Loh-Doyle J, et al. - This research was initiated in order to investigate the efficacy of vena cavoscopy in the scrutiny of intraluminal vena caval tumor involvement. It was discovered that vena cavoscopy using a flexible cystoscope was a practical technique. This method could be utilized intra-operatively for ensuring the clearance of residual thrombus burden within the inferior vena cava and to evaluate for caval invasion.