PV, portal vein; SMV, superior mesenteric vein; CV, coronary vein; IMV, inferior mesenteric vein; SA, splenic artery; SV, splenic vein; LGEA, left gastroepiploic artery; LGEV, left gastroepiploic vein
; SGA, short gastric artery; SGV, short gastric vein.
An imaging-based diagnosis of venous invasion was established when one of the following criteria were satisfied: 1) tumoral enhancement in the lumen of the vein, 2) tumor protruding through the course of a vein, and 3) distention of the vein due to extension of the gastric tumor Right and left gastric veins, aberrant left gastric vein (ALGV), right and left gastroepiploic veins
, superior mesenteric vein (SMV), short gastric veins, and the portal vein were evaluated for tumoral invasion (Figure 1).
Although gastric veins usually drain directly into the portal vein, they can also drain first into the superior mesenteric vein (SMV) and then the portal vein via the right and left gastroepiploic veins
. Therefore, tumor cells may spread into the portal system in patients with gastric cancer to cause a tumor thrombus there or, rarely, to create a tumor thrombus within the SMV [1, 4].