LAUSR

The oblique vein of the left atrium (vein of Marshall) is a small vessel that descends obliquely on the back of the left atrium and ends in the coronary sinus near the area where great cardiac vein continues into the coronary sinus. Its cannulation can be useful, e.g. before selected electrophysiology procedures such as paroxysmal focal atrial fibrillation ablation. Because the vein of Marshall should also be avoided at the site of the implantation of the left ventricle lead, knowledge about its existence, position or diameters could be useful. There is a lack of complex data about the possibilities of visualizing the vein of Marshall in cardiac computed tomography. 354 patients were included into the research. Cardiac computed tomography (Aquilion 64, Toshiba: 64 slices, 0.5 mm; retrospective gating; contrast enhanced) was performed for all of the patients. A precise retrospective analysis of the CT data in all phases (every 10%) of the cardiac cycle during post processing was performed including searching for the target vein by using Vitrea workstations (Vital Images). Both multi planar reformatted reconstructions (MPR) and 3D volume renderings were used. The analyses were performed by two experienced researchers (more than 200 coronary venous system analyses previously performed). The vein of Marshall was found in 66 of the 354 patients (16.6%). An example of the visualization is presented in the figure below (MPR and 3D volume rendering). Its ostium to coronary sinus was found an average of 42.6±10.8 mm from the coronary sinus ostium to the right atrium. This value was statistically higher (p=0.0082) in the men (45.3±11.2) compared to the women (38.5±9.7). The vein of Marshall is a small vessel; its average diameter was 1.8±0.8 mm and length of the visible vessel that was measured was 8.7±7.5 mm. It was visualized statistically more frequently (p=0.0009) in the end-systolic phases (30–40–50% RR; 68.85% cases) compared to the end-diastolic phases (70–80% RR; 21.31% cases). Occasionally, it was optimally visualized in the other phases (9.83%). It is possible to visualize the vein of Marshall using cardiac computed tomography. Because it exists in about 20% of population, during visualization, special attention needs to paid to obtaining quality images in CT especially in the end-systolic phases. Vein of Marshall imaging (VR, MPR) Type of funding source: None