Cole Latvis - Immersion Week 8 - Expanding Research Aims and Preparing for Long-term Collaboration

Up until this week I had focused most of my time on observing cardiology procedures and clinical work. I learned about nuclear scans, electrophysiology labs, catheterizations, cardiothoracic surgery, and patient interactions. With so much time spent on these aspects of immersion, it was hard to feel like I was making significant and quality contributions to the research project I was tasked with in Dr. Weinsaft’s lab. This changed over the last week, as I spent my entire week making great progress in my research.

A brief summary of my project is as follows. When patients present with significant ascending aortic aneurisms, they are in danger of developing a life-threating type A dissection that can lead to sudden aortic rupture and death. As a preventive measure the ascending aorta is surgically replaced with a vascular graft, typically Dacron. The graft eliminates the risk of type A dissection and greatly prolong life. However, Dacron and other graft materials are poorly biomimetic, which leads to downstream consequences. For instance, Dacron is very stiff and inelastic compared to the native aorta. Less energy from left heart contractions is absorbed by the vessel wall, resulting in greater flow velocities and wall shear stresses downstream of the graft in non-grafted regions. The non-grafted aortic wall suffers as it experiences increased strain, changes in stiffness, and altered distensibility. My project is to investigate the long-term effect of ascending aorta grafting and quantify the extent of changes in the distal regions of the aorta. To do this, I have been working with cardiac MRI data taken from relevant patients and controls.

In previous weeks I calculated the peak circumferential strain for four regions of the thoracic aorta in 23 patients. On Monday, I was finally able to present my findings to my mentor, Dr. Weinsaft. He was excited about the data and encouraged me to calculate other numbers such as factional area change of the aorta segments. After exploring the image analysis software and talking with fellows in the lab, I figured out how to reliably measure end-diastolic and end-systolic areas. The analysis went quickly, so I eagerly looked into other mechanical properties I could derive from the area measurements. In all, I generated circumferential strain, time-to-peak strain, fractional area change, stiffness, and distensibility values for each of the four segments of the thoracic aorta.

By Friday all my data collection was complete, and I ran statistical analysis. Dr. Weinsaft seem very happy with the amount I was able to get done and now wants me to write the data up into an abstract to be submitted to an MRI conference in February. However, we want to strengthen the analysis first by expanding the sample size. For the rest of the day, I worked with a resident to identify new volunteers whose preexisting MRI images would be useful. At the end of the day, I generated de-identified versions if my excel sheet and talked with Dr. Weinsaft about how I can continue analysis from Ithaca. We plan to continue our work together remotely as a collaboration so the work can be complete.  

I am now much more excited for this project since it has momentum and feels meaningful, which is frustrating now that immersion is over. However, Dr. Weinsaft and I plan to work together more remotely.

Immersion has been a wonderful experience. The exposure to hospital operations and medical procedures really helped me better understand where clinical needs are and how I can tailor my engineering work to fit best into the system. I learned about new devices, and the perspectives of doctors on current practice and potential new technologies. The program also put me in contact with many new friends and potential collaborators. I have even established a new project I will continue with in Ithaca. I am very thankful for this opportunity and to those who made it possible. Thank you!