Even though the space of cardiology has witnessed significant advancements in recent times, heart disease remains the primary cause of death in the US with approximately 23.5% of the total deaths being accounted for some kind of heart condition. While this remains a matter of concern, the use of minimally invasive delivery systems like catheters for the diagnosis and therapy of cardiovascular diseases has revolutionized the medical industry. We talked to Principal R&D engineer Karthik Bujuru, who has a strong background in development of complicated structural heart delivery systems from concept to commercialization in start-ups and mature business environments.
Karthik talked about properly designed catheters that have become necessary to navigate the patient vasculature without causing dissection, to facilitate appropriate positioning of the catheter tip for delivery of therapy to targeted tissue in the heart, and to bring consistency in the procedural outcomes without heavily relying on operational skills of cardiologists. Further, Karthik also explained some factors that affect the performance of the catheters include the complexities of distinct anatomies of patients, complex 3-d structure of the heart, and the usability of device. Additionally, due to gaps in the understanding of physician user needs and translating them to successful designs also causes discrepancies between the expected and actual procedural outcomes.
He also talked about some of the great technological advancements in the last decade with regards to the tools available for successful design and development of catheters that have allowed interventional cardiologists to treat complex heart disease conditions. Sharing an example, Karthik mentioned that for the treatment of arrythmia- a disease condition caused by irregular beating of heart, some new catheter designs of electrophysiology catheters which consist of electrodes that can efficiently stimulate and record electrical impulses are used for better navigation in the heart, and for accurate mapping of the heart to determine location of problem causing tissue. The same catheters are now equipped with larger tip electrodes that are capable of delivering larger amounts of RF energy for ablation and using efficient irrigation of the tip to prevent overheating and burning of the tissue. These advancements in EP catheters have allowed for reduction in procedure times, efficient and accurate ablation of arrythmia causing heart tissue that prevented recurrence of disease conditions like atrial fibrillation and atrial flutter.
It was with the help of his vast experience of working on Electrophysiology, TAVI and TMVR catheters that Karthik could share multiple examples to highlight different intricacies of catheter development. In another example, he shared that advancements in cardiovascular catheter designs include the ones used in Transcatheter Aortic Valve Replacement (TAVR) and Transcatheter Mitral Valve Replacement (TMVR). Advancements in polymer science has brought forward different grades of plastics that can be engineered to use in the catheter designs. The distal section of the catheter that needs to be flexible and be able to track the curves of the vasculature and heart can be made from soft amorphous copolymers like low durometer PEBAX and Thermoplastic Elastomer Urethane (TPE-U). Other distinct characteristics of some of these plastics is that they can soften with temperature and moisture in the patient body which can allow for unique applications. The proximal sections of the catheter which do not need to be as flexible can be made from semi-crystalline polymers like Nylon, HDPE, Polyamide etc. To minimize inter catheter friction, and catheter friction with the patient anatomy, special coatings that are hydrophilic can also be used for improved performance. The catheters’ internal diameters can also be lined with PTFE that is known to have least amount of friction with interacting catheters/guidewires which is also used to prevent thrombus and haemolysis. For catheter support structure, various densities of the stainless-steel braids can be used to make flexible/stiff braids or combination of both kind of braids can be used to design the catheters. Therefore, he explains that polymer science innovations and judicious material selection has allowed for improving the performance of complex cardiovascular catheters in the last decade.
In conclusion, Karthik talked about the future scope of catheter development. Technological advancements have paved the way for the design and development of modern catheters that are safe, efficient, and tailored to the specific needs of the patients. Furthermore, polymer science advancements allow for the engineering of catheters with different kinds of plastics, providing the necessary flexibility and support required for various applications. Overall, all these developments hold great promise for the future of cardiovascular care, allowing for better patient outcomes and improved quality of life.