New methods in diagnosis and therapy
Successful percutaneous coronary intervention using a 4-in-3 “Slender Mother and Child” PCI technique

Introduction

Since percutaneous coronary intervention (PCI) was in­troduced by Grüntzig, there has been significant down-sizing of PCI devices [1]. This progressive reduction in catheter size has been associated with a progressive decrease in complications, mainly those related to the access site [2–4]. In addition, down-sizing of catheters has reduced the volume of contrast medium that must be injected [5]. Although PCI using a 5-Fr guiding catheter is expected to attenuate complications such as bleeding and radial artery occlusion, virtual 3-Fr PCI using a 5-Fr sheathless guiding catheter could lead to less invasive PCI as a result of reduction in puncture size [6]. However, a 5-Fr guiding catheter may limit the PCI devices and techniques that can be used compared with a 6-Fr guiding catheter.

Recently, a 4-Fr KIWAMI ST01 HeartrailTM guiding ca­theter (Terumo, Japan) and a 4-Fr i-WorksTM straight guiding ca­theter (MEDIKIT, Japan) have been used in the clinical setting [7]. These guiding catheters were developed to im­prove stent delivery in patients with coronary artery disease. These guiding catheters are inserted into a 6-Fr guiding catheter resulting in a 4-in-6 system.

In this article, we present a new system for PCI called the 4-in-5 system and 4-in-3 system.

Case reports

Case 1



A 77-year-old Japanese man visited the outpatient clinic of our institution because of dyspnea on exertion. Coronary angiography (CAG) showed that there was a severely stenotic lesion in the right coronary artery (RCA). He underwent PCI for the RCA lesion. A 5-Fr JR 4.0 HeartrailTM guiding catheter (Terumo, Japan) was positioned in the ostium of the RCA. After wiring into the RCA with a Runthrough NSTM hypercoat guidewire (Terumo, Japan), pre-dilatation was performed using a 3.0 mm × 12 mm LIFESPEAR HPTM balloon catheter (Lifeline, Japan). We tried to deliver a 3.0 mm × 14 mm NoboriTM stent (Terumo, Japan), but the stent could not pass the stenotic lesion because of a proximal stent that had been implanted previously. Although we tried the two-wire technique, the stent still could not be advanced. Next, we inserted a 4-Fr KIWAMI HeartrailTM guiding catheter (Terumo, Japan) into the 5-Fr guiding catheter. After using a balloon catheter to anchor the 5-Fr guiding catheter, a 4-Fr guiding catheter was inserted at the proximal site of the lesion. The stent was implanted and the final CAG result was excellent (Figures 1 and 2).



Case 2



A 65-year-old Japanese man visited the outpatient clinic of our institution because of chest pain on exertion. Coronary angiography showed that there was a severely stenotic lesion in the RCA. He underwent PCI for the RCA lesion. A 5-Fr AL 1.0 WorksTM guiding catheter (MEDIKIT, Japan) was positioned in the ostium of the RCA. After wiring into the RCA with a Wizard3TM guidewire (Lifeline, Japan), pre-dilatation was performed using 2.0 mm × 15 mm MINI TREKTM balloon catheters (Abbott, USA). We tried to deliver a 2.5 mm × 24 mm NoboriTM stent (Terumo, Japan), but the stent could not pass because of a stent that had been implanted previously at the proximal site of the lesion. Although we tried the two-wire technique, the stent still could not pass. Next, we inserted a 4-Fr i-WorksTM guiding catheter (MEDIKIT, Japan) into the 5-Fr guiding catheter.

After using a balloon catheter to anchor the 5-Fr guiding catheter, a 4-Fr guiding catheter was advanced into the proximal site of the lesion. The stent was implanted and the final CAG result was excellent (Figure 3).

Discussion

We report two cases of successful PCI using the 4-in-3 technique. This technique is the so-called “Slender Mo-ther and Child” technique, where a 4-Fr “child” guiding catheter is inserted into a 5-Fr “slender mother” sheathless guiding catheter (virtual 3-Fr PCI system). Because the performance of a 5-Fr sheathless PCI system appears to be comparable to one using a 5-Fr guiding catheter, while the puncture-site damage remains equivalent to that of a 3-Fr introducer sheath, it is called a virtual 3-Fr PCI system.

Saito et al. demonstrated that based on the radial artery inner diameter, 72.6% of female and 85.7% of male Asian patients could physically accept a 6-Fr sheath [8]. The ratio of the radial artery to sheath diameter has been shown to be an important predictor of the reduction in radial artery flow after transradial intervention, and radial occlusion rates are significantly lower if the ratio of radial artery inner diameter/sheath outer diameter is ≥ 1.0. Thus, less invasive PCI using 5-Fr, 5-Fr sheathless and 4-Fr guiding catheters is expected to be widely adopted by interventional cardiologists to attenuate access site-related complications [2]. We have reported that down-sizing of the sheath reduces bleeding complications and radial artery occlusion after transradial catheterization [3]. Although some techniques are available for slender PCI using 5-Fr and 4-Fr guiding catheters, these catheters may limit the PCI devices and techniques that can be used [9–11]. In our cases, Nobori stents were deployed through a 4-Fr “child” catheter. Most currently available stents including bare metal stents (Integrity, Medtronic, USA; MULTI-LINK 8, Abbott, USA; S-Stent, Biosensors International, Ltd.) and drug-eluting stents (Nobori, Terumo, Japan; XIENCE PRIME, Abbott, USA; PROMUS Element, Boston Scientific, USA; Resolute Integrity, Medtronic, USA) are compatible with 4-Fr guiding catheters. However, there is a possibility that the tortuosity of the access artery might compress the inner lumen of the catheters, and these stents may not pass through 4-Fr guiding catheters in some patients.

In addition, combinations such as a 5-Fr HeartrailTM guiding catheter (Terumo, Japan) and a 4-Fr KIWAMI ST01 HeartrailTM guiding catheter (Terumo, Japan), and a 5-Fr WorksTM guiding catheter (MEDIKIT, Japan) and a 4-Fr i-Works guiding catheter (MEDIKIT, Japan) have been recommended to match the outer diameter of the “child” guiding catheter with the inner diameter of the “slender mother” guiding catheter. Without this type of matching, it may be difficult to insert a “child” guiding catheter from one manufacturer into a “slender mother” guiding catheter from another manufacturer.

If it is difficult to deploy a stent into the target lesion in slender PCI, then our “Slender Mother and Child” system may be useful to deliver the stent.

In conclusion, we present a new PCI system called a 4-in-3 technique. Although this system could increase the possibility of slender PCI using a 5-Fr guiding catheter, it limits the PCI devices and techniques that can be used.

References

 1. Grüntzig A, Schneider HJ. The percutaneous dilatation of chronic coronary stenosis – experiments and morphology. Schweiz Med Wochenschr 1977; 107: 1588.

 2. Ikari Y, Matsukage T, Yoshimachi F. Coronary intervention: less invasive strategy in PCI. Cardiovasc Interv Ther 2012; 27: 84–92.

 3. Honda T, Fujimoto K, Miyao Y, et al. Access-site related complications after transradial catheterization can be reduced with smaller sheath size and statins. Cardiovasc Interv Ther 2012; 27: 174–180.

 4. Islam AHMW, Munwar S, Talukder S, et al. Slender percutaneous coronary intervention via transradial approach by using 5Fr guide catheter: an updated single center experiences. Cardiovasc J 2013; 5: 160–164.

 5. Nozue T, Michishita I, Mizuguchi I. Impact of catheter down-sizing and power injector use on the amount of contrast medium delivered. Cardiovasc Interv Ther 2010; 25: 24–28.

 6. Takeshita S, Saito S. Transradial coronary intervention using a novel 5-Fr Sheathless guiding catheter. Catheter Cardiovasc Interv 2009; 74: 862–865.

 7. Hiwatashi A, Iwabuchi M, Yokoi H, et al. PCI using a 4-Fr “child” guide catheter in a ”mother” guide catheter: Kyushu KIWAMI® ST registry. Catheter Cardiovasc Interv 2010; 76: 919–923.

 8. Saito S, Ikei H, Hosokawa G, et al. 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.

 9. Yoshimachi F, Masutani M, Matsukage T, et al. Kissing balloon technique within a 5 Fr guiding catheter using 0.010 inch guidewires and 0.010 inch guidewire-compatible balloons. J Invasive Cardiol 2007; 19: 519–524.

10. Yoshimachi F, Ikari Y, Matsukage T, et al. A novel method of PercuSurge distal protection in a five French guiding catheter without an Export aspiration catheter. J Invasive Cardiol 2008; 20: 168–172.

11. Yoshimachi F, Aida Y, Miura D, et al. Percutaneous coronary intervention without use of guiding catheters for extreme downsizing: the Emperor’s new clothes technique. Cardiovasc Interv Ther 2013; 28: 213–215.