Subintimal stenting

Subintimal Stenting as a Bail-Out Strategy for Iatrogenic Coronary Artery Dissection

A 61-year-old male patient has been complaining of heart failure symptoms for the past 12 months. Transthoracic echocardiography showed hypokinesia of the anterior interventricular septum and apical segments and a moderately depressed left ventricular function (EF 33%). Coronary angiography was performed using the right transradial approach without difficulty or any complications. (Figure 1)

Figure 1. (A-B) Diagnostic angiography revealed a totally occluded left anterior descending artery (LAD) (yellow arrow) after the first septal perforator branch. (C) The left circumflex artery was a dominant vessel with no significant stenosis. (D) The right coronary artery was non-dominant.

Percutaneous coronary intervention (PCI) of the LAD was then performed. The J CTO score and EuroCTO CASTLE score was 2, while the PROGRESS CTO score was 1. Sion Blue (Asahi Intecc, Japan) was the workhorse wire used with a 135 cm Caravel microcatheter (Asahi Intecc, Japan). Antegrade wire escalation technique was used. (Figure 2-6)

Figure 2. PCI of the left anterior descending artery. (A) A Fielder XT-R (Asahi Intecc, Japan) followed by a (B) Gaia Second (Asahi Intecc, Japan) wire was used to cross the lesion.

Figure 3. There was difficulty in advancing the micro catheter towards the mid segment. (A) Pre-dilatation using semi-compliant balloons: 1.0 x 15 mm Sapphire (OrbusNeich, Hong Kong) and a 1.5 x 15 mm Sprinter Legend (Medtronic, USA). (B) Contrast injection did not reveal any flow suggesting wire entry into the subintimal space. (C) Parallel wire technique using a Miracle 3 was done but the wire continued to go to the same track.

Figure 4. Intravascular (IVUS) imaging showed the wire to be initially in the true lumen (A-B), then into a false channel for a short segment (C-D), with re-entry into the true lumen distally (E).

Figure 5. (A-B) Distal true lumen entry was confirmed with wire passage into the septal collateral ({) connecting the LAD to the LCX and aspiration of blood from the microcatheter. (C) Since there were no major side branches on the dissected area, prolonged balloon inflation was done using a 2.5 x 25 mm Sprinter Legend semi compliant balloon (Medtronic, USA) for 120 seconds on the mid segment to further dilate the true lumen while compressing the subintimal space (false channel) into the wall.

Figure 6. (A) TIMI 3 flow was achieved except for the apical segment of the LAD which did not have any flow. (B) A 2.5 x 38 mm Zotarolimus-eluting stent (Resolute Onyx) (Medtronic, USA) was deployed on the proximal to mid segment. Wiring of the apical segment was done to restore flow (+).

Figure 7. Final shot showed a TIMI Grade Flow of 3 on the LAD including the apical segment no loss of side branches.

The patient was asymptomatic and hemodynamically stable throughout the procedure with no ECG changes. Dual anti-platelet therapy with Aspirin and Clopidogrel were given.