Peristaltic pump assemblies in which the closing and opening of a pivoting or sliding door is coordinated with movement of the occlusion bed toward and away from the rotor assembly to engage and disengage tubing within the occlusion pathway are disclosed. The trocar comprises a plurality of ablation stylets mounted for movement from within the trocar to positions extending from the trocar. The projections retain the U-shaped bolts on the first object.