Comparison of holding power of metal and absorbable hemostatic clips

Metal hemoclips remain in the tissue permanently. Metal clips will interfere with the interpretation of a computed tomography or magnetic resonance imaging scan. Polydixanone polymer clips (Absolak extra clips; Ethicon Endo-Surgery, Cincinnati, OH) are completely absorbable. Absolak extra clips will not interfere with a computed tomography or magnetic resonance imaging scan and will encircle 360 degrees vessels for extra security. The aim of this study was to test the holding strength of the metal hemoclips and Absolak clips and the amount of pressure that will cause slippage of the 2 types of clips.

The study period was from April 2001 to December 2002 and the study included 74 patients undergoing colectomy. There were 40 men and 34 women. Patient ages ranged from 33 to 86 years (average, 64.5 y). The clips were applied on the dissected vessels of the specimen. Part I of the study was as follows: a rubber band was applied to the protruding part of the clip and a balance weight then was tied onto the rubber band. The weight was increased gradually by 50-g units. The weight that caused slippage of the clip was recorded. Part II of the study was as follows: a correctly sized angiocatheter was inserted individually into the artery and vein and attached to a sphygmomanometer. The intravascular pressure was increased by inflating the balloon of sphygmomanometer and the amount of pressure that caused slippage of the clips was recorded.

Part I of the study determined that an artery could hold 406.4 +/- 46.1 g, a vein could hold 247.3 +/- 36.5 g, and both arteries and veins could hold 621.6 +/- 24.9 g without slippage when a single hemoclip was applied. No slippage occurred when an Absolak or double hemoclips were applied to the vessel(s). Part II of the study determined that a hemoclip would slip off of a vein when the pressure was increased to 156.6 +/- 8.4 mm Hg. Double clips would slip off of a vein when the pressure was increased to 257.6 +/- 9.6 mm Hg. No hemoclip slipped off of an artery after application even if the amount of pressure was increased to 300 mm Hg. No Absolak clip slipped off after application to an artery or vein even if the amount of pressure was increased to 300 mm Hg.

Absolak clips can withstand a higher weight than single hemoclips without slipping off of an artery and/or vein. Likewise, Absolak clips can withstand a higher intravascular pressure without slippage than single or double hemoclips when applied to a vein.