Background & Objectives: Free flap transfer has become a routine surgery to close tissue defects. Microvascular thrombosis leading to free flap failure still remains a serious threat; it can occur due to external or intrinsic thrombogenic factors, such as hypercoagulability. The aim was to evaluate influence of preoperative thrombogenic factors on incidence of transferred tissue thrombosis in patients undergoing microvascular surgery.
Materials & Methods: In the prospective observational study were enrolled 51 patients undergoing microvascular free flap surgery. Demographical data and external thrombogenic factors were recorded. Preoperatively, ROTEM® was performed to assess coagulation status in parallel with routine coagulation tests. Association between external thrombogenic factors, hypercoagulability detected by routine coagulation tests or ROTEM and surgical outcomes was analyzed. Postoperatively, surgical outcome was recorded in terms of free flap thrombosis and free flap necrosis.
Results: 51 patients with mean age 39 ± 13 years undergoing free flap surgery were analyzed. Preoperatively external thrombogenic factors were identified for 25 patients: recent trauma for 15/51 (29.4%), ischemic heart disease and atherosclerosis for 6/51 patients (12%), tetra-, para paresis or neurofibromatosis for 3/51 (6%), obesity + recent trauma 1/51 (2%). Out of 25 high thrombotic risk patients, 3/25 (12%) had hyperfibrinogenemia and 11/25 (44%) had hyperfibrinogenemia combined with thrombocytosis. The incidence of hyperfibrinogenemia/thrombocytosis between patients with recent trauma and other thrombogenic risk factors was similar, 8/15 (53%) vs. 5/9 (55%), respectively. Hypercoagulation detected by fibrinogen/platelet ratio (FPR) ≥ 42 was found in 15/51 (29%) patients, mostly in high thrombotic risk group, 13 (52%) out of 25 had hypercoagulability. Hypercoagulability was significantly more often diagnosed by ROTEM in patients with recent trauma compared to those with other risk factors, 10/15 (67%) vs. 2/9 (22%), p = 0.03. Free flap thrombosis was found in 9/51 (18%), free flap necrosis in 10/51 (20%) cases. Thrombosis and necrosis significantly more often developed in high thrombosis risk patients comparing to others, 8 vs. 1 and 8 vs. 2, p = 0.008 and p = 0.03.
Conclusion: Patient thrombogenic factors have notable influence on free flap surgery results, correlating with incidence of transferred tissue thrombosis. Early preoperative identification of potentialy high-risk patients provides a possibility to modify surgical and anesthesiological management in order to improve surgical outcome.
Disclosure of Interest: None declared