Abstract
Treatment of chronic total occlusion (CTO) lesions remains a major challenge for interventional cardiology. In previous coronary artery bypass graft (CABG) patients, when antegrade native CTO percutaneous coronary intervention (PCI) is not feasible, a retrograde approach through an occluded bypass conduit could be a treatment option; however this approach carries risk for unique complications, some of which can be serious. We describe a case of retrograde CTO PCI through an occluded saphenous vein graft (SVG) complicated by an extensive rupture of the vein conduit.
Highlights
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Treatment of chronic total occlusion lesions remains a major challenge for interventional cardiology.
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In previous coronary artery bypass graft patients, when antegrade native CTO percutaneous coronary intervention is not feasible, a retrograde approach through an occluded bypass conduit could be a treatment option; however this approach carries risk for unique complications, some of which can be serious.
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We describe a case of retrograde CTO PCI through an occluded saphenous vein graft complicated by an extensive cutting of the vein conduit.
1
Introduction
In previous CABG patients, treatment of a native coronary artery CTO is preferable to treatment of an SVG CTO supplying the same territory , because PCI of an occluded SVG may be challenging. Antegrade flow may not be frequently restored and even if SVG PCI is successful, the long-term SVG patency is low . Therefore when antegrade native CTO PCI is not feasible, retrograde PCI of the native coronary artery CTO through an occluded SVG could be a treatment option . Either arterial or saphenous vein bypass conduits can be used for retrograde access in patients who have had prior CABG surgery. However, retrograde approach to CTO carries risk for unique complications , especially when an SVG is used. A potentially catastrophic complication is graft’s rupture, which can lead to tamponade and death .
2
Case presentation
A 61-year-old male former smoker with dyslipidemia and hypertension was admitted in our Institution for effort angina. The patient had a history of previous infero-postero-lateral non ST-elevation myocardial infarction in 1997, when he was 46 year old, with angiographic evidence of severe three vessels disease. The patient underwent CABG with right internal mammary artery (RIMA) to left anterior descending artery (LAD), left internal mammary (LIMA) to obtuse marginal branch (OM) and sequential SVG to postero-lateral branch (PL) and to posterior descending artery (PDA).
Before admission in our Hospital a previous myocardial perfusion SPECT showed moderate inducible ischemia in the inferior segments. EF was 33%, with hypokinesia of the infero-postero-lateral wall. Due to these findings the patient underwent diagnostic coronary angiography that showed the patency of both of arterial bypass conduits, a complete ostial occlusion of the sequential SVG to PL and to PDA with a retrograde filling of the distal part of the vein conduit ( Fig. 1 A ). Native right coronary artery (RCA) was also chronically totally occluded in the mid portion. A previous antegrade unsuccessful native RCA CTO PCI attempt was performed. Therefore, we decided to perform further CTO PCI attempt using retrograde approach through the SVG. We used an LCB SH 7 Fr guiding catheter to engage the occluded SVG to PDA. An OTW 1.5 mm balloon was then advanced just in front of the occlusion and a guidewire step-up approach was performed using in succession a Fielder XTA and an Ultimate Bros 3 that was able to navigate into the occluded SVG reaching distal true lumen of the bypass conduit. The OTW balloon was then easily advanced until the distal part of the SVG without any resistance. A selective tip injection from the OTW system confirmed its proper position into the distal true lumen of the graft, without any sign of contrast staining or extravasation ( Fig. 1 B). Due to the finding of patency of the distal SVG segment, before continuing the retrograde attempt, we tried to recanalize occluded SVG antegradely. However despite several dilatation of the vein conduit with an OTW 2.0 mm balloon inflated at low pressure (8 atm), we didn’t achieve a blood flow restoration through the graft. So we decided, as previously scheduled, to continue the RCA CTO PCI procedure retrogradely. We exchanged the OTW balloon with a Corsair that was easily advanced until distal RCA over a Sion wire, without any resistance. After a guidewire step-up a Conquest Pro wire was able to cross the mid RCA CTO lesion, reaching the proximal true lumen of the artery. Proper position of the retrograde guidewire was confirmed by an antegrade injection from the antegrade guiding catheter. The retrograde wire was then advanced and trapped into the antegrade IM SH 6 Fr guiding catheter to provide sufficient backup for Corsair advancement. Retrograde guidewire trapping into RCA guiding catheter was accomplished by a 2.0 × 15 mm monorail balloon inserted antegradely with no guide wire support ( Fig. 1 C). Despite strong back-up provided by retrograde guidewire trapping, it was not possible to advance retrogradely the Corsair microcatheter through the lesion due to the heavy calcifications into the CTO body; so after several unsuccessful attempts, we decided to exchange it with a Rujin OTW 1.25 mm balloon (Terumo, Japan) which has a smaller crossing profile (0.0165 inch) than the Corsair (0.033 inch), to perform retrograde crossing and dilatation. Notably the Corsair tip wasn’t deformed. After few minutes the patient developed chest discomfort with hemodynamic instability. An immediate selective angiography of the SVG showed large contrast extravasation at the level of both of distal anastomosis to PDA and to PL, while other graft segments were free from any damage ( Fig. 1 D–E). Due to these angiographic findings and due to the reason that we didn’t want to lose the only retrograde access to RCA CTO, we decided to go on covering both of the sides of contrast extravasation with two different covered stents, instead of using coils to embolize the graft.
After successful deployment of two covered stents at the level of anastomoses, an angiographic control showed an extensive progression of the rupture that involved also the big curve of SVG mid part ( Fig. 1 F). A 2.5 mm balloon was immediately advanced and inflated into the proximal part of the bypass conduit; despite prolonged balloon inflation and anticoagulation reversal, we observed persistence of blood extravasation. So we decided to implant further covered stents along the mid part of the SVG. After five covered stents deployment there was no more blood mediastinal extravasation, except at the anastomosis level, where was already persistent but into the coronary sinus (see Conclusion section), without significative pericardium spilling ( Fig. 1 G) . However there was angiographic evidence of further damage progression at the ostium, with high risk of rupture; so we planned to deliver another covered stent. Before advancing the last stent, an angiographic control showed complete thrombotic occlusion of the SVG ( Fig. 1 H–I). The arterial pressure was stable and the patient was completely asymptomatic, so we decided not to deliver any other device. An echocardiographic examination showed minimal pericardial effusion at the level of right ventricular apex, without any hemodynamic compromise ( Fig. 2 A–D ), then we stopped the procedure. The day after the procedure a CT scan didn’t show any sign of mediastinal hematoma and confirmed total thrombotic occlusion of the SVG ( Fig. 2 E–G). The patient was discharged three days after the procedure.
