Two-Layer Dural Patch for Spinal Defect Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical implants for repairing defects in the dura mater often result in minimal or uneven seals, leading to potential leaks and tissue damage due to their design, which allows for only single-layer application or suturing, lacking additional layers to prevent leakage and protect underlying tissues.
Innovation Solution
A surgical implant with a top and bottom layer, where the bottom layer can change between a relaxed and tensioned state, allowing it to fit within the defect and provide a more effective seal, while the top layer remains outside to prevent further intrusion, and is made of collagen to promote healing and integration with the body's tissues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer dural patch is used for repair, then the implant structure is simple and easy to apply, but the seal is minimal or uneven leading to potential leaks
Solution Approach 1:
The dural patch is divided into two distinct layers: an inner layer positioned inside the dural defect and an outer layer positioned outside the defect. This segmentation allows each layer to perform specific functions - the inner layer provides internal support and the outer layer provides external reinforcement, together creating a robust multi-layer seal that prevents leaks while maintaining manageable complexity through modular design
Solution Approach 2:
The invention transitions from a single-layer (one-dimensional) patch to a two-layer (two-dimensional) structure with layers positioned on opposite sides of the dural defect. This dimensional expansion creates a more comprehensive seal by addressing leakage pathways from both internal and external perspectives, effectively blocking CSF leaks that would penetrate through a single layer
2Reliability
If sutures are used to attach the dural patch, then the patch can be secured in place, but tissue damage may occur below the dura mater due to the suturing process
Solution Approach 1:
The patch system separates the fixation function from the protective function by using two layers. The outer layer can be sutured to the dural edges for secure fixation, while the inner layer remains positioned inside the defect to protect underlying tissues from suture penetration and mechanical damage, thus achieving reliable fixation without compromising tissue safety
Solution Approach 2:
The inner layer acts as an intermediary protective barrier between the suturing process and the underlying neural tissues. By placing this layer inside the defect before or during suturing of the outer layer, it mediates the potential harmful effects of sutures on delicate tissues while still allowing secure attachment of the patch system
3Reliability
If a dural patch is laid on top of the tear or sewn as a single layer, then the application process is simple, but leakage can occur at the suture line or suture holes when contents develop higher pressure
Solution Approach 1:
The two-layer configuration segments the sealing function into internal and external components. The inner layer positioned inside the defect provides primary sealing against pressure-driven leakage, while the outer layer provides secondary reinforcement. This segmentation ensures that even if pressure increases at the suture line, the multi-layer structure prevents leakage that would occur with a single layer
Solution Approach 2:
The inner layer is positioned inside the dural defect beforehand to provide pre-existing protection and reinforcement at the repair site. This prior cushioning ensures that when CSF pressure increases, there is already a protective layer in place to prevent leakage, rather than relying solely on the outer layer and sutures
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 implant achieves a more secure and long-term seal, reducing fluid leakage and tissue damage, allowing for better healing by conforming to the defect and being resorbed as the body repairs the area, while minimizing platelet aggregation and promoting endothelialization.
Implementation Method 1
the dural patch is either slowly reabsorbed into the body and replaced by the patient's own dural tissue
Implementation Method 2
integrated in such a way that at least some dural tissue grows over the surface of the patch material to maintain a watertight seal
Implementation Method 3
the bottom layer can change between a relaxed and tensioned state, allowing it to fit within the defect and provide a more effective seal
Implementation Method 4
an initial seal that becomes leaky when the contents develop higher pressure including leaking at the suture line or suture holes because there are no additional layers to block leakage
Implementation Method 5
promoting endothelialization
Implementation Method 6
minimizing platelet aggregation
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~3C
AI summary
A surgical implant for repairing a defect. The implant has a first layer and a second layer. Each layer is flexible and planar. The first layer has an inner portion remote from a periphery, and an outer portion between the periphery and the inner portion. The second layer has an inner portion remote from a periphery, and an outer portion between the periphery and the inner portion. A bottom surface of the first layer near the inner portion thereof is connected to top surface of the second layer near the inner portion thereof so that the inner portion of the top layer is fixed relative to the inner portion of the second layer and the outer portion of the first layer is moveable relative to the outer portion of the second layer.