[A Consensus Statement of the German-speaking Society for Reconstructive Microsurgery (GSRM): What Imaging Modalities are Necessary for Visualisation of Connecting Vessels prior to Microsurgical Transplantation in the Lower Extremity?].

At a consensus workshop, the following questions were discussed regarding the preoperative imaging of recipient vessels prior to microsurgical transplantation in the lower extremity: • Is preoperative imaging necessary for patients with clinically intact peripheral vasculature undergoing microsurgical reconstruction of the lower extremity? • Which imaging modality (if required) best visualises the arterial recipient vessels for microsurgical flap reconstruction in the lower extremity? • In which cases is imaging of the venous outflow tract indicated prior to microsurgical flap reconstruction of the lower extremity: should it be performed routinely or only in selected cases, and which modality is best suited for this purpose?At an interdisciplinary expert workshop held by the German-speaking Society for Reconstructive Microsurgery (GSRM) in Aachen in 2024, the experiences of the participating experts were discussed in the context of the current literature addressing these questions. The workshop aimed to develop recommendations for applying imaging diagnostics that take into account individual patient characteristics, and to establish a consensus-based diagnostic algorithm.Regarding the above-mentioned questions, the participants reached the following consensus: • Routine baseline assessment of the arterial recipient vessels by means of clinical examination and duplex ultrasonography is recommended prior to free flap transfer in the lower extremity. • If additional imaging is required, CT angiography (CTA) or MR angiography (MRA) should be used. In younger patients, MRA should be preferred. Additionally, dynamic imaging using duplex ultrasonography should be performed. Digital subtraction angiography (DSA) should primarily be reserved for cases where intervention is anticipated; diagnostic DSA without intervention should be limited to specific indications. • The evaluation of the venous recipient vessels using duplex ultrasonography is considered useful. If venous pathology is present, further imaging - preferably MR phlebography - should be performed.