Electrocautery-Facilitated Crossing (ECFC) of Chronic Total Occlusions

Abstract: Background. The use of electrocautery (EC)-facilitated re-entry in an aorto-ostial chronic total occlusion (CTO) of the right coronary artery (RCA) was first described in 2016. Since then, it has been utilized sporadically, but little is reported about the use of EC in lesion crossing during CTO percutaneous coronary intervention (PCI). The objective of this study is to describe the efficacy of EC-facilitated crossing (ECFC) of CTOs. Methods. We report a case series of ECFC of CTOs where standard techniques are either not suitable or ineffective. We utilized stiff, high tip-load, and tapered guidewires energized with EC to facilitate wire crossing of wire-uncrossable CTOs. Results. A total of 293 CTO-PCIs were performed at our institution between October 16, 2016 and October 30, 2018 and ECFC was attempted in 6 cases (2%); 5 cases were retrograde and 1 case was both antegrade and retrograde. All 6 cases were classified as very difficult by the J-CTO score of ≥3. ECFC was performed in 2 aorto-ostial lesions, 3 lesions at the major bifurcation, and 1 lesion in the proximal obtuse marginal. The successful crossing of the target lesion was achieved using ECFC in 5 cases (83%). We were unable to cross 1 lesion of severe in-stent restenosis with stent fracture at the distal RCA bifurcation. Despite attempting ECFC, both antegrade and retrograde crossing remained unsuccessful. There were no ECFC-related complications. Conclusion. The use of energized stiff guidewires to perform ECFC can be of great value for CTO lesions when standard CTO techniques fail. ECFC should only be performed with caution by experienced and high-volume operators to avoid complications.

Key words: chronic total occlusions, complex PCI, percutaneous coronary intervention

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is rapidly evolving.¹ Despite high success rates with the use of the hybrid algorithm and contemporary equipment, operators around the world continue to describe new and innovative techniques to further improve success.^1-3 The use of electrocautery (EC)-facilitated re-entry in an aorto-ostial right coronary artery (RCA)-CTO was first described in 2016.⁴ Although utilized sporadically by operators around the world, little is reported about the use of EC in lesion crossing during CTO-PCI. We report a case series of EC-facilitated crossing (ECFC) of both aorto-ostial and non-aorto-ostial CTOs.

Methods

A total of 293 CTO-PCIs were performed at our institution between October 16, 2016 and October 30, 2018, in which ECFC was performed in 6 patients (2%). The relevant clinical and procedural data of all 6 cases are shown in Supplemental Table S1 (available at www.invasivecardiology.com). All cases were performed by an experienced and high-volume CTO operator (KA). We describe the interventional details of 2 representative cases.

Patient #1. A 60-year-old female with a history of radiation for Hodgkin’s lymphoma underwent cardiac catheterization for angina and abnormal stress myocardial perfusion imaging. She was found to have severe triple-vessel coronary artery disease involving the ostial left main (LM), mid left anterior descending (LAD) coronary artery, and an aorto-ostial CTO of the RCA. She was deemed to be a poor surgical candidate due to a history of chest radiation and porcelain aorta. She underwent PCI of the LM and LAD with drug-eluting stents. She was referred for PCI of the RCA-CTO as she continued to have angina refractory to medical therapy (Figures 1A and 1B; Video 1, supplemental videos available at www.invasivecardiology.com). A 7 Fr EBU 3.75 guide catheter (Medtronic) was advanced from right radial access and used to cannulate the LM. The primary retrograde approach was chosen due to the aorto-ostial occlusion. A septal collateral from the LAD was crossed with a Sion guidewire (Asahi Intecc) and then subsequently with a Caravel microcatheter (Asahi Intecc) (Figure 1C). Retrograde wire escalation using multiple stiff tapered guidewires, such as the Gaia 3, Confianza Pro 12, Astato XS 20, and Astato XS 40 (all Asahi Intecc), were unsuccessful. The Caravel microcatheter was then exchanged for a FineCross microcatheter (Terumo), through which an Astato XS 40 guidewire was advanced. The back end of the retrograde Astato XS 40 guidewire was connected to a unipolar EC pencil with forceps, and the ground pad was placed on the patient.⁴ An 8 Fr JR4 guide catheter was advanced through right femoral access and placed in the right coronary cusp next to the RCA ostium. Aortogram was performed at multiple projections to localize the RCA ostium. A Confianza Pro 12 guidewire was advanced through the JR4 guide catheter to engage the ostium. The retrograde Astato XS 40 guidewire was energized in cutting mode at 50 J for a 3-second burst, with successful crossing into the aorta using the antegrade guidewire as a marker (True Lumen Puncture) (Figure 1D; Video 2). To better attempt manipulation, the Astato XS 40 guidewire was exchanged for a Gaia 3 wire, which crossed into the aorta using a retrograde approach. However, advancement of the retrograde microcatheter, as well as a low-profile balloon, was unsuccessful. The Gaia 3 guidewire was then removed, and an R350 guidewire (Teleflex) was used to cross into the aorta, which was snared and externalized. The externalized guidewire enhanced the support and allowed advancement of the microcatheter using an anterograde approach. The retrograde approach was therefore converted to an antegrade approach, and orbital atherectomy (Cardiovascular Systems, Inc) followed by PCI with drug-eluting stents was performed in standard fashion, achieving successful revascularization of the RCA (Figure 1E; Video 3).

Patient #2. A 75-year-old male with a history of coronary artery bypass graft surgery underwent cardiac catheterization for worsening angina. He was found to have a patent left internal mammary artery (LIMA) graft to the LAD and a saphenous vein graft (SVG) to a diagonal. The dominant left circumflex (LCX) artery was chronically occluded at the origin (Video 4), with an occluded SVG to the LCX. The patient was referred for CTO-PCI of the LCX after a failed attempt.

Eight Fr EBU 4.0 and 7 Fr JR 4 catheters through bilateral femoral access were used to cannulate the left and right coronary system, respectively. A primary retrograde approach was used due to proximal cap ambiguity. The epicardial collaterals from the RCA were crossed with a Sion guidewire and subsequently with a Caravel microcatheter (Figure 2A). Attempts of direct puncture into the LM artery with retrograde wire escalation (with Gaia 3, Confianza Pro 12, Astato XS 20, and Astato XS 40) were unsuccessful. The back end of the retrograde Astato XS 40 guidewire was connected to a unipolar EC pencil with forceps, and the ground pad was placed on the patient.⁴ A 5.0 x 8 non-compliant balloon through the antegrade guide was inflated in the LM into the LAD. While deflating the balloon, the retrograde Astato XS 40 was energized in cutting mode at 50 J for a 3-second burst, with successful puncture into the LM (Figure 2B). The guidewire was de-escalated to a Gaia 3 guidewire that was advanced to the antegrade guide catheter. The retrograde guidewire was trapped in the antegrade guide catheter to facilitate the advancement of the retrograde microcatheter. The guidewire was exchanged for an R350 guidewire for externalization. The retrograde approach was then converted to an antegrade approach, and orbital atherectomy followed by PCI with DES was performed in a provisional fashion from the LM into the LCX (Figure 2C; Video 5).

Discussion

In this case series, we describe the use of stiff, energized, high tip-load, and tapered guidewires, such as Confianza Pro 12 and Astato XS 20/40 (Asahi Intecc) and Hornet 14 (Boston Scientific) with EC in crossing wire-uncrossable CTOs. We attempted ECFC with stiff guidewires in 6 CTO lesions during the study period; 2 aorto-ostial RCA lesions, 3 lesions at the major bifurcation (2 ostial LCX and 1 distal RCA bifurcation), and 1 lesion in the proximal obtuse marginal. The ECFC was performed through the retrograde approach in all 5 cases, both antegrade and retrograde in 1 case. Successful crossing was achieved in 5 cases (83%). We were unable to cross 1 lesion of severe in-stent restenosis with stent fracture at the distal RCA bifurcation. Despite using a 0.014˝ Astato XS 40 guidewire energized with EC cutting at 70 J, antegrade and retrograde crossing remained unsuccessful. All 6 cases were classified as very difficult by their J-CTO scores of ≥3. There were no ECFC-related complications; 1 patient had radial artery perforation, which was managed conservatively.

The energized stiff guidewire with EC is utilized to puncture the inferior vena cava and aortic wall to establish transcaval large-bore access.⁵ This technique was subsequently utilized by Nicholson et al to perform EC-assisted re-entry into the aorta to successfully cross an aorto-ostial RCA-CTO.⁴ We expanded the use of the energized stiff guidewire to perform ECFC to non-aorto-ostial lesions, where standard CTO techniques are either not suitable or ineffective. Similarly, we introduced the use of energized 20 g and 40 g tip, tapered guidewires to penetrate such lesions. ECFC should only be utilized in cases without anatomic ambiguity, to achieve particular goals such as puncturing of the distal or proximal caps or re-entry into the true lumen. We used antegrade guidewires, knuckle guidewires, balloons, and extension catheters to resolve any ambiguity before using ECFC.

Furthermore, the distance of the ECFC crossing was <10 mm in all lesions. We recommend using stiff guidewires, such as a Confianza Pro, Hornet, or Astato. Although electrically insulated microcatheters are the preferred option for using EC-energized guidewires to achieve transcaval access, we used three different types of microcatheter (Finecross, Caravel, and Corsair Pro). In 1 case, the tip of the Caravel microcatheter melted while using ECFC with a Confianza Pro 12 guidewire. The Caravel microcatheter was thereafter exchanged for a FineCross microcatheter to successfully perform ECFC. We utilize 50-70 J in cutting mode, using 3-second bursts; however, it is unclear how much energy is sufficient to perform ECFC, which should be explored further in studies with a larger sample size. The use of EC in coagulation mode is not recommended, as it can result in extensive myocardial thermal injury. We did not have ECFC-related complications; however, caution is warranted as ECFC in this case series was performed in highly selected lesions with anatomic suitability by an operator with extensive experience with CTO-PCI.

Conclusion

The use of energized stiff guidewires to perform ECFC can be of great value for CTO crossing when standard CTO techniques fail. ECFC should only be performed with caution by experienced and high-volume CTO-PCI operators to avoid complications. As the use of ECFC continues to grow, further studies are needed to identify a uniform protocol for use, and to determine the efficacy and safety of this procedure.

View the Accompanying Video Series Here

From the Division of Cardiology, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted July 4, 2019, provisional acceptance given July 9, 2019, final version accepted August 1, 2019.

Address for correspondence: Khaldoon Alaswad, MD, Henry Ford Hospital, 2799 West Grand Blvd, Detroit, MI 48202. Email: Kalaswa1@hfhs.org

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