Toolbox: Guide Extension
If selective guide engagement continues to be an issue, a guide extension catheter can be railed into a coronary over a coronary wire with or without balloon-assisted tracking.

- A J-wire can be used for more selective engagement of coronaries through the balloon-expandable valve frame.
- It is very useful in finding the diamond in front of the ostia and the catheter can be railed over it for coronary engagement.