Stent-Graft Curvature Control Using Tightenable Suture Loop
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Solution Overview
Problem
Current stent-graft deployment methods face challenges in highly curved lumens like the aortic arch, leading to incomplete sealing, leakage, and premature fatigue due to imprecise placement, especially in areas with short necks of healthy vascular wall, resulting in increased operating time and potential failure.
Innovation Solution
A compressible and curvable stent-graft structure with a loop of suture material that tightens to fit the device's curvature, allowing for precise alignment and secure sealing, along with a tie element to secure the knot without external devices, and a constricting mechanism to prevent barbs from engaging the vessel wall during deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If stent-graft is deployed into highly curved lumen such as aortic arch using conventional methods, then the device can be placed in challenging anatomical locations, but the proximal end of the stent-graft is liable to be incorrectly fitted such that it incompletely seals around the inner wall of the aorta
Solution Approach 1:
The stent-graft is pre-formed with a curved configuration that matches the anatomy of the aortic arch. This preliminary shaping allows the device to conform to the curved lumen upon deployment, eliminating the need for post-deployment adjustment and ensuring proper sealing at the proximal end against the aortic wall.
Solution Approach 2:
The stent-graft incorporates a tie element that can be adjusted to modify the curvature parameter of the device. By tightening or loosening the tie element, the curvature of the stent-graft can be precisely controlled to match the specific anatomical requirements of the patient's aortic arch, ensuring optimal placement and sealing.
2Adaptability or versatility
If conventional deployment methods are used in lumens with short necks of healthy vascular wall, then the procedure can be attempted in more locations, but there is a limit to the length of neck of healthy vascular wall which is needed to provide a seal around the proximal end of the stent-graft
Solution Approach 1:
The stent-graft is pre-configured with a curved shape and adjustable tie element that allows the proximal end to conform precisely to the aortic wall even in locations with short healthy vascular necks. This preliminary configuration ensures that the sealing surface is optimized before deployment, enabling reliable sealing in previously unsuitable anatomical locations.
Solution Approach 2:
The tie element provides dynamic adjustability of the stent-graft curvature after deployment. This allows the device to be fine-tuned in situ to achieve optimal contact with the aortic wall, ensuring reliable sealing even when the available healthy vascular wall is limited in length.
3Ease of operation
If the stent-graft is not fitted precisely in position, then the procedure may need to be repeated by withdrawing the device back into its delivery introducer, but this increases operating time, trauma to the patient and does not guarantee a successful outcome
Solution Approach 1:
The stent-graft is pre-formed with the appropriate curvature and equipped with a tie element for fine adjustment. This preliminary preparation allows the device to be positioned correctly on the first attempt by matching the curvature to the aortic arch anatomy before deployment, eliminating the need for time-consuming withdrawal and repositioning operations.
Solution Approach 2:
The adjustable tie element enables precise control of the stent-graft curvature parameter during deployment. This allows the operator to optimize the fit to the specific anatomical geometry of the patient's aortic arch, ensuring correct placement on first attempt and avoiding repeated procedures that increase operating time and patient trauma.
Data Source
AI summary
A stent-graft (100) is provided with a tightenable loop element (104) having a first end terminated in a slip knot or self-tightening knot (112) and a second end which is received in and can slide in the knot (112). The knot (112) is tied by a suture to the stent-graft (100) so as to be fixed thereto. The loop (104) is fitted to the stent-graft (100) in a manner as to pass between the inside to the outside of the graft material and in such a manner that controlled curvature of the stent-graft (100) is possible, in particular control of the overlapping of adjacent stents held within the zone of the loop (104). An introducer assembly is also disclosed which includes a control cannula (120) able to the fixed to the stent-graft (100) during the deployment procedure, as well as a mechanism of suture loops (150, 152) at the proximal end of the stent-graft (100) for retaining this in a constricted form during the process of curving the latter during the deployment process.