15 May 2020
How to use a guide-extension catheter for stent delivery
Population ageing is increasing. Therefore extensive coronary artery calcification is a frequent finding and results in complex coronary interventions. Despite the improvement of stent- and balloon- profile, delivery can be challenging due to vessel tortuosity and calcified plaque... Discover the tips and solutions proposed by Lucas Joerg and Johannes Rigger!
Frequency of the problem:
Expert level:
Summary
Population ageing is increasing. Therefore extensive coronary artery calcification is a frequent finding and results in complex coronary interventions. Despite the improvement of stent- and balloon- profile, delivery can be challenging due to vessel tortuosity and calcified plaque. Mother in child catheters (Guidezilla ®, GuideLiner®, Telescope®, TrapLiner®) facilitate the delivery of material in such complex lesions. Proper handling of these devices is crucial to prevent serious complications. Both “balloon-assisted tracking technique (BTT)” and “balloon surfing technique (BST)” are methods to facilitate mother in child catheters through tortuous vessels minimizing vessel injury. We aim to illustrate two options to use guide extensions safely.
The problem
Lack of (guiding) support, tortuous and calcified vessels often impede stent delivery. Mother in child catheters are an efficient alternative to the often unsuccessful, former techniques like buddy wires or distal balloon anchoring. Despite their efficiency, they are prone to harm the vessel wall if not handled properly. The following two techniques may reduce vessel injury and complications...
Principal idea
To advance the guideliner safely, using either BTT or BST technique is recommended.
- BTT: A Balloon is placed in the coronaries downstream to the guide extension. It is then advanced by pushing it forward while holding the inflated balloon in place. When it reaches the balloon edge, it is deflated and the catheter is advanced over it. So the balloon invaginates completely into the guide extension.
- BST: A small (2.0mm - 2.5mm) balloon is inflated at the end of the guide-extension catheter, partially protruding into the artery to form a soft tip. Then the whole bundle is advanced.
Material needed
Mother in child catheter (5F-7F), work horse wire, Balloon (compliant or noncompliant, doesn’t matter)
Method step-by-step
Balloon assisted tracking technique (BTT)
Step 1: A balloon is placed and inflated downstream to the mother in child catheter
Step 2: While holding the balloon in place, the mother in child catheter is pushed forward
Step 3: the balloon is deflated during persistent pressure on the mother in child catheter
Step 4: mother in child catheter in place
2 - Balloon surfing technique (BST)
Step 1: a balloon is inflated at the end of the guide-extension catheter, partially protruding into the artery to form a soft tip
Step 2: pushing the bundle downstream; surfing through the coronaries until the point of interest is reached
Points of specific attention
- mother in child catheters are very helpful but mind the possible complications
- do not inject through a guideliner into the coronaries! (CAVE: spiral dissection!)
- never advance a guideliner without a balloon (either BTT or BST is ok, find your technique of preference)
- let the vessel breathe! Don’t forget to remove the guideliner out of the vessel (watch out for pressure dampening)
A word from the reviewer - Pierre Deharo
Very useful tool kit where you will learn how to use a guide catheter extension. Nowadays, the need for guide extension is becoming more and more frequent. It allows safe delivery of coronary devices, improves your PCI outcomes and reduces the risks of complications such as stent loss. Therefore, this technique needs to be mastered and will help you on a daily basis.
Authors
5 comments
I use a modified version of the BTT with a distal deflated balloon, with the balloon shaft acting as a support along which I can push the guide extension catheter. This minimises trauma to the vessel wall and allows effective positioning of the guide extension catheter to facilitate stent delivery.
We do inject dye through a well-positioned guideliner, with reduced flow rates. Else you would always have to remove and replace it
This lecture is very helpful. Thank you so much!
BTT is the classical Anchor technique, Useful but not preventing damage to arterial wall caused by GCE edge. The BST is the so called Torpedo technique, akin to the BAT technique for radial crossing, which effectively protect arterial wall from GCE injury, but less effective than the BTT (only pushing force, no distal anchor + pushing). There's a third technique that is the most useful when the previous ones fail, the inchworming technique, in which a SC balloon is inflated just outside GCE tip to make room, and the GCE is advanced on the balloon immediately after its deflation, the balloon is then advanced outside the GCE tip and inflated again. The process is repeated several times until you manage to reach your destination. This is the ultimate technique to advance your GC extension through uncrossable calcific bends.
Thank for your sharing! I often use guide-extension catheter during difficulty delivery of stent or maybe balloon (CTO lesions). In some situations, I modified BBT, extension guide was let next to proximal inflated balloon (2.0-2.5 mm in diameter). Next step, balloon down and extension guide surfied over the deflated balloon to distal vessel.