The effects of preoperative oral antibiotic use on the development of surgical site infection after elective colorectal resections: A retrospective cohort analysis in consecutively operated 90 patients

PURPOSE

The influence of oral antibiotic use together with mechanical bowel preparation (MBP) on surgical site infection (SSI) rate, length of hospital stay and total hospital costs in patients undergoing elective colorectal surgery were evaluated in this study.

METHODS

Data from 90 consecutive patients undergoing elective colorectal resection between October 2006 and September 2009 was analyzed retrospectively. All patients received MBP. Patients in group A were given oral antibiotics (a total 480 mg of gentamycin, 4 gr of metronidazole in two divided doses and 2 mg of bisacodyl PO), whereas patients in group B received no oral antibiotics. Exclusion criteria were emergent operations, laparoscopic operations, preoperative chemoradiotherapy, intraoperative colonoscopy prior to the creation of an anastomosis or antibiotic use within the previous 10 days. SSI, length of hospital stays and total hospital charges were evaluated.

RESULTS

Patients in both study groups, group A (n = 45) and group B (n = 45), were similar in terms of age, BMI, diverting ileostomy creation, localization and stage of the disease. Patients receiving oral antibiotics demonstrated a lower rate of wound infections (36% vs. 71%, p < 0.001), shorter hospital stay (8.1 ± 2.4 days vs. 14.2 ± 10.9 days, respectively, p < 0.001) and similar rates for anastomotic leakage (2% vs. 11%, p = 0.20). The mean ± SD total hospital charges were significantly lower in Group A (2.699 ± 0.892$) than that in Group B (4.411 ± 4.995$, p = 0.029).

CONCLUSION

Preoperative oral antibiotic use with MBP may provide faster recovery with less SSI and hospital charges.

Cancer associated fibroblasts have phenotypic and functional characteristics similar to the fibrocytes that represent a novel MDSC subset

Circulating fibrocytes were reported to represent a novel myeloid-derived suppressor cell (MDSC) subset and they were also proposed to be involved in the tumor immune escape. This novel fibrocyte subset had a surface phenotype resembling non-monocytic MDSCs (CD14^-CD11c^hiCD123^-) and exhibited immunomodulatory roles. Most effector functions of fibrocytes (circulating fibroblast-progenitors) are accomplished as tissue fibroblasts, likewise in the tumor microenvironment. Therefore, fibroblasts at tumor tissues should be evaluated whether they display similar molecular/gene expression patterns and functional roles to the blood-borne fibrocytes. A chemically induced rat breast carcinogenesis model was utilized to obtain cancer associated fibroblasts (CAFs). CAFs and normal tissue fibroblasts (NFs) were isolated from cancerous and healthy breast tissues, respectively, using a previously described enzymatic protocol. Both CAFs and NFs were analyzed for cell surface phenotypes by flow cytometry and for gene expression profiles by gene set enrichment analysis (GSEA). PBMCs were cocultured with either NFs or CAFs and proliferations of PBMCs were assessed by CFSE assays. Morphological analyses were performed by immunocytochemistry stainings with vimentin. CAFs were spindle shaped cells unlike their blood-borne counterparts. They did not express CD80 and their MHC-II expression was lower than NFs. Although CAFs expressed the myeloid marker CD11b/c, its expression was lower than that on the circulating fibrocytes. CAFs did not express granulocytic/neutrophilic markers and they seemed to have developed in an environment containing T_HELPER2-like cytokines. They also showed immunosuppressive effects similar to their blood-borne counterparts. In summary, CAFs showed similar phenotypic and functional characteristics to the circulating fibrocytes that were reported to represent a unique MDSC subset.