Risk Factors for a Systemic Inflammatory Response After Major Oral Cancer Surgery with Microvascular Free Flap Reconstruction: An Exploratory Retrospective Analysis.

Objective: Microvascular free flap reconstruction represents the standard approach for restoring bone and soft tissue defects following oral cancer resection. Systemic inflammatory response syndrome (SIRS) is known to influence surgical outcomes, however the determinants and risk factors contributing to its development remain incompletely understood. This retrospective study aimed to identify risk factors for SIRS and their association with postoperative complications in-patients undergoing oral cancer surgery with simultaneous microvascular reconstruction. Material and Methods: A total of 123 consecutive patients (37 females and 86 males) who underwent oral cancer surgery with curative intent and primary defect reconstruction using microvascular free flaps at the university medical center of Rostock between January 2011 and December 2016 were included and analyzed. Data were retrospectively extracted from the institutional hospital information systems Copra, Medlinq and SAP. Results: SIRS was observed in 51 cases (41.5%). Univariate analyses identified multiple significant predictors for the occurrence of SIRS (p < 0.05), including number of additional needed operations, anastomosis revisions, intraoperative blood loss, hemoglobin drop, postoperative blood transfusions, inflammatory markers, preoperative leukocyte count, postoperative ibuprofen and dexamethasone use, ICU stay and Clavien-Dindo score. In multivariate analysis, preoperative leukocyte count (adj. OR = 1.3, 95% CI: 1.16-1.79), postoperative transfusions (adj. OR = 1.003, 95% CI: 1.002-1.006), intraoperative blood loss (adj. OR = 1.002, 95% CI: 1.001-1.003), postoperative dexamethasone (adj. OR = 0.032, 95% CI: 0.002-0.62) and ibuprofen administration (adj. OR = 14.6, 95% CI: 1.3-163.70) remained independent predictors. Conclusion: Clinicians should be aware of risk factors associated with systemic inflammatory response after major oral cancer surgery. Preoperative leukocyte count and intraoperative blood loss should be given particular attention, as they emerged as critical independent predictors. The observed associations may suggest a protective association for dexamethasone and a risk-increasing association for ibuprofen administration. Both findings, however, should be regarded as exploratory signals rather than definitive clinical guidance. Given the limited number of exposed patients, potential causal relationships require further investigation.