手术部位感染(SSI)是胃肠外科手术最常见的术后并发症之一，显著延长此类患者的住院时间、增加经济与社会负担。因此，早期预测SSI具有显著的临床意义。本研究旨在探讨腹部生理学特征(包括皮下脂肪厚度、腹直肌厚度与腹腔深度)与结肠癌根治性切除术后SSI的相关性及其预测价值。

回顾性募集2015年1月至2017年12月行择期结肠癌根治性切除术的所有患者，根据术后是否出现SSI，将所有入选患者分为SSI组与非SSI组。利用"倾向评分匹配法"筛选得到基线特征一致的两组患者。所有数据分析均在GraphPad Prism 7.0与SPSS 23.0中完成。比较两组间一般特征、术前与术中临床数据以及腹部生理学特征，连续变量以均数±标准差表示，组间比较使用独立t检验；分类变量以频数(%)表示，组间比较使用检验卡方检验。将具有统计学差异的变量代入logistic回归方程，并利用接收者操作特征曲线(ROC)计算其临床预测价值。

共计纳入374例入选患者，利用"倾向评分匹配法"分别得到55例基线特征匹配的两组患者，两组间的性别、年龄、BMI、既往手术史、吸烟史、基础疾病、切口等级、ASA评分、肿瘤部位、肿瘤病理分期均无差异。SSI组术前白蛋白显著低于非SSI组[(36.6±3.9) g/L比(39.2±3.6) g/L，P＝0.002)]，两组间术前白细胞计数、血红蛋白、C反应蛋白差异均无统计学意义。两组间手术时间、吻合方式差异均无统计学意义。SSI组腹直肌厚度[(9.4±2.7) mm比(8.1±2.1) mm, P＝0.014)]、腹腔深度[(82.3±23.6) mm比(71.7±23.8) mm, P＝0.029)]均高于非SSI组，而皮下脂肪厚度差异均无统计学意义。进一步logistic回归分析显示："腹直肌厚度与腹腔深度乘积"是SSI的显著危险因素(OR＝1.007, P<0.001)。ROC分析显示："腹直肌厚度与腹腔深度乘积"具备较好的临床预测价值(AUC＝0.83，敏感度＝55.8%，特异度＝95.3%)。

腹直肌厚度与腹腔深度与结肠癌根治性切除术后手术部位感染显著相关，两者乘积能够较好预测此类患者术后SSI发生风险。

Surgical site infection (SSI) is common postoperative complication after gastrointestinal surgery, could increase hospital stay and ecnomic and social burden. Therefore early prediction and intervention of SSI is important. The aim this study is to investigate the association between abdominal physiological features (including subcutaneous fat thickness (SFT), rectus abdominis thickness (RAT) and abdomen depth) and the occurrence of SSI in patients receiving radical resection of colorectal cancer.

We conducted a retrospective case-control study. All patients were divided into SSI or non-SSI groups using propensity score match. All statistical analysis was performed by using GraphPad Prism version 7.0 and SPSS version 23.0. Demographics, clinical characteristics, periopeartive data were compared between groups. Continuous variables were presented as (±s) and compared by using independent t test. Categorical variables were presented as percentage (%) and were compared by using Chi-square test. Significant elements were subsequently brought into logistic regression and receiver-operating characteristic analysis for further identification.

A total of 374 patients were enrolled, and 55 patients in each group were eventually matched. Gender, age, BMI, previous surgical history, tobacco usage history, concomitant disease, incision classification, ASA score, tumor location and pathological stage were all similar between groups. Patients in SSI group exhibited lower preoperative albumin [(36.6±3.9) g/L vs. (39.2±3.6) g/L, P=0.002)], higher RAT [(9.4±2.7) mm vs.(8.1±2.1) mm, P=0.014)], AD [(82.3±23.6) mm vs. (71.7±23.8) mm, P=0.029)] and the multiplied value (RAT×AD) (P=0.002) compared to patients in non-SSI group. RAT×AD was an independent risk factor for SSI (OR=1.007, P<0.001), and could serve as a biomarker for SSI prediction (AUC=0.83, 95%CI: 0.74~0.91) in this cohort of patients.

Preoperative rectus abdominis thickness and abdomen depth correlate with the risk of postoperative SSI in patients receiving elective radical resection of colon cancer.