The effect of hemostatic dressing prototypes for the uniformed services on selected blood coagulation parameters in pigs

Potential novel role of the human amniotic membrane as a sustainable hemostat

OBJECTIVES

Acute hemorrhage can cause significant morbidity and mortality arising from trauma, bleeding disorders, surgical procedures, or obstetric complications. Surgical hemostasis methods may fail to stop acute bleeding due to the complex bleeding dynamics of each bleeding type. Therefore, developing safe and effective topical hemostatic agents remains crucial. The human amniotic membrane (hAM) has established clinical evidence of effectiveness in promoting wound healing and tissue regeneration. Despite its unique biological and immunologic properties and its structural composition of established hemostatic elements, the hemostatic role of hAM has not been yet explored. The present study aimed to investigate this potential role and to describe the development protocol and characterization of hAM-derived topical hemostat.

METHODS

Surface electron microscope (SEM) imaging and Fourier transform infrared (FTIR) spectroscopy were used for characterization, and mouse models with induced peritoneal and tail wound bleeding were employed to evaluate the hemostatic effectiveness using physiological studies, in comparison to a chitosan-based combat-scale hemostat.

RESULTS

The hAM hemostat showed a distinctive composition by SEM and FTIR. Applying equal masses of the hAM hemostat, the commercial hemostat, or a combination reduced peritoneal wound bleeding time to averages of 108.4, 86.2, and 76.8 s, respectively, compared to the control group (300 s). Tail wound bleeding times were similarly reduced with no significant difference between the hAM and the commercial hemostat (P values = 0.29, 0.34 in peritoneal and tail wounds, respectively). Neither hemostat affected coagulation time.

CONCLUSION

This study describes a simple cost-effective preparation protocol for a hAM-based hemostatic agent. The long-recognized safety, sustainability, and immunotolerance advantages of hAM can establish superiority over commercial hemostats with reported safety concerns. Robust research validation in larger-scale bleeding models is required for wider applications and severe bleeding types.

The Use of Large Animal Models in Trauma and Bleeding Studies

BACKGROUND

 Major trauma often results in significant bleeding and coagulopathy, posing a substantial clinical burden. To understand the underlying pathophysiology and to refine clinical strategies to overcome coagulopathy, preclinical large animal models are often used. This review scrutinizes the clinical relevance of large animal models in hemostasis research, emphasizing challenges in translating findings into clinical therapies.

METHODS

 We conducted a thorough search of PubMed and EMBASE databases from January 1, 2010, to December 31, 2022. We used specific keywords and inclusion/exclusion criteria centered on large animal models.

RESULTS

 Our review analyzed 84 pertinent articles, including four animal species: pigs, sheep, dogs, and nonhuman primates (NHPs). Eighty-five percent of the studies predominantly utilized porcine models. Meanwhile, sheep and dogs were less represented, making up only 2.5% of the total studies. Models with NHP were 10%. The most frequently used trauma models involved a combination of liver injury and femur fractures (eight studies), arterial hemorrhage (seven studies), and a combination of hemodilution and liver injury (seven studies). A wide array of coagulation parameters were employed to assess the efficacy of interventions in hemostasis and bleeding control.

CONCLUSIONS

 Recognizing the diverse strengths and weaknesses of large animal models is critical for trauma and hemorrhage research. Each model is unique and should be chosen based on how well it aligns with the specific scientific objectives of the study. By strategically considering each model's advantages and limitations, we can enhance our understanding of trauma and hemorrhage pathophysiology and further advance the development of effective treatments.

The Influence of Haemostatic Dressing Prototypes for the Emergency Services on the Histopathological Parameters of Porcine Muscle

BACKGROUND/AIM

Haemostatic dressings for the uniformed and rescue services are an integral part of life-saving equipment for controlling post-traumatic haemorrhage. The aim of this study was to assess the influence of active constituent substances and materials of haemostatic dressings on muscle tissue and muscle regeneration after traumatic injury.

MATERIALS AND METHODS

Three hemostatic dressing prototypes were analysed: OBR/G/S sponge: dressing material sponge made of Na-Ca chitosan/algal composite microfibers and nanofibers; OBR/MBT/S: tactic gauze modified with a polymer mixture of Na-Ca chitosan/algal composite microfibers and nanofibers, impregnated with a moderate amount of procoagulants (22.9 g/m²); and OBR/MS/S: seton gauze modified with a polymer mixture of Na-Ca chitosan/algal composite microfibers and nanofibers, impregnated with a moderate amount of procoagulants (18.0 g/m²), with chitosan (ChitoClearhqg 95) and sodium alginate (Protanal LF10/60 FT) as the coagulants. The experiment was conducted on 20 pigs which were euthanised 24 h, 7 or 14 days after wound dressing. Samples of porcine muscle tissue were subjected to qualitative histopathological analysis.

RESULTS

Histopathological analysis of muscle tissues from the experimental pigs revealed that the application of modified seton (OBR/MS/S) produced the most satisfactory results. The observed changes were similar on all dates that samples were collected and in all experimental groups, and minor differences in their extent were observed between groups. Regenerative processes were most advanced, and retrograde changes were least apparent in animals treated with OBR/MS/S.

CONCLUSION

Modified seton (OBR/MS/S) induced the least tissue reaction and was most effective in promoting tissue regeneration after injury.

The Effect of Haemostatic Dressing Prototypes for the Emergency Services in the Porcine Haemostatic System

BACKGROUND/AIM

Coagulopathy can develop when hemostatic dressings are used to stop massive bleeding, even in patients without prior history of clotting disorders. The selection of procoagulants, which effectively control bleeding and prevent disseminated intravascular coagulation (DIC) and thrombosis, is a significant challenge. The aim of this study was to evaluate the effect of two prototypes of haemostatic dressing in the porcine haemostatic system.

MATERIALS AND METHODS

The total number of animals used in our experiments was 24. Group I: pigs were treated with the developed prototype of sponge dressing, made of Na-Ca chitosan/algal composite of microfibers and nanofibers. Group II: animals were treated with a seton gauze modified with a polymer mixture of Na-Ca chitosan/algal composite of microfibers and nanofibers. Group III: animals were treated with non-hemostatic dressing and this group was the control. Blood was sampled five times to determine changes in the coagulation and fibrinolytic profiles: before injury: i) at 1 h, ii) at 24 h, iii) at 7, and iv) at 14 days following injury.

RESULTS

Significant changes were observed in the coagulation parameters, in the total numbers of white blood cells and platelets in groups I and II, compared to controls.

CONCLUSION

The modified haemostatic dressings used in this study produced a strong procoagulant effect in pigs. This, together with high fibrinogen concentrations, which can cause DIC, require further studying.