Vitamin K-dependent proteins in patients undergoing head and neck free flap surgery – a prospective observational study

BACKGROUND/OBJECTIVES: Vitamin K dependent proteins are involved in numerous biological processes, including coagulation, cancer development and inflammation, but their profile and functions in many patient groups and conditions are still unknown. The aim of this study was to describe vitamin K dependent proteins in patients undergoing head and neck free flap surgery, with the hypothesis that these patients experience postoperative vitamin K deficiency. METHODS: A prospective observational study including 39 patients undergoing extensive head and neck resection and reconstruction using free flap(s) was conducted with analyses of the γ-carboxyglutamic acid-containing proteins desphospho-uncarboxylated Matrix Gla Protein (dp-uc-MGP), Growth arrest-specific gene 6 (Gas6) and Protein Induced by Vitamin K Absence/Antagonist for FII (PIVKA-II), as well as soluble Axl receptor (sAxl), on the day of surgery and postoperative (POD) days 1, 2 and 6. Changes from preoperative levels were explored using Kruskal-Wallis test with a Dunn's post hoc multiple comparison's test. RESULTS: < 0.001). No significant changes were seen in dp-uc-MGP or sAxl levels. CONCLUSIONS: Patients undergoing head and neck free flap surgery show signs of vitamin K deficiency during the first postoperative week.