Real-time MHz-OCT for planning, monitoring, and functional assessment during off-pump coronary artery bypass (OPCAB) surgery on the beating heart

• Applicants: Professor Dr. Robert Alexander Huber; Professor Dr. Thomas Pühler
• Subject Area: Medical Physics, Biomedical Technology ; Cardiac and Vascular Surgery
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 578849818

The goal of the project is to improve coronary artery bypass surgery for long-term, high-quality patient care. The suitability of MHz-OCT technology will be examined in three areas: (1) preoperative planning, (2) intraoperative monitoring, and (3) postoperative function assessment. (1) Preoperative planning aims to use MHz-OCT to determine the optimal bypass site. Before bypass surgery, coronary angiography is typically performed to locate stenoses. However, this method has limitations, as it often fails to detect soft plaques and does not provide a transmural view. This increases the risk of incorrect decisions regarding the incision site. MHz-OCT could address this by providing a high-resolution, tomographic image of the vessels, making both calcified and lipid-rich plaques visible from the outside. The goal is to evaluate the suitability of MHz-OCT for this application and identify technical challenges. (2) Intraoperative monitoring seeks to improve the quality of the anastomosis using live 4D MHz-OCT. Anastomosis quality is crucial to the success of the surgery, as coronary vessels are very small and require microsurgical techniques. MHz-OCT enables real-time monitoring and displays three-dimensional structures with microscopic resolution and minimal latency. This could be particularly useful for inexperienced surgeons by making errors in the anastomosis immediately visible and correctable. Precise measurement of the anastomosis area through OCT could further enhance surgical success. Additionally, 4D-OCT videos can be used for training purposes and long-term monitoring of the surgical outcome. Various methods for visualizing the large datasets are being explored. (3) Postoperative function assessment will explore dynamic multi-angle 4D MHz-OCT for the evaluation of anastomosis quality. After surgery, the bypass function is typically checked using Transit Time Flow Measurement (TTFM), which has limitations, as it does not provide a complete visualization of the anastomosis. In contrast, Doppler-based MHz-OCT technology allows for visualization of blood flow in both the bypass and the coronary artery. In addition, dynamic OCT can represent the degree of tissue perfusion. The goal is to further develop the OCT technology to enable vectorial blood flow measurement. A special scanning head will be designed to capture the complex anastomosis site from various angles. In the long term, OCT technology aims to provide a comprehensive evaluation of tissue perfusion and blood distribution after surgery, contributing to quality control and long-term monitoring. Feasibility studies will support further development and clinical application of this technology.

• DFG Programme: Research Grants