24 Oct 2023
Inner curvature technique for the implantation of a balloon-expandable valve
A problem-solving step by step tutorial
Find out more about this technique that allows smooth and controlled navigation across the aortic arch along the inner curvature, facilitating the advancement and positioning of the delivery system, and avoiding unnecessary scraping of the aortic wall.
Frequency of the problem:
Expert level:
Summary
Learn more about a simple TAVI technique that allows smooth and controlled navigation along the inner curvature of the aortic arch. It consists of a clockwise rotation of a balloon-expandable delivery system handle with simultaneous catheter advancement and careful wire management. This method facilitates the advancement and positioning of the delivery system and may be considered in difficult anatomical situations, while avoiding unnecessary contact with the aortic wall.
The Problem
During TAVI using the ballon-expandable SAPIEN 3 / Ultra (Edwards Lifesciences) transcatheter heart valve (THV), navigation of the delivery system across the aortic arch may be challenging in specific anatomies: acute aortic arch angulation, horizontal ascending aorta, tortuosity or aneurysms. Similarly, crossing the aortic valve can be problematic in severe aortic valve calcification (Video 1).
These factors may increase the required manipulation and tension, pushing the delivery system to the outer curvature of the aorta for more friction and risking injury of the aortic wall or debris detachment (Figure 1). In some cases, crossing the aortic valve may not be possible.
Figure 1: Illustration of the Inner Curvature technique
(A) Standard advancement brings the delivery system into the outer curvature.
(B) The Inner Curvature technique allows smoother and highly controlled navigation across the aortic arch and aortic valve placement. It can be achieved by a clockwise rotation of the handle of the delivery system (a) with simultaneous catheter advancement (b) and careful wire management (c).
Another challenging scenario is the positioning of the delivery system during the redo TAVI procedure, which requires minimal interaction with the previously implanted TAVI prosthesis.
The Principal idea
A technique that allows smooth and controlled navigation across the aortic arch along the inner curvature may facilitate the advancement and positioning of the delivery system, thus avoiding unnecessary scraping of the aortic wall.
Material needed
None
Method step-by-step
After insertion of the delivery system into the large bore sheath and assembly of the Sapien 3/Ultra valve on the balloon, the valve should be positioned in the descending aorta distal to the left subclavian artery. Here, the catheter should be flexed and slowly advanced with simultaneous clockwise rotation of the delivery handle and cautious tension on the stiff wire (Figure 1; Video 2).
The degree of rotation may be between 90° and 180°, and the rotational tension should be maintained until the arch has been crossed. This simple manoeuvre will bring the delivery system into the inner curvature of the aortic arch and ascending aorta for more controlled navigation, minimizing contact with the aortic wall (Video 3).
In TAV-in-TAV cases, the inner curvature technique facilitates negotiation through the previous TAVI prosthesis, avoiding interaction (Video 4).
Points of specific attention
The operator should rotate the delivery system clockwise with simultaneous forward advancement and wire control, avoiding overturning.
This technique works with most devices, including the Navitor (Abbott) and the ACURATE (Boston Scientific) platforms (Video 5), even though it is commonly not necessary for the latter. However, the effect is most distinct with the Sapien device, and in our experience, it does not work with the Octacor system (Meril Life Sciences).
Supplementary video
A word from the reviewer - Dr Radoslaw Parma
Challenging anatomical settings require modification of TAVI implantation techniques, which improve delivery system trackability and pushability while centralising the nosecone during aortic valve passage.
The solutions focus on decreasing TAVI system arterial wall contact and improving central system passage. To achieve the first goal, operators may use access site sheaths, devices with compliant shafts and polymeric coating, distal system deflection or catheter rotation in angulated segments. The second aim may be accomplished with stiffer LV wires, distal system deflection or delivery catheter rotation.
The presented technique of shaft rotation may offer a solution for both reducing aortic wall contact and directing the nosecone towards the anteriorly positioned aortic valve orifice. The rotation should be started in the descending aorta while maintaining forward catheter movement to transport turning forces to the system nosecone. Catheter torque may increase its pushing force through a calcified and stenosed bicuspid aortic valve. Pulling on the stiff LV wire will further improve system rotation and centralisation in the aortic valve while avoiding contact with the outer curve of the ascending aorta.
Learning the skill increases operator performance in complex settings yet may limit the advantages of commissural alignment used for self-expandable systems. Excessive Sapien system rotation by 180 degrees may direct the valve towards the outer aortic cure. Evolut Pro+ shaft rails define shaft trajectory. Flexible Acurate and Navitor systems are known to be guided by the LV wire and may not need a frequent change of positioning practices.
The inner curvature technique adds to precious operator skills to minimise TAVI risk to our patients.
1 comment
THX Radek for excellent presentation of the technique. Crystal clear !