An Indocyanine Green Light for Cross-Leg Free Flap Division: Presentation of the Technique and Review of Literature.

Abstract

Background: Cross-leg free flaps (CLFFs) and cross-leg cable bridge flaps (CLCBFs) are essential techniques in reconstructive surgery for complex lower limb defects when local options or suitable recipient vessels are unavailable. Although the surgical approaches are well established, standardized protocols for flap division, ischemic preconditioning, and perfusion assessment are lacking.

Methods: This study presents a systematic review of the literature on CLFFs and CLCBFs, focusing on division timing, conditioning methods, and perfusion evaluation. A total of 38 studies involving 319 patients were identified through PubMed and EuroPMC searches in March 2025. Additionally, we present a case of a 23-year-old man with a 25 × 15-cm tibial defect reconstructed using a cross-leg latissimus dorsi free flap, where indocyanine green (ICG) angiography was employed to assess perfusion prior to flap division.

Results: Pedicle division was most commonly performed between 3 and 6 weeks postoperatively. Ischemic preconditioning-typically through intermittent clamping-was reported in 54% of studies. Among studies that described perfusion assessment, 75% used clinical pedicle clamping, whereas 25% utilized ICG angiography. Our case demonstrated the successful application of ICG imaging to confirm neovascularization and enable safe, early flap division without complications.

Conclusion: CLFF and CLCBF techniques are effective for limb salvage but require individualized postoperative protocols. Ischemic preconditioning and objective perfusion assessment, particularly using ICG angiography, may support earlier and safer flap division, minimizing patient morbidity and hospital stay.