Absence of bilateral radial pulsations
Dialysis fistulae
Known difficult anatomic variations (radial loops, lusoria artery)
Need for large-bore guiding catheters (≥7 French)
During learning curve
21.3 Diagnostic Coronary Angiography
In general, start with native coronary angiography. Complete occlusion of a native vessel that supply blood flow to a contractile left ventricular segment without collaterals or a competitive (“to-and-fro”) flow mean that there is a patent graft that should be selectively cannulated later on. On the other hand, clear visualization of distal segments of a native coronary artery tells you that the graft has no or minimal anterograde flow.
21.3.1 Catheter Selection
Multipurpose catheters, such as TIG, Brachial type K curves can be used for native coronary angiography, but in general are not useful for graft cannulation. Sometimes the AL1 curve allows both native and SVG selective angiography, but it is not our initial default strategy. The JL 3.5 catheter also allows easy access to both coronary ostia in most cases and occasionally engages SVG with a high take-off in ascending aorta. JL or TIG shapes can be useful in selective contralateral subclavian artery cannulation. Table 21.2 summarizes catheter selection for selective engagement of bypass grafts
Table 21.2
Catheter selection for bypass grafts engagement during diagnostic and intervention procedures
Free aorto-coronary grafts | Right radial | Left radial |
|---|---|---|
To RCA | JR4, JL3.5, multipurpose, AL1, AR2 | JR4, multipurpose, AL1, AR2 |
To Cx | AL1, AL2, extra-backup | AL1, AL2 |
To LAD/diagnonal | AL1, AL2, multipurpose | AL1, AL2 |
Pedicled grafts | ||
LIMA | JL3.5 or TIG or Simm then exchange IMA or JR4 | LIMA, JR4, Williams 3D |
RIMA | IMA, JR4, Williams 3D | Simm then exchange IMA or JR4 or Vertebral |
Our routine strategy is starting with a JL 3.5 catheter. After selective left coronary imaging, the catheter is gently pulled back and, after straightening its primary curve with the help of a conventional 0,035’ wire it is rotated clockwise and advanced for selective right coronary angiography. Once native coronary artery imaging is finished, a short try of engaging a SVG to left circumflex system with the JL catheter can be done applying a careful pull-back and small rotation while in LAO 45° view. Most commonly, a different catheter will be necessary as explained below.
21.4 Saphenous Vein Grafts
Saphenous vein grafts (SVGs) are commonly used in patients with multivessel coronary disease. In general, patients have one or two proximal aortic anastomoses. Right coronary SVG are more anterior and have a slightly lower take off compared to left coronary SVG. We recommend using the left radial approach for selective engagement of SVG for diagnostic or intervention purposes.
If your usual choice for right coronary artery cannulation is a Judkins Right (JR) catheter, it is a good advice to try it also for SVG imaging. In general, it is not difficult to engage the SVG to distal right coronary territory through the left arm with a JR or MP catheters. Coming from the right arm, these catheters usually are less useful. For SVGs originating from less anterior or the left side of the aorta, that is, those oriented to the left circumflex or left descending coronary artery, Amplatz left catheters represent usually a better option (Fig. 21.1). Our default strategy is AL 1 shape, both for diagnostic and interventions in SVG. Sometimes an AL 2 curve is a better option, especially from the right arm or in case of significant aortic dilatation. Moving from a typical LAO view to a RAO view trying to visualize lateral take-off of these left-oriented aortocoronary grafts are sometimes helpful in challenging cases.
Fig. 21.1
Selective angiography of saphenous vein graft to obtuse marginal branch using AL 1 catheter
The selection of an appropriate guiding catheter is a key point for transradial approach in presence of SVG. A good support is often needed to overcome complex lesions and need for distal filters. Accordingly, we recommend 6 F guiding catheters and the left radial approach. AL 1 is the usual choice for SVG to left coronary territories and JR4 or multipurpose guiding catheters for right coronary SVG. In some cases, AL1 offers better support also for right coronary SVG (example in Fig. 21.2). Another solution could be using extra-backup curves typically used for left coronary interventions by reshaping the primary curve with the straight part of the 0.035’ wire (that never should be pushed outside the catheter during this procedure). Finding a good support from your guiding catheter is usually the “Achilles heel” of transradial interventions on SVG, compared to native vessels. Fortunately, lesser support from guiding catheters can sometimes be overcome using catheter extensions such as Heartrail™ or GuideLiner™ [12].
Fig. 21.2
Complex PCI of saphenous vein graft (SVG) to distal right coronary artery disease treated by left radial approach. Coronary angiography had shown chronic total occlusion of left main, total occlusion of the left internal thoracic graft and severely and diffusely disease of left marginal branches. Patient was in cardiogenic shock and was considered not suitable for a third revascularization surgery and PCI of restenotic SVG was performed. Severely diseased femoral and iliac arteries precluded intraaortic balloon insertion. Panel a: baseline angiography taken with a 5 F Judkins Left 3.5 diagnostic catheter showing severe stenosis at proximal third (black arrow) and focal in-stent restenosis (white arrow). Panel b: the same angiographic view showing perfect alignment of a 6 F AL1 guiding catheter and distal protection device in place. Panels c and d: final result after placing to everolimus-eluting stents showing adequate expansion and no signs of distal embolization. Recovery of good collateral flow to left descending artery was achieved.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
