Change of angiostructure and hemodynamics in lymph node metastases in rabbits

Objectives. Experimental models of lymph node metastasis were developed for Doppler sonography. Methods. Cervical lymph node (LN) metastasis was induced by the implantation of a VX-2 tumor on the oral floor of 10 rabbits. Twenty metastatic LNs were observed weekly by power Doppler sonography, and the presence of an avascular area and the peripheral vessels were evaluated. The time-averaged maximum velocity (TAMx) at the hilum was also measured. Results. The percentage of the metastatic LNs presenting with an avascular area increased over time. The peripheral vessels were detected in 14 of 20 LNs. The peak time of the TAMx significantly correlated to that of the initial detection of the avascular area. Conclusions. In the beginning, metastatic LNs were depicted as hypervascular structures while the TAMx at the hilum increased. Later, an avascular area was detected and the TAMx at the hilum decreased, which resulted in a blood supply to the node from the peripheral vessels.