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Yu, Melissa

University of British Columbia

Mandibular reconstruction with a fibula free flap is a common method for restoring form and function to patients with segmental mandible defects. The conventional strategy for reconstruction is a freehand technique, but this makes it difficult to achieve adequate contact between bone segments. More recent technology uses virtual surgical planning to 3D print cutting guides. However, this process can take days to weeks of preparation, during which the tumour can progress beyond the resection margins, rendering the initial plan obsolete. A day-of-surgery approach combats this limitation using image guidance to bring surgical planning into the operating room. This provides surgeons with the flexibility to respond to intraoperative changes while maintaining the benefits of guided approaches. A proof-of-concept system was developed by previous graduate students that demonstrated comparable accuracy to 3D printed guides but significantly prolonged the operative time. Therefore, the objective of this work is to prepare the day-of-surgery approach for clinical implementation by addressing the key limitations of the existing system. This thesis details our efforts to reduce its intraoperative time, update its virtual surgical planning (VSP) algorithm, and introduce guided navigation to support segment positioning. We used a motor cognitive modelling diagram to identify areas of inefficiency within the integrated procedure and inform usability improvements to the software workflow. We also updated the VSP algorithm to align with the version developed by the ISTAR group to automate surgical planning and support future dental implant considerations. We then used this VSP to guide a surgeon through the precise micromanipulator adjustments required to move a segment into its target position. These changes were evaluated by ENT surgeons through a simulated mandibular reconstruction procedure on anatomical models. We generated five reconstructions with comparable accuracy to the previous cadaver study, and reduced operative time to an average of only 215 minutes. This represents a key step towards its clinical implementation by demonstrating that the day-of-surgery system can be implemented into mandibular reconstruction surgery without introducing significant delays to the operation.

Text

2024-01-10

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87195

Biomedical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/