Preoperative Anemia Is a Predictor of Worse Postoperative Outcomes Following Open Pancreatoduodenectomy: A Propensity Score-Based Analysis

BACKGROUND: Preoperative anemia is a common clinical situation proved to be associated with severe outcomes in major surgeries, but not in pancreatic surgery. We aim to study the impact of preoperative anemia on morbidity and mortality in patients undergoing open pancreatoduodenectomy and use propensity score matching (PSM) to balance the basal data and reduce bias. METHODS: We analyzed the data of consecutive patients undergoing open pancreatoduodenectomy with a complete record of preoperative hemoglobin, at two pancreatic centers in China between 2015 and 2019. Anemia is defined as hemoglobin less than 12 g/dl for male and 11 g/dl for female, following Chinese criteria. We compared clinical and economic outcomes before and after PSM and used logistic regression analysis to assess the correlation between variables and anemia. RESULTS: The unmatched initial cohort consisted of 517 patients. A total of 148 cases (28.6%) were diagnosed with anemia at admission, and no case received a preoperative blood transfusion or anti-anemia therapy. After PSM, there were 126 cases in each group. The rate of severe postoperative complications was significantly higher in the anemia group than in the normal group (43.7% vs. 27.0%, p = 0.006), among which the differences in prevalence of clinically relevant postoperative pancreatic fistula (CR-POPF) (31.0% vs. 15.9%, p = 0.005) and cardiac and cerebrovascular events (4.0% vs. 0.0%, p = 0.024) were the most significant. The costs involved were more in the anemia group (26958.2 ± 21671.9 vs. 20987.7 ± 10237.9 USD, p = 0.013). Among anemic patients, receiver operating characteristic (ROC) curve analysis shows the cut-off value of hemoglobin, below which, patients are prone to suffer from major complications (104.5 g/l in male and 90.5 g/l in female). Among all patients, multivariate analysis showed that preoperative obstructive jaundice [odds ratio (OR) = 1.813, 95% confidence interval (CI) (1.206–2.725), p = 0.004] and pancreatic ductal adenocarcinoma [OR = 1.861, 95% CI (1.178–2.939), p = 0.008] were predictors of anemia. Among paired patients, preoperative anemia [OR = 2.593, 95% CI (1.481–5.541), p = 0.001] and malignant pathology [OR = 4.266, 95% CI (1.597–11.395), p = 0.004] were predictors of postoperative severe complications. CONCLUSION: Preoperative anemia is a predictor of worse postoperative outcomes following open pancreatoduodenectomy and needs to be identified and treated.