[Morphology and anatomical variations of the left gastric vein]

Objective: To explore the gross morphology and variation characteristics of the left gastric vein (LGV) by means of cadaveric anatomical measurement and three-dimensional imaging reconstruction. Methods: A total of 39 adult cadaver specimens fixed with 4% formaldehyde solution from Zhongshan School of Medicine, Sun Yat-sen University, and 40 cases of abdominal contrast-enhanced CT imaging data of patients with gastric cancer admitted to the Seventh Affiliated Hospital of Sun Yat-sen University between January 2023 and December 2024 were included in this study. Specimens with obvious decomposition, tissue deformation, structural damage, or a history of upper abdominal surgery were excluded; patients with pathologically confirmed gastric cancer and CT images suitable for three-dimensional vascular reconstruction were selected, while those complicated with liver cirrhosis, portal hypertension, or a history of major upper abdominal surgery were excluded. The perigastric and perihepatic vessels were exposed in cadaver specimens to observe the morphology and course of the LGV and measure related anatomical parameters; the imaging data were scanned with dual-source CT using standardized parameters, and three-dimensional vascular reconstruction was performed on a post-processing workstation. The LGV was classified according to the Lee criteria. Results: Cadaveric dissection showed that the LGV originated from the middle of the lesser curvature of the stomach, coursed leftward along the lesser curvature, received 2-3 esophageal veins at the inferior margin of the esophageal hiatus, and then obliquely descended rightward to drain into the hepatic portal vein. Both cadaveric dissection and imaging detected three drainage sites of the LGV: the hepatic portal vein, the portal vein angle, and the splenic vein. CT angiography (coronal plane) and cadaver specimens both showed that the proportion of drainage into the hepatic portal vein was the highest [52.5% (21/40) vs. 53.8% (21/39)], followed by the splenic vein [35.0% (14/40) vs. 41.0% (16/ 39)], and the least common was drainage into the portal vein angle [12.5% (5/40) vs. 5.1% (2/39)]. The length of the LGV was (40.3±7.4) mm in cadaver specimens and (48.4±11.9) mm on imaging; the distance from the drainage site to the portal vein angle was (13.8±8.1) mm in cadaver specimens and (13.1±8.2) mm on imaging. In both the imaging group and the cadaver group, the type Ip accounted for the highest proportion of LGV classification, at 40.0% (16/40) and 41.0% (16/39), respectively, and no type IV was detected in either group. The proportion of type II in the imaging group was 22.5% (9/40), which was higher than that in the cadaver group (7.7%, 3/39); the proportion of type Ia in the cadaver group was 25.6% (10/39), which was higher than that in the imaging group (15.0%, 6/40); the proportions of type IIIa (20.0% in the imaging group vs. 20.5% in the cadaver group) and type IIIp (2.5% in the imaging group vs. 5.1% in the cadaver group) were similar between the two groups. Conclusions: There are certain variations in the anatomical course and diameter of the LGV. The LGV most commonly drains into the hepatic portal vein, and is mainly classified as type I.