Complex coronary artery disease revascularization planning with computed tomography and 3-dimensional hologram

From the Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan; CORRIB Research Centre for Advanced Imaging and Core Laboratory, University of Galway, Galway, Ireland; Department of Cardiovascular Surgery, Mount Sinai Morningside, New York, NY; The University of Texas Health Science Center at Houston, Houston, Tex; HeartFlow, Inc, Mountain View, Calif; Department of Cardiology, Royal Blackburn Hospital, Blackburn, United Kingdom; and Department of Medicine, University of Central Lancashire, Preston, United Kingdom. Disclosures: The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest. Received for publicationMarch 8, 2023; revisions received April 8, 2023; accepted for publication April 11, 2023; available ahead of print May 8, 2023. Address for reprints: Patrick W. Serruys, MD, Interventional Medicine and Innovation, National University of Ireland, Galway (NUIG), University Rd, Galway, H91 TK33, Ireland (E-mail: patrick.serruys@nuigalway.ie). JTCVS Techniques 2023;20:96-8 2666-2507 Copyright 2023 The Author(s). Published by Elsevier Inc. on behalf of The American Association for Thoracic Surgery. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1016/j.xjtc.2023.04.017 Holograms of the preand post-CABG CT, surgical images, and post-CABG 3D printing model.


Video clip is available online.
A 71-year-old man was referred for consideration of coronary revascularization on the background of stable coronary artery disease in the context of exertional and occasional rest angina. His medical history included hypertension, dyslipidemia, well-controlled human immunodeficiency virus infection, and spinal stenosis. Per Mount Sinai Morningside Hospital regulation, additional institutional review board approval was not required. The patient provided written informed consent for publication of study data. The patient was enrolled in the FASTTRACK CABG trial (NCT 04142021), which aims to assess the feasibility of CCTA and FFR CT to replace coronary angiography as CABG guidance.
A coronary computed tomography angiogram (CCTA) with CT-fractional flow reserve (FFR CT ) was performed to plan revascularization and showed functionally significant triple-vessel coronary artery disease. There were respective fibrocalcific lesions and soft plaque in the proximal and distal parts of the right coronary artery. There were also significant fibrocalcific lesions in the left main stem, left anterior descending artery (LAD), LAD-first diagonal (D1) bifurcation, left circumflex artery, and ramus intermedius. Mixed plaques were found in the first obtuse marginal branch (OM1), with soft plaques in the distal LAD, D1, and OM1. Both anatomical and functional SYN-TAX scores were 66. 1 Thus, the heart team concluded that the patient should receive coronary artery bypass surgery (CABG). The patient was enrolled in the FASTTRACK CABG trial (NCT 04142021), which aims to assess the feasibility of CCTA and FFR CT to replace coronary angiography as CABG guidance.
A 3-dimensional (3D) hologram was reconstructed from the CCTA, and preoperative measurements were performed to estimate the length of grafts needed to be harvested. The hologram reconstruction and measurements were performed using the CarnaLife Holo software (MedApp). The diameter of the right and left internal mammary arteries (RIMA, LIMA) and the distance from the internal mammary arteries to the corresponding coronary beds were measured. The distances between the LIMA to the D1 and the RIMA to the right coronary artery-posterior descending artery (PDA) were 38.6 mm and 88.5 mm, respectively. The predicted lengths for the radial artery (RA) grafts between the LAD and OM1 and the PDA and the left posterolateral artery were 57.3 mm and 51.9 mm, respectively (Figure 1, A and B; Video 1).
Using this information for guidance, the patient underwent 5-vessel full-arterial, no-aortic touch, off-pump CABG via a median sternotomy with the following grafts: LIMA sequentially to D1 and LAD; RA as a T graft from LIMA to OM1; and RIMA-radial extension to PDA and left posterolateral. The hologram estimation of graft lengths ensured that only the left RA needed to be harvested (Figure 1, C and D). Assessment of transit time flow showed satisfactory flow in all grafts, with low pulsatility indexes. His postoperative course was uneventful; he was extubated on day 1 postoperatively and discharged home on day 4.
At 30-day follow-up, he was angina-free, and repeated CCTA showed all grafts were patent, yielding a post-CABG SYNTAX score of 2. 1 Another hologram was reconstructed using the post-CABG CTCA, and this showed the lengths of the RA grafts were 56.5 mm (LAD to OM1) and 53.1 mm (PDA to left posterolateral), which were similar to the pre-CABG estimations of 57.3 mm and 51.9 mm, respectively ( Figure 1, E and F). A 3D-printing model was prepared for further evaluation (Figure 1, G and H).

DISCUSSION
This is the first case to demonstrate that planning complex coronary revascularization can be achieved purely with CCTA, FFR CT , and 3D holograms. CCTA has the advantage of providing simultaneously an anatomic overview and plaque composition, which are both essential for risk stratification. 2 Moreover, CCTA enables the distal lumen of total occlusions to be visualized, which helps identify targets for CABG. 3 FFR CT provides physiological assessment on top of anatomical information. However, the complex interaction between the stenosis of the native vessel and the grafts is still difficult to predict preoperatively. According to the SYNTAX III trial, functional assessment alters the decision of the heart team in more than 7% of cases and modifies the vessel for revascularization in 12% compared with CCTA alone. 4 The addition of 3D holograms can further empower surgeons to virtually visualize and manipulate complex anatomy by themselves before and during the actual operation. 5 With contemporary software, they can plan the precise length of the grafts to be harvested, allowing them to make an individualized plan for their patient. This case demonstrates that visualization and measurements can be performed in real-time. It is important to emphasize that all measurements were performed with gestures and voice commands, allowing measurements without breaking sterility. This mixed-reality setting has the advantage of providing high-definition images while preserving situational awareness, which is ideal for surgeons. The current report showcases that it is safe and feasible to make complex and individualized revascularization plans without invasive coronary angiography entirely. Ultimately, it is the patient, who received expedited revascularization, was exposed to less radiation, and suffered from less tissue damage, who benefited the most from these technological advances.