Septal Collaterals in a Chronic Total Occlusion

Abstract

Objective

Percutaneous coronary intervention of a chronic total occlusion (CTO) should be considered in patients with angina or with documented ischemia. We present a patient with angina and stress echocardiography positive for ischemia in the anterior wall.

Key Steps

The coronary angiography revealed a CTO in the left anterior descending artery, and a percutaneous approach was decided. The antegrade dissection reentry was unsuccessful. Retrogradely, through the ipsilateral septal collaterals, a SUOH wire was successfully advanced distally to the CTO. Externalization of the RG3 was successful, and the antegrade microcatheter was advanced inside the distal septal. Successful percutaneous coronary intervention of the left anterior descending artery was performed.

Potential Pitfalls

Ping pong technique was not used, making the procedure challenging for equipment delivery.

Take-Home Messages

One injection, one solution technique can be applied in selected cases with ipsilateral septal collaterals. Careful evaluation of the coronary anatomy before the procedure is mandatory.

Graphical Abstract

The key indication for percutaneous coronary intervention of a chronic total occlusion (CTO) is symptom improvement resistant to medical therapy or with a large area of documented ischemia in the territory of the occluded vessel, and it has gained widespread traction in the hands of experienced operators. Dual angiography in general is a mandatory policy when intervention in a CTO is planned. On the other hand, having performed a preoperative plan of the anatomy can sometimes switch from a dual- to a single-injection technique, as in the following case due to the presence of interventional ipsilateral collaterals.^1,2

Take-Home Messages

• •The interventional cardiologist should carefully examine the collateral channels in a chronic total occlusion and the possible septal communication that supply the occluded vessel.
• •In selected cases, a dual-contrast injection may not be required, and an “one injection, one solution” approach can be applied, reducing the procedural challenges and the radiation exposure duration.

The following procedure outlines the steps of an angioplasty in a CTO in the left anterior descending artery (LAD), taking advantage of the septal collaterals and by using a single catheter both for the antegrade and retrograde approach.

Case Summary

A 54-year-old patient was examined in the cardiology unit due to stable angina (Canadian Cardiovascular Society scale II-III). His past medical history included smoking and hypertension. He had a positive family history of coronary artery disease. He was taking ramipril for hypertension. His electrocardiogram revealed sinus rhythm, and echocardiography showed reduced systolic motion in the anterior wall with a left ventricle ejection fraction of 40%. Stress echocardiography was positive for reversible ischemia in the anterior wall and the apex of the left ventricle. The invasive coronary angiography demonstrated a CTO of the LAD and no significant stenoses from the right coronary artery (RCA) and left circumflex (Video 1). It was decided to perform percutaneous coronary intervention in the LAD.

Procedural Steps

First of all, a 6-F sheath was inserted in the left radial artery, and a 7-F sheath was inserted in the right radial artery. Α guide catheter JR 6-F was engaged in the RCA, and a guide catheter CLS 3,5 7-F was engaged in the left coronary artery.

A part of the mid-distal LAD was outlined retrograde by the ipsilateral septal collaterals and from epicardial collaterals from the RCA (Figures 1 and 2, Video 2).

Figure 1.

Dual-Contrast Injection and Red Arrow Pointing the Distal Cap of Left Anterior Descending Artery Chronic Total Occlusion in Cranial View

Figure 2.

Dual-Contrast Injection Demonstrating the Same Frame, the Second With Red Demarcation of the Septal Communication in a Right Anterior Oblique Cranial View

At first, it was decided to follow an antegrade approach, keeping in mind the nice delineation of the ipsilateral septal collaterals. Using a floppy wire (Boston Scientific), a Corsair Pro XS microcatheter was advanced in the LAD in the proximal cap. Then the floppy wire was removed, and a Gaia Next 3 wire was advanced in the proximal cap in order to perform antegrade dissection re-entry in the LAD. It is a hydrophilic wire, with 1-1 torque response and great control inside the CTO, ideal for increased antitrapping power inside this tough and calcified lesion. The wire was advanced to a small extent in the CTO segment, but the gap was long enough to continue the antegrade dissection re-entry approach with safety (Figure 3). In order to minimize the risk of intraprocedural complications and to minimize the radiation exposure time, it was then decided to switch to a retrograde approach. For this purpose, a Pronavi 1.9 microcatheter was introduced inside the proximal ipsilateral septal, and using contrast injection, we delineated the collateral communication between the septals. This microcatheter has a tapered soft tip of 1.4-F, making it ideal for good pushability in difficult-to-enter branches. A SUOH 03 wire was navigated between the septals, and it was successfully advanced in the mid part of the LAD, after the CTO segment (Figures 4 and 5). Its flexible tip and shaft provide superb trackability and crossability in severe tortuosity.

Figure 3.

Antegrade Approach Using a Microcatheter Corsair Pro XS and a Gaia Next 3

Figure 4.

Contrast Injection Through the Pronavi Microcatheter (Red Arrow) Inserted Inside the Ipsilateral Septal Branch and Delineation of Septal Communication and Antegrade Microcatheter Presence in the Left Anterior Descending Artery (Blue Arrow)

Figure 5.

Successful Wire Advance in the Distal Part of Left Anterior Descending Artery Through the Septal Communication Using a SUOH 03 (Red Arrow)

The wire inside the Pronavi was then exchanged with a GAIA second—high penetration and good torqueability—in order to be advanced in the CTO segment retrogradely. GAIA second approached the left main stem angiographically, through the CTO segment (with retrograde wire escalation) (Figure 6, Video 3). In order to determine the right position of the GAIA inside the LAD, intravascular ultrasound was performed, which confirmed the intraluminal presence of both wires (Figure 7). The retrograde wire was exchanged with an RG3 wire, and it was tipped inside the antegrade microcatheter Corsair Pro XS, inside the CLS guide catheter, in order to externalize it (Tip In) (Figure 8, Video 4). The Corsair microcatheter was then advanced through the LAD and inside the distal septal branch right after the CTO segment (Video 5), and then it was exchanged with a dual-lumen microcatheter RECROSS. A Gladius MG was used to successfully cross the LAD to the distal part (Figure 9, Video 6). TIMI flow grade 3 was achieved using semi-compliant balloons measuring 2 × 20 mm and 2.5 × 20 mm inside the CTO segment. Finally, 3 stents (Promus PREMIER 2.75 × 32 mm, 3 × 32 mm, 3.5 × 28 mm) were implanted consecutively inside the LAD, achieving an excellent angiographic result with TIMI flow grade 3 (Figure 10, Video 7). Both radial sheaths were removed, and radial artery compression devices were used.

Figure 6.

Retrograde Wire Gaia Second Was Advanced Through the Retrograde Microcatheter Inside the Proximal Left Anterior Descending Artery and Left Main Stem (Red Arrow)

Figure 7.

Intravascular Ultrasound Run Ensuring the Right Intraluminal Position of Both Antegrade and Retrograde Wires Inside the Left Anterior Descending Artery (Red Arrows)

Figure 8.

Tip in (Red Arrow) of the Retrograde Wire (RG3) Inside the Antegrade Microcatheter Inside the CLS Guide Catheter

Figure 9.

Exchange With Antegrade Dual Lumen Microcatheter RECROSS (Red Arrow) Inside the Septal Branch and Successful Wire Insertion Through the Distal Part of the Left Anterior Descending Artery

Figure 10.

Final Angiographic Result After Stent Implantation in the Left Anterior Descending Artery

TIMI flow grade 3.

Potential Pitfalls

No collateral communication was noted from the RCA to the LAD, restricting the contrast injection–only antegrade and raising the likelihood of associated complications. In this case, the ping pong technique was not used, making the procedure more strenuous for equipment delivery (only a 7-F guide catheter was engaged in the left main stem). This technique refers to the engagement of the target vessel alternated between 2 guide catheters, as externalizing the wire via the antegrade guide catheter is often difficult.³ Moreover, a radial approach can be challenging in the case of a complex aortic arch anatomy, but settling on this approach can reduce access-site complications.

Conclusions

The septal-to-septal approach is an established technique that uses the delineated septal communication to navigate retrogradely to the CTO with high success rates, an acceptably low frequency of complications, and favorable mid- to long-term outcomes.¹ “One injection, one solution” can describe the breakthrough minimal approach for this case, without the use of the ping pong technique, by employing a single catheter, creating new frontiers in the previously complex CTO management. This innovative one-injection technique, with a single 7-F catheter via the radial artery, is an advancement in CTO treatment, which must be kept in consideration in selected cases, to reduce procedural complications (single radial or femoral arterial access), the amount of contrast injected, and radiation exposure duration.

Equipment List.

Equipment Used in CTO Intervention Involving Septal Collaterals

Guide catheters	•CLS 3,5 7-F: guide catheter engaged in the left main (Boston Scientific) •JR 4 6-F: guide catheter engaged in the RCA (Boston Scientific)
Microcatheters	•CLS 3,5 7-F: guide catheter engaged in the left main (Boston Scientific) •JR 4 6-F: guide catheter engaged in the RCA (Boston Scientific)
Wires	•GAIA next 3: guide wire inserted through the Corsair Pro XS antegradely (ASAHI) •SUOH 03: guide wire inserted through the Pronavi microcatheter and surfing in the septal collaterals (ASAHI) •GAIA second: guide wire crossing the CTO retrogradely exchanged from the SUOH inside the Pronavi (ASAHI) •RG3: wire used for ‘tip in’ technique inside the antegrade microcatheter (ASAHI) •Gladius MG: guide wire inserted inside the LAD (ASAHI)
PCI balloons and drug- eluting stents	•Maverick balloons 2 × 20 mm and 2,5 × 20 mm for inflation inside the CTO (Boston Scientific) •Drug eluting stents Promus premier 2.75 × 32 mm, 3 × 32 mm, 3.5 × 28 mm for final percutaneous coronary intervention (PCI) in the LAD (Boston Scientific)
Imaging	•Intravascular ultrasound (IVUS) Avvigo+ (Boston Scientific)

Funding Support and Author Disclosures

Brosmed Industry is handling the open access fee. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Appendix

Video 1

Coronary angiography, in right anterior oblique cranial view, where the CTO in the LAD is presented.

Video 2

Contrast injection through the microcatheter where the septal collateral communication is depicted.

Video 3

Antegrade and successful retrograde crossing of the CTO in the LAD.

Video 4

Externalization of the RG3 wire through the antegrade microcatheter Corsair Pro Xs.

Video 5

Corsair Pro Xs is advanced in the LAD and inside the distal septal, through the retrograde RG3.

Video 6

Exchanging the Corsair Pro Xs microcatheter with Recross microcatheter.

Video 7

Final angiographic result, post PCI.