INTRODUCTION

The challenges of treating vascular injuries in combat trauma are exacerbated by difficulties in providing self-aid, initial pre-hospital care, and complex evacuation under active combat conditions. The modern firearms used in the war in Ukraine often cause complex limb injuries, involving damage to bones, muscles, nerves, arteries, and veins. Blast injuries account for a significant portion of major vascular damage.

Combat-related injuries to major blood vessels are one of the most challenging areas in military trauma surgery. Critical factors for successful treatment outcomes include the well-organized and timely transport of wounded personnel to specialized vascular units and the prompt provision of highly specialized surgical care^{1, 2}.

During the evacuation stages of soldiers with vascular injuries of the limbs to combat support hospitals (typically located within 5-10 km of the combat zone), surgeons must always consider the option of external shunting. In such cases, combat medics have the option to use either linear or looped temporary vascular shunts. Linear shunts are inserted into the vessel lumen and follow its path without bending (the most commonly available sizes are 8, 10, 12, and 14 Fr linear internal shunts)^{3, 4}. Looped shunts are inserted in a looped configuration. Prior to 2022 in Ukraine, these shunts were primarily used for carotid artery temporary shunting; however, they are also well-suited for use in major limb arteries^{5, 6}.

The use of temporary shunting of peripheral arteries to maintain distal vascular perfusion is rare in civilian surgical practice but is gaining popularity in the treatment of military trauma. A report from the Regional Vascular Surgery Unit of The Royal Victoria Hospital, Belfast, demonstrated that early intraluminal artery/vein shunting to restore arterial inflow and venous outflow in patients with complex lower limb vascular injuries reduced the incidence of adverse events, including contractures, ischemic nerve paralysis, and amputations⁷.

MATERIALS

In a specialized medical center, we conducted an analysis of the feasibility of reconstructive surgery in 192 soldiers with blast injuries to the upper or lower limbs involving major vascular damage. These patients were evacuated from a combat support hospital at varying intervals, with 143 arriving within 24 hours and 49 beyond 24 hours. Eighty-seven (45.31%) of the injured arrived at the specialized medical center with hemostatic tourniquets applied or the injured artery ligated, while 105 (54.68%) had undergone temporary external shunting of the major artery.

Upon admission to the specialized vascular surgery center, blood flow through the shunt was absent in 36 out of the 105 cases (34.28%). The primary endpoint for analyzing the effectiveness of external arterial shunting in the combat support hospital was the amputation rate in the specialized hospital.

The statistical analysis involved calculating the odds ratio (OR), a key measure used to numerically express the extent to which the presence or absence of a certain outcome is associated with the presence or absence of a specific factor in a given statistical group. The confidence interval (CI) was set at 95%, determined as ±1.96 of the standard error.

RESULTS

Major arterial injuries represent one of the most critical aspects of surgery. Soldiers with major vascular injuries caused by blast trauma often die within hours of being wounded, especially in cases of injuries to large vessels in the chest or abdominal cavity. Most patients hospitalized in specialized medical centers typically have limb vessel injuries. This is likely due to the fact that temporary hemostasis methods for limb vessel injuries are more accessible during combat action. If a soldier can quickly recognize a limb vascular injury and apply a tourniquet, their chances of survival and later receiving specialized vascular surgical care increase significantly.

The custom loop shunt (CLH), proposed by the vascular surgeons at the V.T. Zaytsev Institute of General and Emergency Surgery of the National Academy of Medical Sciences of Ukraine, was fixed within the injured vessel using tourniquets.

The overall amputation rate was 34.89%, with 23.77% of amputations occurring when evacuation was under 24 hours and 67.34% when evacuation exceeded 24 hours (OR 0.15 [0.07-0.37], p=0.001). Wounded soldiers evacuated to a specialized center within 24 hours had an 85% higher chance of limb salvage. This chance increased to 94% in soldiers with a functioning shunt (OR 0.06 [0.01-0.54], p=0.004) and to 85% with a non-functioning shunt (OR 0.15 [0.04-0.64], p=0.012). For soldiers with a hemostatic tourniquet or ligated vessel, the odds ratios were 0.37 (0.17-0.84, p=0.027) and 0.44 (0.18-1.12, p=0.133), respectively.

DISCUSSION

The outcomes of treating soldiers with blast injuries and damage to major vessels depend on several factors, including the specifics of the wound (whether the limb is preserved or completely amputated), the type of vessel (arterial or venous), the nature of the vessel injury (closed or open), vessel diameter, vessel rupture or wall damage, blood loss volume, the stage of shock, the distance of the injury from medical stabilization points or the hospital, the time and conditions of evacuation, and the accuracy of medical care provided at all stages of treatment^{9, 10}.

All these factors influence the severity of acute limb ischemia and the condition of the wounded soldier. The most important factor is the evacuation time, which directly affects the likelihood of limb amputation^{11, 12}.

Most general surgeons assigned to work in combat support hospitals in the combat zone have limited experience in vascular surgery. Therefore, they undergo training beforehand, which includes general principles for managing vascular injuries and stabilizing patients with severe blood loss. A combat surgeon should be familiar with surgical access to blood vessels, principles of distal and proximal vascular control, proper surgical management of blast-induced vessel injuries, and options for temporary shunting or vessel repair for further evacuation to specialized medical centers.

CONCLUSIONS

1. The use of temporary shunting to restore limb perfusion in combat conditions is an effective method that reduces the risk of amputations. Its efficacy is particularly high when soldiers are evacuated to specialized medical centers within 24 hours.

2. The development and application of the original loop shunt (CLH) in Ukraine for temporary shunting have shown better results compared to linear shunts, providing higher vessel patency and reducing complication rates.

3. In combat conditions, the organization of quality evacuation and the preparation of surgeons in vascular control techniques are critical factors for preserving injured limbs. Adherence to vascular control recommendations in field settings significantly enhances the effectiveness of treatment.