ADVERTISEMENT
The Chameleon`s Technique: A Novel 3-in-6 Mother-and-Child Technique for Simultaneous Contralateral Angiography During Transradial Angioplasty of CTO via One Guide and One Puncture Site
Abstract: In order to obviate double arterial access for bi-coronary visualization during transradial intervention of chronic total coronary occlusions, a novel technique was used. A 3-in-6 mother-and-child technique was applied in which a 3 Fr intracoronary catheter was advanced via a 6 Fr guide into the artery supplying collaterals to the distal occluded segment of the right coronary artery (RCA). The same guide was used, with the 3 Fr catheter in situ, to visualize the occluded target vessel. With double contrast injections, the guidewire could be guided through the RCA occlusion while the intraluminal position could be visualized and confirmed. This was followed by successful drug-eluting stent implantation. This method to visualize both coronary arteries simultaneously is named the “Chameleon’s technique.”
J INVASIVE CARDIOL 2015;27(11):E248-E251
Key words: transradial approach, percutaneous coronary interventions, coronary occlusions
_________________________________________
In order to assess proper intraluminal wire position during percutaneous coronary intervention (PCI) for coronary occlusions, simultaneous contralateral coronary angiography is mandatory.1 As a chameleon can look into different directions simultaneously, it is possible to visualize the right and left coronary arteries in one angiography run. This is helpful to manipulate the intracoronary guidewire during angioplasty of chronic total occlusions (CTOs) by imaging the collaterally filled occluded segment of the target artery. Usually this requires the use of two puncture sites and two catheters.
I have already described the “one puncture, one guide” (1P1G) technique to visualize both arteries with one multipurpose guide during transradial intervention (TRI) of CTOs.2 The shortcoming of this technique, however, is the risk of losing distal access of the guidewire once the catheter is turned into the opposite coronary sinus and back.
In order to overcome this problem, a 130 cm, 3 Fr intracoronary catheter with side holes has been developed (Balton) (Figure 1). The course of the occluded artery can be visualized by using this device as an intracoronary catheter, advanced in the opposite donor coronary artery supplying collaterals to the occluded segment.
Technique
A 6 Fr multipurpose catheter (such as Kimny, Barbeau, Ikari, Multipurpose, Amplatz Left 1, Judkins Left 3.5) is connected by a Y-connector to an automatic or hand-held 
injection system (Figure 2). After having cannulated and filmed the right coronary artery (RCA) and left coronary artery (LCA) with the same guide, the catheter is turned toward the donor coronary artery, supplying the collaterals. A 3 Fr catheter is introduced into the 6 Fr guide and loaded with an intracoronary 0.014˝ wire. Over this wire, the 3 Fr catheter is advanced to a point distal in the donor artery. The wire is removed and a hand-held injection syringe is connected to the 3 Fr catheter. The wire is removed and the 6 Fr guide is now turned into the contralateral coronary sinus, as close as possible or into the ostium of the coronary artery. An angiogram of the RCA and LCA is now made simultaneously and the course of the occluded artery is verified.
Subsequently, with wires of progressive tip load, attempts are made to cross the occlusion. The relation between the tip of the wire and lumen of the vessel distal to the occlusion is verified by simultaneous angiography. The wire can be redirected or advanced according to findings.
When the wire appears to take the correct intraluminal course, the 3 Fr catheter is no longer of use and can be removed out of the 6 Fr guide, allowing selective angiography of the target vessel. At this point, the operator is able to use all necessary materials, such as microcatheters, balloons, and stents.
Case Description
A 63-year-old female patient with a positive family history and with stable angina pectoris had a positive scintigraphy scan, showing ischemia in the inferoposterior wall. She underwent coronary angiography. The RCA was occluded and the left anterior descending (LAD) coronary artery had an intermediate lesion. The left circumflex (LCX) was normal. The patient was accepted for transradial intervention (TRI) of the CTO-RCA. In a second stage, the LAD lesion would be assessed by fractional flow reserve (FFR) and followed by TRI if necessary.
TRI of this CTO was attempted via right radial approach. Angiography and angioplasty were performed via a 6 Fr Kimny guide (Boston Scientific). The CTO segment was located in segment 3 of the RCA (Figure 3). The distal segment of the RCA was visualized by LCA angiography. The distal ramus descendens posterior (RDP) 
was filled by collaterals originating from the LAD and the proximal RDP by a well-developed collateral from the LCX (Figure 4). A 3 Fr JR4 catheter (Balton) was advanced over a guidewire deep into the LCX (Figure 5). Subsequently, the 6 Fr guide was turned toward the RCA and simultaneous injections of the RCA and LCA were made, displaying the course of the RCA and a long totally occluded segment.
The occlusion could be penetrated by a Pilot 150 wire (Abbott Vascular) and the intraluminal wire position was confirmed by double injection (Figures 6 and 7). The 3 Fr catheter was removed and the RCA was predilated from distal to proximal, followed by placement of three Firehawk (Microport) stents (2.75 x 29 mm distal, 2.75 x 23 mm mid, and 2.75 x 18 mm proximal). Following postdilatation with a 3.0 balloon, the result was satisfactory.
Discussion
Simultaneous visualization of the occluded coronary segment and guiding the CTO wire by 3-in-6 mother-and-child technique was successful. The obvious advantage of this method is the use of only one puncture site, reducing risk for bleeding and discomfort to the patient.
A potential limitation of this technique is the subselective cannulation of the target vessel. However, visualization and back-up are good enough to guide the wire toward the occluded segment. For complex CTOs, a microcatheter can be of additional value to guide, support, and exchange the guidewire. For less complex CTOs, use of a wire alone without the use of an additional microcatheter will usually do. Once the wire seems to be properly positioned, the 3 Fr catheter has no further function after the last control injection and can subsequently be removed. From that moment, the operator is free to use any material to open the occluded artery, such as microcatheters, predilating balloons, and stents.
Of course, this patient-friendly approach needs additional development and refinement.
Dr Fuminobu Yoshimachi (Department of Cardiology, Tokai University School of Medicine, Isehara City, Kanagawa, Japan) has recently described the use of microcatheters instead of 3 Fr catheters via 5 Fr guides in the same setting (submitted for publication).
We both agreed to name the family of techniques that include the 1P1G, microcatheters in 5 Fr guides, and 3 Fr catheters in 6 Fr guides the “Chameleon’s technique.”
Conclusion
A 3-in-6 mother-and-child technique is described for distal visualization during TRI of a CTO, which obviates the need for a second puncture site.
References
1. Weisz G, Moses JW. Contemporary principles of coronary chronic total occlusion recanalization. Catheter Cardiovasc Interv. 2010;75:S21-S27.
2. Kiemeneij F. Simultaneous transradial coronary angioplasty and contralateral coronary angiography with a single guide catheter for total coronary occlusions. J Invasive Cardiol. 2014;26:87-90.
______________________________________
From the Tergooi Hospital, Department of Cardiology, Blaricum, The Netherlands.
Disclosure: The author has completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The author reports no conflicts of interest regarding the content herein.
Manuscript submitted April 22, 2015, provisional acceptance given April 23, 2015, final version accepted April 25, 2015.
Address for correspondence: Ferdinand Kiemeneij, MD, PhD, Tergooi Hospital, Department of Cardiology, Rijksstraatweg 1, 1261 AN Blaricum, The Netherlands. Email: ferdi@euronet.nl
