Objective To investigate the influencing factors for postoperative abdominal infection and the prognosis in gastric cancer.

Methods The retrospective study was conducted. The clinicopathological data of 1 129 patients who underwent gastrectomy for gastric cancer in the Peking University Cancer Hospital from March 2017 to March 2022 were collected. There were 819 males and 310 females, aged (61±11)years. Observation indicators: (1) surgical conditions and postopera-tive complications; (2) factors influencing postoperative abdominal infection in gastric cancer; (3) postoperative abdominal infection and short‑term clinical outcomes in gastric cancer; (4) postopera-tive abdominal infection and long‑term survival in gastric cancer. Measurement data with normal distribution were represented as Mean±SD. Measurement data with skewed distribution were repre-sented as M(Q₁,Q₃), and comparison between groups was conducted using the Mann Whitney rank sum test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test. Univariate analysis was conducted using the Logistic regression model, and multivariate analysis was conducted using the backward stepwise Logistic regression model. The Kaplan‑Meier method was used to calculate survival rate and draw survival curve, and the Log‑Rank test was used for survival analysis.

Results (1) Surgical conditions and postoperative complications. Of the 1 129 patients receiving gastrectomy for gastric cancer, there were 496 cases receiving open surgery and 633 cases receiving laparoscopic surgery, respectively. The operation time and volume of intraoperative blood loss of 1 129 patients were 206(132,280)minutes and 100(15,185)mL. There were 87 cases receiving multivisceral resection. Of the 1 129 patients, there were 345 patients with postoperative complications, including 139 cases of abdominal infectious compli-cations, 70 cases of other infectious complications, 136 cases had non‑infectious complications, and there were 784 patients without post-operative complications. Cases with postoperative complica-tions classified as Clavien-Dindo grade 0, grade Ⅰ, grade Ⅱ, grade Ⅲ, grade Ⅳ, grade Ⅴ were 784, 34, 248, 55, 5, 3. (2) Factors influencing postoperative abdominal infection in gastric cancer. Results of multivariate analysis showed that age, operation time, multivisceral resection, ratio of radical resection (R₁/R₀) were independent factors influencing postoperative abdominal infection in gastric cancer (odds ratio=1.031, 1.006, 0.325, 0.036, 95% confidence interval as 1.011-1.050, 1.003-1.009, 0.188-0.562, 0.004-0.348, P<0.05). (3) Post-operative abdominal infection and short‑term clinical outcomes in gastric cancer. The postoperative duration of hospital stay and treatment cost of 139 gastric cancer patients with postoperative abdominal infection were 20(15,30)days and 13.8(11.9,17.5)thousand yuan, respectively. The above indicators of 784 gastric cancer patients without postoperative compli-cations were 10(8,11)days and 9.6(8.7,10.8)thousand yuan, respectively. There were significant differences in the above indicators between patients with postoperative abdominal infection and patients without postoperative complications (Z=-15.867, -14.574, P<0.05). (4) Postoperative abdominal infection and long-term survival in in gastric cancer. Of the 1 129 patients, 3 patients died during the perioperative period, and 1 126 patients were followed up for 33.5(23.0,48.0)months. During the follow-up period, 219 patients died. The overall survival time of the 137 gastric cancer patients (excluding 2 perioperative deaths) with postoperative abdominal infectious complications and the 784 gastric cancer patients without postoperative complications were 32.0(23.0,47.0)months and 33.7(22.3,47.3)months during the follow-up period, showing a significant difference between them (χ²=6.773, P<0.05).

Conclusions Abdominal infection is the most common complication after gastrec-tomy for gastric cancer. Age, operation time, multivisceral resection, ratio of radical resection (R₁/R₀) are independent factors influencing postoperative abdominal infection in gastric cancer. Compared with patients without postoperative complications, patients with postoperative abdominal infection after receiving gastrectomy for gastric cancer have longer postoperative duration of hospital stay, high treatment cost and poor prognosis.