Relationship between preoperative albumin level and risk of site-specific anastomotic leakage in digestive tract surgery: a systematic review and meta-analysis

Background: The relationship between preoperative albumin levels and the risk of anastomotic leakage after digestive tract surgery is unclear, and the optimal albumin threshold for minimizing leakage risk remains unknown. Here, we conducted a meta-analysis to evaluate this association, with the aim of determining the optimal albumin threshold to maximize stratification of leakage risk. Methods: Eligible studies assessing the relationship between preoperative albumin level and the risk of postoperative anastomotic leakage were identified. Odds ratios (ORs) were pooled for lower versus higher albumin level using random-effects models. Multiple subgroup and sensitivity analyses were conducted to confirm the consistence and robustness of the main findings. The cut-off albumin level for identifying anastomotic leakage risk was calculated through receiver operating characteristic curve analysis. Results: Thirty-three studies including 31,108 participants were finally included in the analysis. A lower versus higher albumin level was associated with a 2.67-fold greater risk of anastomotic leakage in digestive tract surgery (OR, 2.67; 95% confidence interval, 1.85–3.87; P <0.01). The association remained consistent across subgroup and sensitivity analyses. An albumin level of 3.75 g/dL was determined as the optimal threshold for risk stratification of anastomotic leakage. Conclusion: Lower preoperative albumin levels were associated with a 2.67-fold greater risk of anastomotic leakage than higher levels, and 3.75 g/dL was identified as the optimal threshold for risk stratification, thus highlighting the need for nutritional support and monitoring in patients undergoing digestive surgery.