Objective To investigate the clinical value of cephalosporin combined with morinidazole in the prevention of surgical site infection (SSI) for gastrointestinal fistula.

Methods The retrospective cohort study was conducted. The clinicopathological data of 107 patients with gastrointestinal fistula who undergoing selective digestive tract reconstruction surgery in General Hospital of Eastern Theater Command from January to December 2017 were collected. There were 76 males and 31 females, aged from 18 to 79 years, with a median age of 46 years. Of 107 patients, 43 cases receiving cephalosporin for prevention of SSI were allocated into cephalosporin monotherapy group, 64 cases receiving cephalosporin combined with morinidazole were allocated into combination therapy group, respectively. Observation indicators: (1) incidence of SSI; (2) stratification; (3) pathogen culture results of SSI; (4) adverse drug reaction; (5) follow-up. Follow-up using outpatient examination and telephone interview was performed to detect other complications of patients. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was analyzed using the independent sample t test. Measurement data with skewed distribution were represented as M(range), and comparison between groups was analyzed using the Mann-Whitney U test. Count data were described as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability.

Results (1) Incidence of SSI: 29 of 107 patients had postoperative SSI, including 15 cases with superficial SSI, 7 cases with deep SSI, and 7 cases with organ/space SSI. There were 18 cases of cephalosporin monotherapy group with SSI, including 7 cases with superficial SSI, 5 cases with deep SSI, and 6 cases with organ/space SSI. The above indicators were 11, 8, 2, 1 of combination therapy group, respectively. There was a significant difference in the overall SSI between the two groups (χ²=7.925, P<0.05). There was also a significant difference in the organ/space SSI between the two groups (P<0.05). There was no significant difference in the superficial SSI between the two groups (χ²=0.305, P>0.05). There was no significant difference in the deep SSI between the two groups (P>0.05). (2) Stratification: there were 10 cases and 33 cases with type Ⅱ incision and type Ⅲ incision in the 43 cases of cephalosporin monotherapy therapy group, respectively. The above indicators were 11 and 53 in the combination group, respectively. For the type Ⅱ incision, 1 patient of cephalosporin monotherapy group had SSI, and 2 cases of combination therapy group had SSI, showing no significant difference between the two groups (P>0.05). For the type Ⅲ incision, 17 patient of cephalosporin monotherapy group had SSI, and 9 cases of combina-tion therapy group had SSI, showing a significant difference between the two groups (χ²=11.499, P<0.05). (3) Pathogen culture results of SSI: of 29 patients with SSI, 21 were positive for bacterial culture, including 12 cases with single bacterial infection, 9 cases with mixed infection of multi-bacteria. A total of 33 strains were cultured. (4) Adverse drug reaction: there was no adverse drug reaction in the 107 patients. (5) Follow-up: 107 patients were followed up for 30 days after surgery. No complication occurred in the 107 patients.

Conclusion Cephalosporin combined with morini-dazole can be used to prevent the SSI for patients with gastrointestinal fistula.