1.1 Adjustment of patient’s preoperative nutritional status Yan speed, Department of Oncology, Affiliated Hospital of Qinghai University
Patients with gastric cancer are mostly accompanied by different changes of nutritional metabolism such as wasting, anemia and low protein. Nutritional assessment can be made through biochemical examination, and preoperative nutritional status adjustment should be performed for patients who are not suitable for surgery. Some doctors lack understanding of this for various reasons: (1) they think that only tumor removal can change the nutritional status of patients and rush to surgery; (2) there are no reliable indicators for preoperative nutritional status assessment, so they cannot accurately select which patients are suitable for nutritional therapy; (3) preoperative nutritional therapy can promote tumor growth and delay surgery; (4) once there are surgical complications, there are surgical nutritional escorts However, this involves a lot of risks and risks. However, this is at great risk and increases the financial burden of the patient. Pre-operative nutrition can increase the safety of surgery and reduce post-operative complications. After the change of nutritional status, tumors that are considered unresectable before surgery can be removed and palliative surgery can be turned into radical surgery, which is a great progress brought by modern surgical nutrition to the development of surgery. So, what kind of patients are suitable for preoperative nutritional therapy? A simple indicator is body mass index (BMI), which is an objective indicator of weight and nutritional status. For mild malnutrition, enteral nutrition (EN) should be administered 5 days before surgery, and for severe malnutrition, nutrition therapy should be administered for 2 to 3 weeks. Traditional nutritional therapy is to provide adequate energy and ammonia sources, and as research progresses, disease-directed enteral nutrition emerges. Gastric cancer is often associated with malnutrition and immunocompromise. The addition of immune-mediating substrates such as glutamine, arginine, nucleotides, N-3 fatty acids, etc. to the formulation of EN is known as “immunontrition” (EN), which protects the gastrointestinal mucosa as a barrier. TPN should be administered to patients who cannot be enterally nourished before surgery or whose nutritional status is very poor. In mild cases, TPN therapy should be performed 3 days before surgery, and in severe cases, systemic TPN therapy should be performed.
1.2 Adjustment of preoperative respiratory function
As risk factors, such as smoking history, chronic respiratory diseases, advanced age, obesity, etc., the methods of response are anti-smoking and anti-inflammatory, airway decontamination, and respiratory function training. Patients with low respiratory function in the preoperative examination should be prepared for intraoperative and postoperative respiratory complications and treatment measures.
1.3 Responses to circulatory system diseases
Common circulatory system diseases include ischemic heart disease, coronary heart disease, valvular disease, arrhythmia and hypertension. For those who still have risk factors after treatment, they should be closely observed and prepared for countermeasures during and after surgery.
1.4 Preoperative preparation for diabetic patients
For patients whose blood glucose is controlled by diet before surgery, blood glucose and ketone body should be tested before surgery, and appropriate amount of insulin should be used according to blood glucose changes after surgery; for patients who take oral hypoglycemic drugs before surgery, regular amount of insulin 12-20u/d should be given in 3 times 3 days before surgery, and insulin should be given according to blood glucose changes on the day of surgery and after surgery; for patients whose blood glucose is controlled by insulin before surgery, insulin should be given in 3 times 3 days before surgery. For patients whose blood glucose is controlled with insulin before surgery, equal amount of insulin is given 3 days before surgery to control blood glucose and correct acidosis and ionic disorders, and the insulin dosage is adjusted according to blood glucose changes during and after surgery.
It is generally believed that fasting blood sugar should be kept at 7.25-8.34 mmol/L before surgery and should not exceed 11.1 mmol/L, and should be kept at 6.7-11.1 mmol/L during surgery, which is safer. Too high blood glucose (>13.9 mmol/L) induces ketoacidosis; too low blood glucose (<2.8 mmol/L) can increase the risk of surgery. In cases of combined pancreatic body tail resection, pancreatic islet B cells are destroyed in large numbers, which increases the risk of diabetes after surgery. Blood glucose should be controlled at 3.9-6.1mmol/L, and blood glucose changes should be closely detected (30-60min), and insulin dosage should be adjusted in time.
2 TNM staging of gastric cancer
UICC, AJCC and JCC modified the TNM staging in 1997 after a lot of clinical validation and years of discussion, and it is promoted worldwide.
T – hair tumor
Tis : Carcinoma in situ
T1 ： Invasion of mucosa and submucosa
T2 ： Invasion of intrinsic muscular layer and subplasma layer
T3 : Invasion of plasma membrane surface
T4 : Invasion of adjacent organs
TX : Unknown
N – lymph nodes
N0 : No metastasis in the lymph nodes
N1 : 1 to 6 lymph node metastases
N2 : 7 to 15 lymph node metastases
N3 : More than 15 lymph node metastases
NX : Not known
M – distant metastasis
M0 : No distant metastasis
M1 : With distant metastasis
MX ： Unknown
Among the TNM stages of gastric cancer, the most controversial is the N stage. Previously, it was divided into N1, N2 and N3 based on the distance of metastatic lymph nodes from the lesion, and now it is divided into N1, N2 and N3 based on the number of metastatic lymph nodes, requiring that more than 15 lymph nodes must be detected in each case. There is some difficulty in the actual operation. In addition, it is difficult to achieve preoperative N staging with the existing examination technology, and it is difficult to accurately determine the metastasis of lymph nodes before surgery, which adds a certain degree of difficulty to the design of treatment plans. Some domestic units have made some progress by using the combined detection of spiral CT, MRI and ultrasonic endoscopy, which provides a reference for the selection of surgical indications. According to the preoperative TNM stage, the following surgical plan can be designed: Stage IA: endoscopic mucosal resection (EMR). Stage IB: laparoscopic or open surgery (D1). Stages II and IIIA are the best indications for D2 or D3 surgery. Stages IIIB and IV: combination therapy (preoperative chemotherapy + surgery + postoperative combination therapy). As shown in Table 3-1.
Table 3-1 TNM staging
0
Tis
N0
M0
Ⅰ A
Ⅰ B
T1
T1
T2
N0
N1
N0
M0
M0
M0
Ⅱ
T1
T2
T3
N2
N1
N0
M0
M0
M0
ⅢA
T2
T3
T4
N2
N1
N0
M0
M0
M0
ⅢB
T3
N2
M0
IV
T4
T1, T2, T3
Any T
N1, N2, N3
N3
Any N
M0
M0
M1