Introduction. Modern military conflicts make many challenges for military surgeons associated with the use of new types of weapons – hollow point bullets. The solution to this problem, firstly, depends on studying the characteristics of the terminal ballistics of such ammunition and comparing the data obtained with the characteristics of traditional weapon. The aim of the work is to conduct experimental modeling of the wound canal and residual wound cavity, which is formed due to plastic deformation from hollow point and non-hollow point bullets. Materials and methods. The studies were carried out on 40 blocks of ballistic plasticine, in each of which one shot was fired from an AKS-74 assault rifle and a ZBROYAR Z-10 carbine. Depending on the type of ammunition, the blocks of ballistic plasticine were divided into 4 groups: Group 1 – 10 blocks into which shots were made with 5.45 mm non-hollow point military cartridges with "PS" bullets with a steel core "7N6"; Group 2 (10 blocks) – 5.45x39 mm cartridges with "V-Max" hollow point bullets; Group 3 (10 blocks) – with cartridges 7.62x39 mm; Group 4 (10 blocks) – cartridges 7.62x39 mm with hollow point bullets of the "SP" type. Results and discussion. Only for a 5.45 mm military cartridge with "PS" bullets, both inlet and outlet bullet holes were detected in all 10 observations. When using non-hollow point bullets, the outer area of ​​the bullet inlet correlates with the caliber of the projectile (1.6 times larger when using 7.62 mm bullets). For hollow point bullets, the caliber of the projectile does not significantly affect the area of ​​the inlet (P < 0.05). The expansive properties of the bullet significantly increase the area of ​​the bullet hole by 14.87-31.2 times compared to non-hollow point ammunition. Increasing the caliber of the non-hollow point bullet leads to a significant increase in the area of ​​the sagittal section of the residual wound cavity in 1.59-2.03 times; whereas the expansive properties of the bullet do not significantly affect either the perimeter or the area of ​​the sagittal section of the residual wound cavity. For non-hollow point bullets, the volume of the residual wound cavity is more correlated with the caliber of the bullet (increases by 3.36 times); whereas for an hollow point bullet, its caliber has a smaller effect on the volume of the residual cavity (increases by 1.37 times). The expansive properties of the bullet affect the volume of the residual wound cavity in two ways: for 5.45 mm bullets the residual wound cavity increases 1.49 times, for 7.62 mm bullets it decreases 1.65 times. The use of hollow point bullets of 7.62 mm leads to greater collateral damage (zone of secondary necrosis, molecular shock) due to the scattering of the kinetic energy of the bullet to the elastic deformation of near-woundary tissues compared to non-hollow point analogues. The use of 5.45 mm expansive bullets leads to the formation of a larger volume of irreversible damage due to plastic deformation compared to non-hollow point analogues. Conclusions. The resulting model of plastic deformation of soft tissues, depending on the type of modern small arms, showed the dependence of the spatial configuration of the inlet bullet hole, residual wound cavity and deformation and fragmentation of the bullet on the caliber of the cartridge and its expansive properties.

Relevance. Local armed conflicts of recent decades around the world are characterized by the use of hollow point (HP) bullets, which is another challenge for military surgeons. This confirms the importance for scientific research, in particular, experimental, aimed at studying the ballistic properties of various types of ammunition and the characteristics of the injuries caused by them in the wounded people. Simulation of a gunshot wound canal is an integral stage in the study of the gunshot wounds formation mechanism and is the subject of research in wound ballistics. Objective of the work is to develop an experimental model for ballistic imitation of the plastic deformation of biological tissues caused by the action of HP and non-HP bullets. Materials and methods. The studies were carried out on 40 blocks of ballistic plasticine, in each of which one shot was fired from an AKS-74 assault rifle and a ZBROYAR Z-10 carbine. Depending on the type of ammunition, the blocks of ballistic plasticine were divided into 4 groups: group I - 10 blocks, into which shots were made with non-HP military cartridges 5.45 mm with "PS" bullets with a steel core "7N6"; Group II (10 blocks) - 5.45x39 mm cartridges with V-Max HP bullets; group ІІІ (10 blocks) - with cartridges 7.62x39 mm; group IV (10 blocks) - cartridges 7.62x39 mm with HP bullets of the "SP" type. Results. It was found that when using non-HP bullets, the outer area of ​​the inlet ball hole correlates with the projectile caliber (1.6 times more than when using 7.62 mm bullets). For HP bullets, the caliber of the projectile does not significantly affect the area of ​​the entrance opening (P <0.05). The expanding properties of the bullet significantly increase the area of ​​the bullet hole by 14.87-31.2 times compared to non-HP ammunition. An increase in the caliber of non-HP bullets leads to a significant increase in the area of ​​the sagittal section of the residual wound cavity by 1.59-2.03 times; The expanding properties of bullets of different calibers have a different effect on the volume of the residual wound cavity: for 5.45 mm bullets, the residual wound cavity increases 1.49 times, for 7.62 mm bullets it decreases 1.65 times. Conclusions. The type of small arms, the caliber of the cartridge, its expanding properties affect the spatial configuration of the main ballistic indicators arising in the proposed model of plastic deformation of soft tissues. The use of HP bullets leads to the formation of a larger volume of irreversible damage due to plastic deformation in comparison with non-HP analogs.

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Resume. The experience of providing medical care during the anti-terrorist operation in eastern Ukraine has shown that in the structure of modern combat surgical trauma gunshot wounds with soft tissue defects are 64.9-68.2%, of which 36.4-37.5% small and medium, 28.5-30.7% are large and very large defects. Goal: To improve the results of surgical care for soft tissue defects by introducing differentiated surgical tactics for wound closure to each level. Material and methods. The total amount of the study was 136 wounded with shrapnel, bullet and explosive injuries from April 2014 to September 2018. Determination of surgical tactics for closing soft tissue defects was performed on the basis of metric classification, taking into account the area, volume and anatomical areas of the lesion. Results. The combination of metric characteristics of wound defects by area, volume and location of wounds in a single classification allowed to offer a comprehensive approach to sorting the wounded by the level of medical care and determine further reconstructive surgical tactics to close soft tissue defects. Conclusions. The introduction of differentiated surgical tactics in wounded with gunshot defects of the soft tissues at the all levels of medical care improved functional results: the proportion of satisfactory increased from 46.9% to 53.7%, the relative number of unsatisfactory decreased from 18.8% to 11.6%

There was made the analysis of wound ballistics of modern expansive bullets in comparison with shell bullets on 25 blocks of ballistic plasticine (ROMA PLASTILINA No. 1, Ballistic Testing Backing Material), made in the USA, in which one shot from an AKS-74 automatic firearm and carbine ZBROYAR Z-10 with an optical sight was fired. The bullet speed was the highest in  5.45x39 caliber cartridge with a V-max bullet. – 1185 m/s, low in the bullet caliber cartridge .308 Win with a bullet SP, – 664 m/s. The difference is significant at the level of significance α=0.05. In terms of the size of the entrance hole, the largest is from the bullet of cartridge .308 Win with a bullet SP – 10.0 cm, the smallest - from the bullet "PS" with a steel core 5.45x39 mm, cartridge sample of the year 1974 (7H6) – 1.2 cm. The difference is significant at the level of significance α=0.05. In the expansive bullet of type "V-Max" of shortgun cartridge of caliber 5.45x39 mm, the size of the entrance hole was 9.1 cm, with asterial shape having radial  gaps and turned edges of ballistic plasticine on the outside. All cartridges with expansive bullets did not have an exit hole after the shot. The dimensions of the formed residual cavity were the largest after firing with .308 Win caliber cartridge with a bullet SP – 25.0x5.0 cm., the smallest – bullet of a military caliber cartridge of 5.45x39 mm (7H6) – 6.0x4.0 cm. The difference is significant at significance level α=0.05. The shape and character of the residual cavity in ballistic plasticine was significant for all expansive bullets, in contrast to the bullet of a military cartridge 5.45x39 mm (7H6), where no such changes are detected. The considerable signs of expansion properties and deformation of the bullet in the form of a "flower of death" were identified in the bullet of caliber cartridge .308 Win with a bullet SP, other bullets with expansive properties showed significant fragmentation, with the location of fragments both in the residual cavity and outside its borders at different distances. Expansive bullets differ significantly at the level of significance α=0.05. The low flight speed of bullets (m/s) of .308 Win caliber cartridges with bullets BTHP and SP is due to their structure, weight, and caliber. Bullet of type V-max with cartridge 5.45x39 mm has the highest speed – 1185 m/s, and due to its design has significant expansive properties. Common to expansive bullets is a entrance hole, the blind nature of the lesion with the presence of a  large residual cavity, which is due to kinetic energy return 114.37 E, J/mm2 inside the object of lesion. Fragmentation of expansion bullets occurs inside an object with fragments located at different distances. A .308 Win caliber cartridge with  SP bullet causes deformation of s bullet by the type of "death flower" causing significant damage.

Background A gunshot wound to the colon is a frequent injury in armed conflicts. An example of a high-energy modern weapon is hollow-point bullets, which is associated with increased tissue damage and lethal outcome. The aim of this study was to evaluate gunshot injuries to the colon in combat patients and to assess the difference in clinical features of patients with colon injuries by hollow-point versus shape-stable bullets. Patients and methods Analyses of clinical data were performed on 374 male soldiers from the Armed Forces of Ukraine with gunshot abdominal wounds with injury to the colon in East Ukraine between 2014 and 2020. Out of 374 injured, 112 (29.9%) patients were diagnosed with penetrating gunshot bullet wounds: 69/112 (61.6%) were injured by shape-stable bullets, and the hollow-point bullets injured 43/112 (38.4%) patients. Results More severe hemorrhagic shock stages were in patients injured by hollow-point bullets: shock stages III-IV was in 25 (58.1%) patients injured by the hollow-point bullets vs. 17 (24.6%) patients injured by shape-stable bullets (p = 0.0004). Left colon parts were more frequently injured as compared to the right colon side or transverse colon: 21 (48.8%) patients were injured by the hollow-point bullets (p < 0.0001), and 41 (59.4%) patients were injured by the shape-stable bullets (p = 0.032). A significant difference was identified for the frequent injury to the middle colon within the entire cohort (p = 0.023). Patients injured by the hollow-point bullets demonstrated a higher frequency of 3–5 areas of colon gunshot defects, which was detected in 18 (41.8%) patients injured by hollow-point bullets and none with shape-stable bullets injury (p = 0.0001). Colon Injury Scale (CIS) IV was detected in 7 (16.3%) patients injured by the hollow-point bullets as compared to 2 (2.9%) patients injured by shape-stable bullets (p = 0.011). Colostomy was performed in 14 (69%) patients injured by shape-stable bullets and in 12 (27.9%) patients injured by hollow-point bullets (p > 0.05). 15 (35%) patients died after injury by the hollow-point bullet, whereas 9 (13%) patients after damage by the shape-stable bullets (p = 0.0089). Conclusions All patients should be suspected to have an injury by bullet with expanding properties in case of penetrating abdominal injury (absent of outlet wound) and careful revision of the abdomen must be performed to identify possible multiorgan injury as well as multiple gunshot defects of the intestine.

Objective. Analysis of experience of the medical help delivery to the wounded persons, suffering a gun-shot fighting abdominal trauma and treated in Military–Medical Clinical Centre of Eastern Region, determining a further steps, concerning optimization of the treatment-diagnosis measures in this category of patients. Materials and methods. Medical cards of 27 stationary patients with a gun-shot penetrating woundings of abdominal cavity, who were operated on the first stage in mobile hospitals with further transportation to Military–Medical Clinical Centre of Eastern Region, were studied. Concerning the missile characteristic, causing the wounding, there were 20 fragmentation woundings (іsolated – 2, multiple – 5, combined – 13), the bullet – 7 (іsolated – 1, multiple – 3, combined – 3). There were also 7 thoraco-abdominal woundings, of them 6 – the fragmentation, 1 – the bullet. In 18 patients the treatment consisted of a one-staged operative intervention performance, in 9 of them –in several stages. Among the wounded persons, who needed multi-staged treatment, 77.8% have had the large bowel damage. Results. The reoperations performance, which were more characteristic for the wounded persons with the large bowel damages, was folllowed by morbidity (adhesional ileus, peritonitis, etc.), enhancement in 2.6 times of purulent complications of postoperative wound, and in 2 times – of the average index of stationary stay, what have demanded a proportionally enhanced expenses from the health-care military system. Conclusion. Among the gun-shot penetrating woundings of abdominal cavity the multiple and combined fragmentation woundings prevailed. As a result, a statistically significant association between damages of large bowel and enhancement of prediction for the morbidity development and the treatment duration was established, using the method of correlation-regression analysis. The large bowel woundings constitute a predictor of more severe course of fighting abdominal trauma and development of complications, what leads to necessity for elaboration of differentiated approach to operative treatment of this wounded persons’ category with objective to reduce a stationary stay and possibility of the morbidity development.

Objective. To raise the efficacy of radiological diagnosis of the gun-shot abdominal woundings, using modern highly informative methods of medical visualization with determination of their sensitivity and specificity. Materials and methods. Retrospective analysis was done of the results of radiological diagnosis, endovideosurgical and invasive interventions under the radiological methods guidance in 70 injured persons with the gun-shot abdominal woundings, to whom a qualified surgical aid with some elements of specialized help was delivered in 2014-2020 yrs. Average age of the injured persons have constituted 30 complete years old. There were 68 (97.1%) men and 2 (2.9%) women. The results of digital roentgenography, ultrasonographic diagnosis, laparoscopy/laparocentesis, thoracoscopy/thoracocentesis, the puncture-draining interventions under the radiological methods guidance in the injured persons with the gun-shot abdominal woundings were compared to results of the multidetector computed tomography with dynamical contrasted enhancement as a “gold standard” of diagnosis of the gun-shot abdominal woundings and criterion of the foreign bodies visualization (metallic shrapnel, bullets, fragments of bone, drains etc.). Results. The main mechanism of damage in the affected persons with the gun-shot abdominal woundings were shrapnel, created as a result of application of various kinds of the gun-shot and explosive weapons. The part of the gun-shot shrapnel woundings statistically significantly prevailed over part of the bullet and explosive woundings. In accordance to the wound channel kind, the part of blind woundings have had prevailed over parts of the through and multiple woundings statistically significantly (p < 0,05). On a mobile tactical level the rate of application of ultrasonic diagnosis and digital roentgenography for primary selection and diagnostic monitoring was statistically significantly (p < 0.05) higher, than of other methods of medical visualization, what may be explained by improvement and optimization of the treatment and diagnosis tactics, application of urgent sonography in trauma and other modified protocols. Optimal diagnostic system was determined in accordance to indices of sensitivity and specificity of the medical visualization methods, endovideosurgical and puncture-draining interventions under the radiological methods of control - the multidetector computed tomography with dynamical contrasted enhancement. Conclusion. High sensitivity (99%) and specificity (98%) of the multidetector computed tomography with dynamical contrasted enhancement permits to apply it as a method of medical visualization of the gun-shot abdominal woundings for diagnostic selection of wounded persons and the diagnosis establishment.