Hyperglycemia and risk of adverse outcomes following microvascular reconstruction of oncologic head and neck defects

Introduction: Our aim is to examine the correlation between perioperative hyperglycemia and post-operative outcomes following microvascular reconstruction of head and neck defects. Patients and methods: Retrospective review of a prospectively collected database of 350 consecutive patients who underwent microvascular reconstruction of malignant head and neck defects over a 2 year period. The relationship between perioperative hyperglycemia (>= 180 mg/dL) and the incidence of the following complications was evaluated: flap loss, flap-related complications and surgical site infections (SSI). Sub-group analysis based on timing of hyperglycemia was also performed. Results: We identified 313 patients (89.4%) in the normoglycemic group and 37 patients (10.6%) in the hyperglycemic group. Baseline demographics, tumor stage, operative variable were comparable. There were no significant differences in flap-related complications and overall mortality. SSI were significantly higher in the hyperglycemic cohort (48% vs. 28%, p=0.01). On multivariate analysis, hyperglycemia [OR 2.07; 95% CI, 1.87-4.89], perioperative insulin administration [OR 4.805; 95% CI, 2.18-10.60], prolonged operative time [OR 1.003; 95% CI, 1.002-1.025] and higher Charlson co-morbidity indices [II: OR 2.286 & III: OR 2.284] were independent predictors of SSI. On sub-group analysis, only patients with early (POD 1) post-operative hyperglycemia had a significant OR for SSI (OR 1.88; 95% CI, 1.07-3.29). Conclusion: Our findings suggest that perioperative hyperglycemia, specifically during the first 24 h post-operatively, is associated with SSI in microvascular head and neck reconstruction. This association highlights the need for strict screening of head and neck patients for hyperglycemia especially in the immediate post-operative period.