The study evaluates the efficacy of Ropivacaine-Poloxamer 407 hydrogel in reducing postoperative pain following open gastrectomy.

Inclusion Criteria:

1. Patients with a histologically confirmed diagnosis of gastric adenocarcinoma prior to surgery.
2. Patients who have undergone a complete surgical resection (R0 resection).
3. Patients with an ASA (American Society of Anesthesiologists) score of 3 or below.
4. Patients aged 20 years or older.

Exclusion Criteria:

1. Patients under 19 years of age.
2. Presence of ascites or peritoneal metastasis.
3. Patients who have undergone preoperative chemotherapy or radiotherapy.
4. Diagnosis of malignancies other than gastric cancer.
5. Uncontrolled diabetes, autoimmune diseases, hypertrophic scars, or keloid history affecting wound healing.
6. History of allergy or adverse reactions to Ropivacaine or other local anesthetics.
7. Pregnant women.
8. Patients with preoperative chronic pain conditions, including CRPS.
9. Patients with long-term preoperative use of opioid analgesics.
10. Patients with psychiatric disorders deemed likely to interfere with study participation.
11. Patients with severe liver disease, renal disease, or arrhythmia.