Suture-Controlled Prosthetic Heart Valve Deployment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge of implanting self-expanding prosthetic heart valves via catheterization includes rapid expansion causing migration, difficulty in repositioning and retrieval, and the need for balloon post-dilation procedures, which complicate the implantation process.
Innovation Solution
A delivery apparatus with an annular stent and sutures that allow controlled expansion and contraction, enabling precise positioning and retrieval of the prosthetic valve by adjusting tension on the sutures to manage radial convergence and axial foreshortening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a self-expanding prosthetic valve is deployed from a delivery cylinder, then the prosthetic valve expands to functional size, but the rapid expansion causes the prosthetic valve to migrate or jump from the desired deployment position
Solution Approach 1:
The delivery apparatus uses a dynamic constraint mechanism where the prosthetic valve is initially constrained within the delivery cylinder, then gradually released through controlled expansion. The system transitions from a static constrained state to a dynamic controlled expansion state, allowing the operator to regulate the expansion speed and prevent migration by maintaining positional control throughout the deployment process
Solution Approach 2:
The prosthetic valve is pre-positioned within the delivery cylinder at the desired deployment location before expansion begins. The delivery apparatus is advanced to the target site with the valve already in place, and then controlled expansion is initiated. This preliminary positioning ensures that when expansion occurs, the valve starts from the correct position and can be gradually deployed without jumping or migrating
2Reliability
If the prosthetic valve is expanded to functional size, then it can perform its valve function, but the increased radial profile causes the prosthetic valve to engage the native anatomy and prevents free movement for repositioning
Solution Approach 1:
The system employs dynamic control of the expansion state, allowing the prosthetic valve to transition between compressed and expanded configurations. The delivery apparatus maintains a mechanical connection to the valve even in the expanded state, enabling the operator to control the degree of expansion and facilitate repositioning by temporarily reducing radial profile while maintaining functional capability
Solution Approach 2:
The delivery apparatus is designed to maintain engagement with the prosthetic valve throughout the deployment and repositioning process. The preliminary design of the delivery system includes features that allow controlled manipulation of the expanded valve, such as retrieval mechanisms or repositioning capabilities built into the delivery catheter system
3Ease of operation
If sufficient radial force is applied to compress the prosthetic valve for retrieval, then the valve can be retracted, but it is difficult to exert sufficient force without damaging the valve or patient anatomy
Solution Approach 1:
The delivery apparatus uses a dynamic compression mechanism that applies controlled radial force through the delivery catheter. The system can gradually increase compression force while monitoring valve response, allowing retrieval without requiring excessive force that could damage the valve or patient anatomy. The mechanical advantage of the delivery system amplifies operator input force into controlled radial compression
4Reliability
If a balloon post-dilation procedure is performed to expand the prosthetic valve to nominal diameter, then paravalvular leakage is reduced, but the procedure adds time and complexity to the implantation process
Solution Approach 1:
The delivery apparatus is designed to pre-expand or pre-position the prosthetic valve at the correct nominal diameter before implantation. The controlled expansion mechanism within the delivery system ensures the valve reaches its full functional size in a single step during deployment, eliminating the need for a separate post-dilation procedure and reducing overall implantation time while maintaining proper valve sizing to prevent paravalvular leakage
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Facilitates controlled expansion and repositioning of prosthetic heart valves, reducing migration and simplifying the implantation procedure by allowing for gradual expansion and easier retrieval, thereby improving procedural efficiency.
Implementation Method 1
the stent is configured to radially expand and axially foreshorten from a first state to a second state... increasing tension of the first plurality of sutures causes the first plurality of apices of the stent to radially converge
Implementation Method 2
the stent is configured to radially expand and axially foreshorten from a first state to a second state and to radially compress and axially elongate from the second state to the first state
Data Source
Figure 1~2
Figure 3~4
Figure 5~6C
AI summary
A delivery apparatus for a prosthetic implant can include an elongate first shaft, a first suture guide coupled to the first shaft, an elongate second shaft, and a second suture guide coupled to the second shaft. The first shaft can extend coaxially through the second shaft and the second suture guide, the first suture guide can be disposed distal to the second suture guide, and the first suture guide and the second suture guide can be configured to be axially movable relative to each other.