Novel intraperitoneal hemostasis device prolongs survival in a swine model of noncompressible abdominal hemorrhage

Development of a two-hit lethal liver injury model in swine

PURPOSE

Noncompressible truncal hemorrhage remains a leading cause of preventable death in the prehospital setting. Standardized and reproducible large animal models are essential to test new therapeutic strategies. However, existing injury models vary significantly in consistency and clinical accuracy. This study aims to develop a lethal porcine model to test hemostatic agents targeting noncompressible abdominal hemorrhages.

METHODS

We developed a two-hit injury model in Yorkshire swine, consisting of a grade IV liver injury combined with hemodilution. The hemodilution was induced by controlled exsanguination of 30% of the total blood volume and a 3:1 resuscitation with crystalloids. Subsequently, a grade IV liver injury was performed by sharp transection of both median lobes of the liver, resulting in major bleeding and severe hypotension. The abdominal incision was closed within 60 s from the injury. The endpoints included mortality, survival time, serum lab values, and blood loss within the abdomen.

RESULTS

This model was lethal in all animals (5/5), with a mean survival time of 24.4 ± 3.8 min. The standardized liver resection was uniform at 14.4 ± 2.1% of the total liver weight. Following the injury, the MAP dropped by 27 ± 8mmHg within the first 10 min. The use of a mixed injury model (i.e., open injury, closed hemorrhage) was instrumental in creating a standardized injury while allowing for a clinically significant hemorrhage.

CONCLUSION

This novel highly lethal, consistent, and clinically relevant translational model can be used to test and develop life-saving interventions for massive noncompressible abdominal hemorrhage.

Injectable Self-Expanding/Self-Propelling Hydrogel Adhesive with Procoagulant Activity and Rapid Gelation for Lethal Massive Hemorrhage Management

Developing hydrogels that can quickly reach deep bleeding sites, adhere to wounds, and expand to stop lethal and/or noncompressible bleeding in civil and battlefield environments remains a challenge. Herein, an injectable, antibacterial, self-expanding, and self-propelling hydrogel bioadhesive with procoagulant activity and rapid gelation is reported. This hydrogel combines spontaneous gas foaming and rapid Schiff base crosslinking for lethal massive hemorrhage. Hydrogels have rapid gelation and expansion rate, high self-expanding ratio, excellent antibacterial activity, antioxidant efficiency, and tissue adhesion capacity. In addition, hydrogels have good cytocompatibility, procoagulant ability, and higher blood cell/platelet adhesion activity than commercial combat gauze and gelatin sponge. The optimized hydrogel (OD-C/QGQL-A30) exhibits better hemostatic ability than combat gauze and gelatin sponge in rat liver and femoral artery bleeding models, rabbit volumetric liver loss massive bleeding models with/without anticoagulant, and rabbit liver and kidney incision bleeding models with bleeding site not visible. Especially, OD-C/QGQL-A30 rapidly stops the bleedings from pelvic area of rabbit, and swine subclavian artery vein transection. Furthermore, OD-C/QGQL-A30 has biodegradability and biocompatibility, and accelerates Methicillin-resistant S. aureus (MRSA)-infected skin wound healing. This injectable, antibacterial, self-expanding, and self-propelling hydrogel opens up a new avenue to develop hemostats for lethal massive bleeding, abdominal organ bleeding, and bleeding from coagulation lesions.

A novel inflatable device for perihepatic packing and hepatic hemorrhage control: A proof-of-concept study

INTRODUCTION

Uncontrolled bleeding is the primary cause of death in complex liver trauma and perihepatic packing is regularly utilized for hemorrhage control. The purpose of this study was to investigate the effectiveness of a novel inflatable device (the airbag) for perihepatic packing using a validated liver injury damage control model in swine.

MATERIAL AND METHODS

The image of the human liver was digitally isolated within an abdominal computerized tomography scan to produce a silicone model of the liver to mold the airbag. Two medical grade polyurethane sheets were thermal bonded to the configuration of the liver avoiding compression of the hepatic pedicle, hepatic veins, and the suprahepatic vena cava after inflation. Yorkshire pigs (n = 22) underwent controlled hemorrhagic shock (35% of the total blood volume), hypothermia, and fluid resuscitation to reproduce the indications for damage control surgery (coagulopathy, hypothermia, and acidosis) prior to a liver injury. A 3 × 10 cm rectangular segment of the left middle lobe of the liver was removed to create the injury. Subsequently, the animals were randomized into 4 groups for liver damage control (240 min), Sponge Pack (n = 6), Pressurized Airbag (n = 6), Vacuum Airbag (n = 6), and Uncontrolled (n = 4). Animals were monitored throughout the experiment and blood samples obtained.

RESULTS

Perihepatic packing with the pressurized airbag led to significantly higher mean arterial pressure during the liver damage control phase compared to sponge pack and vacuum airbag 52 mmHg (SD 2.3), 44.9 mmHg (SD 2.1), and 32 mmHg (SD 2.3), respectively (p < 0.0001), ejection fraction was also higher in that group. Hepatic hemorrhage was significantly lower in the pressurized airbag group compared to sponge pack, vacuum airbag, and uncontrolled groups; respectively 225 ml (SD 160), 611 ml (SD 123), 991 ml (SD 385), 1162 ml (SD 137) (p < 0001). Rebleeding after perihepatic packing removal was also significantly lower in the pressurized airbag group; respectively 32 ml (SD 47), 630 ml (SD 185), 513 ml (SD 303), (p = 0.0004). Intra-abdominal pressure remained similar to baseline, 1.9 mmHg (SD 1), (p = 0.297). Histopathology showed less necrosis at the border of the liver injury site with the pressurized airbag.

CONCLUSION

The pressurized airbag was significantly more effective at controlling hepatic hemorrhage and improving hemodynamics than the traditional sponge pack technique. Rebleeding after perihepatic packing removal was negligible with the pressurized airbag and it did not provoke hepatic injury.