Thrombophilia and Preoperative Deep Venous Thrombosis and Their Effect on Free Flap Survival: A Scoping Review.

Background: A proper preoperative planning is essential to prevent flap failure. However, venous workup for flaps has not been commonly performed or utilized as a preoperative screening tool. A scoping review was conducted to explore preoperative venous system screening, including deep vein thrombosis diagnosis, and its effect on flap survival rate. This review identified existing gaps of knowledge and emphasized potential research areas for future studies. Methods: Two independent reviewers searched 3 electronic databases from inception to September 2020. Retrieved appropriate articles were selected systematically by title, abstract, and full review of the article. Studies were included if they enrolled patients who had thrombophilia or deep venous thrombosis (DVT) preoperatively and had undergone a free flap reconstruction. For eligible studies, the following information was extracted: basic demographics (sex, age, comorbidities), preoperative scans type, free flap type, clotting mode (causes), wound type, and flap survival. Results: Seventeen articles were found eligible for this review. Traumatic aetiology was found in 63 (33.6%) patients, while 124 (66.3%) patients had a non-traumatic aetiology. Preoperative screening for patients with non-traumatic aetiology was reported in 119 patients. In these patients, the flap survived in 107 (89.91%) patients. Four studies investigating patients with traumatic DVT aetiology, 60 patients (out of 63) had a preoperative computed tomography angiography or duplex. Those patients had 100% flap survival rates. Conclusion: Further investigations are required to identify venous thrombosis incidence in patients with non-traumatic thrombosis aetiology as this cohort of patients is at high risk of flap failure. Finally, the prognostic validity of available preoperative screening tools to identify high-risk patients should be assessed, such as imaging techniques, which would include venous duplex scanning, may prevent failure in free flap surgery.