Peripheral Vein Dilation via Controlled Blood Pumping

Solution Overview

Problem

Current methods for creating durable and reliable vascular access sites for hemodialysis, such as arteriovenous fistulas and grafts, face high failure rates due to small vein diameters and intimal hyperplasia, leading to complications and increased morbidity and mortality in patients with end-stage renal disease, with no effective method to persistently increase vein diameter for eligible patients.

Innovation Solution

A system and method using a blood pump to increase wall shear stress and blood speed in peripheral veins, thereby inducing vein dilation and remodeling, allowing veins initially ineligible for hemodialysis access or bypass grafts to become usable by maintaining elevated blood flow and shear stress for several days to weeks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If rapid blood flow is created through AVF to drive vein dilation, then vein diameter increases, but turbulence causes vein wall scarring and obstruction

Engineering Contradiction:

Improveblood flow speedVSAvoidvein wall scarring

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by using a blood pump to gradually increase vein diameter over time (several days to weeks) before creating the AVF connection. This preparatory dilation prevents the turbulence and scarring that would occur with immediate rapid flow, as the vein is pre-adapted to handle increased flow rates.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs periodic action through intermittent blood pumping sessions that gradually increase vein diameter over multiple days or weeks. This staged approach allows the vein to adapt progressively to increased flow rates, preventing the sudden turbulence that causes intimal hyperplasia and scarring.

Inventive Principle:

Principle #19Periodic action

2Adaptability or versatility

If vein diameter is increased through rapid flow, then more patients become eligible for AVF, but about 50%-60% of sites still fail to mature due to small vessel diameter and scarring

Engineering Contradiction:

Improvepatient eligibility for AVFVSAvoidAVF maturation success rate

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by using a blood pump to gradually increase vein diameter over time (several days to weeks) before creating the AVF connection. This preparatory dilation prevents the turbulence and scarring that would occur with immediate rapid flow, as the vein is pre-adapted to handle increased flow rates.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of vein diameter through controlled blood pumping that gradually enlarges the vessel. This parameter change makes previously ineligible veins suitable for AVF creation while maintaining wall integrity and preventing scarring, thereby improving both eligibility and success rates.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If banding is used to restrict lumen diameter to reduce flow, then vein wall scarring is minimized, but vein diameter becomes too small for adequate hemodialysis access

Engineering Contradiction:

Improvevein wall scarringVSAvoidblood flow rate

Core Design Contradiction:

Object-affected harmful factorsVSSpeed

Solution Approach 1:

The patent inverts the conventional approach by doing the opposite of banding: instead of restricting lumen diameter to reduce flow, it uses blood pumping to increase lumen diameter while maintaining high flow rates. This reversal achieves both goals—adequate flow for hemodialysis and minimized scarring—by enlarging the vein before AVF creation.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies preliminary action by using a blood pump to gradually increase vein diameter over time (several days to weeks) before creating the AVF connection. This preparatory dilation prevents the turbulence and scarring that would occur with immediate rapid flow, as the vein is pre-adapted to handle increased flow rates.

Inventive Principle:

Principle #10Preliminary action

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

This approach effectively increases the diameter of peripheral veins, making them suitable for hemodialysis access or bypass grafts, reducing the need for less desirable vascular access methods and associated complications, and improving patient outcomes by enhancing vein patency and reducing mortality risks.

Implementation Method 1

increase the wall shear stress (WSS) on the endothelium of the vein is the major factor driving vein dilation

Methodology Applied

Scientific EffectWall shear stress: Shear Stress

Data Source

PatentUS11724018B2System and method to increase the overall diameter of veins

Publication Date: 2023.08.15 AMPLIFI VASCULAR INC

AI summary

A system and method for increasing the speed of blood and wall shear stress (WSS) in a peripheral vein for a sufficient period of time to result in a persistent increase in the overall diameter and lumen diameter of the vein is provided. The method includes pumping blood at a desired rate and pulsatility. The pumping is monitored and adjusted, as necessary, to maintain the desired blood speed, WSS and pulsatility in the peripheral vein in order to optimize the rate and extent of dilation of the peripheral vein.