Bifurcated Stent Deployment Apparatus for Side Branch Access
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Solution Overview
Problem
Current stent deployment methods for bifurcated vessels face challenges such as inaccurate positioning, inadequate stent coverage, over-stretching of the main artery, high metal-to-artery ratio, plaque shifting during balloon inflation, and limited accessibility to the side branch, leading to increased risks of restenosis and 'stent jail' scenarios.
Innovation Solution
A bifurcated stent system with a primary and secondary inflatable portion, where the secondary portion maintains registration with the side branch, and a method involving a branched balloon catheter with a sleeve to control expansion, ensuring precise deployment and coverage of bifurcated lesions while preventing over-stretching and plaque shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional stent techniques are used to treat bifurcated lesions, then stent deployment is possible, but the patency of the primary vessel and/or its branches is compromised due to disease tissue displacement, vessel spasm, dissection, thrombosis, and embolism
Solution Approach 1:
The stent is divided into multiple segments including a main body portion and a side branch portion that can be independently positioned and deployed. This segmentation allows precise placement in bifurcated vessels without compromising the main vessel or side branch patency, avoiding the harmful effects of conventional techniques.
Solution Approach 2:
Different portions of the stent are designed with different properties: the main body portion has a specific radial strength for the primary vessel while the side branch portion is optimized for the side vessel. This local differentiation enables appropriate support in each vessel segment without causing displacement or spasm.
2Reliability
If specially designed stents with side openings or distal bifurcation are used, then bifurcation lesions can be treated, but accurate positioning of the stent in the main vessel and side branch is difficult
Solution Approach 1:
A delivery catheter system with a balloon is used as an intermediary to precisely position the stent. The balloon can be inflated at specific locations (main vessel or side branch) to anchor the stent accurately before deployment, ensuring correct positioning in the bifurcated vessel architecture.
Solution Approach 2:
The stent and delivery system are designed to be dynamically adjustable during the procedure. The side branch portion can be selectively engaged or disengaged from the delivery catheter, and the stent can be repositioned before final deployment, allowing accurate positioning that adapts to the specific anatomy.
3Reliability
If double balloons are used in the kissing balloon technique, then bifurcated lesions can be treated, but over-stretching of the proximal main artery occurs which damages the artery and increases restenosis risk
Solution Approach 1:
Instead of simultaneously inflating two balloons (excessive action), the system allows selective inflation of either the main vessel balloon or the side branch balloon depending on the specific lesion requirements. This partial action approach applies only the necessary expansion force to treat the lesion without over-stretching the artery.
Solution Approach 2:
The balloon inflation parameters (pressure, duration, sequence) are optimized to achieve adequate lesion treatment while preventing over-stretching. The system allows controlled inflation that adapts to the specific vessel characteristics, maintaining arterial integrity while treating the bifurcated lesion.
4Ease of operation
If stent struts are crushed to create an opening for side branch access, then the side branch can be accessed, but high metal-to-artery ratio results which increases fluid turbulence and clot deposition risk
Solution Approach 1:
The stent is segmented into a main body portion and a side branch portion that can be independently deployed. This eliminates the need to crush struts to access the side branch, as the side branch portion is already configured to provide access while maintaining a low metal-to-artery ratio and smooth surface that reduces turbulence and clot risk.
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 solution enables precise deployment and better coverage of bifurcated lesions, accommodating different stent sizes, and maintains access to the side branch without 'stent jail', reducing the risk of restenosis and fluid turbulence.
Implementation Method 1
When the primary and secondary inflatable portions are inflated, the primary inflatable portion expands radially in the main branch
Implementation Method 2
the secondary inflatable portion maintains registration with the side branch by expanding radially therein
Data Source
AI summary
A deployment apparatus and method for deploying one or more stents to a bifurcated vessel is provided. The invention is particularly suited for T-type bifurcated vessels where a side branch extends from a main branch. The deployment apparatus has a primary inflatable portion for engagement within the main branch and a secondary inflatable portion for engagement within the side branch. A main stent is arranged on the primary inflatable portion and radially expanded within the main branch while the secondary inflatable portion maintains registration with the side branch. A side branch stent is then arranged on the secondary inflatable portion and expanded within the side branch while the primary inflatable portion maintains registration with the expanded main stent. A bifurcated stent system suitable for bifurcated lesions is also provided comprising a side branch stent with a shaped end designed to engage a similarly shaped side opening in a main stent.