Abstract: Objective　 To study the relationship between perioperative coagulation related indexes and postoperative complications of free flap repair for oral and maxillofacial malignant tumor. Methods From May 2015 to October 2019, the data of patients who suffered from oral and maxillofacial malignant tumor and underwent radical resection and free flap reconstruction in oral and maxillofacial surgery of our hospital were retrospectively analyzed. The blood coagulation function test results of patients before and on the first morning after operation were collected, and the complications related to flap after operation were recorded. Patients with flap related complications were divided into observation group and the rest were divided into control group. SPSS 23.0 software was used. T test was used for quantitative data and chi-square test was used for qualitative data. P< 0.05 indicated that there was significant difference. Results 270 patients were included in this study, of which 12 cases (4.4%) were divided into observation group and 258 cases (95.6%) were divided into control group. There was no significant correlation between skin flap complications and patients’ age, chemoradiotherapy, history of alcohol and tobacco intake. Compared with the control group, D-dimer in the observation group decreased significantly (P < 0.001), while fibrinogen in the first morning blood increased significantly (P = 0.012). Univariate logistical regression analysis showed that fibrinogen in the first morning blood was were significant correlation with flap compromise. There was no difference in other coagulation indexes between the two groups. Conclusion The decrease of D-dimer before operation and the increase of fibrinogen 12 hours after operation in patients with oral and maxillofacial malignant tumor treated with free flap may indicate the occurrence of flap related complications.

Key words: oral malignant tumor, flap related complications, D-dimer, fibrinogen