Design and making a model/prototype for the suture-less Coronary Artery Bypass Grafting (CABG) connector

• Main Author: Hu, Hongsheng.
• Other Authors: Chua Leok Poh
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/54178
• Institution: Nanyang Technological University

Coronary heart disease is one of the top causes of death in the world. It cannot be cured but be managed by medication. If medication fails to manage the conditions, surgery would be required. One possible surgery would be coronary artery bypass surgery. Conventionally, the anastomosis of the graft and artery is done by suturing but suturing would cause damage to the vessel walls. Hence sutureless methods to complete the anastomosis would be needed to reduce damage to the vessel walls. One way would be to use a connector that does not require suturing to secure the graft to the artery. Thus, the objective of this project is to design a sutureless coronary artery bypass connector. In this project, there are three design concepts of a sutureless connector in which one of the designs would be chosen based on the evaluation criteria. The pre-surgical and surgical procedures for each design would be described in this report. Design C was chosen as it has the highest rating among the three designs. Some biocompatible materials and manufacturing technology would be mentioned in the later part of the report. The materials chosen for Design C are nitinol and stainless steel. Nitinol is used to make the connector and clip while the forceps device and top cover are made of stainless steel. Nitinol is chosen for its lower stiffness and biocompatibility to reduce restriction on the motion of the vessel walls. Stainless steel is chosen as it is stiff enough to pierce the walls of the vessels. The manufacturing processes chosen are electric discharge machining (EDM) and selective laser sintering (SLS). EDM is used to produce parts with small dimensions and better surface finish though it may be more time consuming. SLS helps to decrease the manufacturing time but the surface finish would not be as good as EDM. Design C does damage to vessel walls by piercing the vessel walls hence Design C can still be improved on to reduce the amount of damage to the vessels.