`Exhibit 1020
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`Page 1 of 5
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`Catheterization and Cardiovascular Interventions 63:452– 456 (2004)
`
`Basic Science Review
`
`New Method to Increase a Backup Support of
`a 6 French Guiding Coronary Catheter
`
`Saeko Takahashi,1* MD, Shigeru Saito,1 MD, Shinji Tanaka,1 MD, Yusuke Miyashita,1 MD,
`Takaaki Shiono,1 MD, Fumio Arai,1 MD, Hiroshi Domae,1 MD, Shutaro Satake,1 MD, and
`Takenari Itoh,2 PhD
`
`A 6 Fr guiding catheter is commonly used in the percutaneous coronary intervention
`(PCI). However, one of the limitations of the 6 Fr guiding catheter is its weak backup
`support compared to a 7 or an 8 Fr guiding catheter. In this article, we present a new
`system for PCI called the five-in-six system. Between March 2003 and September 2003,
`this system was tried on eight chronic total occlusion cases. The advantage of the
`five-in-six system is that it increases backup support of a 6 Fr guiding catheter. Catheter
`Cardiovasc Interv 2004;63:452– 456.
`© 2004 Wiley-Liss, Inc.
`
`Key words: five-in-six system; backup support; 6 Fr guiding catheter; chronic total
`occlusion
`
`INTRODUCTION
`
`Currently, a 6 Fr guiding catheter is commonly used in
`percutaneous coronary intervention (PCI), since its use
`can decrease access site complication, enable early am-
`bulation, and reduce the consumption of the contrast dye
`[1– 4]. Major limitations of a 6 Fr guiding catheter are the
`inner lumen is not big enough to accommodate bulky
`atherectomy devices, and its backup support is not strong
`compared to a 7 or an 8 Fr catheter. In this report, we
`demonstrate a new technique for PCI called the five-
`in-six system, which increases a backup support of a 6 Fr
`guiding catheter.
`
`MATERIALS AND METHODS
`The Five-in-Six System
`The five-in-six system is a method of inserting a 5 Fr
`guiding catheter (Heartrail, Terumo, Japan) into a 6 Fr
`guiding catheter to increase backup support. As we insert
`the 5 Fr inner guiding catheter into the target artery
`through the outer 6 Fr guiding catheter, stronger backup
`support can be generated (Fig. 1A).
`This 5 Fr Heartrail straight guiding catheter is 120 cm
`in length, whereas the 6 Fr guiding catheter is 100 cm.
`The 5 Fr Heartrail catheter has a very soft 13 cm end
`portion. This soft end portion can easily negotiate the
`tortuous coronary artery with the minimal damage and
`then it can be inserted more deeply into the artery. The
`inner lumen of the 5 Fr Heartrail catheter is 0.059⬘ in
`
`diameter; it can accept normal balloons or stent delivery
`systems less than 4.0 mm in diameter. The inner lumen of
`the outer 6 Fr catheter needs to be more than 0.071⬘ in
`diameter to accommodate the 5 Fr Heartrail catheter;
`Launcher
`(Medtronic), Heartrail,
`and Radiguide
`(Terumo) guiding catheters can meet this inner lumen
`diameter.
`
`In Vitro Experiments
`We measured the backup support of this five-in-six
`system in vitro using an experimental system. The artery
`model had three curves simulating tortuous coronary
`arteries. It was filled with water that was kept at 37°C
`(Fig. 1B). A guiding catheter was engaged into the os-
`tium of the artery model. Then a rapid-exchange balloon
`catheter (Ryujin 2.5 ⫻ 20 mm; Terumo) was pushed into
`
`1Division of Cardiology and Catheterization Laboratories, Heart
`Center of ShonanKamakura General Hospital, Kamakura City,
`Japan 2Research and Development Section of Ashitaka Fac-
`tory, Terumo Corporation, Fujinomiya City, Japan
`
`*Correspondence to: Dr. Saeko Takahashi, Division of Cardiology and
`Catheterization Laboratories, Heart Center of ShonanKamakura Gen-
`eral Hospital, 1202-1 Yamazaki, Kamakura City, 247-8533, Japan.
`E-mail: saekot@wa2.so-net.ne.jp
`
`Received 8 October 2003; Revision accepted 10 September 2004
`
`DOI 10.1002/ccd.20223
`Published online in Wiley InterScience (www.interscience.wiley.com).
`
`© 2004 Wiley-Liss, Inc.
`
`
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`Page 2 of 5
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`New System to Increase Backup Support
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`453
`
`Fig. 1. A: The whole five-in-six system. B: A coronary artery model.
`
`the artery model along a regular PCI guidewire (BMW,
`Guidant) at a constant speed of 5 mm/sec by a pushable
`gauge machine (Fig. 2A). The pushable gauge machine
`can measure a resistance of a balloon catheter. The
`maximal backup support of this experimental system was
`defined as the resistance of a balloon catheter when the
`guiding catheter could not keep a coaxial engagement to
`the artery model and the catheter was pushed away. If the
`guiding catheter has a stronger backup support, it can
`stand up to the higher resistance of a balloon catheter.
`In the five-in-six system, the backup support was mea-
`sured while protruding the 5 Fr catheter into the artery
`model out of the outer 6 Fr catheter by 0, 5, 10, and 15
`mm (Fig. 2B). Then the maximal backup support was
`measured in the 6, 7, and 8 Fr guiding catheters
`(Heartrail) alone as well as in the five-in-six system.
`Each measurement was repeated 10 times. Data were
`expressed as mean ⫾ standard deviations. Comparison of
`continuous variables between equivalent groups was cal-
`culated by ANOVA. P value ⱖ 0.05 was considered
`statistically insignificant.
`
`Switching to Five-in-Six System During PCI
`When we could not cross a lesion by a balloon catheter
`or a stent delivery system in the regular 6 Fr system, we
`switched to the five-in-six system. First, the balloon
`catheter or the stent delivery system was removed from
`
`the 6 Fr guiding catheter, while the PCI guidewire and
`the 6 Fr guiding catheter remained in situ. Second, the
`Y-connector that was connected to the 6 Fr guiding
`catheter was also removed (Fig. 3A). Third, a 5 Fr
`guiding catheter was inserted along the PCI guidewire to
`the 6 Fr guiding catheter (Fig. 3B). At this point, the 5 Fr
`guiding catheter should not protrude out of the tip of the
`6 Fr guiding catheter (Fig. 3C). Finally, we connected the
`Y-connector with the 5 Fr guiding catheter and devices
`were delivered through it. The side tube of the Y-con-
`nector of the 5 Fr guiding catheter was connected with
`the pressure and contrast dye lines (Fig. 3D). Before we
`advanced the 5 Fr catheter into the target artery, we first
`put a balloon catheter near the target lesion in the artery
`(Fig. 3E). Keeping a slight tension on the balloon cath-
`eter, we pushed the 5 Fr guiding catheter out slowly in
`order to avoid the possible injury to the coronary artery
`by the tip of the 5 Fr catheter (Fig. 3F).
`
`RESULTS
`In Vitro Results
`Figure 4 shows in vitro results of the backup support.
`Only inserting the 5 Fr guiding catheter into the 6 Fr
`catheter increased the backup support from 63.1 ⫾ 2.1 of
`a 6 Fr guiding catheter alone to 72.0 ⫾ 3.7 gram force
`(gf; P ⬍ 0.01). When the inner catheter was protruded by
`
`
`
`Page 3 of 5
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`454
`
`Takahashi et al.
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`Fig. 2. A: A schematic drawing of the five-in-six system. a
`denotes a model coronary artery; b, a 6 Fr outer guiding cath-
`eter; c, a 5 Fr inner guiding catheter; d, a balloon catheter; e, a
`pushable gauge machine. Star symbol: the maximal backup
`support of this experimental system was defined as the resis-
`tance of a balloon catheter when a 6 Fr guiding catheter could
`not keep a coaxial engagement to the artery model. B: The
`backup support was measured while protruding a 5 Fr catheter
`into the artery model out of a 6 Fr catheter by 0, 5, 10, and 15
`mm.
`
`5 mm into the artery, its backup support was 106.5 ⫾ 3.9
`gf, which was stronger than 96.7 ⫾ 2.6 gf generated by
`a 7 Fr guiding catheter alone (P ⬍ 0.01). The five-in-six
`system can generate a stronger backup support by a
`longer insertion of the 5 Fr catheter into the artery model.
`
`CASE REPORT
`
`Between March 2003 and September 2003, the five-
`in-six system was tried on eight chronic total occlusion
`(CTO) cases (Table I). In seven out of these eight cases,
`the balloon catheter could cross the CTO lesions with the
`use of the five-in-six system. The following case is one of
`the successful five-in-six system procedures.
`A 73-year-old male with a previous history of a stent-
`ing of the mid right coronary artery (RCA) was referred
`for a coronary angiography because of shortness of
`breath for the past several months. His coronary angiog-
`raphy showed the chronic total occlusion at the distal
`
`Fig. 3. A: A Y-connector is removed from the 6 Fr guiding
`catheter. B: A 5 Fr guiding catheter is inserted along the PCI
`guidewire to the 6 Fr guiding catheter. C: The 5 Fr guiding
`catheter should not protrude out of the tip of the 6 Fr guiding
`catheter. D: The Y-connector is connected with the 5 Fr guiding
`catheter. E: A balloon catheter is put near the target lesion. F:
`The 5 Fr guiding catheter is pushed out slowly. a denotes a 6 Fr
`guiding catheter; b, a Y-connector; c, a PCI guidewire; d, a 5 Fr
`guiding catheter; e, a balloon catheter.
`
`In vitro data results. The five-in-six system can gener-
`Fig. 4.
`ate a stronger backup support by a longer insertion of the 5 Fr
`catheter into the artery model.
`
`
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`Page 4 of 5
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`New System to Increase Backup Support
`
`455
`
`TABLE I. Patient Characteristics
`
`Case
`no.
`
`Age
`
`Sex
`
`Target
`vessel
`
`1
`2
`3
`4
`5
`6
`7
`8
`
`73
`55
`56
`64
`75
`65
`77
`70
`
`M RCA
`M LAD
`F
`RCA
`M RCA
`F
`LAD
`M LAD
`M
`LCx
`M RCA
`
`PCI guidewire
`
`Uncrossed
`6 Fr guiding catheter
`balloon size
`2.5 ⫻ 20 Amplatz 1.0
`Cross-It 100
`1.5 ⫻ 20
`Short tip left Judkins 4.0 Conquest Pro
`1.5 ⫻ 20 Amplatz 1.0
`Conquest Pro
`1.5 ⫻ 20 Amplatz 1.0
`Whisper LS
`1.2.5 ⫻ 15
`Short tip left Judkins 3.5 Cross-It 100
`1.5 ⫻ 20
`Extra backup
`Magic FA
`1.5 ⫻ 15 Amplatz 1.0
`Miracle 12
`1.5 ⫻ 15
`Short tip Amplatz 1.0
`Conquest Pro
`
`Puncture
`site
`
`Duration
`of CTO
`DM HL HT
`⫹
`⫹ ⫹ ⬍ 10 months
`Radial artery
`⫹
`⫹ ⫹ 3 years
`Radial artery
`⫺
`⫹ ⫹ 4 years
`Radial artery
`⫺
`⫺ ⫹ 1 year
`Radial artery
`⫺
`⫹ ⫹ 4 months
`Radial artery
`Brachial artery ⫹
`⫹ ⫹ 3 months
`⫹
`⫺ ⫹ 3 months
`Radial artery
`⫹
`⫹ ⫹ Unknown
`Radial artery
`
`Result
`
`Success
`Success
`Success
`Success
`Success
`Success
`Failed
`Success
`
`Fig. 5. A: The distal edge of the stent in RCA was totally occluded with bridging collaterals. B: A balloon catheter could not pass
`the CTO lesion. B1 denotes a balloon catheter. C: A balloon catheter could cross the lesion by using five-in-six system. C1 denotes
`the tip of the 6 Fr guiding catheter; C2, the tip of the 5 Fr guiding catheter; C3, the balloon catheter, which could cross the lesion.
`D: A final angiogram after a stent implantation.
`
`
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`Page 5 of 5
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`Takahashi et al.
`
`edge of the previous stent with bridging collaterals (Fig.
`5A). We inserted a 6 Fr AL-1 guiding catheter (Heartrail)
`into RCA via the right radial artery. A PCI guidewire
`(Cross-It 100; Guidant) successfully crossed the lesion.
`However, a 2.5 ⫻ 20 mm balloon (Ryujin; Terumo)
`could not pass the lesion (Fig. 5B). The guiding catheter
`showed a good coaxial engagement into the coronary
`artery, but its backup support was inadequate. Then we
`switched to the five-in-six system. While inserting the 5
`Fr catheter into RCA by about 15 mm, the same balloon
`could successfully pass and dilate the total occlusion
`(Fig. 5C). Finally, a 3.0 ⫻ 28 mm stent (Penta; Guidant)
`was successfully placed in the lesion (Fig. 5D).
`
`DISCUSSION
`
`In this article, we demonstrate a new approach for the
`coronary interventions to increase the backup support of
`a 6 Fr guiding catheter. A strong backup support of a
`guiding catheter is essential in achieving a successful
`result in PCI [3,4]. In vitro experimental model showed
`that the five-in-six system could generate a better backup
`support compared to a 6 or even a 7 Fr guiding catheter
`alone. In seven of our eight clinical cases, the use of this
`technique created a stronger backup support, then we
`could cross the lesions by balloon catheters successfully.
`It clearly shows that this system is effective at increasing
`the backup support of a 6 Fr guiding catheter.
`Due to an improvement of a guidewire technology, the
`success rate of PCI for CTO lesions is improving [5].
`However, it is still a big problem that a balloon catheter
`sometimes cannot pass through the CTO lesion after a
`PCI guidewire has successfully passed through. Several
`techniques have been proposed to create a better backup
`support. A deep engagement of the guiding catheter into
`the coronary artery and a buddy wire technique are
`already well known for increasing the backup support
`[6 – 8]. Recently, a new technique, the Anchor balloon
`technique, was reported by Fujita et al. [9]. In our cases,
`we could not use these techniques because of their com-
`plicated CTO lesions.
`Changing a guiding catheter is another option to get
`better backup support. If we start PCI with a 6 Fr guiding
`catheter, we can change to a 7 or an 8 Fr guiding catheter,
`which can generate better backup support [3,4]. Amplatz
`or Voda guiding catheters are very well known because
`their designs give strong backup support [10 –12]. How-
`ever, when we try to exchange the guiding catheters,
`there is a significant risk of losing the position of the PCI
`guidewire, which has already crossed the lesion.
`
`In one patient who had a severely calcified CTO le-
`sion, this system could not produce enough backup sup-
`port to cross the lesion by a balloon catheter. However,
`we can conclude that this five-in-six system will work in
`many clinical situations when we need a stronger backup
`support of a 6 Fr guiding catheter.
`
`REFERENCES
`1. Saito S, Ikei H, Hosokawa G, Tanaka S. Influence of the ratio
`between radial artery inner diameter and sheath outer diameter on
`radial artery flow after transradial coronary intervention. Catheter
`Cardiovasc Interv 1999;46:173–178.
`2. Kiemeneij F, Laarman GJ, Odekerken D, Slagboom T, van der
`Wieken R. A randomized comparison of percutaneous translumi-
`nal coronary angioplasty by the radial, brachial and femoral ap-
`proaches: the access study. J Am Coll Cardiol 1997;29:1269 –
`1275.
`3. Talley JD, Mauldin PD, Becker ER. A prospective randomized
`trial comparing the benefits and limitations of 6Fr and 8Fr guiding
`catheters in elective coronary angioplasty: clinical, procedural,
`angiographic, and economic end points. J Interv Cardiol 1995;8:
`345–353.
`4. Metz D, Meyer P, Touati C, Coste P, Petiteau PY, Durand P,
`Faivre R, Lefevre T, Elaerts J. Comparison of 6F with 7F and 8F
`guiding catheters for elective coronary angioplasty: results of a
`prospective, multicenter, randomized trial. Am Heart J 1997;134:
`131–137.
`5. Saito S, Tanaka S, Hiroe Y, Miyashita Y, Takahashi S, Satake S,
`Tanaka K. Angioplasty for chronic total occlusion by using ta-
`pered-tip guidewires. Catheter Cardiovasc Interv 2003;59:305–
`311.
`6. Bartorelli AL, Lavarra F, Trabattoni D, Fabbiocchi F, Loaldi A,
`Galli S, Montorsi P. Successful stent delivery with deep seating of
`6 French guiding catheters in difficult coronary anatomy. Catheter
`Cardiovasc Interv 1999;48:279 –284.
`7. Peels HO, van Boven AJ, den Heijer P, Tio RA, Lie KI, Crijns HJ.
`Deep seating of six French guiding catheters for delivery of new
`Palmaz-Schatz stents. Cathet Cardiovasc Diagn 1996;38:210 –
`213.
`8. Saucedo JF, Muller DW, Moscucci M. Facilitated advancement of
`the Palmaz-Schatz stent delivery system with the use of an adja-
`cent 0.018⬙ stiff wire. Cathet Cardiovasc Diagn 1996;39:106 –110.
`9. Fujita S, Tamai H, Kyo E, Kosuga K, Hata T, Okada M, Naka-
`mura T, Tsuji T, Takeda S, Bin Hu F, Masunaga N, Motohara S,
`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.
`10. Mehta S, Margolis JR, Traktman M, Kramer B, Trautwein R,
`Gasso J, Nader R. Voda guiding catheter is superior to amplatz
`guiding catheter for performing left circumflex PTCA. J Invas
`Cardiol 1994;6:229 –233.
`11. Hoang V, Urban P, Chatelain P, Metz D, Camenzind E, Brzostek
`T, Rutishauser W. Randomized evaluation of six French voda-
`type guiding catheters for left coronary artery balloon angioplasty.
`Cathet Cardiovasc Diagn 1995;35:53–56.
`12. Abhaichand RK, Lefevre T, Louvard Y, Morice MC. Amplatzing
`a 6 Fr Judkins right guiding catheter for increased success in
`complex right coronary artery anatomy. Catheter Cardiovasc In-
`terv 2001;53:405– 409.
`
`