Synergistic Effects of Perioperative Complications on 30-Day Mortality Following Hepatopancreatic Surgery

Background: Data on the interaction effect of multiple concurrent postoperative complications relative to the risk of short-term mortality following hepatopancreatic surgery have not been reported. The objective of the current study was to define the interaction effect of postoperative complications among patients undergoing HP surgery on 30-day mortality. Methods: Using the ACS-NSQIP Procedure Targeted Participant Use Data File, patients who underwent HP surgery between 2014 and 2016 were identified. Hazard ratios (HRs) for 30-day mortality were estimated using Cox proportional hazard models. Two-way interaction effects assessing combinations of complications relative to 30-day mortality were calculated using the relative excess risk due to interaction (RERI) in separate adjusted Cox models. Results: Among 26,824 patients, 10,886 (40.5%) experienced at least one complication. Mortality was higher among patients who experienced at least one complication versus patients who did not experience a complication (3.0 vs 0.1%, p < 0.001). The most common complications were blood transfusion (16.9%, n = 4519), organ space infection (12.2%, n = 3273), and sepsis/septic shock (8.2%, n = 2205). Combinations associated with additive effect on mortality included transfusion + renal dysfunction (RERI 12.3, 95% CI 5.2–19.4), pulmonary dysfunction + renal dysfunction (RERI 60.9, 95% CI 38.6–83.3), pulmonary dysfunction + cardiovascular complication (RERI 144.1, 95% CI 89.3–199.0), and sepsis/septic shock + renal dysfunction (RERI 11.5, 95% CI 4.4–18.7). Conclusion: Both the number and specific type of complication impacted the incidence of postoperative mortality among patients undergoing HP surgery. Certain complications interacted in a synergistic manner, leading to a greater than expected increase in the risk of short-term mortality.