2.1 Patients
We retrospectively analysed patients who were diagnosed with advanced gastric cancer complicated with obstruction in a clinical centre from June 2017 to January 2020. The inclusion criteria were 1. patients who were diagnosed with advanced gastric cancer with obstruction according to gastroscopy and computed tomography (CT) examinations; 2. confirmed as gastric cancer by the pathology; and 3. patients who underwent GTC. The exclusion criteria were patients with an obstruction caused by tumours in the pancreas, bile duct, duodenum and other tissues.
The study was approved by local Ethics Committee, and informed consent was obtained from all patients.
2.2 GTC procedures
Seldinger method was used to insert a vascular sheath through the right femoral artery. A 5F angiographic catheter (RLG or RH TPYE, Terumo, Tokyo, Japan) was placed in the celiac trunk, and the contrast medium was injected to show the blood supply of the branches of the celiac arteries. The main artery of the tumour blood supply was superselected by using a 2.9F microcatheter and a 2.7F microwire (Progreat, Terumo Medical Corp, Torkyo, Japan) depending on the tumor site; for example, the catheter was inserted into the left gastric artery for cancer of the upper and central stomach, and through the hepatic and gastroduodenal arteries into the right gastroepiploic artery for cancer of the lower part of the stomach13. Oxaliplatin (100mg/m2) and docetaxel (50mg/m2) were used as arterial chemotherapy, and lipiodol (10 mL) mixed with oxaliplatin (2 mL) was used as embolic. Oxaliplatin, docetaxel and lipiodol mixed with oxaliplatin injected sequentially, and the injection time exceeded 5 minutes. When the mixture of lipiodol and oxalipatin was found to completely deposit in the tumour area and reflux to other blood vessels, the intervention was ended. After the intervention, the femoral artery was pressed for 15 minutes (Fig 1).
And the post-embolization syndrome, such as fever, abdominal pain, renal insufficiency, bleeding or gastric perforation after the GTC was carefully observed.
2.3 Following chemotherapy
Three cycles of neoadjuvant DOS chemotherapy was performed every 3 weeks in this study. GTC was used as a first cycle of neoadjuvant chemotherapy14. The second and the third cycle involved oxaliplatin (100mg/m2) and docetaxel (50mg/m2) were administered intravenously on the first day, and S-1 (40mg/m2) was orally taken from day 1 to day 14. If the patients could not orally take S-1, 5-FU was administered intravenously instead.
2.4 Surgery
After three cycles of chemotherapy, patients underwent gastroscopy and CT examinations to assess whether gastrectomy could be performed by two gastrointestinal surgeons with more than 10 years of experience. Patients were considered inoperable if they meet the following manifestations: 1. locally advanced cancer, including mesenteric root or para-abdominal lymph node metastasis that was highly suspected by imaging or biopsy confirmed, 2. lymph node invaded or surrounded large blood vessels (except for spleen artery), 3. gastric cancer with distant metastasis, and 4. tumor invasion of surrounding organs, extensive adhesions, and tumor fixation which presented technically unresectable.
2.5 Definitions
This study assessed effectiveness based on the following indicators: 1. technical success, 2. clinical success, 3. complications, 4. pre-intervention and post-intervention obstruction remission, and 5. survival. The technical success of GTC referred to the successful selection of tumour-nourishing blood vessels and injection of chemotherapy drugs and embolic agents. Clinical success was defined as the score of GOOSS becoming higher above 2 after the intervention.
The time point at which the GOOSS was evaluate were before and 1 week after intervention. The scores were defined as follows: 0 no oral intake, 1 liquid only, 2 soft solids, and 3 complete or full diet15. The Eastern Cooperative Oncology Group (ECOG) performance status (PS) was defined as follows: 0, normal activity; 1, able to walk freely and engage in light physical activities, but not heavy physical activities; 2, able to move freely and take care of themselves but have lost the ability to work, and are only able to participate in activities for no less than half of the wake time; 3, only able to partially perform self-care, and a bed or wheelchair is used for more than half of the wake time; and 4, completely bedridden16.
The length of hospital stay is defined as the time from the start of the GTC to the discharge or the death of the patient. Complications were designated as intraoperative complications, bleeding, perforation, and they were classified according to Clavien-Dindo classification17. Overall survival was defined as the time from intervention to death or the end of the study if the patient was still alive.
2.6 Statistical analysis
Categorical and continuous data are presented as proportions, medians, and means and standard deviation, depending on the distribution. Independent-sample t test and Mann-Whitney U test were used to compare the indicators before and after the intervention. The Kaplan-Meier test was used to analyse the relationship between preoperative factors and overall survival (OS). The Cox proportional hazard model was used for univariate analyses. All statistical analyses were performed using SPSS 22.0 software. Tests of the hypothesis were statistically significant when the P value of a two-sided test was <0.05.