Evaluation der Unterschenkelarterien vor mikrochirurgischem Fibulatransfer. MRA vs. DSA.

BACKGROUND: Since the introduction of the fibula flap by Taylor in 1975, and its first application in the lower jaw by Hidalgo in 1989, it has become an option of first choice in mandibular reconstruction of large oromandibular defects. Perfusion of the osteomyocutaneous fibula transplant is based on the peroneal artery. To avoid postoperative ischaemia of the lower leg after sacrificing this artery, especially in smokers, adequate perfusion must be guaranteed preoperatively by radiological evaluation. Progress in the field of magnetic resonance angiography (MRA) enables an increasing number of primary non-invasive evaluations of vessels. The aim of this prospective study was to answer the question of whether MRA enables a accurate representation of anatomical variation and pathological stenoses of the lower leg vessels and can therefore replace conventional digital subtraction angiography (DSA). MATERIALS AND METHODS: We carried out conventional DSA of the lower leg before raising a fibula transplant and postoperative MRA with contrast medium in a prospective study with 15 patients. Vessels were assessed for atherosclerotic, occlusive or hypoplastic changes and anatomical variations by three radiologists. RESULTS: High resolution of MRA enables a reliable judgement of the lower leg vessels. Hypoplastic vessels, stenoses, occlusion or atherosclerotic changes of the vessels could definitely be detected by MRA just as by DSA. Thus, all patients without these diagnosed contraindications could be operated successfully. CONCLUSION: MRA of the lower leg enables a definitive determination of the vessel quality and the site of preference for harvesting the flap. Because MRA is a low risk procedure, can be carried out on an outpatient basis and causes no radiation load, it should be preferred to conventional DSA.