Читать книгу Interventional Cardiology - Группа авторов - Страница 117
Guide catheter selection Functional design of modern guide catheters
ОглавлениеGuide catheters permit safe intubation of the coronary ostia, accurate hemodynamic monitoring, injection of contrast, and passage of guidewires, balloons, and stents. The clinical, anatomic, and angiographic scenario must be considered when selecting the size, shape, and length of a guide catheter. Modern catheters have a soft tip to reduce the risk of vessel trauma during intubation or manipulation. The wall consists of an outer layer which retains a predefined curve and increases shaft stiffness to provide backup support during intervention, a middle layer of wire braid to increase kink resistance, improve torque transmission, and shaft radiopacity, and a smooth lubricated inner layer to facilitate the transit of equipment. Guide catheters have thinner walls than diagnostic catheters to increase inner lumen size and can be easily damaged by excessive rotation (Table 5.1).
Table 5.1 Guide catheter inner lumen size by manufacturer and outer lumen size.
| Guide/manufacturer | Outer lumen size (French) | ||||
|---|---|---|---|---|---|
| 5 | 6 | 7 | 8 | ||
| Launcher/Medtronic | Inner lumen (in) | 0.058 | 0.071 | 0.081 | 0.090 |
| Vista Brite Tip/Cordis | 0.056 | 0.070 | 0.078 | 0.088 | |
| Mach1/Boston Scientific | NA | 0.070 | 0.081 | 0.091 | |
| Viking/Guidant Abbott | NA | 0.068 | 0.078 | 0.091 | |
| Wiseguide/Boston Scientific | NA | 0.066 | 0.076 | 0.086 |
When difficulty is encountered in engaging the coronary ostia, one must first consider whether the guide catheter shape is appropriate. The use of a supportive 0.035inch guidewire within the catheter can facilitate manipulation. Similarly, deep inspiration by the patient can facilitate coronary intubation. In the case of excessive vascular tortuosity or calcification, the use of a peripheral sheath long enough to straighten the most tortuous arterial segments can improve guide catheter maneuverability. The optimal view for left and right coronary intubation is the left anterior oblique because in most patients it offers the least superimposition of the coronary ostia with the left and right aortic sinuses.
