Bioresorbable Foam Skull Base Closure for Transnasal CSF Leak Sealing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Repairing large skull base openings and preventing cerebrospinal fluid leaks remains a challenge in trans-nasal skull base surgeries, with existing materials and methods being inadequate for securing and sealing these openings.

Innovation Solution

A bioresorbable foam closure device with a phase-separated polymer and a surgical tool for trans-nasally closing skull base openings, where the device is deformed to fit the opening and reverts to its original shape to secure and seal the defect, using a polymer with specific porosity and mechanical properties to prevent leaks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional closure materials and methods are used for skull base openings, then the surgical procedure can be completed, but the reliability of sealing the opening and preventing cerebrospinal fluid leaks is insufficient

Engineering Contradiction:
Improvesealing reliabilityVSAvoidcerebrospinal fluid leaks
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The closure device utilizes a porous structure with interconnected pores that allows tissue ingrowth while maintaining a seal. The porous material provides mechanical interlocking with surrounding tissues, enhancing the reliability of the closure and preventing cerebrospinal fluid leaks through the opening.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The closure device is constructed from composite materials that combine different properties - a biocompatible outer layer for sealing, an inner porous structure for tissue integration, and potentially bioresorbable components that degrade over time as natural healing occurs. This composite approach addresses multiple requirements simultaneously.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the closure device is designed with high structural integrity to seal large openings, then sealing effectiveness improves, but the device complexity increases

Engineering Contradiction:
Improveclosure effectivenessVSAvoiddevice structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The closure device is divided into distinct functional segments - a sealing portion for closing the opening, a stem portion for anchoring, and potentially a scaffold portion for tissue regeneration. This segmentation allows each component to be optimized independently while maintaining overall simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The closure device employs a flexible membrane or thin-walled structure that can conform to the irregular geometry of skull base openings. This flexible shell provides adequate sealing without requiring complex rigid structures, maintaining simplicity while achieving reliability.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If the closure device uses rigid structure to maintain shape and seal effectiveness, then sealing reliability improves, but the ease of insertion through nasal cavity decreases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidinsertion ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The closure device incorporates dynamic characteristics - it is delivered in a compressed or collapsed state through the nasal cavity, then expands to its functional shape once positioned at the skull base opening. This dynamic transformation allows easy insertion while maintaining structural integrity for effective sealing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The closure device is designed to be nested within a delivery catheter or sheath during insertion. The device collapses or folds to fit within the narrow delivery system, then deploys or expands upon reaching the target site, enabling easy navigation through the nasal cavity while maintaining sealing reliability.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 closure device effectively seals and promotes the repair of large skull base openings, reducing cerebrospinal fluid leaks and enhancing the integrity of cerebrovascular structures post-surgery.

Implementation Method 1

a phase-separated polymer having a porosity of greater than 50%

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

a deformable head at a distal region, the shaft and the deformable head cooperate to define a lumen to accommodate a portion of the closure device. Upon actuation of the control surface, the deformable head moves between a first state in which the deformable head is outside of the second region of the dispensing tip and a second state where the deformable head is at least partially within the second region of the dispensing tip.

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

the closure device includes a stem portion having a proximal end and a distal end, and a head portion at the distal end of the stem portion... the head portion is inserted through a nasal cavity and through the opening such that the head portion is in the cranial cavity and the stem portion extends through the opening and into the nasal cavity. Once released, the closure device at least partially reverts to the free shape such that the stem portion fills the opening and the head portion abuts an inner surface of the cranium

Methodology Applied
Scientific EffectElastic recovery: Elastic Recovery

Data Source

PatentEP4260821B1Skull base closure systems
Publication Date: 2026.02.18 STRYKER EUROPEAN OPERATIONS LIMITED
  • EP4260821B1 patent drawingFigure 1~4
  • EP4260821B1 patent drawingFigure 5~6
  • EP4260821B1 patent drawingFigure 7A~8B

AI summary

A bioresorbable foam closure device (10) for trans-nasally closing an opening (300) in a base of a skull (302) is presented. The device (10) comprises a stem portion (12) having a proximal end (14) and a distal end (16), the stem portion (12) having a first diameter, and a head portion (18) at the distal end (16) having a second diameter being larger than the first diameter. The head portion (18) comprises a film layer (20) and a foam layer (22), wherein a porosity of the film layer (20) is greater than a porosity of the foam layer (22). The film layer (20) is disposed at a distal end (16) of the closure device (10) and the foam layer (22) of the head is disposed between the film layer (20) and the stem portion (12). The head portion and the stem portion comprise a phase-separated polymer having an amorphous segment and a crystalline segment. Moreover, the closure device (10) is configured to be deformed from a free shape to a constricted shape, inserted through a nasal cavity and into the opening (300), and released to at least partially revert back to the free shape such that the stem portion (12) fills the opening (300) and the head portion (18) abuts an inner surface of the skull (302) as well as dura, thereby securing the closure device (10) in position and sealing the opening (300).