Utility of Caudal Angulation for Venous Access under Fluoroscopic Guidance during Cardiovascular Implantable Electronic Device Implantation

Background: Axillary venous access is preferred for CIED implantation. The procedure is usually performed under fluoroscopic guidance in anteroposterior (A-P) view. However, there is a lack of perception of depth in this view with a fear of creating complications. Caudal fluoroscopy (adding 30 degrees-35 degrees caudal angulation to A-P projection) has been proposed to circumvent this problem. Objective: The aim of this study was to elucidate the advantages of caudal fluoroscopy using fluoroscopic images, contrast venograms, and CT angiography images of axillary vein. Methods: The fluoroscopic images and contrast venograms obtained in the A-P view were compared with caudal fluoroscopy in patients undergoing CIED implantation at our centre. Also, the CT angiography images of axillary vein were reconstructed to understand the relative anatomy of the vein and the underlying lung parenchyma, simulating these 2 projections. Results: The CT angiography images, contrast venograms, and fluoroscopic images confirmed that caudal fluoroscopy allows better visualization of the vein in relation to the lung parenchyma and rib cage. Analysis of fluoroscopic images revealed that the bend of the first rib formed a conical prominence in caudal fluoroscopy. This served as an important bony landmark for successful venous access, which was usually obtained while the needle was being directed towards this prominence in caudal fluoroscopy. Conclusions: The proposed advantages of caudal fluoroscopy for CIED implantation have been elucidated by analysis of CT angiography images, contrast venograms, and fluoroscopic images.