retrograde recanalization technique for use after failed antegrade angioplasty in chronic femoral artery occlusions. J Endovasc Ther, 2012; 19: 23-29 15) Spinosa DJ, Leung DA, Harthun NL, Cage DL, Fritz Angle J, Hagspiel KD, Matsumoto AH: Simultaneous antegrade and retrograde access for subintimal recanalization of peripheral arterial occlusion. J Vasc Interv Radiol, 2003; 14: 1449-1454