Clinical Study Of The Posterior Gastric Artery And The Lymph Nodes Around It In Patients With Gastric Cancer

Objective: To collect and analyse the anatomical features of the posterior gastric artery(PGA).To clarify the existence and metastasis of lymph nodes around the PGA in patients with gastric cancer.To analyse the relationship between the PGA with its surrounding lymph nodes and the clinicopathological features of patients with gastric cancer.To explore the possible contribution of the PGA in the lymphatic metastasis of gastric cancer.Methods: The study was conducted in two parts.The first part of the study was a crosssectional study of data from 52 patients with gastric cancer who underwent total or proximal gastrectomy at the Department of Gastroenterology,the First Affiliated Hospital of Dalian Medical University from January 2020 to November 2022.Patients were explored intraoperatively for the existence of the PGA,and those with PGA were measured for relevant anatomical features(the length of the PGA,the distance from the root of the PGA to the celiac trunk)and were performed with dissection of the lymph nodes around the PGA.Statistical methods were used to describe and analyse the data on the existence of the PGA and the existence and metastasis of the lymph nodes around the PGA,respectively.The clinicopathological factors associated with these conditions were then identified.The second part of the study expanded the sample size through retrospective analysis.This was done to further search for clinicopathological factors associated with the presence of the PGA using data from 122 patients with gastric cancer.Regional lymph nodes with metastatic conditions associated with the PGA were selected and further explored for risk factors for metastasis by univariate and multifactorial analyses.Results: In the first part of the study,the PGA was found in 39(75.0%)of the 52 patients with gastric cancer,with a mean length of the PGA of 3.51 ± 0.823 cm and a mean distance from the root of the PGA to the celiac trunk of 6.73 ± 1.712 cm.36 lymph nodes around the PGA were detected in 20 of the 39 patients who underwent the dissection of lymph nodes around the PGA.The analysis of factors for the existence of lymph nodes around the PGA showed that the gross type of the tumour and the total number of dissected lymph nodes were associated with the identification of lymph nodes around the PGA(P = 0.007 and P = 0.022 respectively),with more dissected lymph nodes being an independent factor(OR = 1.105,95% CI: 1.019-1.199,P =0.016).Analysis of the risk factors for the metastasis in the lymph nodes around the PGA showed that the total number of positive lymph nodes,the No.3 lymph node metastasis and the No.11 lymph node metastasis were associated with the metastasis of the lymph nodes around the PGA(P = 0.043,P = 0.028 and P = 0.020 respectively).The second part of the study found the existence of the PGA in 72(59.0%)of the 122 patients with gastric cancer who were included in the retrospective analysis.The existence of the PGA was associated with the total number of positive lymph nodes,No.11 lymph node metastasis and No.2 lymph node metastasis(P = 0.035,P = 0.001 and P = 0.035 respectively).Further multifactorial analysis of risk factors for metastasis in No.11 lymph nodes and No.2 lymph nodes respectively showed that the existence of the PGA was an independent risk factor for metastasis in No.11 lymph nodes(OR =12.649,95% CI: 1.569-101.943,P = 0.017)but not in No.2 lymph nodes(OR = 3.594,95% CI: 0.751-17.190,P = 0.109).Conclusion: The PGA has a high frequency.Careful identification of the PGA during PGA-related procedures is recommended,followed by reasonable preservation or disconnection of the PGA.The detection of lymph nodes around the PGA is not an isolated case.Gastric cancer can lead to metastasis in the lymph nodes around the PGA.The overall risk of metastasis in the lymph nodes around the PGA is low in patients with gastric cancer,but the risk of metastasis increases in the following conditions including: No.3 lymph nodes metastasis,No.11 lymph nodes metastasis,advanced tumour stage,and extensive metastases in other regional lymph nodes.Gastric cancer cells may metastasize to No.11 lymph nodes through the lymphatic drainage pathway of the PGA.In total or proximal gastrectomy for advanced gastric cancer,complete dissection of No.11 lymph nodes as well as the lymph nodes around the PGA is recommended if the patient has the PGA.