Classification of Anatomic Variations in the Left Gastric Vein during Laparoscopic Gastrectomy

Abstract

Background: The left gastric vein (LGV) is an important blood vessel requiring dissection during gastric surgery. Since the drainage patterns of the LGV vary, it is easily injured, and bleeding from the LGV may be difficult to control. This study therefore analyzed anatomic variations in the LGV observed during laparoscopic gastrectomy. Methods: LGV drainage patterns were analyzed relative to intraoperative vascular anatomy in 1325 patients with gastric cancer who underwent radical resection from May 2007 to June 2012. The rates of occurrence of these anatomic variants were determined, and lymph node dissection and surgical outcomes were described. Results: The location of the LGV was identified during laparoscopic gastrectomy in all 1325 patients. The LGV passed to the ventral side of the splenic artery (SpA) and common hepatic artery (CHA) in 743 patients (56.1%, type 1); the dorsal side of the CHA in 550 patients (41.5%, type 2); the dorsal side of the SpA in 4 patients (0.3%, type 3); and along the hepatogastric ligament, draining directly into the liver, in 21 patients (1.6%, type 4). In 7 patients (0.5%), the LGV was absent, and the right gastric vein was enlarged (type 5). The mean number of suprapancreatic LNs (Nos. 7-9) retrieved from all patients was 7.99 ± 3.89, and the mean number of LN metastases was 1.17 ± 2.11. Comparison of findings during the first part of the study period with later in the study period, when surgeons were more experienced, showed that operation time (P<0.05) and intraoperative blood loss (P<0.05) were significantly lower in the later period. Conclusions: The LGV in most patients runs across the ventral side of the SpA and CHA, or along the dorsal side of the CHA. Knowledge of different anatomic variations will help avoid damage to the LGV during laparoscopic gastrectomy.