TWI, in partnership with Vascutek Ltd and the Technology Strategy Board is developing a new generation of endovascular devices for the treatment of Abdominal Aortic Aneurysms (AAA) which would involve use of rapid automated manufacturing methods.
AAA is a life-threatening disease which occurs when a section of the abdominal aorta, the body's main circulatory vessel, weakens and bulges outward to form a fragile, balloon-like swelling called an aneurysm. If the aneurysm ruptures, the patient is at high risk of death as a result of internal bleeding. AAA is mainly treated by two methods; using a conventional approach for treatment of weakened portions by surgical replacement of the affected portion of the aorta or, more recently, by minimally invasive endovascular repair. Endovascular grafts such as the Anaconda manufactured by Vascutek Ltd are used to treat AAA using the less invasive approach.
Currently, Vascutek uses highly labour intensive procedures for manufacturing the Anaconda. Although the selling price of endovascular devices is much higher than conventional grafts, the manufacturing costs are also higher. This is mainly due to the complexity of the devices and the current slow, labour intensive, manual assembly process. One of the most time consuming operations is the attachment of the supporting Nitinol ring-stents to the polyester graft fabric. This is currently performed by hand sewing with needle and suture.
New technologies such as ultrasonic welding, laser welding and adhesive bonding will be thoroughly investigated at TWI and the most effective technology will be taken to the next stage leading towards an automated manufacturing procedure. The new methods will be incorporated into a manufacturing unit and, following the specification of quality control techniques, the unit will be made ready for production. TWI's particular strength is materials joining and it has 15 years of expertise in textiles joining including the development of new techniques in the areas of welding and adhesive bonding. In particular, laser welding has been developed in the last few years and has shown great promise for rapid and effective automated joining of textiles. This work provides a sound base for the selection of a suitable manufacturing method for the endovascular devices to align with new product development.
For more information on this project, and joining methods for medical devices please contact us.