SAFER Endovascular Bypass via Balloon Fenestration

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Solution Overview

Problem

Current antegrade dissection and re-entry techniques for percutaneous coronary intervention, such as Subintimal Tracking And Re-entry (STAR) and antegrade fenestration and re-entry (AFR), face challenges in predicting guidewire re-entry into the distal true lumen, result in larger-than-necessary dissections, and often lead to permanent occlusion of side branch vessels and reduced TIMI flow grade, failing to effectively treat subintimal hematomas and restore flow to side branches.

Innovation Solution

The SAFER technique involves advancing a guidewire with a knuckle into the subintimal space, forming a balloon catheter opening between the subintimal and true lumens, and traversing this opening with the guidewire to re-enter the true lumen, maintaining the knuckle's position distal to the balloon to ensure precise re-entry and minimize dissection, while inflating the balloon to create permanent fenestrations for effective hematoma drainage and flow restoration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If antegrade dissection and re-entry techniques (STAR, AFR) are used to cross occlusion, then guidewire can be advanced into subintimal space, but predictability of re-entry location into distal true lumen is poor

Engineering Contradiction:

Improvepredictability of re-entry locationVSAvoiddifficulty of navigating transient fenestrations

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The balloon catheter is inflated in advance to create a fenestration opening in the subintimal membrane before guidewire re-entry is attempted. This preliminary action ensures a predictable and stable re-entry location, eliminating the need to navigate transient fenestrations that form and disappear during the procedure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The procedure separates the fenestration creation and guidewire re-entry into distinct phases: first the balloon creates a permanent opening, then the guidewire is advanced through this stable opening. This segmentation allows each step to be optimized independently, improving overall predictability and ease of operation.

Inventive Principle:

Principle #1Segmentation

2Productivity

If antegrade dissection and re-entry techniques are used, then occlusion can be crossed, but dissection size becomes larger than necessary

Engineering Contradiction:

Improveocclusion crossing capabilityVSAvoiddissection size

Core Design Contradiction:

ProductivityVSVolume of moving object

Solution Approach 1:

The balloon catheter is positioned and inflated at a specific local site within the subintimal space to create a fenestration of precise, controlled size. This localized approach ensures the dissection is no larger than necessary to achieve re-entry, minimizing damage to surrounding tissue while maintaining occlusion crossing capability.

Inventive Principle:

Principle #3Local quality

3Productivity

If subintimal dissection is performed with larger dissection size, then occlusion can be crossed, but intra-extra-plaque space hematoma occurs and side branch vessels become permanently occluded

Engineering Contradiction:

Improveocclusion crossing successVSAvoidside branch vessel occlusion and hematoma

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The fenestration is created at a precisely controlled location and size using the balloon catheter, ensuring the dissection is minimal and localized. This prevents excessive dissection that would cause hematoma formation and occlusion of side branch vessels, while still maintaining the ability to cross the occlusion.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The balloon inflation that could potentially cause hematoma is instead used to create a controlled, permanent fenestration opening. By directing the dissection energy into creating a stable re-entry pathway rather than uncontrolled expansion, the harmful effect is converted into a beneficial, predictable opening for guidewire re-entry.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 SAFER technique improves predictability of guidewire re-entry, maintains patency of side branch vessels, effectively drains subintimal hematomas, and restores flow to side branches, offering advantages over existing techniques by creating permanent fenestrations and allowing direct crossing into the distal true lumen, reducing the complexity of navigating transient fenestrations.

Implementation Method 1

forming at least one opening in a subintimal membrane by inflating the inflatable balloon catheter

Methodology Applied

Scientific EffectPressure: Pressure Increase

Data Source

PatentUS20240341796A1Endovascular method for bypassing an occlusion

Publication Date: 2024.10.17 CARLINO MAURO

AI summary

An endovascular method for bypassing an occlusion is disclosed. A distal end of a guidewire may be advanced through a microcatheter and into a subintimal space of an artery of a patient, where a knuckle may be formed at the distal end of the guidewire, and the guidewire with the knuckle at the distal end thereof may be advanced to the occlusion. An inflatable balloon catheter may be placed over the advanced guidewire and distal to the occlusion, and the inflatable balloon catheter may be inflated to form at least one opening in a layer separating the subintimal space from a true lumen, whereby the guidewire may traverse the at least one opening.