Roller Pump Induced Tubing Wear: Another Argument in Favor of Arterial Line Filtration

Abstract

Pump head tubing was studied to determine if internal wear occurred during routine cardiopulmonary bypass. Several segments of silicone rubber tubing were examined in a scanning electron microscope following clinical perfusion. In each case, the proper degree of occlusion had been set just prior to beginning bypass. The roller pump was a six-inch dual roller type, and the tubing was 3/8 inch ID with 3/32 inch wall thickness. Blood flow rates ranged from 3.8 to 5.2 liters per minute, and duration of the pump runs ranged from 35 to 220 minutes. Evidence of tubing wear on the lumenal surfaces was observed and was related to time and flow rates. Two grooves opposite one another and corresponding to the location of maximum flexure were present in every sample examined. Alterations in the tubing surface were seen in the areas adjacent to the grooves. Craters ranging from 50 µm along with some degree of smoothing of the normal surface texture were seen. Presumably, some spallation had occurred, and particles had been pumped downstream. Use of an arterial line filter with this type of tubing is recommended.