Flexible Cannula Subretinal Drainage Device
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Solution Overview
Problem
Current methods for draining fluid from the subretinal space, such as transscleral drainage, require a steep learning curve and can lead to complications like retinal incarceration and hemorrhage, while internal approaches like peripheral retinotomy also pose challenges in accessing the macula for treating conditions like macular degeneration.
Innovation Solution
A subretinal drainage device featuring a flexible cannula with atraumatic distal end and a slidable needle that can be advanced through the choroid to aspirate fluid or deliver therapeutic agents directly to the subretinal space from a suprachoroidal approach, minimizing trauma and avoiding retinal incarceration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transscleral drainage is used to drain subretinal fluid, then drainage can be achieved, but the procedure requires a steep learning curve and carries high risk of complications such as retinal incarceration and hemorrhage
Solution Approach 1:
A flexible cannula is introduced as an intermediary device between the sclera and choroid, providing a safe pathway for needle insertion. The cannula acts as a guide and protective sheath, allowing the needle to be advanced through the choroid to the subretinal space without requiring the operator to directly manipulate the needle through delicate retinal tissue, thereby reducing the learning curve and complication risks
Solution Approach 2:
The flexible cannula is inserted and positioned in the suprachoroidal space before needle advancement. This preliminary positioning establishes a predetermined safe trajectory and provides visual or tactile guidance for subsequent needle insertion, allowing the operator to follow the pre-established path rather than attempting direct needle placement through multiple tissue layers
2Reliability
If peripheral retinotomy is used to drain subretinal fluid, then drainage can be achieved, but retinopexy is required to repair retinal incarceration
Solution Approach 1:
The flexible cannula serves as a mediator that allows access to the subretinal space through the suprachoroidal approach, avoiding direct retinal incisions. The cannula's presence in the suprachoroidal space provides a safe corridor for fluid drainage and therapeutic agent delivery without creating retinal wounds that would require repair
Solution Approach 2:
Instead of approaching the subretinal space from the retinal side (retinotomy), the invention inverts the approach by accessing the subretinal space from the suprachoroidal side. This reverse approach eliminates the need for retinal incisions and subsequent retinopexy procedures
3Manufacturing precision
If needle insertion is performed perpendicular to the retina, then direct access to subretinal space can be achieved, but the margin for error is very small and complications are more likely
Solution Approach 1:
The flexible cannula introduces a curved or angled trajectory for needle insertion, replacing the straight perpendicular approach. The cannula can be bent or angled to follow the contours of the eye's anatomy, providing a more forgiving insertion path that accommodates variations in tissue thickness and reduces the precision requirements for needle placement
Solution Approach 2:
The invention changes the insertion dimension from a direct perpendicular approach to an oblique or tangential approach through the suprachoroidal space. By approaching the subretinal space at an angle rather than directly perpendicular to the retina, the procedure gains additional spatial dimensions for error correction and provides a more tolerant insertion path
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 device allows for effective drainage of subretinal fluid and localized delivery of therapeutic agents, reducing the risk of complications and improving treatment outcomes for conditions like macular degeneration without requiring a steep learning curve.
Implementation Method 1
aspirating fluid from the subretinal space via the needle
Data Source
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 aspirate fluid from the subretinal space. The fluid may be present from a retinal detachment, a macular hemorrhage, or other condition present before the procedure begins. The method may further include injecting the fluid in the subretinal space via the needle, in which case the fluid may be a balanced salt solution or other bleb fluid. The method may further include injecting a therapeutic agent into the subretinal space after aspirating the bleb fluid. The volume of injected bleb fluid may be greater than the volume of injected therapeutic agent.