Читать книгу Interventional Cardiology - Группа авторов - Страница 109

An operative report describing graft number and insertions, a prior coronary angiogram or a CT coronary angiography is imperative to reduce the chances of missing a graft as well as to reduce fluoroscopy dose and procedure time spent hunting for an unknown number of grafts. An aortogram can be helpful for graft localization, potentially saving time and contrast, but it is not a panacea, because grafts can sometimes be missed completely when the take off is covered by the aorta and flow is slow. The insertions of vein grafts can vary substantially, in particular after redo bypass surgery. A rule of thumb is that the aorto‐ostial insertions of vein grafts to the left coronary system tend to arise lower and more anterior for grafts to an anterior artery (e.g. LAD) and progressively more superior and leftward as the insertion site moves more toward left lateral (e.g. diagonal, intermediate, obtuse marginal, AV circumflex). In the RAO view, left‐sided grafts can be intubated by pointing the catheter toward the right of the screen. Right‐sided grafts can be found in LAO by dragging the catheter pointing to the left of the screen along the ascending aorta starting above the RCA ostium. Selective intubation with the catheter coaxial to the graft origin is essential to optimize visualization of the distal anastomosis and grafted distal native arteries. The catheter tip is often misaligned when there is a vertical origin of a vein graft to the RCA intubated with a JR catheterA more coaxial intubation is allowed by a Multipurpose or right coronary bypass (RCB) catheter for a right‐sided graft and a Multipurpose, Amplatz or left coronary bypass (LCB) for left‐sided grafts. (Figure 4.5) The views are selected according to the native coronary segment where the graft inserts, minimizing overlapping and two perpendicular views are often required.

Figure 4.5 Guiding catheter selection for SVG to right coronary artery: (a1) JR catheter via the left radial and especially the right radial artery are rarely effective in coaxial intubation of vertical grafts for the RCA. (a2) AL1 or 2 catheters via right radial or left radial artery may require more manipulation but are more often successful (a3) Multipurpose catheters are the shape of choice via right radial, left radial artery or also femoral approach. Guiding catheter selection for SVG to circumflex artery: (b1) JR catheter or, (b2) more predictably, AL1 or AL2 catheters are effective in achieving selective engagement of the posterior lower grafts to the LCx or diagonal branches (b3) High and posterior take off can be challenging from both radial arteries and most often requires a large Amplatz guide. Guiding catheter selection for LIMA to LAD (c1) Classic IMA catheter via left radial artery (c2) classic IMA via femoral artery. Steering for selective cannulation can be made problematic by extreme subclavian tortuosities.

A recent multicenter study that included almost 1500 patients with previous CABG undergoing SVG angiography and PCI showed that the radial approach is safe and achieves similar results with overall less number of catheters and trend toward lower contrast volume as compared to the femoral approach; overall, patients undergoing procedures through the radial approach had significantly less bleeding complications. In the majority of these patients a left radial approach was preferred because of the need for concomitant visualization of the left internal mammary artery [3].