Background and Objective: Thrombosis due to inherited hypercoagulability is an issue that has been raised in microvascular flap surgery previously. We analyzed the association of a single nucleotide polymorphism (SNP) in rs2066865 in the fibrinogen gamma chain (FGG) gene, alteration in plasma fibrinogen concentration, and presence of microvascular flap thrombosis. Materials and Methods: A total of 104 adult patients with microvascular flap surgery were subjected to an analysis of the presence of SNP rs2066865 in the FGG gene. Alterations in plasma fibrinogen concentration according to genotype were determined as a primary outcome, and flap thrombosis was defined as a secondary outcome. Results: Flap thrombosis was detected in 11.5% of patients (n = 12). Successful revision of anastomosis was performed in four patients, resulting in a microvascular flap survival rate of 92.3%. We observed an increase in plasma fibrinogen concentration in genotype G/A and A/A carriers (G/G, 3.9 (IQR 4.76-3.04); G/A, 4.28 (IQR 5.38-3.18); A/A, 6.87 (IQR 8.25-5.49) (A/A vs. G/A, p = 0.003 and A/A vs. G/G, p = 0.001). Within group differences in microvascular flap thrombosis incidence rates were observed—G/G 6/79 (7.59%); G/A 5/22 (22.7%); A/A 1/3 (33.3%) (OR 0.30 95%; CI 0.044 to 0.57), p = 0.016; RR 3.2—when G/G versus G/A and A/A were analyzed respectively. Conclusions: A/A and G/A genotype carriers of a single nucleotide polymorphism in rs2066865 in the fibrinogen gamma chain gene had a higher plasma fibrinogen concentration, and this might be associated with an increased microvascular flap thrombosis incidence rate. Determined polymorphism could be considered as a genetic marker associated with microvascular flap thrombosis development. To confirm the results of this study, the data should be replicated in a greater sample size.

Microvascular flap surgery is a reliable method for reconstructive surgery. To avoid and foresee free flap thrombosis advancement after microvascular flap surgery, patient assessment, flawless surgical technique, and eligible perioperative care are pivotal. In this prospective observational study, we aimed to elucidate the most common inherited single nucleotide polymorphisms (SNPs) attributable to free flap thrombosis. A total of 152 patients undergoing microvascular flap surgery during the study period of 2016–2019 were analysed for five SNPs: rs6025 in Factor V Leiden (FVL) gene, rs1799963 in Factor II (FII) gene, rs2066865 in Fibrinogen Gamma Chain gene (FGG), rs2227589 in SERPINC 1 gene and rs1801133 in Methylene Tetrahydrofolate Reductase (MTHFR) gene. Activated protein C resistance (aPCR), prothrombin, antithrombin (AT), fibrinogen and homocysteine plasma levels were measured to determine association with the analysed SNPs and with free flap thrombosis advancement. Our preliminary results show that carriers of FVL mutation were associated with aPCR, as we observed significantly lower aPCR plasma levels in carriers of genotype C/T, as compared to C/C; p = 0.006 (CI 95%, 0.44 to 1.19). Additionally, mean fibrinogen plasma levels were higher in carriers of FGC gene rs2066865 genotype A/A (5.6 ± 1.81 g/l), as compared to G/A and G/G; p = 0.04 (CI 95%, 0.007 to 1.09); p = 0.004 (CI 95%, 0.48 to 2.49), respectively. The study group included 12 patients (7.9%) with free flap thrombosis. For one patient free flap thrombosis advancement might have been related to the rs6025T – FVL mutation with a PCR plasma level 1.21. Lower aPCR levels was associated with carriers of FVL rs6025 C/T and higher fibrinogen plasma levels with carriers of FGG rs2066865 A/A, suggesting that these genotypes might predict higher free flap thrombosis risk, but we found no significant association between analysed SNPs and free flap thrombosis advancement.