[Analysis of splenic hilar lymph node metastasis in advanced gastric cancer and dissection techniques]

To study the status of splenic hilar lymph nodes(No.4sa, No.10 or No.11d lymph nodes) metastasis and to investigate the proper dissection technique in patients with advanced gastric cancer.

A retrospective study was performed to investigate 590 patients who underwent D2 curative proximal or total gastrectomy for gastric carcinoma from January 2006 to December 2009. Clinicopathological factors such as sex, age, location of the primary tumor, tumor sizes, gross type, depth of invasion, microscopic classification, neoadjuvant chemotherapy and the metastasis of adjacent lymph node were analyzed with univariate and multivariate analysis. Influence of combined splenectomy or pancreatectomy on lymph node dissection was also investigated.

The overall ratio of metastatic lymph node(positive lymph nodes/lymph nodes harvested) in the splenic hilum was 17.5%(99/565). The positive rates of No.4sa, No.10, No.11d lymph nodes were 17.8% (41/230), 13.9%(29/209), and 22.8%(29/127), respectively. A total of 7.1%(42/590) of the patients had lymph node metastasis in the splenic hilum. Multivariable logistic regression analysis showed that age, tumor size, depth of tumor invasion, positive metastasis of No.4sb lymph node were independent risk factors for lymph node metastasis in the splenic hilum region. When comparing patients undergoing combined splenectomy or pancreatectomy(n=23) and those who did not undergo combined organ resection (n=553), the ratios of metastatic lymph node in the splenic hilum were 14.8%(4/27) and 17.2%(91/527), respectively, and the difference was not statistically significant(P>0.05). The postoperative complication rates were 26.1%(6/23) and 5.4%(30/553), respectively, and the difference was statistically significant(P<0.05). The operative mortality rates were 4.3% and 0.9%, respectively, and the difference was not statistically significant(P>0.05).

Metastasis to lymph nodes in the splenic hilum region in patients with gastric cancer possesses a certain pattern, and it is associated with tumor location, size, depth of invasion, and metastasis in No.4sb. Combined resection of the spleen or pancreas does not result in increased number of harvested lymph nodes or positive lymph nodes, yet is associated with higher complication rate. Therefore, combined organ resection should be meticulous.