Meta-analysis Of Risk Factors For Anastomotic Leakage After Low Anterior Resection For Rectal Cancer

Objective:Through meta-analysis,the risk factors of anastomotic leakage after low anterior resection of rectal cancer were discussed,and the characteristic relationship between the possible risk factors and anastomotic leakage was clarified,in order to provide theoretical basis for further prevention of anastomotic leakage in clinical practice.Methods:Relevant literature on risk factors of anastomotic leakage after low anterior resection of rectal cancer was searched by computer.CNKI,Wanfang,Vip,CBM,Cochrane Library,Pub Med,Embase,and Web of science databases were selected from domestic and foreign databases in order.The search time was limited to January 2015 to December 2021.According to the established inclusion and exclusion criteria,two statisticians independently conducted literature screening,data extraction and quality evaluation,and applied Review Manager 5.3 software to analyze the effective data.Data are expressed by Odds Ratio(OR)and 95%confidence interval(CI).Results:A total of 20 publications were included after screening,including 7450 patients with rectal cancer,of which 602 developed anastomotic leakage after surgery,with a combined incidence of leakage of 8.1%(602/7450).Male patients with rectal cancer had a higher risk of anastomotic leakage after undergoing low anterior resection than female patients(OR=1.84,95%CI:1.53-2.21,P<0.00001).The risk of postoperative anastomotic leakage in patients with age≥60 years old was higher than that in patients with age<60years old(OR=1.05,95%CI:0.80-1.38,P=0.73).The incidence of postoperative anastomotic leakage was higher in patients with BMI(Body Mass Index,BMI)≥28 kg/m~2than in patients with BMI<28 kg/m~2(OR=4.14,95%CI:1.31-13.05,P=0.02).The risk of postoperative anastomotic leakage was higher in patients with preoperative albumin levels<35 g/L than in those with preoperative albumin levels≥35 g/L(OR=2.94,95%CI:1.90-4.53,P<0.00001).Patients with preoperative comorbid diabetes mellitus had a higher risk of postoperative anastomotic leakage(OR=2.59,95%CI:1.85-3.61,P<0.00001).Patients with combined intestinal obstruction were more likely to develop postoperative anastomotic leakage than those without combined intestinal obstruction(OR=3.04,95%CI:1.98-4.67,P<0.00001).Patients who received preoperative neoadjuvant radiotherapy had a higher risk of postoperative anastomotic leakage than those who did not receive preoperative neoadjuvant radiotherapy(OR=2.04,95%CI:1.49-2.77,P<0.00001).Patients with tumor diameter≥3 cm had a higher risk of postoperative anastomotic leakage compared to patients with tumor diameter<3 cm(OR=1.15,95%CI:0.78-1.68,P=0.49).The incidence of postoperative anastomotic leakage was higher in patients with tumors distal to the anal verge≤5 cm compared to those with tumors distal to the anal verge>5 cm(OR=2.38,95%CI:1.43-3.97,P=0.0009).Patients with TNM stage Ⅲ and Ⅳ tumors had a higher risk of postoperative anastomotic leakage than patients with stage Ⅰ and Ⅱ tumors(OR=1.90,95%CI:0.73-4.99,P=0.19).Patients undergoing laparoscopic surgery were more likely to develop postoperative anastomotic leakage than those undergoing open surgery(OR=1.07,95%CI:0.87-1.32,P=0.54).Patients with preserved LCA(Left Colonic Artery,LCA)had a lower risk of postoperative anastomotic leakage than patients without preserved LCA(OR=1.59,95%CI:0.72-3.52,P=0.25).The incidence of postoperative anastomotic leakage in patients without preventive stoma was higher than that in patients with preventive stoma(OR=1.50,95%CI:1.17-1.94,P=0.002).The risk of postoperative anastomotic leakage in patients with retained anal tube was lower than that in patients without retained anal tube(OR=1.18,95%CI:0.44-3.22,P=0.74).The incidence of anastomotic leakage in patients with postoperative diarrhea was higher than that in patients without postoperative diarrhea(OR=3.13,95%CI:1.79～5.48,P<0.0001).Conclusion:Male,BMI≥28 kg/m~2,preoperative albumin level<35 g/L,preoperative combined with diabetes,preoperative combined with intestinal obstruction,preoperative neoadjuvant radiotherapy and chemotherapy,distance from the distal end of the tumor to the anal margin≤5 cm,Non-preventive stoma,and occurrence of postoperative diarrhea are the main risk factors for anastomotic leakage after low anterior resection of rectal cancer.In contrast,age,surgical approach(open or laparoscopic),tumor diameter,tumor TNM stage,whether the left colonic artery was preserved,and whether an anal tube was retained did not differ in the incidence of anastomotic leakage.