Fig. 8.1
Comparing the Judkin’s catheter and EBU catheter in transradial intervention
Results of the first international transradial practice survey (Fig. 8.2) shows that standard extra back-up guiding catheters, especially EBU 3.5 (Medtronic, Minneapolis has been regarded as the first option in dealing with left coronary artery (LCA) intervenion compared to JL and other catheters [1].
Fig. 8.2
(a) Preferred guiding catheter for left descending artery via transradial approach. (b) Preferred guiding catheter for left circumflex artery via transradial approach
The characteristics which make up an effective GC in TRI includes strong support, a large lumen, flexible manipulation and an atraumatic design. large majority of operators prefer to use 6-F catheter size. AdroitTM (Manufactured by Cordis comapany) has the largest inner lumen diameters among all the available 6Fr extra back-up shape GCs in the markets (Table 8.1). A large inner lumen design makes management of complex TRI possible including complex operations (Step balloon kissing, rotablator, etc) with a 6 F catheter, child in mother technique and better visibility especially when there are multiple devices within the GC. An ideal GC allows for a perfect balance between GC support and manoeuvrability allowing for easy engagement, easy adjustment, flexible changes of support mode, easy deep engagement, pressing against the contralateral aortic wall or aortic valve easily and a stable GC tip. The EBU catheter has these attributes which can be credited to the flexible manipulation of the primary curve yet strong coaxial support from the secondary curve.
Table 8.1
The inner lumen diameter of multiple EBU shape guiding catheter
Vista brite tip Inner diameter | Launcer Inner diameter | Adroit Inner diameters | |
|---|---|---|---|
Manufacture | Cordis | Medtronic | Cordis |
5 F | 0.056″ | 0.058″ | – |
6 F | 0.070″ | 0.071″ | 0.072″ |
7 F | 0.078″ | 0.081″ | – |
8.2 The Size Selection of GC
Selection of the size of the GC is done according to the width of AO root (from the echocardiograph and coronary angiogram) and the orientation of the LCA. When the AO width is <3.0 cm, 3.0–3.5 cm and >3.5 cm the EBU size used is 3.0, 3.5 and ≥3.75 respectively. If the LM is oriented downwards, the EBU should be a half size larger (G1, blue). If the LM is oriented upwards the EBU should be half a size smaller G3, (yellow), in comparison to when the LM is horizontal (G2, green) (Fig. 8.3).
Fig. 8.3
Selection of size of the guiding catheter according to width of aortic root and orientation of left main
The other reason for using a catheter that is half a size larger is to increase back up for complex coronary lesions, including diffused lesions, Angulated lesions, left radial artery approach and LCX lesions.
8.3 Manipulation of EBU Catheter
8.3.1 Manipulation Method of EBU Catheter in Normal Conditions
The best view to engage an EBU catheter is LAO 45 or LAO caudal view. The basic methods to engage the EBU GC to LM ostium is the “rotating and pulling” or “Advancing and forming U shape”. However, due to a tortuous subclavian artery and widened AO root, a high take off or downward orientation of the LM ostium is not unfrequently met. Other methods of engaging the EBU catheter should be tried.
Rotating and pulling
This is the most common method to engage the EBU catheter to LM ostium. It involves the following steps. First step : Placing the guide wire into the aortic sinus under the fluoroscopy guidance. The wire should be curved just above the level of the sinotubular ridge so that it is located in the posterior sinus (Fig. 8.4a). Second step: While advancing the EBU catheter into the ascending aorta, manipulate it in a clockwise manoeuvre so that the tip of GC is directed to the left side (Fig. 8.4b). In the case of a tortuous brachiocephalic trunk, it is necessary to ask the patient to take a deep breath and hold it, which can facilitate the advancement of the EBU. After the EBU is shaped successfully in the posterior sinus, do not retract the wire from the GC until the air is removed.
Fig. 8.4
Engaging the EBU by rotating and pulling (Image provided courtesy of Medtronic Inc. © Medtronic Inc. All rights reserved)
Third step
Pull it and rotate in a clockwise fashion if necessary. Generally, the GC jumps from posterior sinus to left sinus (Fig. 8.4b, c). Fourth step: Continue to withdraw the EBU to the level of the ostium of LCA, and rotate it with clockwise or anticlockwise torque until the catheter intubates the LM ostium (Fig. 8.4d).
Advancing and forming U shape
After the EBU is shaped in the posterior sinus, retract the wire till the secondary curve, then pull the GC softly and advance it into the left sinus (Fig. 8.5a). Instead of pulling the catheter up, aided by the force from the aortic sinus and opposite aortic wall, advance the GC until the tip reaches the level of the ostium of LCA. Ensure the GC maintains appropriate tension in case of it being bent backwards (Fig. 8.5b). When the tip of the EBU reaches the level of the ostium of LCA, rotate the catheter clockwise or anticlockwise to get close to the ostium of LCA (Fig. 8.5c). Once the GC tip is close to the ostium of LCA, do not remove the exchanged guidewire from GC until a PTCA guidewire is advanced into the LCA to keep the GC stabilized (Fig. 8.5d). The coaxial alignments of a GC to the LM ostium could be further obtained with the help of a PTCA guidewire or balloon catheter (Fig. 8.5d). While adjusting GC coaxiality, caution should be paid to avoid LM injury due to deep engagement (Fig. 8.5e). By siting in the aortic sinus, the guide can be kept stable without entering the LM ostium, which will be especially useful for left main ostial leiosns or LM body lesions with a short LM (see left main ostial lesions).
Fig. 8.5
Engaging EBU by advancing and forming U shape (Image provided courtesy of Medtronic Inc. © Medtronic Inc. All rights reserved)
8.3.2 Manipulation Method of EBU Catheter During a High Takeoff
Advancing and forming a U shape of EBU catheter is most effective when deals with a high take off left main ostium (See Fig. 8.5).
For an unfolded aorta and high take off LM ostium, EBU catheter tends to being bent up by rotating and pulling maneuver and result in cannulation failure (Fig. 8.5a). A 0.035″ J type stiff wire can be used to effectively modulate the opening degrees of the GC tip (Fig. 8.5b) so that the tip of the catheter could go into the left sinus; The wire is then retracted back and kept in the GC ; by withdrawing and rotating the catheter, simultaneously accommodating the patient’s breathing, the coronary ostium is finally engaged (Figs. 8.5c and 8.6).
Fig. 8.6
Engaging EBU by rotating and pulling with the support of stiff wire for high take off LCA (Image provided courtesy of Medtronic Inc. © Medtronic Inc. All rights reserved)
If above methods fails, the horizontal rotation method could be attemped. In this method the tip of GC is at the same level of the LM ostium, while the EBU is kept open by a stiff wire. The GC is then rotated to search for the LM ostium. If coaxiality is not satisfactory, it can be solved by advancing a PTCA wire into the coronary artery, while the GC is manipulated to keep it co-axial (Fig. 8.7).
