Microsurgery is a highly complex surgical procedure on small body parts performed by a dedicated surgical team. An operating microscope is typically used to obtain a precise view of the soft tissues. The complexity of the microsurgical procedure makes it a suitable application of virtual/augmented reality technology for training purpose. In this paper, we present an overview of our simulator and then describe the visualization work that reconstructs the magnified view of the operating area from medical images. Our 3D linear level octree(LLO) based volume rendering algorithm, and newly proposed dynamic linear level octree (DLLO) based 4D volume rendering algorithm are integrated with a texture-based renderer to form the visualization component. In contrast to the conventional algorithms, our method achieves fast rendering speed, reduced requirement for texture bandwidth and combined surface-volume rendering for realistic and interactive PCbased medical simulations.