Clinical and Instrumental Features of Traumatic Arteriovenous Fistulas after Gunshot Wounds of the Lower Extremities

Objective. To study the clinical and instrumental features of arteriovenous fistulas (AVF) after gunshot wounds of the lower extremities and to present the classification of these fistulas. Material and methods. We retrospectively assessed the diagnostic data in 60 wounded patients with gunshot combat trauma of the lower extremities between March 1, 2023 and July 31, 2023. All the wounded were men aged 34.5±8.9 years. The median time since gunshot combat injury was 13 days. Examination included duplex ultrasound and CT angiography. Results. All patients with AVF were symptomatic. The main complaints were pain within AVF area and foreign bodies. AVF was localized on the left lower limb in 32 (53.3%) patients and on the right lower limb in 28 (47.7%) patients. Mean ankle-brachial index on the affected limb was 0.76±0.08 vs. 0.99±0.09 on the contralateral limb (p<0.001). AVF following direct damage to the artery and vein with a foreign body near neurovascular bundle was registered in 46 (76.7%) cases, AVF due to indirect damage by a shock wave — in 14 (23.3%) cases. AVF between femoral vessels (artery and vein) was registered in 18 (30%), between popliteal vessels — in 17 (28.3%), between tibioperoneal trunk and posterior tibial veins — in 8 (13.3%), between tibial vessels — in 17 (28.3%) cases. Single hole AVF was found in 58 (96.7%), double hole AVF — in 2 (3.3%) cases. Mean width of arteriovenous anastomosis was 5.9±2.2 mm. False arterial aneurysm was found in 33 (55%) patients including 2 ones with “arteriovenous aneurysm”, i.e. fistula with the great vein inside the false arterial aneurysm. Small false aneurysm was detected in 3 (9.1%), medium — in 12 (36.3%), large — in 19 (57.6%) cases. Saccular false aneurysms prevailed (91%) over multi-chamber (6%) and fusiform (3%) aneurysms. Peak arterial blood flow velocity below AVF was 49.5±21.8 cm/sec, in contralateral limb at the same level — 66.9±24.8 cm/sec (p<0.001). Uncomplicated and complicated AVFs were found in 36 (60%) and 24 (40%) patients, respectively. Original classification of gunshot AVFs of the lower extremities is proposed. Conclusions. The features of traumatic AVFs after gunshot wounds of the lower extremities are symptomatic nature, arterial steal syndrome of distal segments and complications in 40% of cases. The most important criteria of gunshot AVFs of the lower extremities are segment of damage (iliac, femoral, popliteal, tibial), the number of anastomoses (single/double/multiple hole), presence/absence of false aneurysm, kind, size and shape of false aneurysm.