Staged arteriovenous loops: A retrospective cohort study of 84 patients

Arteriovenous loops (AVLs) are widely used as an alternative to vein grafts in free flap reconstruction. Although single-stage AVLs are well established, the safety profile and clinical implications of staged AVLs continue to be incompletely defined.

A retrospective cohort study was conducted by including 84 patients who underwent staged AVL reconstruction between 1998 and 2025. Demographic data, defect characteristics, surgical variables, AVL-related complications, and free flap outcomes were analyzed. Patients were stratified according to the occurrence of AVL thrombosis prior to flap transfer. Multivariate logistic regression was used to identify independent predictors of thrombosis.

AVL thrombosis prior to flap transfer occurred in 10 patients (11.9%), with a mean time to thrombosis of 1.9 ± 1.1 days. Septic recipient bed was the only independent predictor of AVL thrombosis (odds ratio 5.8; p = 0.013). Patients with prior AVL thrombosis had higher rates of pedicle thrombosis during flap transfer (42.9% vs 5.5%; p = 0.013), without increased flap loss. Overall, flap necrosis occurred in 3 cases (3.8%).

Thrombosis of staged AVLs is an early event that is strongly associated with septic recipient beds. When promptly recognized and appropriately managed, prior AVL thrombosis does not preclude successful free flap reconstruction.