Читать книгу Interventional Cardiology - Группа авторов - Страница 110

The left internal mammary artery (LIMA) graft is usually prognostically the most important. Selective intubation of the LIMA with demonstration of the entire length of the graft and native vessel including any lesions and collateral supply is the standard. The origin of the left subclavian artery is usually engaged in the AP view. An 0.035‐inch J‐wire is used to lead before the catheter is advanced over it to reduce the risk of trauma to the vessels. If difficulty is encountered with an abnormal aortic arch, severe tortuosity, or stenosis, intubation of the left subclavian may be easier in the LAO view, using non‐selective contrast injections to delineate the anatomy and a JR rather than an internal mammary artery (IMA) catheter can help engaging the left subclavian. If it is possible to insert the catheter over a wire into the subclavian artery, an IMA catheter can be inserted via a 300‐cm J‐wire. A 0.035‐inch steerable polymer jacketed soft J‐wire (Terumo) guide is helpful if extreme tortuosity prevents passage of the standard J‐wire guide. Once the catheter tip is near the ostium of the LIMA, the AP view is most useful for engagement. The JR catheter tip is often too horizontal or too short to engage the ostium of the LIMA; in this case an IMA catheter or the even more acute shorter hook of a Bartorelli‐Cozzi (BC) catheter are the shapes of choice. Before contrast injection – including test injections – it is important to remember to check that the pressure tracing does not indicate wedging of the catheter tip against the vessel wall. If selective intubation via the femoral route proves elusive despite multiple attempts, the left radial route can offer a safer alternative A drawback of the left radial route is that right internal mammary artery (RIMA) grafts cannot be engaged, although successful intubation of the LIMA via the right radial route has been previously described [4]. A left radial approach is definitely helpful when the LIMA originates from the straight portion of the subclavian but selective cannulation may prove more difficult when it originates from the ascending limb where also catheters coming from the radial are challenged by the tortuosity of the subclavian (Figure 4.5). The first angiographic view for the LIMA requires panning from origin to the distal LAD. The views that best show the insertions are RAO cranial and left lateral. Collateral filling of other vessels should also be documented. Intubation to the diaphragm of a pedicle RIMA graft follows the same principles as for the LIMA, but with even greater care in view of the close proximity of the right internal carotid artery.