Augmented Reality Guidance for the Resection of Missing Colorectal Liver Metastases: An Initial Experience

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Modern chemotherapy achieves the shrinking of colorectal cancer liver metastases (CRLM) to such extent that they may disappear from radiological imaging. Disappearing CRLM rarely represents a complete pathological remission and have an important risk of recurrence. Augmented reality (AR) consists in the fusion of real‐time patient images with a computer‐generated 3D virtual patient model created from pre‐operative medical imaging. The aim of this prospective pilot study is to investigate the potential of AR navigation as a tool to help locate and surgically resect missing CRLM.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>A 3D virtual anatomical model was created from thoracoabdominal CT‐scans using customary software (VR RENDER<jats:sup>®</jats:sup>, IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM<jats:sup>®</jats:sup>, Karl Storz, Tüttlingen, Germany). Virtual and real images were manually registered in real‐time using a video mixer, based on external anatomical landmarks with an estimated accuracy of 5 mm. This modality was tested in three patients, with four missing CRLM that had sizes from 12 to 24 mm, undergoing laparotomy after receiving pre‐operative oxaliplatin‐based chemotherapy.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>AR display and fine registration was performed within 6 min. AR helped detect all four missing CRLM, and guided their resection. In all cases the planned security margin of 1 cm was clear and resections were confirmed to be R0 by pathology. There was no postoperative major morbidity or mortality. No local recurrence occurred in the follow‐up period of 6–22 months.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>This initial experience suggests that AR may be a helpful navigation tool for the resection of missing CRLM.</jats:p></jats:sec>