Variable Length Stent Delivery with Axial Compression

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Solution Overview

Problem

Current stents often have fixed lengths that may not match patient anatomy, leading to complications such as irritation or the need for replacement, and variable length stents face challenges with delivery, positioning, and length adjustment due to premature extension or compression during placement and removal.

Innovation Solution

A stent design featuring a body with coils in a helical pattern, adjustable gaps between coils, and a suture system for axial compression, allowing for controlled length adjustment and secure positioning within the body, along with a stent delivery system using a cannula and pusher for precise placement and retrieval.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed length stent is used, then the stent structure is simple and manufacturing is easy, but the stent may be too short or too long for patient anatomy causing irritation or complications

Engineering Contradiction:

Improvestent length adaptability to patient anatomyVSAvoidstent structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The stent body is designed with compressible coils that can dynamically adjust their length along the longitudinal axis. The coils are arranged in a helical pattern with gaps that allow compression and expansion, enabling the stent to adapt its length to match the patient's ureter anatomy while maintaining structural integrity during delivery and deployment.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The stent body is segmented into multiple coils arranged in a helical pattern, where each coil can independently compress and expand. This segmentation allows the overall stent length to be adjusted by compressing or expanding the coil structure, providing adaptability to different anatomical lengths without requiring multiple separate stents.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If a variable length stent is used, then the stent can adapt to different patient anatomies, but delivery, positioning, and length adjustment become challenging due to premature extension or compression

Engineering Contradiction:

Improvestent length adjustabilityVSAvoiddelivery and positioning ease

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The stent is pre-compressed to a shorter length for delivery through the ureter, and the delivery system includes a pusher device that maintains this compressed state during insertion. The pusher applies axial compression to prevent premature expansion during delivery, ensuring the stent remains in a manageable size until it is deployed at the target location.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A pusher device serves as an intermediary tool during delivery and positioning. The pusher applies controlled axial compression to the stent body, preventing premature expansion of the coils. This intermediary mechanism allows the operator to maintain the stent in a compressed state during delivery and then selectively expand it at the desired location using a release mechanism.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Length of moving object

If the stent body is compressed to reduce length for delivery, then the stent can be delivered through narrow passages, but the lumen diameter may be compromised

Engineering Contradiction:

Improvestent length for deliveryVSAvoidlumen diameter

Core Design Contradiction:

Length of moving objectVSStrength

Solution Approach 1:

The stent employs dynamic coil compression where the helical coils are compressed along the longitudinal axis to reduce overall stent length for delivery. The coil structure is designed to maintain its lumen diameter when in the expanded state, while allowing compression during delivery. The gaps between coils are configured to permit compression without permanently compromising the lumen integrity.

Inventive Principle:

Principle #15Dynamics

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

Enables accurate and efficient delivery, positioning, and removal of stents with adjustable lengths, reducing complications and improving patient comfort by accommodating individual anatomical needs and minimizing irritation.

Implementation Method 1

Axial compression of the body may be controllable by applying proximal tension to the distal suture

Methodology Applied

Scientific EffectAxial compression: Compression

Implementation Method 2

a body comprising coils about a longitudinal axis of the stent and along the length of the stent between a proximal end and a distal end in a substantially helical pattern

Methodology Applied

Scientific EffectHelical structure mechanics:

Data Source

PatentUS20240130874A1Devices, systems, and methods for delivering a stent

Publication Date: 2024.04.25 BOSTON SCIENTIFIC SCIMED INC

AI summary

The present disclosure relates generally to the field of medical devices. In particular, the present disclosure relates to delivering a variable length stent within a patient. In one example, a stent may include a body comprising coils about a longitudinal axis of the stent and along the length of the stent between a proximal end and a distal end in a substantially helical pattern. The coils may define a lumen along the longitudinal axis through the center of the body. A distal tube may have a wall extending from the distal end of the body. A first aperture may extend through the wall of the distal tube into the lumen. A distal retention member may extend from the distal tube. A distal suture may have a mid-portion. The mid-portion may extend through the first aperture.