Magnetic resonance lymphography as three-dimensional navigation for lymphaticovenular anastomosis in patients with leg lymphedema

Abstract

Precise mapping of functional lymphatic vessels is essential for successful lymphaticovenular anastomosis (LVA). This study aimed to clarify the precision of magnetic resonance lymphography (MRL) in detecting lymphatic vessels prior to LVA. Eighteen patients with leg lymphedema were recruited for this prospective study. All patients underwent MRL before LVA to obtain three-dimensional coordinates of lymphatic vessels from MRL images. The precision of MRL for detecting lymphatic vessels was evaluated and compared with those of other contrast techniques. Twenty legs from 18 patients were analyzed. A total of 40 skin incisions were made, 32 of which were determined by MRL. The precision of MRL to detect lymphatic vessels was 94%. With the addition of MRL, the number of lymphatic vessels identified preoperatively was increased as compared with indocyanine green lymphography (ICG-L) alone. Assuming a detection sensitivity of MRL for lymphatic vessels of 1, those of other contrast techniques were 0.90 for ICG-L under microscopy, 0.73 for patent blue staining, and 0.43 for ICG-L before incision. Whereas ICG-L before incision could not detect lymphatic vessels at depths greater than 17.0 mm, all deeper anastomosed lymphatic vessels were identified by MRL. Lymphatic vessels enhanced on MRL can be reliably identified intraoperatively. MRL is a promising preoperative examination in LVA that can selectively depict suitable lymphatic vessels even in deep tissue layers.