Preoperative Detection of Inadequate Saphenous Vein by Noncontrast Three-dimensional Computed Tomography

Abstract

─ 24 ─ I. Introduction Despite the widespread use and superior patency of the arterial graft for coronary artery bypass grafting (CABG), the saphenous vein (SV) continues to be the most commonly used graft. The SVs, however, sometimes have anatomical problems such as varicose veins, small or large diameter, and duplication. Ultrasonography has been the main modality for preoperative SV evaluation because of its simplicity and low invasiveness 1) ; however, it has drawbacks, such as a lack of objectiveness, poor reproducibility, and difficulty in capturing the entire image of SV. Meanwhile, computed tomography (CT) can clearly visualize the SV without contrast. Although CT is performed as a standard preoperative examination for CABG in Japan, it is only used for evaluating the thoracoabdominal area in most facilities. To evaluate graft suitability of the SV preoperatively, we extended the CT scanning range to the lower extremities. The present study was conducted to clarify the usefulness of CT in the preoperative evaluation of the SV and to elucidate the incidence of an inadequate SV as a graft. II. Materials and methods From October 2017 to February 2019, preoperative noncontrast three-dimensional (3D) CT of the lower extremities was performed in 54 patients undergoing CABG. CT examinations were performed using a 320-multidetector CT system (Aquilion 1 ; Canon Medical Systems Corp., Otawara, Japan) or a 128-multidetector CT system (Somatom Definition Flash ; Siemens Medical Solutions, Forchheim, Germany). All thin-section axial images were reconstructed with the volume-rendering method using a Synapse Vincent workstation (Fujifilm Medical Co., Ltd, Tokyo, Japan). The CT scanning range was extended to the lower extremities in addition to the contrast enhanced thoracoabdominal CT which performed as a standard preoperative examination, thoracoabdominal area was contrasted and the pelvis to the ankles was noncontrast. The patient was in the supine position and legs mildly supinated. Imaging took approximately 5

Comment to: saphenous vein characteristics evaluated using three‐dimensional contrastless computed tomography before coronary artery bypass grafting

“…Previously, we investigated the results of non-contrast 3D-CT SV evaluation in preoperative patients with CABG [2]. The results of our study, which included 54 patients, revealed that nearly 40% of the patients had SVs that were inappropriate for grafting.…”