Eccentric Anchor Stent Arteriovenous Shunt
Solution Overview
Problem
There is a need for an arteriovenous (AV) shunt that can be quickly and simply delivered and secured in place via a minimally invasive intravascular procedure, capable of directing blood flow into and out of the fluid passageway, particularly for treating conditions like chronic obstructive pulmonary disease (COPD) where traditional methods are invasive and have long recovery times.
Innovation Solution
An arteriovenous shunt assembly featuring a self-expanding stent graft with an eccentrically and externally mounted anchor stent at each end, allowing partial diversion of blood from the artery to the vein while ensuring the majority of blood in the vein continues downstream, utilizing self-expanding materials like nickel-titanium alloys for secure apposition within blood vessels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If open surgical techniques are used to form anatomic connections or fistulas between adjacent vessels, then reliable vascular connection is achieved, but patient recovery time is prolonged and surgical invasiveness increases
Solution Approach 1:
The device segments the vascular connection function into two parts: the shunt body creates the fistula pathway, while the anchor stents provide secure attachment to vessel walls. This segmentation allows percutaneous delivery of the shunt body while maintaining reliable connection through the anchor stents, reducing surgical invasiveness and recovery time compared to traditional open surgery.
Solution Approach 2:
The anchor stents serve as intermediary elements between the shunt body and the blood vessel walls. These stents provide a secure attachment mechanism that bridges the shunt device and the vascular system, enabling reliable vascular connection through minimally invasive percutaneous insertion rather than requiring open surgical techniques.
2Loss of time
If percutaneous catheter-based techniques are used to create shunts between adjacent vessels, then surgical invasiveness is reduced and recovery time is shortened, but secure anchoring and proper blood flow direction become challenging
Solution Approach 1:
The device segments the anchoring function from the shunt body by incorporating separate anchor stents that can be independently deployed. These anchor stents provide secure attachment to vessel walls while the shunt body maintains its percutaneous delivery advantage, thus achieving both minimally invasive insertion and reliable anchoring.
Solution Approach 2:
The anchor stents are positioned eccentrically relative to the shunt body, creating an asymmetric configuration. This asymmetric placement allows the shunt to direct blood flow into and out of the fluid passageway while the anchor stents provide secure attachment to the vessel walls, solving both the anchoring security and flow direction challenges simultaneously.
3Reliability
If an AV shunt directs all blood flow through the fluid passageway, then oxygenation improvement is maximized, but downstream blood supply may be compromised
Solution Approach 1:
The shunt design incorporates local quality variations through its asymmetric positioning and eccentric anchor stent configuration. The shunt directs a portion of blood flow through the fluid passageway to improve oxygenation locally, while allowing the majority of blood to continue flowing downstream through the main vessel, thus achieving oxygenation improvement without compromising downstream blood supply.
Solution Approach 2:
Rather than directing all blood flow through the fluid passageway, the shunt implements partial action by diverting only a portion of the blood flow. This partial diversion is sufficient to improve oxygenation while maintaining adequate downstream blood supply, avoiding the harmful effects of complete flow redirection.
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
The solution enables efficient and minimally invasive creation of a fluid connection between arteries and veins, improving oxygenation and cardiac output with reduced obstruction, thus addressing the limitations of existing AV shunt technologies.
Implementation Method 1
Each anchor stent is constructed from a self-expanding material such as a shape memory alloy or elastic metal wirework structure
Implementation Method 2
A self-expanding stent graft having a self-expanding anchor stent mounted eccentrically and externally about at least one end segment of the stent graft
Data Source
AI summary
An arteriovenous shunt includes a self-expanding stent graft having a self-expanding anchor stent mounted eccentrically and externally about at least one end segment of the stent graft. A fluid passageway extends between open first and second ends of the shunt. The anchor stent has an expanded diameter greater than an expanded diameter of the stent graft. The expanded diameter of the stent graft is smaller than the artery or vein into which it is deployed. Methods of deploying the arteriovenous shunt are also disclosed.