Study On Damage Control Resuscitation Strategy And REBOA Training For Pelvic Hemostasis Of Pelvis Simulated Blast Fragment Injury

1 ObjectivesThere are three objectives of the current study.First,to research the damage control resuscitation strategy of pelvic combat fragmentation injury in modern war,and establish a rabbit model of pelvic combat injury simulating blast fragment injury.Second,to observe the injury characteristics and explore the resuscitation effect of hemostatic fluid resuscitation combined with damage control surgery(DCS)in this animal model.Third,to investigate the damage control surgical training and resuscitation effect of resuscitation aortic balloon occlusion(REBOA)in zone III without imaging support after short-term standardized procedural skill training in a porcine pelvic blast fragment injury model.2 Methods2.1 Twenty-five rabbits were injured on a multi-functional animal compound combat injury platform under the condition of shock wave pressure of 10 Kpa and one fragment.After injury,the rabbits were packed and bandaged and invasive blood pressure monitoring was performed.Blood samples were collected before injury and 30 min after injury for routine blood tests,arterial blood gases and thromboelastography.CT scan and autopsy were performed to check for injuries.The Abbrieviated Injury Scale(AIS)was used to calculate the coefficient of variation to evaluate the uniformity of the model.2.2 The 48 rabbits were randomly divided into four groups: Group A rabbits were observed after pelvic injury as a control group,DCS was performed after pelvic injury in group B rabbits,DCS and surrogate plasma fluid resuscitation were performed after pelvic injury in group C rabbits,Group D rabbits received DCS after pelvic injury with tranexamic acid,concentrated fibrinogen,prothrombin complex for damage control resuscitation(DCR).Blood was collected for laboratory testing such as thrombelastogram immediately(0 h)after injury,1 h,2 h,4 h and 8 h after injury.2.3 Thirty pigs were randomly divided into 6 groups,and pelvic blastfragments were established on the multi-functional animal compound combat injury platform,and the trainees were randomly assigned to 6 groups to perform REBOA operation for pelvic hemostasis.The REBOA balloon was placed in the area III of the abdominal aorta for pelvic hemostasis by method of anatomical landmark.Computed tomography angiography(CTA)was used to check the position of the balloon and the hemostasis effect after each operation.Feedback the CTA results to the operators.Each step of the REBOA operation conducted by each group was timed to judge the timeliness of the REBOA operation.The accuracy of the REBOA insertion operation was judged by the CTA results.The results of the first operation and the fifth operation of each group were compared to analyze the accuracy and timeliness of the operation before and after the training.3 Results3.1 All rabbits showed severe pelvic fracture with multiple organ injury,and the severity of the injury was relatively reproducible.The AIS score coefficient of variation(CV)was10.32%.Severe shock occurred 5 min after injury,with decreased alkali residue,fibrinogen concentration,and red cell and platelet counts.The mortality within 3 hours after injury was36%.The coagulation reaction time(R)rapidly shortened to 5.67±1.63 min within 5 min after injury,and then gradually extended to 7.60±3.30 min 1h after injury,and then shortened again(P <0.05);There was no significant difference in K value of coagulation formation time and MA value of maximum thrombosis amplitude at each time point(P >0.05).3.2 The survival rate and some laboratory tests were different among groups.The mortality of group B was slightly lower than that of group A,but there was no significant difference in creatine and BUN concentrations between the two groups.There was no significant difference between group C and groups A and B at 0 h,but at 8h after injury,the concentrations of creatine and BUN in group C were lower than those in groups A and B.The physiological parameters and coagulation and fibrinolysis parameters of rabbits in group D were significantly improved,organ function was better,and mortality was lower.3.3 The animal model of blast fragment injury of porcine pelvis was successfully established.The time of REBOA placement(from skin cutting to balloon expansion was completed)was reduced from 15.4±1.9min before training to 3.6±0.7min,and the time from exposing the femoral artery to completion of balloon dilation was reduced from 3.2±0.3min before training to 0.5±0.1min.The time spent before and after training was statistically significant(P <0.001).The correct rate of balloon placement after training was significantly higher than that before training(100%vs66.7%),and the incidence of complications was significantly lower than that before training(16.7%vs66.7%).4 Conclusion4.1 This study successfully established a reproducible model of pelvic blast burst fragmentation in rabbits.The injury included severe pelvic fracture accompanied by organ damage and massive hemorrhage.The early injury was severe and the coagulation function state fluctuated sharply,and targeted comprehensive resuscitation strategy was needed to improve the success rate of treatment.4.2 Hemostatic fluid resuscitation combined with DCS under the guidance of TEG and POC can improve the hemodynamics,blood physiology,coagulation fibrinolysis disorders,liver and kidney function,and reduce the mortality of rabbit pelvic blast fragment model.4.3 In this study,an animal model of porcine pelvic blast fragment injury was established,and the hemostatic effect of REBOA placed in area III was studied based on CTA image analysis.After short-term procedural training,non-vascular surgery or interventional surgeons can skillfully and accurately use the body surface positioning method to place REBOA in abdominal aorta III region of pigs without imaging support such as CT or fluoroscopy to complete pelvic hemostatic operation,with a low incidence of vascular surgical complications.