Factors Associated with Postoperative Gallstone Formation in Gastric Cancer Patients: a Systematic Review and Meta-analysis

Objective In this meta-analysis, we analyzed the risk factors for gallstone formation after gastric cancer surgery. Methods Relevant studies published from 1990 to 2017 were retrieved from the Pub Med, Embase, Medline, Web of Science, Cochrane Library, Springer Link, Chinese Biomedical Literature, and Wanfang databases. We performed a meta-analysis to determine the odds ratio and 95% confidence interval（95% CI）. Results Nineteen studies were included in the meta-analysis: four randomized controlled trials（RCTs）, 10 case-control studies, and five cohort studies. The 19 studies included 32 to 16,045 patients. The pooled OR（95% CI） and P-values of the OR（95% CI） were 1.89（1.25, 2.86）（P = 0.003） for gastric resection, 0.22（0.12, 0.40）（P ＜ 0.00001） for vagus nerve retention, 1.73（1.45, 2.06）（P ＜ 0.00001） for digestive tract reconstruction, 0.80（0.54, 1.17）（P = 0.25） for pylorus-preserving gastrectomy, 0.59（0.33, 1.04）（P = 0.07） for the degree of lymph node dissection, 1.98（0.50, 7.86）（P = 0.33） for D12 lymph node dissection, and 1.33（1.15, 1.54）（P ＜ 0.0001） for diabetes. Conclusions Our findings indicate that partial gastrectomy, vagus nerve preservation, and physiological digestive tract reconstruction can reduce the incidence of gallstones after gastrectomy. Diabetes is a contributory factor to gallstone formation. There was no significant difference in the incidence of gallstones based on pylorus preservation/non-preservation, the degree of lymph node dissection, or D12 lymph node dissection. This is the first meta-analysis to comprehensively analyze the risk factors for gallstone formation after gastric cancer surgery. We investigated the risk associated with gastric resection, vagus nerve retention, digestive tract reconstruction, PPG, the degree of lymph node dissection, D12 lymph node dissection, and diabetes.