Basic Experiments to Develop Temporary Packing Material Using a Polymer Gel to Control Solid Organ Hemorrhage

Abstract

Background: Towel or gauze packing is usually applied as a temporary hemostatic method in damage control surgery, but "repacking" is sometimes required at the planned reoperation because of re-bleeding after removal of these materials when they adhere strongly to the injured surface. This experiment was conducted to determine the possibility of reliable packing and safe removal using a supramolecular gel as a new packing material. The supramolecular material, which consists of β-cyclodextrin (CD), adamantane (Ad) andpoly acrylamide (pAAm) (β-CD-Ad pAAm gel), has highly flexible, tough, and self-healing characteristics.Materials and Methods: Irregular shaped (3 cm to 4 cm in diameter) gel lumps were prepared from a β-CD-Ad pAAm gel sheet. These gel lumps were used to fill a blunt disruption prepared on the right lobe of porcine liver, and towel packing was carried out by covering the gel lumps to ensure they adequately adhered to the damaged liver surface. After 30 mins the towel and gel lumps were removed, and the area was examined macroscopically for appropriate adhesion to the injured surface, hemostatic efficacy, removability of the gel lump, and presence or absence of re-bleeding. Results:The β-CD-Ad pAAm gel fragments tightly adhered to each other and were re-shaped to fit to the uneven lacerated liver surface, although self-adhesiveness declined when blood was attached to the gel, leading to a reduction in stretchability. However, it was possible to attach free-shaped gel lumps to the complex damaged liver surface. Compression of the lumps from above with a towel enabled packing as usual. When the packed gel lump was removed, adhesion to the injured surface was not observed, and it was possible to remove the gel without causing re-bleeding. Conclusion:This basic experiment suggests that the polymer gel consisting of β-CD-Ad pAAm may be used as packing material instead of conventional gauze or towel packing and that it does not cause re-bleeding on removal. In the near future, trauma surgeons might be able to use a revolutionary hemostatic material for abdominal organ injury.