The novel use of retrograde CTO PCI techniques as a rescue strategy for an acute right coronary artery occlusion due to iatrogenic dissection

Abstract

Coronary artery dissection is a known complication of percutaneous coronary intervention (PCI). Such dissections are often treated by antegrade PCI. When antegrade PCI fails, the options become limited to conservative management or coronary artery bypass grafting (CABG). CABG comes with its own risks, and conservative management can result in a potentially larger infarct.

Here we present a novel use of retrograde chronic total occlusion (CTO) PCI techniques to treat an iatrogenic, type D dissection of the right coronary artery in a young male with an acute coronary syndrome. Reentrance of the true lumen by standard antegrade approaches failed. The rescue strategy using a retrograde CTO PCI approach not only had advantages over surgery and conservative management, but also over antegrade PCI. A soft wire, designed for collaterals, was used to “surf” the dissection and reach the antegrade guiding catheter. Thus, the true lumen could be used. This novel approach provided the advantages both of preserving major side branches, which are often lost with antegrade PCI approaches, and of not unnecessarily puncturing the dissection membrane.

<Learning objective: Extensive iatrogenic coronary artery dissections not amenable to antegrade PCI are typically managed conservatively or by CABG. A novel, bail-out strategy using retrograde CTO PCI techniques provided another treatment strategy. A soft wire, designed for collaterals, was used to “surf” the dissection and reach the antegrade guiding catheter. This method has the great advantage of preserving major side branches, which are often lost with antegrade PCI approaches.>

Introduction

Vessel dissection is a potentially severe complication during percutaneous coronary intervention (PCI). When small, stable, and without flow-limiting effects, dissections produce almost no clinical consequences. Conversely, large, often spiral, dissections may cause abrupt vessel closure by mechanical obstruction due to the dissection membrane or compression of the true lumen by a vessel wall hematoma.

Although the incidence of iatrogenic coronary artery dissection is unclear, histological differences might make it higher with catheter engagement of the proximal right coronary artery (RCA) than with the left coronary artery (LCA) [1], [2], [3]. Prior to the stent-era, iatrogenic dissections often required emergent CABG. Now, even iatrogenic left main dissections may be treated with antegrade PCI and stenting [4]. Nevertheless, entering the true lumen via an antegrade approach occasionally fails, and patients either undergo surgery or are treated conservatively. Here we report the novel use of retrograde chronic total occlusion (CTO) techniques as a rescue procedure for stenting a catheter-induced antegrade spiral dissection of the RCA. This bailout procedure, which preserves coronary anatomy, is worth considering before resorting to surgery or conservative management.

Case report

Patient consent for the reporting of this case was obtained and recorded.

A 35-year-old male with unstable angina (Braunwald subgroup IIIb) of two weeks’ duration was admitted for coronary angiography. Risk factors were family history, hypercholesterolemia, arterial hypertension, and tobacco use. Physical examination and standard laboratory tests were otherwise unremarkable. Electrocardiography showed normal sinus rhythm with Q-waves and negative T-waves in leads III and aVF. Transthoracic echocardiography revealed inferior wall hypokinesia in the basal segment.

Transradial catheterization showed mild atherosclerosis throughout the LCA and a subtotal (99%) type B-stenosis in the proximal RCA with antegrade thrombolysis in myocardial infarction (TIMI) 2 flow. The RCA was visualized via septal collaterals graded CC1. For stenting the proximal RCA, the operator chose a standard 6 Fr Judkins JR 4 guiding catheter (Launcher, Medtronic, Minneapolis, MN, USA). Upon RCA intubation, abrupt occlusion (TIMI 0) due to a type D dissection occurred (Fig. 1A). The patient experienced moderate chest pain, but remained hemodynamically stable. Leads II and III developed ST-segment elevations. The operator attempted reentering the distal true lumen by passing through the dissection with a standard hydrophilic non-polymer coated guidewire (BMW universal 0.0014 inch, Abbott, Santa Clara, CA, USA), but only a right ventricular (RV) branch could be entered. The operator changed to a stiffer wire (Miracle 6, Asahi, Nagoya-shi, Aichi, Japan) and unsuccessfully tried puncturing the dissection membrane to reenter the true lumen. The procedure was stopped. The patient remained stable with chest pain disappearing spontaneously. Three hours later high sensitivity (hs)-troponin increased to three-fold the upper limit of normal. The patient, who developed mild chest pain and persistent ST-segment elevations in the inferior leads, was referred for further treatment. He was given enoxaparin and aspirin and loaded with 60 mg prasugrel. Right femoral access was achieved, and a 7 Fr sheath and 7 Fr RCB-guiding catheter (Launcher, Medtronic) adapted to the proximal RCA were used. The RCA was totally occluded (Fig. 1B). A soft polymer coated guidewire (Fielder XT-R, Asahi) was used with a microcatheter (Finecross, Terumo, Tokyo, Japan) in an attempt to cross gently through the large antegrade dissection by chance, but this failed. Antegrade dye injection was avoided to prevent extension of a mural hematoma.

Fig. 1.

(A) Right coronary artery (RCA) showing spiral dissection with complete vessel occlusion, [left anterior oblique (LAO) 46°, cranial/caudal 0°]; (B) RCA with thrombolysis in myocardial infarction 0 flow prior to rescue strategy (LAO 41°, cranial/caudal 0°).

The retrograde rescue intervention began by accessing the left femoral artery and inserting a 7 Fr sheath and 7 Fr Judkins left 4.0 guiding catheter (Launcher, Medtronic). This short tip guiding catheter was only placed to the ostium so as to avoid touching the antegrade dissection. During LCA injection, septal branches collateralizing the posterior descending artery (PDA) were identified (Fig. 2A). Using a guidewire (Sion, Asahi) and 150 cm microcatheter (Corsair, Asahi), the Corsair catheter was advanced retrogradely through the third septal branch into the PDA distal to the occlusion (Fig. 2B. The soft Sion wire was then used to proceed retrogradely from the definite true lumen to the ostial RCA using gentle maneuvers. It was directed into the antegrade 7 Fr RCB guiding catheter and advanced as far as possible. The Sion wire was trapped with a 2.5 mm × 15 mm Trek Balloon (Abbot Vascular), and the Corsair catheter was advanced into the guiding catheter. The Sion wire was exchanged with a RG3 wire (Asahi) so that a safe, continuous connection from the left to right femoral access sites existed (Fig. 2C). Antegrade dilatation with a 2.5 mm × 30 mm Trek Balloon (Abbot Vascular) was followed by implantation of two drug-eluting stents (Xience, Abbott Vascular), 2.75 mm × 33 mm and 3 mm × 18 mm; pressure up to 20 bar over 45 s each. The final RCA angiogram demonstrated antegrade TIMI 3 flow with preserved RV branch patency; LCA angiography showed normal vessels without retrograde flow into the PDA (Fig. 2D). The total time required for the examination and bail out procedure was 54 min. The total radiation time was 19.1 min with a radiation dose of 26.16 cGy/cm², the total amount of contrast used was 110 mL, and the maximum hs-troponin-T was 0.172 μg/L. The patient was discharged three days later. Echocardiography performed pre-discharge showed no regional wall motion abnormalities.

Fig. 2.

(A) Left coronary artery (LCA) with retrograde filling of distal right coronary artery (RCA) and antegrade wire in RCA, [left anterior oblique (LAO) 61°, cranial/caudal 0°]; (B) LCA angiogram showing retrograde wire through septal vessel into the posterior descending artery of the RCA [right anterior oblique (RAO) 35°, caudal 3°]; (C) RAO-projection showing antegrade dilation via the externalized retrograde wire. The wire is secured within the retrograde Corsair microcatheter to protect septal connections, (RAO 35°, caudal 3°); (D) recanalized RCA post-stenting with antegrade thrombolysis in myocardial infarction 3 flow and no unprotected dissection (LAO 90°, cranial/caudal 0°).

Discussion

When an extensive iatrogenic coronary artery dissection occurs and cannot be treated via an antegrade PCI approach, options are generally limited to CABG or conservative management. In the case reported here, a guiding catheter, one which perhaps had increased torque as a result of using radial access, induced a dissection of the RCA. We treated this with an alternative approach using retrograde CTO PCI techniques, which may be of interest for centers experienced in these techniques. Surgery or a potentially larger infarction associated with conservative management may both be avoided. Furthermore, it has advantages compared to an antegrade approach, which may entail dissection membrane puncturing and side branch loss during subsequent stenting (e.g. rescue subintimal tracking and reentry) [5]. Likewise, intravascular ultrasound, which is often used to find the entry of dissections, was avoided here as we knew the point of entry from the guiding catheter and we wished to compress the subintimal wall hematoma with a stent. Importantly, a soft wire, designed for collaterals, was used for navigating the dissection [6]. This allowed for surfing of the true vessel lumen along the dissection to the antegrade guiding catheter. This differs from standard retrograde CTO procedures, which exchange the soft wire for a stiffer wire to cross the CTO. To the best of our knowledge, such a rescue procedure is not widely used. Bryniarski et al. described the use of a retrograde approach to open an RCA CTO that was complicated by a dissection [7].

There is a need for treatment options beyond surgery and conservative management when antegrade PCI fails in the setting of vessel occlusion due to iatrogenic dissection, and the approach described here fulfills that need. Furthermore, the use of CTO PCI techniques may actually offer advantages over antegrade PCI by preserving coronary anatomy.

Conflict of interest

The authors declare that there is no conflict of interest.