The primary goal of clinical treatment is to relieve obstruction, restore oral feeding, improve nutritional status and improve quality of life in patients with advanced gastric cancer outflow tract obstruction. At present, the common surgical treatment for relieving obstruction is traditional gastrojejunostomy. Although the operation can relieve the obstruction, there are problems such as tumor-induced bleeding, anastomotic invasion, and high incidence of delayed gastric emptying after operation. Partitioned gastrojejunostomy effectively relieves obstruction by anastomosis of a part of the stomach to the jejunum, and isolates the tumor from the anastomosis, which is beneficial to food emptying and can reduce the risk of bleeding and anastomotic invasion. The safety and efficacy of these two procedures are still controversial, mainly because previous studies were retrospective studies or included a small sample size or enrolled patients with different pathological characteristics. The purpose of this study was to compare the safety and efficacy of separated and traditional gastrojejunostomy in the treatment of advanced gastric cancer outflow tract obstruction, and to provide the best choice for the treatment of advanced gastric cancer outflow tract obstruction.

This study is a prospective, multi-center randomized controlled study. Patients with advanced distal gastric cancer with outflow tract obstruction ( clinical stage T4bN + M0 / T3-4N + M1, stage IV ) were enrolled. The outflow tract obstruction was confirmed by upper gastrointestinal angiography. Patients who underwent gastrojejunostomy after preoperative evaluation. After enrollment, the patients were randomly divided into SPGJ group or CGJ group according to the ratio of 1 : 1 by random number table. This study was designed for evaluators ' blinding. Imaging experts who are responsible for determining the primary endpoint ( delayed gastric emptying classification, GOOSS score ), researchers who are responsible for collecting patient-reported outcomes ( such as quality of life questionnaires ), and statisticians who perform final data analysis will be unaware of the patient 's grouping information. This study was divided into four stages : screening period, operation period, medical treatment period and follow-up period.

Inclusion Criteria:

1.Patients and their families were fully aware of this study and voluntarily signed informed consent ; 2.Age 18-75 years old ( including 18 and 75 years old ) ; 3.Distal gastric cancer ( cT4bN + M0 / T3-4N + M1, stage IV ) with locally unresectable, distant metastasis or peritoneal metastasis confirmed by pathology and unable to undergo radical surgery ; 4.Complicated with digestive tract obstruction ( gastric retention confirmed by upper gastrointestinal radiography or gastroscopy, and GOOSS score ≤ 1 ) ; the ECOG score was 0-2 points, and there was no deterioration within 7 days ; 6.ASA score I-III ; 7.No previous anti-tumor therapy ( such as radiotherapy, chemotherapy, targeted therapy, immunotherapy, etc. ) :

The functions of important organs meet the following requirements :

(a) absolute neutrophil count ≥ 1.5 × 109 / L, white blood cell count ≥ 4.0 × 109/L; （b) Platelet ≥ 100 × 109 / L ; （c) Hemoglobin ≥ 60g / L ; （d) TBIL ≤ 1.5 times ULN ; （e) ALT and AST ≤ 2.5 times ULN ; （f) urea / urea nitrogen ( BUN ) and creatinine ( Cr ) ≤ 1.5 × ULN ( and creatinine clearance rate ( CCr ) ≥ 50mL / min ) ; （g) Left ventricular ejection fraction ( LVEF ) ≥ 50 % ; the corrected QT interval ( QTcF ) by Fridericia method was less than 470 ms. （i) INR ≤ 1.5 × ULN, APTT ≤ 1.5 × ULN. 9. women of childbearing age need to take effective contraceptive measures ; 10.No other surgical contraindications ; 11.good compliance, with follow-up.

Exclusion Criteria:

1. Unable to comply with the research program or research procedures ;
2. Patients with other malignant tumors within 5 years before enrollment, except for basal cell or squamous cell carcinoma of the skin after radical resection, or cervical carcinoma in situ ;
3. Patients with active autoimmune diseases or a history of autoimmune diseases within 4 weeks before enrollment ;
4. Previously received allogeneic bone marrow transplantation or organ transplantation ;
5. Cardiovascular diseases with significant clinical significance, including but not limited to acute myocardial infarction, severe / unstable angina pectoris or coronary artery bypass grafting within 6 months before enrollment ; congestive heart failure New York Heart Association ( NYHA ) grade > 2 ; ventricular arrhythmia requiring drug treatment ; lVEF ( left ventricular ejection fraction ) < 50 % ;
6. Active or uncontrolled severe infection ( ≥ CTCAE V5.0 grade 2 infection ) ;
7. Known human immunodeficiency virus ( HIV ) infection. Patients with known clinical history of liver disease, including viral hepatitis [ known as hepatitis B virus ( HBV ) carriers must be excluded from active HBV infection, that is, HBV DNA positive ( > 1 × 104 copies / mL or > 2000 IU / ml ) ; it is known that hepatitis C virus infection ( HCV ) and HCV RNA positive ( > 1 × 103 copies / mL ) ;
8. pregnant ( pregnancy test positive before medication ) or breastfeeding women ;
9. Any other disease with clinically significant metabolic abnormalities, physical examination abnormalities or laboratory abnormalities, according to the judgment of the researchers, it is reasonable to suspect that the patient has a state that is not suitable for enrollment ( such as having seizures and requiring treatment ), or will affect the interpretation of the results of the study, or put the patient at high risk ; the researchers considered that the patients were not suitable for inclusion in this study.](streamdown:incomplete-link)