Flexible cannula for subretinal agent delivery

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Solution Overview

Problem

Current methods for treating macular degeneration, particularly in its 'wet' form, face challenges in delivering therapeutic agents to the subretinal space without causing trauma and ensuring effective absorption, as the macula is difficult to access due to its location beneath the delicate retina layers.

Innovation Solution

A surgical instrument featuring a flexible cannula and needle system is used to deliver a leading bleb fluid to create a separation between the retina and choroid, allowing for the administration of a therapeutic agent directly to the subretinal space, maximizing surface area exposure and minimizing trauma.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a needle is used to directly access the subretinal space, then therapeutic agent delivery is achieved, but trauma to the delicate retina and choroid layers occurs

Engineering Contradiction:

Improvetherapeutic agent deliveryVSAvoidtrauma to retina and choroid

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A flexible cannula is introduced as an intermediary device that accesses the suprachoroidal space and delivers therapeutic agents without directly penetrating the retina or choroid layers. The cannula navigates through the suprachoroidal space to reach the subretinal space, thereby avoiding trauma to the delicate ocular layers while still enabling effective drug delivery to the target site.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces the traditional sharp needle penetration mechanism with a flexible cannula-based system that uses navigation through the suprachoroidal space. This substitution eliminates the need for direct mechanical penetration of the retina and choroid, reducing trauma while maintaining the ability to deliver therapeutic agents to the subretinal space.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Length of moving object

If the macula is accessed from the front of the eye, then the treatment path is direct, but the delicate retina layers must be penetrated causing trauma

Engineering Contradiction:

Improvetreatment path lengthVSAvoidtrauma to retina and choroid

Core Design Contradiction:

Length of moving objectVSObject-affected harmful factors

Solution Approach 1:

The treatment path is segmented into two distinct spaces: the suprachoroidal space for cannula navigation and the subretinal space for therapeutic agent delivery. By dividing the access route into these segments, the cannula can navigate through the safer suprachoroidal space without directly penetrating the delicate retina and choroid layers, thereby reducing trauma while maintaining treatment efficacy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The suprachoroidal space serves as an intermediary pathway that allows the cannula to reach the subretinal space without directly penetrating the retina or choroid. This intermediate route reduces trauma to the delicate ocular layers while still enabling direct delivery of therapeutic agents to the macula.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If therapeutic agents are delivered without leading bleb fluid, then delivery is simpler, but absorption and distribution to the affected area is reduced

Engineering Contradiction:

Improvedelivery process complexityVSAvoidtherapeutic agent absorption and distribution

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

Leading bleb fluid is delivered first to create a fluid pocket or bleb in the subretinal space before delivering the therapeutic agent. This preliminary action prepares the delivery site by creating space and facilitating the subsequent distribution and absorption of the therapeutic agent, thereby enhancing treatment efficacy without significantly increasing procedural complexity.

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 enables efficient and localized delivery of therapeutic agents, enhancing the absorption and distribution of treatments directly to the affected area, thereby improving the efficacy of treatments for macular degeneration.

Implementation Method 1

delivering a first volume of a leading bleb fluid to the subretinal space... delivering a second volume of the leading bleb fluid to the subretinal space... wherein the combination of the delivered first and second volumes of the leading bleb fluid causes a substantial portion of the retina to detach from the choroid

Methodology Applied

Scientific EffectHydrostatic pressure: Pressure Increase

Data Source

PatentUS11759355B1Method of delivering leading blebs and agent to subretinal space

Publication Date: 2023.09.19 GENENTECH INC

AI summary

A method includes inserting a flexible cannula between a sclera and a choroid of an eye. The needle is advanced from a distal end of the flexible cannula, such that the needle pierces the choroid to access a subretinal space of the eye. The needle is used to deliver a first volume of leading bleb fluid to the subretinal space. The delivery of leading bleb fluid is ceased for a duration of time. After expiration of the duration of time, the needle is used to deliver a second volume of the leading bleb fluid to the subretinal space. The combination of the delivered first and second volumes of the leading bleb fluid causes a substantial portion of the retina to detach from the choroid. A therapeutic agent may then be delivered to the subretinal space in the region where the retina is detached from the choroid.