Feasibility and accuracy of real-time 3D-holographic graft length measurement, a sub-study of the FAST-TRACK CABG trial

Abstract

Abstract Background 3D Hologram is an emerging tool for intuitively manipulating and visualizing CT images. Mixed reality (MR) technology can display high-definition 3D holograms while preserving situational awareness. The new MR software offers the possibility to measure 3D objects using hand gestures and voice commands. However, these measurements made on 3D holograms have not been validated. Purpose We aimed to assess the feasibility and accuracy of using CT-derived 3D holograms for bypass graft length measurement. Methods Twenty-seven consecutive cases in the FAST TRACK CABG trial were included. The post-operative CT images performed at 30 days follow-up were analyzed in an independent core lab. Two analysts blinded to clinical information performed Holographic reconstruction and measurement using the CanaLife Holo software (Medapp, Krakow, Poland). (Figure 1) Inter-observer agreement was assessed in the first 20 cases. Another analyst with full access to clinical information performed the validation measurements on the CardIQ W8 system (GE Healthcare, Milwaukee, Wisconsin). (Figure 1) Results A total of 62 grafts (27 left internal mammary artery grafts, 27 saphenous vein grafts, and 8 right internal mammary artery grafts) were measured. There was an excellent inter-observer agreement between the analysts in the first 47 grafts analyzed (interclass correlation 0.9879 [0.9783-0.9933]). (Figure 2A, 2B) On average, holographic reconstruction and measurement of a case took 3 minutes and 36 seconds± 50.74 seconds compared to around 10 minutes per vessel on the traditional CT system. There was no significant difference between the graft length measured by hologram and CT (188.59±51.63 mm vs. 183.95±50.93 mm, p=0.616). The length measured by hologram and CT were similar across different graft types. The measurements of hologram and CT are highly correlated (r=0.973, p <0.001) with an excellent agreement (interclass correlation 0.9928 [0.9880-0.9957]). (Figure2C, 2D) Conclusion Holographic vessel length measurement is feasible, fast, and accurate even for tortuous coronary bypass grafts. This new methodology can empower surgeons to visualize and measure the results of their work by themselves and may provide insights for procedure evaluation. 3D Holograms can eventually empower surgeons to plan the precise length of the arterial and venous grafts to be harvested for every individual case.