Comparative effectiveness of perioperative anticoagulation protocols on flap outcomes and immune-inflammatory profiles in oral squamous cell carcinoma reconstruction

Exploring the retrospective comparative effectiveness of different perioperative anticoagulation regimens on the survival rate, incidence of complications, and dynamic changes in systemic immune inflammatory markers after free flap reconstruction for oral squamous cell carcinoma (OSCC) in this retrospective cohort study. This retrospective cohort analysis recruited patients who underwent radical resection for OSCC and microvascular free flap reconstruction from January 2020 to December 2024. Based on perioperative anticoagulation approaches, all cases were categorized into three groups: control (no prophylactic anticoagulation, n = 82), UFH (unfractionated heparin, n = 84) and LMWH (low molecular weight heparin, n = 82). Clinical, pathological and surgical flap data, as well as inflammatory markers [neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), C-reactive protein (CRP)] were retrieved retrospectively. Multivariate logistic regression was performed to identify independent predictors of microvascular thrombosis and postoperative hematoma (POH). Three groups had comparable overall free flap survival rates ( P > 0.05). The UFH group presented a markedly higher POH rate than the control and LMWH groups ( P < 0.05). LMWH tended to improve the rescue success of microvascular thrombosis. On postoperative days 3 and 7, the LMWH group showed more pronounced declines in NLR and CRP ( P < 0.05), although these exploratory findings require cautious interpretation owing to potential confounding by indication and perioperative events. However, the clinical relevance of these laboratory changes remains to be determined. Multivariate logistic regression analysis showed that anticoagulation regimen was not an independent influencing factor of thrombosis (all P > 0.05). Preoperative CRP level (OR = 1.285, 95% CI: 1.047–1.576, P = 0.016) is an independent risk factor for microvascular thrombosis; The use of unfractionated heparin is a strong independent risk factor for POH (OR = 3.815, 95%CI: 1.144–12.719, P = 0.029), while LMWH does not significantly increase the risk of POH ( P > 0.05), and hypertension is also an independent risk factor for POH occurrence (OR = 3.607, 95%CI: 1.387–9.384, P = 0.009). In OSCC free flap reconstruction, conventional prophylactic anticoagulation did not significantly improve the overall survival rate of the flap. In this retrospective cohort, LMWH was associated with favorable postoperative inflammatory resolution and a lower bleeding risk compared with UFH; however, these findings should be interpreted as hypothesis-generating rather than causal, and warrant prospective validation.