Subintimal Distal Anchor Technique for "Balloon-Uncrossable" Chronic Total Occlusions

Abstract: Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) presents unique challenges and potential complications. The two most common failure modes are inability to cross the lesion with a guidewire and failure to cross the CTO with a balloon after successful guidewire crossing (“balloon-uncrossable” CTO). We present a creative solution to assist crossing of balloon-uncrossable CTOs that entails use of a balloon placed over a wire that has been advanced though the subintimal space to “anchor” the guidewire that has crossed through the CTO true lumen enabling lesion crossing with a balloon. 

J INVASIVE CARDIOL 2013;25(10):552-554

Key words: chronic total occlusions, PCI, complications

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Inability to cross the lesion with a guidewire is the most common reason for failure of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).¹ Failure to cross the CTO after successful guidewire crossing is the second most common cause for CTO PCI failure, occurring in up to 10% of cases.^2,3 Several techniques have been described to assist crossing of “balloon-uncrossable” CTOs, such as the use of the Tornus catheter (Asahi Intecc), maneuvers to increase guide catheter support (such as use of guide catheter extensions and various anchor techniques), use of various microcatheters (such as the Tornus or Corsair [Asahi Intecc] and Finecross [Terumo]), and use of rotational atherectomy or laser.⁴ We report a novel “subintimal distal anchor” technique that can enable crossing of balloon-uncrossable CTOs when other maneuvers fail. 

Technique Description

A 62-year-old man with a history of hypertension, severe peripheral arterial disease, and systolic heart failure presented with limiting angina in spite of optimal medical therapy. Diagnostic angiography revealed a mid-right coronary artery (RCA) CTO with non-obstructive disease in the left anterior descending and circumflex arteries and the patient was referred for CTO PCI. 

Bilateral femoral access was obtained with 8 Fr sheaths and anticoagulation was achieved with unfractionated heparin. Bilateral injection confirmed mid-RCA occlusion with reconstitution via collaterals from the left anterior descending and the circumflex arteries (Figures 1A and 1B). The RCA was engaged with an 8 Fr AL1 guide that fit well and provided good support. Antegrade crossing was successful with a Pilot 200 guidewire (Abbott Vascular) via a Valet microcatheter (Volcano Corporation) (Figure 1C). We were unable to cross the lesion with a balloon in spite of using multiple 1.20 mm, 1.25 mm, and 1.5 mm balloons. Several balloons were inflated at high pressure and ruptured within the proximal cap in an attempt to modify the lesion, without success. A Corsair and Finecross microcatheter also failed to cross (Figure 2A) even after using an 8 Fr Guideliner (Figure 2B) for additional support. 

Several passes with a 0.9 mm coronary laser catheter (Spectranetics) operated at maximum energy and fluency were unsuccessful (Figure 2C), as was use of an anchor balloon in the acute marginal branch (Figure 3A). A Tornus catheter was not available at the time of the procedure. Attempts to exchange the Pilot 200 guidewire for a Rotafloppy guidewire (Boston Scientific) also failed. 

The lesion was crossed subintimally with a second Pilot 200 guidewire that was knuckled to the distal RCA (Figure 3B). Reentry attempts using the Stingray balloon wire (BridgePoint Medical) failed (Figure 3C), likely due to diffuse disease of the distal vessel. We inflated a 3.0 mm balloon over the subintimal wire in the distal RCA that “anchored” the proximal guidewire (Figure 4A) and enabled advancement of a 1.5 mm balloon through the CTO. The RCA CTO was successfully predilated and stented with four everolimus-eluting stents with an excellent final angiographic result (Figure 4B). After the procedure, the patient’s angina resolved.

Discussion

These cases illustrate a creative solution to balloon-uncrossable CTOs, ie, use of a balloon placed over a wire that has been advanced though the subintimal space to anchor the guidewire that has crossed through the CTO true lumen and enable lesion crossing with a balloon. 

Failure to cross a lesion with a balloon is most often due to severe calcification at the occlusion site and can be challenging to overcome. Several strategies have been proposed, and can be summarized into two categories: (1) strategies that increase guide-catheter support; and (2) strategies that provide lesion modification.^2,5-12

Strategies that increase guide-catheter support include deep-guide intubation (which can, however, be challenging with the 8 Fr guides often used for transfemoral CTO PCI), use of guide-catheter extensions, such as the Guideliner catheter (Vascular Solutions) and the Guidezilla (Boston Scientific), and use of various anchor techniques (such as side-branch anchor and distal anchor). 

Strategies that involve lesion modification include “rupturing” small balloons advanced as far as possible into the lesion in an attempt to modify the proximal cap (a technique often called “grenadoplasty”), use of various microcatheters, such as Tornus (specifically designed to “screw into” resistant lesions, creating a channel), Corsair or Finecross, and use of laser or the Crosser catheter (Flowcardia, Inc) or rotational atherectomy. However, rotational atherectomy requires wire exchange for a 0.009˝ dedicated guidewire, which may not always be feasible through the CTO. 

The balloon anchoring technique was initially described by Fujita in 2003 as inflation of a balloon in the side branch of a target coronary vessel to facilitate equipment delivery to a target lesion.⁵ Distal anchoring is a variation of this technique in which a balloon is inflated distal to or at the target lesion to enhance support for equipment delivery.¹¹ A modified version of the distal anchor technique was used to cross a balloon-uncrossable CTO in our patient by performing distal balloon inflation within the subintimal space.

The subintimal distal anchor technique has limitations; it requires subintimal wire crossing, which may not always be feasible, as the wire may track side branches. Subintimal crossing can cause subintimal hematoma that may compress the distal true lumen; this is best prevented by limiting as much as possible the size of the “knuckle” or by using the CrossBoss dedicated microdissection catheter (BridgePoint Medical/Boston Scientific). It is important to ensure that the subintimal guidewire has not exited the adventitia, which is best accomplished using dual injection. Inflating balloons in the subintimal space carries risk of vessel rupture that can be minimized by using intravascular ultrasonography to determine the size of the balloon. For the same reason, inflation pressures are usually <8-10 atm. Distal anchoring also requires at least a 7 Fr guide catheter, which may limit its use in transradial CTO interventions unless sheathless guides are used.

In summary, the subintimal distal anchor technique can be a useful second-line strategy for crossing balloon-uncrossable CTOs.

Acknowledgment. We gratefully acknowledge the tremendous support of the cardiac catheterization laboratory team at the Dallas VA Medical Center for enabling the development of novel catheterization techniques and the performance of clinical research.

References

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From the VA North Texas Healthcare System and University of Texas Southwestern Medical Center, Dallas, Texas. 

The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Michael reports support by a Cardiovascular Training Grant from the National Institutes of Health (Award Number T32HL007360). Dr Banerjee is a consultant for Medtronic and Covidien, discloses research support (grants) from Boston Scientific and Gilead, a patent from the University of Texas Southwestern Medical Center at Dallas, speaker honoraria from Covidien, and stock from MDCare Global and HygeiaTel; spouse holds a Boston Scientific grant and has received consultant honoraria from Abbott. Dr Brilakis is a consultant for Abbott Vascular, Janssen, and St Jude Medical, and is on the speaker’s bureau for Terumo, St Jude Medical, Boston Scientific, and Sanofi; he discloses research support (grant) from Guerbet and honoraria from Boston Scientific, Asahi Intecc, and Sanofi; employment income from Medtronic (spouse).

Manuscript submitted February 22, 2013, provisional acceptance given April 25, 2013, final version accepted July 8, 2013.

Address for correspondence: Emmanouil S. Brilakis, MD, PhD, Dallas VA Medical Center (111A), 4500 South Lancaster Road, Dallas, TX 75216. Email: esbrilakis@gmail.com