Stent Graft with Diameter Reducing Suture Loops

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for treating Type-A dissections in the ascending aorta are limited due to the complexity of the anatomy, which restricts the use of stents and stent grafts, leading to high mortality rates and the need for invasive open surgical procedures.

Innovation Solution

A stent graft assembly with bare stents and diameter restraining devices is designed for precise deployment in the ascending aorta, featuring a tubular graft with stent rings and bare stents that flare outwardly to anchor the graft, minimizing trauma and preventing migration, and an introducer assembly with trigger wires for staged deployment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If open surgical procedures are used to treat Type-A dissections, then the dissection can be treated effectively, but the patient suffers significant trauma and high morbidity

Engineering Contradiction:

Improvetreatment effectivenessVSAvoidpatient trauma

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The treatment approach is segmented into two parts: a stent graft component for sealing the dissection entry tear, and a bare stent component for structural support and anchoring. This segmentation allows the invasive open surgery to be replaced with a less invasive endovascular procedure while maintaining treatment effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The stent graft assembly acts as an intermediary device that can be delivered through the femoral artery and deployed within the ascending aorta without requiring open chest surgery. This intermediary approach bridges the gap between non-invasive delivery and effective treatment of the dissection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If stent grafts are used to treat dissections, then the false lumen can be closed, but accurate placement is difficult in complex lumen geometries

Engineering Contradiction:

Improvefalse lumen closureVSAvoidplacement accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The stent graft is divided into distinct functional zones: a proximal bare stent for anchoring in the aortic root, a mid-section graft for sealing the dissection, and a distal portion for extension. This segmentation allows each component to be optimized for its specific function and facilitates precise placement through staged deployment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bare stent is deployed first to establish a secure anchor point in the aortic root before the graft portion is released. This preliminary action ensures proper positioning and prevents migration, enabling accurate placement in the complex geometry of the ascending aorta.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If the ascending aorta is treated with stents, then endovascular therapy becomes possible, but the short length free of side branches limits placement options

Engineering Contradiction:

Improveendovascular accessibilityVSAvoidavailable aortic length

Core Design Contradiction:

Ease of operationVSLength of moving object

Solution Approach 1:

The stent graft assembly is segmented to provide anchoring functionality at the proximal end through the bare stent in the aortic root, while the graft portion extends distally to treat the dissection. This segmentation allows effective treatment within the limited available length by utilizing different zones for different functions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the stent graft assembly have different properties: the proximal bare stent provides radial strength and anchoring, while the distal graft portion provides sealing and exclusion of the false lumen. This local differentiation optimizes the use of the limited available aortic length.

Inventive Principle:

Principle #3Local quality

4Stability of the object's composition

If barbs are used to prevent stent graft migration, then anchoring is improved, but trauma to the vessel wall increases

Engineering Contradiction:

Improvestent graft positioningVSAvoidvessel wall trauma

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

Instead of using barbs that protrude outward to prevent migration, the invention uses a bare stent that expands radially outward to engage the aortic wall from the inside. This inverted approach achieves anchoring through radial expansion rather than protruding elements, reducing vessel wall trauma.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The bare stent is designed to change its radial dimension from a compressed delivery state to an expanded deployed state. This parameter change enables the stent to anchor securely in the aorta without requiring barbs, as the expanded structure itself provides sufficient friction and mechanical engagement.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9717611B2Stent graft and introducer assembly

Publication Date: 2017.08.01 MED INST INC

AI summary

A stent graft (40) for treating Type-A dissections in the ascending aorta (22) is provided with a plurality of diameter reducing suture loops (56-60) operable to constrain the stent graft during deployment thereof in a patient's aorta. The diameter reducing loops (56-60) allow the stent graft (40) to be partially deployed, in such a manner that its location can be precisely adjusted in the patient's lumen. In this manner, the stent graft can be placed just by the coronary arteries (26, 28) with confidence that these will not be blocked. The stent graft (40) is also provided with proximal and distal bare stents (44,52) for anchoring purposes.